@article{doi101098rspb19630019, author = "Jones, Geoffrey Melvill and Spells, K E", title = "A theoretical and comparative study of the functional dependence of the semicircular canal upon its physical dimensions", year = "1963", journal = "Proceedings of the Royal Society of London. Series B, Biological sciences", abstract = "Abstract It has long been known that, in contrast to the range of variation of body dimensions, the semicircular canals of different animals are approximately similar in size. In the present study, measurements of the internal radius (r) and radius of curvature (R) of the endolymphatic canal were made in 87 species, comprising 46 mammals, 17 birds, 17 fishes and 7 reptiles, using specimens, and photographic records of specimens, already available. Using the principles of dynamical similarity, theoretical arguments are adduced which predict that if Steinhausen’s (1933) interpretation of semicircular canal function is correct there should be very slow increases, systematic but discreet, of r and R with body mass (m). The results of the measurements largely confirmed the theoretical prediction, the actual relations obtained for all species together being: log10100r2 = 0·0945 (±0·0549) log10m+0·2519 and log10100R = 0·0761 (±0·0402) log10m + 2·3797 (where r and R are measured in mm and m in kg), similar relations being obtained for each class examined. It is shown that the observed changes in r and R can to a large extent account respectively for the changes in canal sensitivity and the time constant of cupular return which the theory suggests should be called for by changes in animal shape and body mass.", url = "https://doi.org/10.1098/rspb.1963.0019", doi = "10.1098/rspb.1963.0019", openalex = "W2047451384", references = "doi101007bf01754806, doi101098rspb19530038, doi101113jphysiol1949sp004416, doi101113jphysiol1952sp004752, openalexw2214670474, openalexw587508267, openalexw593727103" } @article{doi101242jeb532501, author = "Kate, J. H. Ten and Barneveld, H. H. Van and Kuiper, J. W.", title = "The Dimensions and Sensitivities of Semicircular Canals", year = "1970", journal = "Journal of Experimental Biology", abstract = "ABSTRACT The dimensions of the semicircular canals of pike can be expressed as allometric functions of the body length L. The equal sensitivity of pike of different sizes to rotatory stimulation can be explained as a quadratic bending of the cupula. In the pike the sensitivity is of the same order of magnitude for the vertical and horizontal semicircular canals. In the pike the growth rate of the volumes of duct and ampulla is the same for the horizontal semicircular canal and for the posterior semicircular canal. The special growth rate of the dimensions of the horizontal semicircular canal of the ray can be explained by a quadratic bending of the cupula. For equally large cupulae the sensitivity of the horizontal semicircular canal is of the same order of magnitude for twenty-three mammals, fourteen birds and one reptile as it is for the pike. Within the limits of error the ‘growth rate’ of the diameter of the narrow duct is the same in mammals as in the pike. At the same body mass the absolute value of the diameter of the narrow duct is smaller in mammals than in the pike by a factor of 1·69. For a body mass of 1 kg the value of the enclosed area of the horizontal semicircular canal is 6 times smaller in mammals than in pike. The model of the overcritically damped oscillator for the semicircular canal remains valid during growth if a quadratic bending of the cupula is assumed.", url = "https://doi.org/10.1242/jeb.53.2.501", doi = "10.1242/jeb.53.2.501", openalex = "W2183473490" } @article{doi101113jphysiol1971sp009657, author = "Jones, G. Melvill and Milsum, John", title = "Frequency—response analysis of central vestibular unit activity resulting from rotational stimulation of the semicircular canals", year = "1971", journal = "The Journal of Physiology", abstract = "1. The neural response of semicircular canal-dependent units in the vestibular nuclei of cats has been examined over a frequency range of sinusoidal rotation extending from 0.004 to 0.9 Hz.2. Frequency-response analysis indicates that, over the range examined, the information contained in the neural signal received by the brain stem was similar to that expected from the mechanical end-organ.3. Over the experimental frequency range, the relation between neural response and mechanical stimulus was found to be dominated by a single time constant of about 4 sec, such that two response regions can be defined above and below a stimulus frequency of (1/4) rad/sec (approximately approximately Hz).4. Above this frequency the information content of the neural signal tends towards that of angular velocity and below that frequency it tends towards that of angular acceleration.5. It is inferred (a) that the so-called;long' time constant of the cat's horizontal canal is about 4 sec and (b) that during most normal head movements containing frequencies below about 1 Hz the informational mode of neural signals generated in the canal and received in the brain stem probably tends towards that of head angular velocity.6. This seems appropriate for the generation of vestibulo-ocular reflex compensation for head movement and for reflex damping (negative velocity feed-back) of unintended head and body movements.7. The average neural gain of central unit responses is estimated at 1264 action potentials/sec, per degree of cupular deflexion. This high value reflects the very small angles of cupular deflexion assessed on the basis of physical characteristics of the canal.8. The results permit a rough estimate of the elastic restoring coefficient of the cupula in the horizontal canal as 2.05 x 10(-3) dyne. cm.", url = "https://doi.org/10.1113/jphysiol.1971.sp009657", doi = "10.1113/jphysiol.1971.sp009657", openalex = "W2029015874", references = "doi101002cne901220306, doi101007bf00941383, doi101098rspb19630019, doi101111j174817161968tb04075x, doi101113jphysiol1949sp004416, doi101152jn1966293467, doi101152jn1969325743, doi101152jn1971344635, doi101152jn1971344661, doi10310900016487009181867" } @article{doi101242dev293721, author = "Howland, Howard C. and Masci, Joseph", title = "The functional allometry of semicircular canals, fins, and body dimensions in the juvenile centrarchid fish, Lepomis gibbosus (L.)", year = "1973", journal = "Development", abstract = "ABSTRACT The ontogenetic allometry of radii of curvature and the tube radii of the semicircular canals of approximately 85 juvenile (2–20 g) centrarchids of the species Lepomis gibbosus (L.) was investigated. The radii of curvature of the semicircular canals have different allometries; these are for the anterior vertical, posterior vertical and horizontal canals respectively. The differences in growth exponents between the anterior and posterior vertical semicircular canals and between the anterior vertical and horizontal semicircular canals were statistically significant (P \< 0 ·02 and P \< 0 ·05 respectively). Body mass and standard length were almost equally good predictors of the radii of curvature of the anterior vertical semicircular canals, but body mass was the better predictor of the radii of curvature of the posterior vertical and horizontal semicircular canals, as judged by the magnitude of the mean squares about the logarithmic regressions of radii on length and mass. By measuring and estimating the area moments of the fins of the fish, the moments of inertia about various axes and the allometry of the characteristic swimming velocity of the fish, we attempted to account for the magnitude and direction of the differences in allometric growth exponents of the radii of curvature of the semicircular canals. Unexplained by our best estimate of growth exponents was the very high value observed for the posterior vertical semicircular canals. No significant correlation could be found between the residuals of the major dimensions of the posterior vertical semicircular canals and those of body width or depth once the influence of body mass was removed. This finding suggests the rejection of the hypothesis that the allometry of this semicircular canal is simply correlated with overall body expansion in its plane. The discrepancies between our predictions and observations of growth exponents could be explained by a gradual increase of the spring constant of the semicircular canals on the order of though they may also be due to other factors neglected in our model, e.g. the allometry of the added mass of the fish. No evidence suggested that the shape of the semicircular canals was altered over the size range of the fish we studied. However, among the fins of the fish and the major body dimensions, only the width and the depth of the fish exhibited growth constants that did not differ significantly from each other. We computed the effective toroidal radii of the non-toroidal-shaped vertical semicircular canals and found that the equivalent toroidal radius of the anterior vertical semicircular canal was consistently greater than that of the posterior vertical semicircular canal. This difference is explicable on the basis of the different moments of inertia of the animal about axes through the center of gravity and parallel to the axes of the semicircular canals. We computed the allometry of the ratios for all three semicircular canals and found in accordance with the prediction of Jones \& Spells that they did not differ significantly from zero. The allometry of the outer tube radii of the several semicircular canals was determined, and, while there was no significant difference in the growth exponents of the tube radii, it was noted that the tube radius of the horizontal semicircular canal was consistently and significantly smaller than that of the vertical semicircular canal. We suggested that this difference might be due to the broader range of frequencies that the fish experienced about its yaw axis. Taken as a whole the data and calculations of this paper generally support the theory that the dimensions of the semicircular canals and the ontogenetic changes in them attune the semicircular canals to the angular frequency spectra that the fish experience about their axes.", url = "https://doi.org/10.1242/dev.29.3.721", doi = "10.1242/dev.29.3.721", openalex = "W1833542087" } @article{doi101001archotol197400780040015003, author = "Phelps, Peter", title = "Congenital Lesions of the Inner Ear, Demonstrated by Tomography: A Retrospective Study of 34 Cases With Special Reference to the Lateral Semicircular Canal", year = "1974", journal = "Archives of Otolaryngology - Head and Neck Surgery", abstract = "One hundred fifty-seven patients with congenital ear lesions of the external and middle ears were studied by tomography. The tomograms showed that 34 of these patients had additional deformities of the inner ear. Many of these deformities, and especially those of the inner ear, could be attributed to thalidomide. The commonest inner ear lesion was a short wide lateral semicircular canal, the cause for which has been discussed embryologically.", url = "https://doi.org/10.1001/archotol.1974.00780040015003", doi = "10.1001/archotol.1974.00780040015003", openalex = "W4300026671" } @incollection{jones1974the, author = "Jones, G. Melvill", title = "The Functional Significance of Semicircular Canal Size", year = "1974", booktitle = "Handbook of Sensory Physiology", url = "https://doi.org/10.1007/978-3-642-65942-3\_5", doi = "10.1007/978-3-642-65942-3\_5", pages = "171-184" } @book{jones1974the1, author = "Jones, G. M", title = "The Functional Significance of Semicircular Canal Size, in Kornhuber, H. H., ed., Vestibular System Part 1", year = "1974", publisher = "Basic Mechanisms, VI/1 of Handbook of Sensory Physiology: Berlin, Springer, p. 171-184", note = "talkorigins\_source = {true}; raw\_reference = {Jones, G. M., 1974, The Functional Significance of Semicircular Canal Size, in Kornhuber, H. H., ed., Vestibular System Part 1: Basic Mechanisms, VI/1 of Handbook of Sensory Physiology: Berlin, Springer, p. 171-184.}" } @article{doi10310900016487509121318, author = "Blanks, R. H. I. and Curthoys, Ian S. and Markham, Charles H.", title = "Planar Relationships Of The Semicircular Canals In Man", year = "1975", journal = "Acta Oto-Laryngologica", abstract = "Principal-component analyses were determined on a series of points measured from the dissected bony labyrinth of ten human skulls, resulting in planar equations for each of the six semicircular canals. Following this, angles were calculated between the ipsilateral canal planes, between opposite synergistically acting canal planes and between each canal and the Reid stereotaxic planes. Results indicated that pairs of ipsilateral canals were nearly perpendicular, with the excpetion of the angle formed between the anterior and horizontal canal (mean = 111 degrees). Pairs of contralateral synergistic canal planes formed angles of 19 degrees between right and left horizontal canal planes and 23-24 degrees between vertical canal pairs. The horizontal canals formed an angle of 25 degrees with the Reid horizontal plane. Mathematical equations of the semicircular canals were used to predict the optimal head position for rotational and caloric stimulation.", url = "https://doi.org/10.3109/00016487509121318", doi = "10.3109/00016487509121318", openalex = "W2114232503", references = "doi101113jphysiol1949sp004416" } @article{doi10310900016487709128843, author = "Curthoys, Ian S. and Blanks, R. H. I. and Markham, Charles H.", title = "Semicircular Canal Functional Anatomy in Cat, Guinea Pig and Man", year = "1977", journal = "Acta Oto-Laryngologica", abstract = "AbstractFormulation of semicircular canal transfer functions have to date been restricted to idealized cases. Recent information in cat, guinea pig and man on the precise orientation of the semicircular canals allows a more realistic specification of the forces acting on the cupulae during any head rotation.This research was supported by grants from the National Health and Medical Research Council of Australia, the US Public Health Service Grant NS-06658, and NASA. Computing Assistance was obtained from the Health Sciences Computing Facility, UCLA, sponsored by NIH Special Research Resources Grant RR-3.", url = "https://doi.org/10.3109/00016487709128843", doi = "10.3109/00016487709128843", openalex = "W1973732073", references = "doi101098rspb19630019, doi101113jphysiol1949sp004416" } @article{openalexw2409010322, author = "Ls, Parnes and Ja, McClure", title = "Effect on brainstem auditory evoked responses of posterior semicircular canal occlusion in guinea pigs.", year = "1985", journal = "PubMed", abstract = "The site of origin of benign paroxysmal positional vertigo is the posterior semicircular canal and when persistent, the condition is known as cupulolithiasis. Singular neurectomy is the current procedure of choice for the treatment of incapacitating cupulolithiasis. The neurectomy is difficult to learn and carries a significant risk of hearing loss. An alternative procedure, whereby the posterior canal is occluded, is discussed. This was performed on 11 guinea pigs and the effect on hearing was measured using brainstem evoked audiometry. Eight animals showed no hearing loss while the other three had a mild to moderate loss of hearing due to intra-operative complications. The effect of canal plugging on hearing compares favorably with the hearing results obtained with singular neurectomy. Posterior semicircular canal occlusion is suggested as a safer and technically easier treatment for incapacitating cupulolithiasis.", openalex = "W2409010322" } @article{doi101177000348949009900502, author = "Parnes, Lorne S. and McClure, Joseph A.", title = "Posterior Semicircular Canal Occlusion for Intractable Benign Paroxysmal Positional Vertigo", year = "1990", journal = "Annals of Otology Rhinology \& Laryngology", abstract = "Benign paroxysmal positional vertigo (BPPV) is most often a self-limited disorder arising from the posterior semicircular canal of the undermost ear in the Hallpike position. Some individuals with this disorder have severe and protracted symptoms requiring more than expectant therapy. We describe two patients with intractable BPPV and profound sensorineural hearing loss in the affected ear treated by transmastoid posterior semicircular canal occlusion. Postoperatively, both were relieved of their BPPV and demonstrated preserved lateral semicircular canal function as measured by electronystagmography. We feel this new procedure provides a simpler and possibly safer alternative to singular neurectomy and should be given future consideration in the treatment of intractable BPPV in a normal-hearing ear.", url = "https://doi.org/10.1177/000348949009900502", doi = "10.1177/000348949009900502", openalex = "W2321584164" } @article{parnes1991posterior, author = "Parnes, Lorne S. and McClure, Joseph A.", title = "Posterior semicircular canal occlusion in the normal hearing ear", year = "1991", journal = "Otolaryngology–Head and Neck Surgery", abstract = "This report outlines our experience with posterior semicircular canal occlusion, a new operative procedure for intractable benign paroxysmal positional vertigo (BPPV). We postulate that the resulting solid canal “plug” prevents endolymph movement within the posterior canal, which effectively fixes the cupula. This selectively abolishes the receptivity of the posterior canal to both angular acceleration and gravity without influencing the other inner ear receptors. We previously reported the success of this procedure in two patients with BPPV and a co‐existing profound sensorineural hearing loss in the affected ear. Since that report, a slightly modified technique has been used to occlude six more posterior canals—five in normal hearing ears. While our follow‐up times range from only 3 to 18 months, all eight patients continue to be relieved of their BPPV. Temporary mixed hearing losses occurred in three of the five ears with normal preoperative hearing. Hearing in all five patients ultimately returned to the preoperative state. We believe this procedure is a simpler and safer alternative to singular neurectomy for the treatment of intractable benign paroxysmal positional vertigo.", url = "https://doi.org/10.1177/019459989110400111", doi = "10.1177/019459989110400111", number = "1", openalex = "W1869664011", pages = "52-57", volume = "104", references = "doi101001archotol194600680050425009, doi1010160090301983901611, doi101152ajplegacy196220261211, doi101177000348949009900502, doi101212wnl373371, doi1012880000553719850800000009, openalexw2409010322" } @article{doi1012880000553719920900000006, author = "Parnes, Lome S. and McClure, Joseph A.", title = "Free‐Floating endolymph particles: A new operative finding during posterior semicircular canal occlusion", year = "1992", journal = "The Laryngoscope", abstract = {Most clinicians accept cupulolithiasis as the pathophysiological mechanism underlying benign paroxysmal positional vertigo (BPPV.) According to this theory, a cupular deposit induces a gravitational effect on the posterior canal crista. Posterior semicircular canal occlusion is a new operative procedure for treating incapacitating BPPV. It is postulated that canal occlusion abolishes endolymph movement within the canal, effectively fixing the cupula and rendering it unresponsive to both angular and linear acceleration (gravity). During two recent canal occlusions, abundant "free-floating particles" were identified within the posterior canal endolymph. When changing the position of the canal in the earth vertical plane, these free-floating particles would move under the influence of gravity. The hydrodynamic drag of the particles would induce endolymph movement with cupular displacement leading to the typical response. This finding supports an alternate explanation to cupulolithiasis as the pathophysiological mechanism underlying BPPV.}, url = "https://doi.org/10.1288/00005537-199209000-00006", doi = "10.1288/00005537-199209000-00006", openalex = "W2081731595", references = "parnes1991posterior" } @article{doi101001archotol1243249, author = "Minor, Lloyd B. and Solomon, David and Zinreich, James and Zee, David S.", title = "Sound- and/or Pressure-Induced Vertigo Due to Bone Dehiscence of the Superior Semicircular Canal", year = "1998", journal = "Archives of Otolaryngology - Head and Neck Surgery", abstract = "OBJECTIVES: To present symptoms, patterns of nystagmus, and computed tomographic scan identification of patients with sound- and/or pressure-induced vertigo due to dehiscence of bone overlying the superior semicircular canal. To describe anatomical findings and outcome in 2 patients undergoing plugging of the superior semicircular canal for treatment of these symptoms. DESIGN AND SETTING: Prospective study of a case series in a tertiary care referral center. PATIENTS AND RESULTS: Eight patients with vertigo, oscillopsia, and/or disequilibrium related to sound, changes in middle ear pressure, and/or changes in intracranial pressure were identified in a 2-year period. Seven of these patients also had vertical-torsional eye movements induced by these sound and/or pressure stimuli. The direction of the evoked eye movements could be explained by excitation or inhibition of the superior semicircular canal in the affected ear. Computed tomographic scans of the temporal bones identified dehiscence of bone overlying the affected superior semicircular canal in each case. Disabling disequilibrium in 2 patients prompted plugging of the dehiscent superior canal through a middle cranial fossa approach. Symptoms were improved in each case. One patient developed recurrent symptoms requiring an additional plugging procedure and developed sensorineural hearing loss several days after this second procedure. CONCLUSIONS: We have identified patients with a syndrome of vestibular symptoms induced by sound in an ear or by changes in middle ear or intracranial pressure. These patients can also experience chronic disequilibrium. Eye movements in the plane parallel to that of the superior semicircular canal were evoked by stimuli that have the potential to cause ampullofugal or ampullopetal deflection of this canal's cupula in the presence of a dehiscence of bone overlying the canal. The existence of such deshiscences was confirmed with computed tomographic scans of the temporal bones. Surgical plugging of the affected canal may be beneficial in patients with disabling symptoms.", url = "https://doi.org/10.1001/archotol.124.3.249", doi = "10.1001/archotol.124.3.249", openalex = "W2110634912" } @article{doi101093brain1214699, author = "Cremer, Paul", title = "Semicircular canal plane head impulses detect absent function of individual semicircular canals", year = "1998", journal = "Brain", abstract = "We studied the human vestibulo-ocular reflex (VOR) in response to head 'impulses': brief, unpredictable, passive, high-acceleration (up to 4000 degrees/s2), low-amplitude (20-30 degrees) head rotations. We delivered the head impulses approximately in the plane of the semicircular canal (SCC) being tested. To test the anterior and posterior SCCs, the head impulses were delivered in a diagonal plane, midway between the frontal (roll) and sagittal (pitch) planes. We recorded head and eye position in three dimensions with scleral search coils in nine normal subjects, seven patients following unilateral surgical vestibular neurectomy and three patients following unilateral posterior SCC occlusion. In the post-surgical patients we demonstrated a severe, permanent VOR gain deficit (0.2-0.3) for head impulses directed toward any single non-functioning SCC. The sensitivity of the test depends on the physiological properties of primary vestibular afferents, and its specificity depends on the anatomical orientation of the SCCs. The diagonal head impulse is the first test of individual vertical SCC function in humans, and together with the horizontal head impulse, forms a comprehensive battery of SCC-plane tests. These canal-plane impulses could be useful in evaluating patients with vertigo or other vestibular disorders.", url = "https://doi.org/10.1093/brain/121.4.699", doi = "10.1093/brain/121.4.699", openalex = "W2134587344", references = "parnes1991posterior" } @article{doi1010970000344619981000000001, author = "Bess, Fred H. and Dodd-Murphy, Jeanne and Parker, Robert A.", title = "Children with Minimal Sensorineural Hearing Loss: Prevalence, Educational Performance, and Functional Status", year = "1998", journal = "Ear and Hearing", abstract = "OBJECTIVE: This study was designed to determine the prevalence of minimal sensorineural hearing loss (MSHL) in school-age children and to assess the relationship of MSHL to educational performance and functional status. DESIGN: To determine prevalence, a single-staged sampling frame of all schools in the district was created for 3rd, 6th, and 9th grades. Schools were selected with probability proportional to size in each grade group. The final study sample was 1218 children. To assess the association of MSHL with educational performance, children identified with MSHL were assigned as cases into a subsequent case-control study. Scores of the Comprehensive Test of Basic Skills (4th Edition) (CTBS/4) then were compared between children with MSHL and children with normal hearing. School teachers completed the Screening Instrument for Targeting Education Risk (SIFTER) and the Revised Behavior Problem Checklist for a subsample of children with MSHL and their normally hearing counterparts. Finally, data on grade retention for a sample of children with MSHL were obtained from school records and compared with school district norm data. To assess the relationship between MSHL and functional status, test scores of all children with MSHL and all children with normal hearing in grades 6 and 9 were compared on the COOP Adolescent Chart Method (COOP), a screening tool for functional status. RESULTS: MSHL was exhibited by 5.4\% of the study sample. The prevalence of all types of hearing impairment was 11.3\%. Third grade children with MSHL exhibited significantly lower scores than normally hearing controls on a series of subtests of the CTBS/4; however, no differences were noted at the 6th and 9th grade levels. The SIFTER results revealed that children with MSHL scored poorer on the communication subtest than normal-hearing controls. Thirty-seven percent of the children with MSHL failed at least one grade. Finally, children with MSHL exhibited significantly greater dysfunction than children with normal hearing on several subtests of the COOP including behavior, energy, stress, social support, and self-esteem. CONCLUSIONS: The prevalence of hearing loss in the schools almost doubles when children with MSHL are included. This large, education-based study shows clinically important associations between MSHL and school behavior and performance. Children with MSHL experienced more difficulty than normally hearing children on a series of educational and functional test measures. Although additional research is necessary, results suggest the need for audiologists, speech-language pathologists, and educators to evaluate carefully our identification and management approaches with this population. Better efforts to manage these children could result in meaningful improvement in their educational progress and psychosocial well-being.", url = "https://doi.org/10.1097/00003446-199810000-00001", doi = "10.1097/00003446-199810000-00001", openalex = "W2143077227" } @article{doi101242dev125133, author = "Hadrys, Thorsten and Braun, Thomas and Rinkwitz-Brandt, Silke and Arnold, Hans-Henning and Bober, Eva", title = "Nkx5-1 controls semicircular canal formation in the mouse inner ear", year = "1998", journal = "Development", abstract = "The inner ear develops from the otic vesicle, a one-cell-thick epithelium, which eventually transforms into highly complex structures including the sensory organs for balance (vestibulum) and hearing (cochlea). Several mouse inner ear mutations with hearing and balance defects have been described but for most the underlying genes have not been identified, for example, the genes controlling the development of the vestibular organs. Here, we report the inactivation of the homeobox gene, Nkx5-1, by homologous recombination in mice. This gene is expressed in vestibular structures throughout inner ear development. Mice carrying the Nkx5-1 null mutation exhibit behavioural abnormalities that resemble the typical hyperactivity and circling movements of the shaker/waltzer type mutants. The balance defect correlates with severe malformations of the vestibular organ in Nkx5-1(-/-) mutants, which fail to develop the semicircular canals. Nkx5-1 is the first ear-specific molecule identified to play a crucial role in the formation of the mammalian vestibular system.", url = "https://doi.org/10.1242/dev.125.1.33", doi = "10.1242/dev.125.1.33", openalex = "W2255213693", references = "doi101001jama199203490230111048, doi1010160092867492905079, doi1010160166223682900765, doi1010160896627395902635, doi101016s089662730080255x, doi101038374062a0, doi101038381603a0, doi101242dev117113, doi101242dev1203603, doi101242dev122113381" } @article{doi1010970000553720001000000019, author = "Johnson, Jacob and Lalwani, Anil K.", title = "Sensorineural and Conductive Hearing Loss Associated With Lateral Semicircular Canal Malformation", year = "2000", journal = "The Laryngoscope", abstract = "Abstract Objective Lateral semicircular canal (LSCC) malformation is one of the most common radiological inner ear malformations. Traditionally, inner ear malformations are thought to be associated with sensorineural hearing loss (SNHL). Recent experience with patients with LSCC malformation suggested that LSCC malformation may be associated with both SNHL and conductive hearing loss (CHL). The auditory phenotype associated with LSCC malformation is not well delineated. The objective of this study is to define the nature of the hearing loss associated with LSCC malformation. Study Design Retrospective review Methods Retrospective review of clinical records, audiological evaluation, and imaging studies. Results Two patients with unilateral and 13 patients with bilateral LSCC malformation were identified. LSCC malformation was associated with CHL in 14\% (4 ears), SNHL in 71\% (20 ears), normal hearing in 11\% (3 ears) and CHL due to atresia in one ear. Hearing loss varied from mild to profound but did not correlate with the severity of LSCC malformation. In bilateral malformation, the hearing loss was asymmetric in half of the cases. Malformation of the posterior limb of the LSCC was always associated with a large vestibular aqueduct. An absent or rudimentary LSCC was invariably associated with a cochlear abnormality. Conclusions LSCC malformation, like other inner ear malformations such as large vestibular aqueduct and X‐linked mixed deafness with perilymph gusher, can be associated with CHL, SNHL, or normal hearing. Children with unexplained conductive hearing loss often undergo exploratory surgery to improve hearing. Given that inner ear malformations may be associated with a pure CHL, it is critical that children undergo computed tomography scan of the temporal bone prior to undergoing exploratory surgery.", url = "https://doi.org/10.1097/00005537-200010000-00019", doi = "10.1097/00005537-200010000-00019", openalex = "W2101322581", references = "doi101002lary1978885723, doi101002lary5540971301, doi101016jrcl201409010, doi101016s0165587699002682, doi1010387783, doi101038ng0398215, doi101126science7839145, doi101242dev125133, doi1012880000553719711000000016, openalexw179653173" } @article{doi101242dev127113, author = "Salminen, Marjo and Meyer, Barbara I. and Bober, Eva and Gruß, Peter", title = "netrin 1 is required for semicircular canal formation in the mouse inner ear", year = "2000", journal = "Development", abstract = "The morphogenetic development of the mammalian inner ear is a complex multistep process, the molecular and cellular details of which are only beginning to be unraveled. We show here that mouse netrin 1, known to be involved in axon guidance and cell migration in the central nervous system, also plays a critical morphogenetic role during semicircular canal formation. netrin 1 is expressed at high levels in the otic epithelium, in cells that will come together to form a fusion plate, a prerequisite for the formation of semicircular canals. In netrin 1 mutant mice, fusion plate formation is severely affected resulting in a reduced anterior semicircular canal and the complete lack of the posterior and lateral canals. Our results suggest that netrin 1 facilitates semicircular canal formation through two different mechanisms: (1) it participates in the detachment of the fusion plate epithelia from the basement membrane, and (2) it stimulates proliferation of the periotic mesenchymal cells which then push the epithelial cell walls together to form the fusion plate.", url = "https://doi.org/10.1242/dev.127.1.13", doi = "10.1242/dev.127.1.13", openalex = "W1902810312" } @article{openalexw2116448167, author = "Lemmerling, Marc and Vanzieleghem, Bart and Mortier, Geert and Dhooge, Ingeborg and Kunnen, Marc", title = "Unilateral semicircular canal aplasia in Goldenhar's syndrome.", year = "2000", journal = "PubMed", abstract = "A patient with Goldenhar's syndrome (oculoauriculovertebral dysplasia) and unilateral aplasia of all semicircular canals is presented. This is the first report of such a finding and may support the hypothesis that Goldenhar's syndrome and the CHARGE association have a common pathogenetic mechanism.", openalex = "W2116448167" } @article{doi101002ajmga10866, author = "Matsunaga, Tatsuo and Hirota, Eiko", title = "Familial lateral semicircular canal malformation with external and middle ear abnormalities", year = "2002", journal = "American Journal of Medical Genetics Part A", abstract = "We report a family with inner ear lateral semicircular canal (LSC) malformation and external and middle ear abnormalities. The family had no history of known syndromes or toxic exposures. Distinct phenotypic manifestations were found in three family members. A young girl exhibited bilateral LSC malformation with a right-sided preauricular tag, a mildly deformed auricle, a stenotic external auditory canal, and a constricted middle ear cavity. She had moderate conductive hearing loss in the right ear but normal hearing in the left ear. Her younger brother exhibited right-sided LSC malformation, microtia, external auditory canal atresia, a malformed middle ear cavity, and abnormal auditory ossicles. He had severe mixed hearing loss in his right ear. Their mother exhibited left-sided LSC malformation without external and middle ear abnormalities, and the hearing was normal in her left ear. None of the three cases had vestibular symptoms, and their results of balance tests were appropriate for the corresponding ages. In contrast, significantly decreased LSC function was revealed by caloric tests in an ear with LSC malformation. Previously, LSC malformation may have been underdiagnosed in patients presenting with external and middle ear abnormalities and their relatives, since this malformation is frequently associated with normal hearing and balance or conductive hearing loss only. To our knowledge, this condition has not been described previously. This condition supports a genetic basis for the combination of LSC malformation and external and middle ear abnormalities and may represent an autosomal dominant condition with variable expressivity.", url = "https://doi.org/10.1002/ajmg.a.10866", doi = "10.1002/ajmg.a.10866", openalex = "W2229205886", references = "doi1010970000553720001000000019" } @article{doi101016s0194599803015936, author = "Yu, Kun‐Hsing", title = "Molecular Genetic Advances in Semicircular Canal Abnormalities and Sensorineural Hearing Loss: A Report of 16 Cases", year = "2003", journal = "Otolaryngology", abstract = "OBJECTIVES: The study goals were (1) to determine if the degree and pattern of semicircular canal dysmorphology and the presence or absence of a cochlea in patients with congenital sensorineural hearing loss predict audiologic outcome, severity, or the frequencies involved and (2) to review the recent advances in molecular genetics of the semicircular canals and correlate this information with audiologic and anatomic patterns seen in our series of patients. DESIGN AND SETTING: We conducted a retrospective study at a tertiary care center with a large otologic and cochlear implant service. PATIENTS AND METHODS: The study population consisted of 16 patients with congenital sensorineural hearing loss in 28 congenitally malformed inner ears consisting of semicircular canal dysplasia or aplasia, with or without cochlear malformation. History, physical examination, computed tomography scans, and serial audiograms were reviewed. Factors analyzed included other phenotypic dysmorphology characteristic of syndromes, audiometric configuration, severity and type of hearing loss, and the presence of associated inner ear anomalies other than the vestibular system. An extensive review of the literature regarding molecular genetic factors in semicircular canal anomalies, with or without cochlear abnormalities, was performed. RESULTS: Sixteen patients (31 ears) were identified with profound sensorineural hearing loss and semicircular canal abnormalities. Only 3 patients had known syndromes, although 4 patients had other congenital anomalies. Most radiographic detectable abnormalities were bilateral. Audiograms of the patients demonstrated pure tone averages between 90 and 100 dB in the affected ears with few exceptions. No correlation was found between type and severity of malformation of either the cochlea or semicircular canals with the severity of hearing loss. There was no stepwise progression of hearing loss increasing malformation severity. Seven of the 16 patients received cochlear implants. Of these 7, 3 patients had cochlear hypoplasia and 1 patient had a common cavity deformity. Audiologic follow-up on all 7 patients revealed improvement in both speech assessment threshold and pure tone average. Presence or absence of the cochlea was not a factor in outcome after cochlear implantation. CONCLUSION: We have assembled the largest series of patients with semicircular canal dysmorphology, with or without various cochlear abnormalities. Our study failed to correlate the type and severity of semicircular canal malformation with any specific audiologic outcome. The variation in hearing loss severity and pattern even in patients with similar bony radiographic findings must be explained by other non-radiologically detectable defects, likely abnormalities in membranous labyrinthine development. New molecular genetic discoveries have linked specific genes to the development of certain inner ear structures in mice studies. The independent development of the individual semicircular canals in relation to the cochlea and vestibule and the variability in hearing loss suggest a more complex embryologic process than merely an arrest in development as previously thought. As genetic studies are extended into humans, we will likely be able to stratify these patients by molecular defect and severity of hearing loss.", url = "https://doi.org/10.1016/s0194-5998(03)01593-6", doi = "10.1016/s0194-5998(03)01593-6", openalex = "W2064605768", references = "doi101002lary5540971301, doi101006dbio19960081, doi101016s0166223698013666, doi101016s0896627300809885, doi101242dev122113381, doi101242dev125193831, doi101242dev1254621, doi101242dev12561123, doi101242dev126112335, doi101242dev127113" } @article{doi1010970012949220030300000023, author = "Minor, Lloyd B. and Carey, John P. and Cremer, Phillip D. and Lustig, Lawrence R. and Streubel, Sven-Olrik", title = "Dehiscence of Bone Overlying the Superior Canal as a Cause of Apparent Conductive Hearing Loss", year = "2003", journal = "Otology \& Neurotology", abstract = "OBJECTIVE: To identify patients with superior semicircular canal dehiscence and apparent conductive hearing loss and to define the cause of the air-bone gap. STUDY DESIGN: Prospective study of patients with superior canal dehiscence. SETTING Tertiary referral center. PATIENTS: Vestibular and/or auditory findings indicative of canal dehiscence and demonstration of superior canal dehiscence on computed tomography of the temporal bone. INTERVENTION: Vestibular-evoked myogenic potentials, three-dimensional eye movement recordings, and surgical resurfacing of the superior canal. OUTCOME MEASURE: Association of superior canal dehiscence with an air-bone gap on audiometry. RESULTS: Four patients with dehiscence of bone overlying the superior canal were found to have air-bone gaps in the affected ears that were greatest at lower frequencies and averaged 24 +/- 7 dB over the frequency range of 250 to 4,000 Hz. Three of these patients had undergone stapedectomy before the identification of superior canal dehiscence. The air-bone gap was unchanged postoperatively. Each patient had an intact vestibular-evoked myogenic potential (VEMP) response from the affected ear, a finding that would not have been expected based on a middle ear cause of conductive hearing loss. One patient underwent resurfacing of the superior canal through a middle fossa approach. Postoperatively, his vestibular symptoms were relieved, and his air conduction thresholds were improved by 20 dB. CONCLUSIONS: Superior canal dehiscence can result in apparent conductive hearing loss. The third mobile window created by the dehiscent superior canal results in dissipation of acoustic energy and is a cause of inner ear conductive hearing loss.", url = "https://doi.org/10.1097/00129492-200303000-00023", doi = "10.1097/00129492-200303000-00023", openalex = "W2089475950" } @article{doi1010970012949220030500000014, author = "Satar, Bülent and Mukherji, Suresh K. and Telian, Steven A.", title = "Congenital Aplasia of the Semicircular Canals", year = "2003", journal = "Otology \& Neurotology", abstract = "OBJECTIVE: To describe the underrecognized inner ear malformation characterized by complete aplasia of the labyrinthine semicircular canals associated with a relatively well-formed cochlea, to investigate its relationship with known syndromic forms of hearing loss, and to hypothesize regarding the potential embryopathogenesis of this anomaly. STUDY DESIGN: A retrospective case review consisting of cases of sensorineural hearing loss with radiographic evidence demonstrating agenesis of the semicircular canals associated with a cochlea that was either morphologically normal or sufficiently well developed to accommodate the full insertion of a cochlear implant electrode. Cases were identified by computerized tomography findings that identified the anomaly under study. SETTING: Departments of otolaryngology and radiology in a tertiary referral center, with a large cochlear implant program serving over 800 patients, more than half of whom are children. PATIENTS: Fifteen patients with the anomaly under study were identified. INTERVENTIONS: Each patient underwent a complete otologic examination, audiometric studies, and high resolution computerized tomography of the temporal bone in axial and coronal planes. MAIN OUTCOME MEASURES: The bony morphology of the cochlea, round and oval windows, vestibule, semicircular canals, and vestibular aqueduct, and the course of the facial nerve were examined. Auditory findings and otologic treatment are presented. RESULTS: Of the 15 identified patients, 4 were nonsyndromic, 9 had CHARGE association (Coloboma of the eye, congenital Heart defects, choanal Atresia, mental and/or growth Retardation, Genital hypoplasia, and Ear anomalies and/or deafness), 1 met criteria for Noonan's syndrome, and one had features of both these syndromes. Although the cochlea was present in all cases, the cochlear morphology was usually abnormal in the CHARGE association patients. Of the 20 ears in the CHARGE subjects, only 3 ears (15\%) were seen to have completely normal development of the cochlea in both the basal and upper turns. The others showed either mild hypoplasia of the upper turns (13 ears, 65\%) or an incomplete partition typical of the classic Mondini deformity (4 ears, 20\%). In the 4 nonsyndromic cases, one subject had bilateral Mondini dysplasia and the other three had normal cochleae. In the entire group, abnormalities of oval window development were common (20 of 30 ears, 67\%), especially in the syndromic cases (18/22, 81\%), but the round window was normal in the majority of cases (73\%). Seven patients in the CHARGE association group had an anomalous course of the facial nerve, which was particularly severe in three. Four patients had congenital unilateral facial paralysis, although two of these children had normal radiographic anatomy of the facial nerve. One patient had bilateral facial weakness. CONCLUSIONS: Syndromic and nonsyndromic cases of isolated semicircular canal aplasia were identified. Except for mild to moderate cochlear dysplasia, and the anomalous course of the facial nerve in some CHARGE association patients, both groups of patients were generally suitable for cochlear implantation if indicated. A high incidence of oval window aplasia with normal round window development may help to explain the embryopathogenesis of this anomaly, considering the sequence of inner ear development.", url = "https://doi.org/10.1097/00129492-200305000-00014", doi = "10.1097/00129492-200305000-00014", openalex = "W2003187305" } @article{doi101148radiol2262010897, author = "Belden, Clifford J. and Weg, Noah and Minor, Lloyd B. and Zinreich, S. James", title = "CT Evaluation of Bone Dehiscence of the Superior Semicircular Canal as a Cause of Sound- and/or Pressure-induced Vertigo", year = "2003", journal = "Radiology", abstract = "PURPOSE: To describe the computed tomographic (CT) findings at different collimation widths associated with superior semicircular canal (SSC) dehiscence syndrome and to determine the frequency of these findings in a control population. MATERIALS AND METHODS: Temporal bone CT scans with 1.0-mm and/or 0.5-mm collimation were obtained in 50 patients with sound- and/or pressure-induced vestibular symptoms. The control population consisted of 50 patients undergoing CT at 1.0-mm collimation and 57 patients undergoing CT at 0.5-mm collimation for other reasons. RESULTS: SSC dehiscence was documented on CT scans in all 36 patients with the clinical syndrome, with bilateral findings in six patients. Six other patients without specific clinical signs appeared to have dehiscence on 1.0-mm-collimated scans. Intact bone overlaying the SSC was subsequently identified with 0.5-mm-collimated CT in each case. On the 1.0-mm-collimated scans in 50 control patients, an area judged as possible or definite dehiscence was identified in 18 of 100 ears. The bone overlaying the SSC was intact in each of the 114 control ears evaluated with 0.5-mm-collimated CT. CT findings from the patients with vestibular symptoms combined with those in the control population indicated that the positive predictive value of an apparent dehiscence in the diagnosis of SSC dehiscence syndrome improved from 50\% with 1.0-mm-collimated CT with transverse and coronal images to 93\% with 0.5-mm-collimated CT with reformation in the plane of the SSC. CONCLUSION: The positive predictive value of CT in identification of SSC dehiscence syndrome improves with 0.5-mm-collimated helical CT and reformation in the SSC plane.", url = "https://doi.org/10.1148/radiol.2262010897", doi = "10.1148/radiol.2262010897", openalex = "W2124107382" } @article{doi101258002221503322113003, author = "Halmagyi, G. Michael and Aw, Swee T. and McGarvie, Leigh A. and Todd, Mike and Bradshaw, Andrew P. and Yavor, R.A. and Fagan, Paul A.", title = "Superior semicircular canal dehiscence simulating otosclerosis", year = "2003", journal = "The Journal of Laryngology \& Otology", abstract = "This is a report of a patient with an air-bone gap, thought 10 years ago to be a conductive hearing loss due to otosclerosis and treated with a stapedectomy. It now transpires that the patient actually had a conductive hearing gain due to superior semicircular canal dehiscence. In retrospect for as long as he could remember the patient had experienced cochlear hypersensitivity to bone-conducted sounds so that he could hear his own heart beat and joints move, as well as a tuning fork placed at his ankle. He also had vestibular hypersensitivity to air-conducted sounds with sound-induced eye movements (Tullio phenomenon), pressure-induced nystagmus and low-threshold, high-amplitude vestibular-evoked myogenic potentials. Furthermore some of his acoustic reflexes were preserved even after stapedectomy and two revisions. This case shows that if acoustic reflexes are preserved in a patient with an air-bone gap then the patient needs to be checked for sound- and pressure-induced nystagmus and needs to have vestibular-evoked myogenic potential testing. If there is sound- or pressure-induced nystagmus and if the vestibular-evoked myogenic potentials are also preserved, the problem is most likely in the floor of the middle fossa and not in the middle ear, and the patient needs a high-resolution spiral computed tomography (CT) of the temporal bones to show this.", url = "https://doi.org/10.1258/002221503322113003", doi = "10.1258/002221503322113003", openalex = "W2150046335" } @article{doi1010970012949220040300000007, author = "Mikulec, Anthony A. and McKenna, Michael J. and Ramsey, Mitchell J. and Rosowski, John J. and Herrmann, Barbara S. and Rauch, Steven D. and Curtin, Hugh D. and Merchant, Saumil N.", title = "Superior Semicircular Canal Dehiscence Presenting as Conductive Hearing Loss Without Vertigo", year = "2004", journal = "Otology \& Neurotology", abstract = "OBJECTIVE: The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained conductive hearing loss without vestibular symptoms. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. DIAGNOSTIC TESTS AND RESULTS: All 10 ears had significant conductive hearing loss. The air-bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (-5 dB to -15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air-bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air-bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the conductive hearing loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. CONCLUSION: SSCD can present with a conductive hearing loss that mimics otosclerosis and could explain some cases of persistent conductive hearing loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with conductive hearing loss without vertigo.", url = "https://doi.org/10.1097/00129492-200403000-00007", doi = "10.1097/00129492-200403000-00007", openalex = "W2005010807" } @article{doi1010970012949220040500000021, author = "Rosowski, John J. and Songer, Jocelyn E. and Nakajima, Hideko Heidi and Brinsko, Kelly M. and Merchant, Saumil N.", title = "Clinical, Experimental, and Theoretical Investigations of the Effect of Superior Semicircular Canal Dehiscence on Hearing Mechanisms", year = "2004", journal = "Otology \& Neurotology", abstract = {HYPOTHESIS: A superior semicircular canal dehiscence affects hearing by introducing a third window into the inner ear that 1) lowers cochlear input impedance, 2) shunts air-conducted sound away from the cochlea resulting in conductive hearing loss, and 3) improves bone-conduction thresholds by increasing the difference in impedance between the vestibule and the round window. BACKGROUND: Superior semicircular canal dehiscence has been linked to a "conductive" hearing loss characterized by a decrease in the sensitivity to air-conducted sound and hypersensitivity to bone-conducted sound. METHODS: Four investigations were performed: 1) laser-Doppler vibrometer measurements of sound-induced umbo velocity in patients with computed tomographic scan-confirmed superior semicircular canal dehiscence; 2) laser-Doppler vibrometry of sound-induced motions of the vestibular lymph (either perilymph or endolymph) exposed in a chinchilla model of superior semicircular canal dehiscence; 3) studies in chinchillas of the effect of superior semicircular canal dehiscence on the cochlea's sensitivity to bone-conducted sounds; and 4) anatomically based theoretical analyses of sound flow through the human cochlea and semicircular canals. RESULTS: The low-frequency umbo velocity in superior semicircular canal dehiscence patients without previous middle ear surgery ranged from normal through high normal. This tendency toward hypermobility suggests a decrease in cochlear impedance. Measurements of sound-induced velocity of the lymph within a superior semicircular canal dehiscence in chinchillas demonstrated sound flow through the dehiscence. Measurements of the cochlear potential demonstrated a superior semicircular canal dehiscence-induced increase in response to bone-conducted sound in eight of nine chinchillas. An anatomically based model of the human ear predicts changes in auditory sensitivity similar to audiometric changes in superior semicircular canal dehiscence. CONCLUSION: The results suggest that superior semicircular canal dehiscence can affect hearing function by introducing a third window into the inner ear.}, url = "https://doi.org/10.1097/00129492-200405000-00021", doi = "10.1097/00129492-200405000-00021", openalex = "W1991050630" } @article{doi10109701mlg000017832455729b7, author = "Minor, Lloyd B.", title = "Clinical Manifestations of Superior Semicircular Canal Dehiscence", year = "2005", journal = "The Laryngoscope", abstract = "OBJECTIVES/HYPOTHESES: To determine the symptoms, signs, and findings on diagnostic tests in patients with clinical manifestations of superior canal dehiscence. To investigate hypotheses about the effects of superior canal dehiscence. To analyze the outcomes in patients who underwent surgical repair of the dehiscence. STUDY DESIGN: Review and analysis of clinical data obtained as a part of the diagnosis and treatment of patients with superior canal dehiscence at a tertiary care referral center. METHODS: Clinical manifestations of superior semicircular canal dehiscence were studied in patients identified with this abnormality over the time period of May 1995 to July 2004. Criteria for inclusion in this series were identification of the dehiscence of bone overlying the superior canal confirmed with a high-resolution temporal bone computed tomography and the presence of at least one sign on physiologic testing indicative of superior canal dehiscence. There were 65 patients who qualified for inclusion in this study on the basis of these criteria. Vestibular manifestations were present in 60 and exclusively auditory manifestations without vestibular symptoms or signs were noted in 5 patients. RESULTS: For the 60 patients with vestibular manifestations, symptoms induced by loud sounds were noted in 54 patients and pressure-induced symptoms (coughing, sneezing, straining) were present in 44. An air-bone on audiometry in these patients with vestibular manifestations measured (mean +/- SD) 19 +/- 14 dB at 250 Hz; 15 +/- 11 dB at 500 Hz; 11 +/- 9 dB at 1,000 Hz; and 4 +/- 6 dB at 2,000 Hz. An air-bone gap 10 dB or greater was present in 70\% of ears with superior canal dehiscence tested at 250 Hz, 68\% at 500 Hz, 64\% at 1,000 Hz, and 21\% at 2,000 Hz. Similar audiometric findings were noted in the five patients with exclusively auditory manifestations of dehiscence. The threshold for eliciting vestibular-evoked myogenic potentials from affected ears was (mean +/- SD) 81 +/- 9 dB normal hearing level. The threshold for unaffected ears was 99 +/- 7 dB, and the threshold for control ears was 98 +/- 4 dB. The thresholds in the affected ear were significantly different from both the unaffected ear and normal control thresholds (P <.001 for both comparisons). There was no difference between thresholds in the unaffected ear and normal control (P =.2). There were 20 patients who were debilitated by their symptoms and underwent surgical repair of superior canal dehiscence through a middle cranial fossa approach. Canal plugging was performed in 9 and resurfacing of the canal without plugging of the lumen in 11 patients. Complete resolution of vestibular symptoms and signs was achieved in 8 of the 9 patients after canal plugging and in 7 of the 11 patients after resurfacing. CONCLUSIONS: Superior canal dehiscence causes vestibular and auditory symptoms and signs as a consequence of the third mobile window in the inner ear created by the dehiscence. Surgical repair of the dehiscence can achieve control of the symptoms and signs. Canal plugging achieves long-term control more often than does resurfacing.", url = "https://doi.org/10.1097/01.mlg.0000178324.55729.b7", doi = "10.1097/01.mlg.0000178324.55729.b7", openalex = "W2060502067" } @article{openalexw2148179955, author = "Morimoto, Allan and Wiggins, Richard H. and Hudgins, Patricia A. and Hedlund, Gary L. and Hamilton, Bronwyn E. and Mukherji, Suresh K. and Telian, Steven A. and Harnsberger, H R", title = "Absent semicircular canals in CHARGE syndrome: radiologic spectrum of findings.", year = "2006", journal = "PubMed", abstract = "BACKGROUND AND PURPOSE: This paper describes the CT findings that characterize the middle and inner ear anomalies in coloboma, heart defects, choanal atresia, mental retardation, genitourinary, and ear anomalies (CHARGE) syndrome. With this information, neuroradiologists will be better prepared to provide clinically relevant information to their referring physicians regarding this rare syndrome. MATERIALS AND METHODS: CT studies from 13 patients were reviewed by 2 neuroradiologists with Certificate of Additional Qualification. Each ear was counted separately for a total of 26 ears. Middle and inner ear anomalies associated with CHARGE syndrome were categorized. Investigational review board approval was obtained. RESULTS: Twenty of 26 (77\%) ears demonstrated cochlear aperture atresia. Four of these ears were evaluated with MR imaging and were found to lack a cochlear nerve. Twenty-one of 26 (81\%) cochlea had some form of dysplasia. Six of 26 (23\%) round windows were aplastic. Three of 26 (12\%) round windows were hypoplastic. Twenty-one of 26 (81\%) oval windows were atretic or aplastic. Fifteen of 26 (58\%) vestibules were hypoplastic or dysplastic. There were 5 of 26 (19\%) enlarged vestibular aqueducts. Twelve of 26 (46\%) vestibular aqueducts had an anomalous course. All cases demonstrated absent semicircular canals. Twenty-three of 26 (88\%) facial nerve canals had an anomalous course. Four of 26 (15\%) tympanic segments were prolapsed. Three of 26 (12\%) temporal bones had an anomalous emissary vein referred to as a petrosquamosal sinus. Twenty-one of 26 (81\%) middle ear cavities were small. Twenty-three of 26 (93\%) ossicles were dysplastic with ankylosis. Three of 26 (12\%) internal auditory canals were small. CONCLUSION: The CT findings that correlate to the anomalies of CHARGE syndrome affect conductive as well as sensorineural hearing. Stenosis of the aperture for the cochlear nerve aperture on CT is suggestive of hypoplasia or absence of the cochlear nerve, which has been demonstrated in some cases by MR. Absence of the cochlear nerve would be a contraindication to cochlear implantation.", openalex = "W2148179955" } @inproceedings{songer2006superior, author = "SONGER, J. E. and ROSOWSKI, J. J.", title = "SUPERIOR SEMICIRCULAR CANAL DEHISCENCE: MECHANISMS OF AIR-CONDUCTED HEARING", year = "2006", booktitle = "Auditory Mechanisms: Processes and Models", url = "https://doi.org/10.1142/9789812773456\_0019", doi = "10.1142/9789812773456\_0019", openalex = "W2329112131", pages = "113-114" } @article{doi101073pnas0704250104, author = "Spoor, Fred and Garland, Theodore and Krovitz, Gail E. and Ryan, Timothy M. and Silcox, Mary and Walker, Alan", title = "The primate semicircular canal system and locomotion", year = "2007", journal = "Proceedings of the National Academy of Sciences", abstract = "The semicircular canal system of vertebrates helps coordinate body movements, including stabilization of gaze during locomotion. Quantitative phylogenetically informed analysis of the radius of curvature of the three semicircular canals in 91 extant and recently extinct primate species and 119 other mammalian taxa provide support for the hypothesis that canal size varies in relation to the jerkiness of head motion during locomotion. Primate and other mammalian species studied here that are agile and have fast, jerky locomotion have significantly larger canals relative to body mass than those that move more cautiously.", url = "https://doi.org/10.1073/pnas.0704250104", doi = "10.1073/pnas.0704250104", openalex = "W1978779308", references = "doi101006jhev19960122, doi1010079781475757026, doi101098rspb19630019, doi105860choice352112" } @incollection{merchant2007superior, author = "Merchant, Saumil N. and Rosowski, John J. and McKenna, Michael J.", title = "Superior Semicircular Canal Dehiscence Mimicking Otosclerotic Hearing Loss", year = "2007", booktitle = "Advances in Oto-Rhino-Laryngology", url = "https://doi.org/10.1159/000098790", doi = "10.1159/000098790", openalex = "W1536272964", pages = "137-145", references = "doi101001archotol1243249, doi101016s0196070900801052, doi101016s0378595503003320, doi101080000164801750388090, doi1010970012949220030300000008, doi1010970012949220030300000023, doi1010970012949220040300000007, doi1010970012949220040500000021, doi101148radiol2262010897, doi101258002221503322113003" } @article{dallan2008bilateral, author = "Dallan, I and Berrettini, S and Neri, E and Casani, A P", title = "Bilateral, isolated, lateral semicircular canal malformation without hearing loss", year = "2008", journal = "The Journal of Laryngology \& Otology", abstract = "Hypothesis: Inner-ear malformations are frequently found in patients with sensorineural hearing loss. However, isolated anomalies of the vestibular part of the inner ear are seldom described, and for this reason their impact on balance is poorly understood. Care report: We present the case of a 38-year-old Caucasian man with recurrent vestibular complaints, with a sensation of linear tilting, but no hearing impairment. Clinical and neuro-otological examinations showed peripheral involvement of the vestibular system, while audiological investigation was within normal limits. High-resolution magnetic resonance imaging of the inner ear, with three-dimensional reconstruction, demonstrated isolated vestibular anomalies involving both the lateral semicircular canal and the utricle. Conclusions: Bearing in mind this case, we speculate that isolated vestibular malformation may not be as rare as previously thought, and should be investigated with the aid of sophisticated imaging techniques. A review of the relative literature, focussing attention on the molecular aspects, is also reported.", url = "https://doi.org/10.1017/s0022215108002740", doi = "10.1017/s0022215108002740", number = "8", openalex = "W2011164453", pages = "858-860", volume = "122", references = "doi101001archotol1287765, doi101002lary5540971301, doi101016jotc200610006, doi101016s0194599803015936, doi1010970000553719991000000018, doi1010970000553720001000000019, doi101242dev125133, doi101242dev126112335, doi1012880000553719870700000004, openalexw1532450920" } @article{doi101097mlg0b013e31814b8d67, author = "Wilkinson, Eric P. and Liu, Gene C. and Friedman, Rick A.", title = "Correction of Progressive Hearing Loss in Superior Canal Dehiscence Syndrome", year = "2008", journal = "The Laryngoscope", abstract = "Abstract A 44‐year‐old woman presented with typical vestibular symptoms of superior semicircular canal dehiscence syndrome (SSCDS). In addition, the patient experienced a rapidly progressive mixed hearing loss in the affected ear prior to surgical intervention that was unresponsive to oral steroid administration. Following middle fossa craniotomy with repair of the dehiscence, the patient's mixed hearing loss resolved to normal levels with no air‐bone gap. In this report, we discuss the possible etiology of this rapidly progressive hearing loss and its implications on the differential diagnosis of patients with new onset mixed hearing losses. We also contrast the index case of progressive mixed loss with the more frequent conductive hearing loss seen in SSCDS.", url = "https://doi.org/10.1097/mlg.0b013e31814b8d67", doi = "10.1097/mlg.0b013e31814b8d67", openalex = "W2086598582", references = "merchant2007superior" } @article{doi101258ar2010100324, author = "Yamashita, Koji and Yoshiura, Takashi and Hiwatashi, Akio and Dashjamts, Tuvshinjargal and Kamano, Hironori and Inoguchi, Takashi and Honda, Hiroshi", title = "Sensorineural hearing loss: there is no correlation with isolated dysplasia of the lateral semi-circular canal on temporal bone CT", year = "2011", journal = "Acta Radiologica", abstract = "BACKGROUND: Inner ear malformations may cause sensorineural hearing loss (SNHL). However, the correlation between the small lateral semi-circular canal (LSCC) and SNHL is controversial. PURPOSE: To determine whether there is a correlation between the two using CT-based measurement. MATERIAL AND METHODS: We retrospectively reviewed the high-resolution CT images of the temporal bone obtained from consecutive patients. A total 136 ears of 68 patients (25 men and 43 women; age range 20-85 years, mean 49.8 years) were included in this study. Patients who were clinically suspected to have otosclerosis were also excluded. Two radiologists independently measured the width and cross-sectional area of the bony island of LSCC. We evaluated the correlation between LSCC bone island width or cross-sectional area and hearing level in all cases using Pearson correlation co-efficients. In addition, we compared hearing levels among the patient group with normal-sized LSCC (≧mean-SD), small LSCC (0.05). No significant difference in hearing levels were found among groups of the normal-sized, small and very small LSCC (P > 0.05). CONCLUSION: We conclude that there is no correlation between isolated small LSCC and SNHL.", url = "https://doi.org/10.1258/ar.2010.100324", doi = "10.1258/ar.2010.100324", openalex = "W2333672208", references = "dallan2008bilateral, doi101001archotol198100790380026007, doi101007s004050090923x, doi101067mhn200351, doi1010970000553719991000000018, doi1010970000553720001000000019, doi1010970000553720020100000001, doi1010970012949220030500000014, doi10109701mlg00002298269659313, doi10109701mlg0000245034776404f, doi1012880000553719860100000005" } @article{doi103174ajnra2498, author = "Huang, Benjamin and Zdanski, Carlton J. and Castillo, Maurício", title = "Pediatric Sensorineural Hearing Loss, Part 1: Practical Aspects for Neuroradiologists", year = "2011", journal = "American Journal of Neuroradiology", abstract = "SNHL is a major cause of childhood disability worldwide, affecting 6 in 1000 children. For children with prelingual hearing loss, early diagnosis and treatment is critical to optimizing speech and language development, academic achievement, and social and emotional development. Cross-sectional imaging has come to play an important role in the evaluation of children with SNHL because otolaryngologists routinely order either CT or MR imaging to assess the anatomy of the inner ears, to identify causes of hearing loss, and to provide prognostic information related to potential treatments. In this article, which is the first in a 2-part series, we describe the basic clinical approach to imaging of children with SNHL, including the utility of CT and MR imaging of the temporal bones; we review the most recent proposed classification of inner ear malformations; and we discuss nonsyndromic congenital causes of childhood SNHL.", url = "https://doi.org/10.3174/ajnr.a2498", doi = "10.3174/ajnr.a2498", openalex = "W2105762623" } @article{doi101002lary23390, author = "Beyea, Jason A. and Agrawal, Sumit and Parnes, Lorne S.", title = "Transmastoid semicircular canal occlusion: A safe and highly effective treatment for benign paroxysmal positional vertigo and superior canal dehiscence", year = "2012", journal = "The Laryngoscope", abstract = "OBJECTIVES/HYPOTHESIS: Transmastoid occlusion of the superior semicircular canal in superior semicircular canal dehiscence (SSCD) syndrome and the posterior semicircular canal in intractable benign paroxysmal positional vertigo (BPPV) will produce resolution of preoperative symptoms. STUDY DESIGN: Retrospective review, quality assurance. METHODS: Sixteen patients with SSCD and 61 patients (65 ears) with intractable BPPV who underwent canal occlusion were reviewed. All patients underwent occlusion of the affected semicircular canal through a transmastoid approach. RESULTS: Preoperative symptoms (vestibular, 13 patients; pulsatile tinnitus, 2 patients; or hyperacusis, 1 patient) were greatly improved or completely resolved in 15 of the 16 SSCD patients who underwent transmastoid occlusion of the superior canal. Hearing was preserved in 14 patients and improved in two patients. Vestibular symptoms were resolved in all intractable BPPV patients who underwent transmastoid occlusion of the posterior canal. One patient had a late recurrence of atypical BPPV. Almost all BPPV patients with normal preoperative hearing have an initial transient postoperative hearing loss, which when tested for is usually a mild to moderate mixed loss. Delayed sensorineural hearing loss was noted in three patients; one loss was profound whereas two were mild. CONCLUSIONS: The transmastoid approach to canal plugging is successful in the treatment of symptoms in both SSCD and intractable BPPV, and is a familiar approach for the otologist. This is a viable alternative to the middle fossa approach for SSCD, thereby avoiding a craniotomy. Transmastoid is the definitive approach for posterior canal occlusion.", url = "https://doi.org/10.1002/lary.23390", doi = "10.1002/lary.23390", openalex = "W2104578602", references = "parnes1991posterior" } @article{doi101002ar22664, author = "Lee, Ju‐Young and Shin, Kang‐Jae and Kim, Jeong‐Nam and Yoo, Ja‐Young and Song, Wu‐Chul and Koh, Ki‐Seok", title = "A Morphometric Study of the Semicircular Canals Using Micro‐CT Images in Three‐Dimensional Reconstruction", year = "2013", journal = "The Anatomical Record", abstract = "It is generally accepted that the three semicircular canals are set at right angles to each other and the lateral semicircular canal is smaller than the anterior and posterior semicircular canals. Precise knowledge of the size and spatial relationships of the semicircular canals is vital, and so the 40 petrous parts of the temporal bones were scanned by micro-CT at a slice thickness of 35 µm. The micro-CT images were used in reconstructing three-dimensional models of the bony labyrinth using computer software. Various dimensions of the semicircular canals were measured using the software, and statistical analysis was performed. The anterior semicircular canal was slightly wider than the posterior semicircular canal, and their heights were similar. The radius of curvature of the lateral semicircular canal was 20\% smaller than those of the anterior and posterior semicircular canals. The angles between the three canals were not exactly 90 degrees: they were 92.1, 84.4, and 86.2 degrees between the anterior and posterior, anterior and lateral, and posterior and lateral semicircular canals, respectively. We obtained high-resolution images of the semicircular canals using three-dimensional reconstruction software, and these were used to precisely measure the angles between the semicircular canals and the area of the distorted circle formed by each semicircular canal.", url = "https://doi.org/10.1002/ar.22664", doi = "10.1002/ar.22664", openalex = "W1592500593", references = "dallan2008bilateral, doi101001archotol1322186, doi101002sici10968644199810727211aidajpa833co2m, doi101002sici10982353199710164aidca1730co2m, doi101016s0047248402001665, doi101016s0194599803015936, doi1010970000553720001000000019, doi1010970000553720020100000001, doi1010970012949220030500000014, doi10109701mlg00002298269659313, doi101097mao0b013e3181a5299b, doi101258ar2010100324, openalexw270402704" } @article{doi101097rct0b013e3182aaf21c, author = "Daocai, Wang and Wang, Qing and Ximing, Wang and He, Jingzhen and Liu, Cheng and Ma, Xiangxing", title = "Size of the Semicircular Canals Measured by Multidetector Computed Tomography in Different Age Groups", year = "2014", journal = "Journal of Computer Assisted Tomography", abstract = "PURPOSE: The purpose of the study was to obtain reference values for the sizes of the semicircular canals (SCCs) on multidetector computed tomographic (CT) images in different age groups. METHODS: Computed tomographic images of the temporal bone of 210 patients, a total of 420 ears without inner ear pathology, have been evaluated. These patients were divided into 4 groups by age: young children (60 years). The inner diameter, maximum height, and width of the SCCs were measured. RESULTS: There was no significant difference in the size of SCC among the 4 age groups. The inner diameter measurements of the anterior SCC, lateral SCC, and posterior SCC were 0.101 ± 0.016, 0.135 ± 0.033, and 0.124 ± 0.021 cm, respectively. The height measurements of the anterior SCC, lateral SCC, and posterior SCC were 0.535 ± 0.086, 0.349 ± 0.090, and 0.490 ± 0.109 cm, respectively. The width measurements of the anterior SCC, lateral SCC, and posterior SCC were 0.567 ± 0.080, 0.302 ± 0.082, and 0.472 ± 0.099 cm, respectively. CONCLUSIONS: The size of SCCs remains constant from children to the elderly people, unlike the other human organs. The reference values provided by multidetector CT can serve as an aid for the interpretation of CT images.", url = "https://doi.org/10.1097/rct.0b013e3182aaf21c", doi = "10.1097/rct.0b013e3182aaf21c", openalex = "W2323693284", references = "doi101002ar22664, doi101258ar2010100324" } @article{doi102463mrms20140112, author = "Naganawa, Shinji and Kawai, Hisashi and Sone, Michihiko and Ikeda, Mitsuru", title = "Ratio of Vestibular Endolymph in Patients with Isolated Lateral Semicircular Canal Dysplasia", year = "2015", journal = "Magnetic Resonance in Medical Sciences", abstract = "PURPOSE: Isolated vestibular-lateral semicircular canal dysplasia (LSCCD) is one of the most common anomalies of the inner ear. However, endolymphatic size in LSCCD is unknown. We measured the size of the endolymph in the vestibule of patients with LSCCD and compared it with that measured in patients without LSCCD. METHODS: We extracted 1102 magnetic resonance (MR) studies for the evaluation of endolymphatic hydrops (EH) from our database of radiology reports. Among these, we found 15 ears from 11 patients with LSCCD; 4 patients had bilateral abnormalities. Seven of the 15 ears demonstrated aplasia and 8 ears, hypoplasia of the lateral semicircular canal (LSCC). The control group consisted of 26 ears from 13 randomly selected patients without LSCCD. We measured the area of endolymph in the vestibule (ELA), total area of vestibular lymph fluid (TLA), and area of the central bony island (CBI) of the LSCC from axial MR images obtained after intratympanic or intravenous administration of gadolinium-based contrast material. The ratio of endolymphatic area to total lymphatic area (\%EL) was defined as \%EL = ELA/TLA × 100.We evaluated the correlation between \%EL and the area of the CBI and compared age, \%EL, degree of cochlear EH, hearing level, and presence of rotating vertigo among the 3 groups (aplasia, hypoplasia, control). RESULTS: The mean \%EL was 76.7\% in the aplasia group, 50.0\% in the hypoplasia group, and 27.8\% in the control group (P 0.05). CONCLUSION: The size of vestibular endolymph was larger in the groups with aplasia or hypoplasia than the control group. Thus, the current diagnostic cut-off value for significant vestibular EH (>50\%) might not be appropriate for ears with LSCCD.", url = "https://doi.org/10.2463/mrms.2014-0112", doi = "10.2463/mrms.2014-0112", openalex = "W2001528188", references = "doi101016jijporl200907013, doi101258ar2010100324" } @article{doi101001jamaoto20163175, author = "Wineland, Andre and Menezes, Maithilee and Shimony, Joshua S. and Shinawi, Marwan and Hullar, Timothy E. and Hirose, Keiko", title = "Prevalence of Semicircular Canal Hypoplasia in Patients With CHARGE Syndrome", year = "2016", journal = "JAMA Otolaryngology–Head \& Neck Surgery", abstract = "Importance: CHARGE syndrome refers to a syndrome involving coloboma, heart defects, atresia choanae, retardation of growth and development, genitourinary disorders, and ear anomalies. However, Verloes revised the characteristics of CHARGE syndrome in 2005 to define this syndrome more broadly. Deficiency of the semicircular canals is now a major criterion for CHARGE syndrome. Objective: To characterize patients with CHARGE syndrome at our center using Verloes' criteria and to reevaluate the nomenclature for this condition. Design, Setting, and Participants: We performed a medical chart review of patients with CHARGE syndrome and reviewed their temporal bone imaging studies at a tertiary care children's hospital affiliated with Washington University in St Louis. Two authors independently reviewed each imaging study (A.W. and K.H.). Radiologic studies, physical findings, genetic tests, and other diagnostic tests were included. Patients with no temporal bone imaging studies were excluded. Results: Eighteen children were included in this study; 13 children (72\%) were male, and the mean (median; range) age of patients at the time of inner ear imaging studies was 2 years (4.5 years; 8 months to 8 years). Coloboma was present in 13 patients (72\%) and choanal atresia in 5 (28\%); semicircular canal anomalies were present in all patients. Additionally, 13 patients (72\%) were diagnosed as having hindbrain anomalies, 17 (94\%) as having endocrine disorders, 17 (94\%) as having mediastinal organ malformations, and all as having middle or external ear abnormalities and development delay. Cleft lip and cleft palate were found in 6 of 14 patients (43\%) who did not have choanal atresia. We tested 16 patients for mutations in the CHD7 gene; 10 were positive (63\%) for mutations, 4 (25\%) were negative, and 2 (13\%) were inconclusive. Conclusions and Relevance: Semicircular canal anomalies were the most consistent finding in our patients with CHARGE syndrome. Given the high prevalence of semicircular canal hypoplasia and importance of imaging for diagnosing CHARGE syndrome, we propose changing the term CHARGE syndrome to 3C syndrome to emphasize the importance of the semicircular canals and to recall the 3 major criteria for diagnosis: coloboma, choanal atresia, and semicircular canal anomaly. The nomenclature would also reference the 3 semicircular canals in each ear. This new name for CHARGE syndrome would provide a mnemonic and focus the disease on the most important clinical criteria for diagnosis.", url = "https://doi.org/10.1001/jamaoto.2016.3175", doi = "10.1001/jamaoto.2016.3175", openalex = "W2551368632" } @article{doi103174ajnra4922, author = "Ho, Mai‐Lan and Moonis, Gul and Halpin, Christopher F. and Curtin, Hugh D.", title = "Spectrum of Third Window Abnormalities: Semicircular Canal Dehiscence and Beyond", year = "2016", journal = "American Journal of Neuroradiology", abstract = "Third window abnormalities are defects in the integrity of the bony structure of the inner ear, classically producing sound-/pressure-induced vertigo (Tullio and Hennebert signs) and/or a low-frequency air-bone gap by audiometry. Specific anatomic defects include semicircular canal dehiscence, perilabyrinthine fistula, enlarged vestibular aqueduct, dehiscence of the scala vestibuli side of the cochlea, X-linked stapes gusher, and bone dyscrasias. We discuss these various entities and provide key examples from our institutional teaching file with a discussion of symptomatology, temporal bone CT, audiometry, and vestibular-evoked myogenic potentials.", url = "https://doi.org/10.3174/ajnr.a4922", doi = "10.3174/ajnr.a4922", openalex = "W2518325555", references = "merchant2007superior" } @article{michel2016isolated, author = "Michel, G. and Espitalier, F. and Delemazure, A.-S. and Bordure, P.", title = "Isolated lateral semicircular canal aplasia: Functional consequences", year = "2016", journal = "European Annals of Otorhinolaryngology, Head and Neck Diseases", url = "https://doi.org/10.1016/j.anorl.2015.09.002", doi = "10.1016/j.anorl.2015.09.002", number = "3", pages = "199-201", volume = "133" } @article{vanrompaey2016hearing, author = "Van Rompaey, Vincent and Van de Heyning, Paul", title = "Hearing preservation techniques in semicircular canal surgery", year = "2016", journal = "The Journal of Laryngology \& Otology", url = "https://doi.org/10.1017/s0022215116004400", doi = "10.1017/s0022215116004400", number = "S3", openalex = "W2591529805", pages = "S125-S126", volume = "130" } @article{doi101515revneuro20160058, author = "Asadi, Houshyar and Mohamed, Shady and Lim, Chee Peng and Nahavandi, Saeid and Nalivaiko, Eugene", title = "Semicircular canal modeling in human perception", year = "2017", journal = "Reviews in the Neurosciences", abstract = "The human vestibular system is a sensory and equilibrium system that manages and controls the human sense of balance and movement. It is the main sensor humans use to perceive rotational and linear motions. Determining an accurate mathematical model of the human vestibular system is significant for research pertaining to motion perception, as the quality and effectiveness of the motion cueing algorithm (MCA) directly depends on the mathematical model used in its design. This paper describes the history and analyses the development process of mathematical semicircular canal models. The aim of this review is to determine the most consistent and reliable mathematical semicircular canal models that agree with experimental results and theoretical analyses, and offer reliable approximations for the semicircular canal functions based on the existing studies. Selecting and formulating accurate mathematical models of semicircular canals are essential for implementation into the MCA and for ensuring effective human motion perception modeling.", url = "https://doi.org/10.1515/revneuro-2016-0058", doi = "10.1515/revneuro-2016-0058", openalex = "W2595919128", references = "jones1974the" } @article{doi1023937247436821510116, author = "Arslan, Serdar and Hasan, Erdogan and Sedat, Durmaz Mehmet and Zeynep, Arslan Fatma and Öncü, Fatih and Tolu, İsmet", title = "Bilateral Isolated Lateral Semicircular Canals Aplasia: MRI Findings", year = "2018", journal = "Clinical Medical Image Library", abstract = "A 38-year-old man was admitted to our department due to recurrent sensations of imbalance and vertigo for two years. Moderate bilateral sensorineural hearing loss was detected. Magnetic resonance imaging demonstrated bilateral isolated aplasia of the lateral semicircular canals.", url = "https://doi.org/10.23937/2474-3682/1510116", doi = "10.23937/2474-3682/1510116", openalex = "W2896931133", references = "michel2016isolated" } @article{doi10410303666999226895, author = "Liu, Yiwei and Sun, Ke and Tang, Jianguo", title = "Isolated Unilateral Horizontal Semicircular Canal Malformation", year = "2018", journal = "Chinese Medical Journal", abstract = "To the Editor: Semicircular canal (SCC) malformation (dystrophy, coloboma, or enlargement) is a kind of inner ear anomaly. It is usually found in congenital syndromes along with the malformation(s) of other structure(s) of any of the parts of the ear including the inner ear. Isolated one SCC malformation is extremely rare and might thereby be easily missed. The present study reports a case of the left lateral SCC (LSCC) aplasia. A 50-year-old woman presented with tinnitus and vertigo for one year, which was relieved by rest. The patient had no history of hearing loss. The vertigo was rotatory, episodic, and positional in nature. She had no relevant personal or family history, and no history of head trauma or use of ototoxic medication. The external auditory canals and tympanic membranes were normal on examination. Pure-tone audiometry was found to be normal [Figure 1a]. Tympanometry revealed a Type A curve. Videonystagmography was normal and revealed no spontaneous nystagmus. The Dix-Hallpike test and roll test were negative as was head-shaking test. Vestibular evoked myogenic potential testing was normal [Figure 1b]. Caloric tests revealed bilateral SCC paresis, which was more on the left side, and persisted for 1 s on the left and 6 s on the right after stimulation with cold water. However, there was no response after stimulating with hot water [Figure 1c].Figure 1: MRI and several functional investigations of isolated malformation of LSCC. (a) Pure-tone threshold audiometry: normal hearing of both ears. (b) VEMP was normal in the bilateral ear. (c) Caloric tests reveal a mild bilateral SCC hyporeflexia: (A) right ear with cold air; (B) right ear with hot air; (C) left ear with hot air; (D) left ear with cold air. (d) MRI with 3D reconstruction: the red arrow shows the interruptive deformity of the left LSCC. (e and f) MRI, axial section, T2HR sequence: the red arrows show the bilateral normal cochlea and the blue arrow shows the left defective LSCC. L: Left; R: Right; VEMP: Vestibular evoked myogenic potential; MRI: Magnetic resonance imaging; LSCC: Left semicircular canal; 3D: Three dimensional.Magnetic resonance imaging (MRI) of the inner ear with three-dimensional (3D) reconstruction revealed a defect in the LSCC, which was characterized by complete coloboma and interruption of the LSCC in proximity to the posterior SCC. However, no other abnormalities were found in other SCCs, vestibule, cochlea, round window, or oval window. The internal auditory canal and cerebellopontine angle were normal [Figure 1d-1f]. Rest and relaxation, symptomatic treatment with vestibular sedatives, and medications to improve blood circulation, nourish nerves, and improve the general well-being were added. One-year follow-up revealed that the vertigo had almost fully resolved, and tinnitus only occurred due to fatigue or exertion. The development of the inner ear begins in the 4th week of intrauterine life. The superior SCC is the first to form at approximately 6 weeks of gestation, followed by the posterior and lateral canals. It is the malformation of the LSCC, which is the last one to develop, that occurs most frequently, and this may be explained by such a sequential development model of inner ear embryogenesis.[1] However, isolated LSCC malformation with a normal vestibular apparatus and cochlea might present challenges to the sequential development theory of the inner ear. SCC malformations are mostly reported in congenital syndromes with multiple deformities such as coloboma, heart defects, atresia choanae, growth retardation, genital abnormalities, and ear abnormalities syndrome.[2] Until the first case was reported by Michel et al. in 2016,[3] the complete breach of just one SCC without congenital syndromes remained completely unknown. Hence, SCC malformations are often overlooked and sidelined in cases with such conditions and do not deserve any special mention in literature, especially if the patient is asymptomatic. The present patient had tinnitus and vertigo but had no hearing loss. Tinnitus and vertigo/dizziness are common complaints encountered by otologists. Although the dizziness experienced by the patient could be explained by SCC dysfunction, it would be impossible to determine whether this dysfunction was due to the SCC malformation or any other lesion since no case that connected dizziness and SCC malformation has been reported to date. The caloric test performed for the patient in the present study demonstrated a weak response for both SCCs although the malformation was unilateral. The absence of hearing loss could be explained by a present research result which indicates that the severity or type of SCC malformation was not correlated with the severity of hearing loss.[4] In addition, the isolated malformation of SCCs might not affect the process of sound conduction. Thus, we suspected that isolated SCC malformation might not produce hearing loss. As a result, no conclusive evidence could confirm the relationship between the imaging findings and symptoms of the patient. Given the fact that the patient led a healthy lifestyle for nearly five decades, it might be concluded that the rolling movements of amniotic fluid during the fetal period might have led to the acclimatization of rotation and contralateral compensation would develop early, and the presently acquired episode of vertigo might be due to other reasons. Treatment was thereby directed toward the control of the tinnitus and dizziness. The objective of the present case report was to draw attention to the existence of an isolated SCC malformation and its timely detection and further management. High-resolution computed tomography (HRCT) and MRI allow the accurate detection of inner ear malformations and are complementary to each other. However, CT is better for imaging bony anatomy, while MRI provides valuable information on the membranous labyrinth, internal acoustic canal, and vestibulo-cochlear nerve. MRI poses no radiation hazard unlike CT. Furthermore, vestibular pathologies diagnosed by both HRCT and MRI are almost similar.[5] The imaging method might be useful, especially when inner ear malformation is strongly suspected. If the primary complaint of the patient was hearing loss, a CT scan would have been suggested to examine the disease of the middle ear or bony labyrinth. In large-scale studies with patients that present with tinnitus, hearing loss, or dizziness, the use of MRI with 3D reconstruction, including the internal auditory canal, might be a good idea, to allow for the detection of more such cases and possibly validate these findings. In summary, the present literature does not satisfactorily describe the relationship between symptom(s), imaging findings, and the pathogenesis of SCC lesions. Hence, empirical and supportive therapy is usually given. However, imaging is crucial for diagnosis and must be combined with the clinical history of the patient, especially the patient's family history and mother's obstetric history. In addition, genetic analysis is also necessary. These would help to determine the treatment and might shed new light on the evolution of this rare and interesting entity, not only from the clinical standpoint, but also for the purpose of pathophysiology research. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understood that their names and initials will not be published and due effort will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Acknowledgments The authors would like to thank Dr. W Bo-Zhen for her excellent work in preparing the pure tone audiogram.", url = "https://doi.org/10.4103/0366-6999.226895", doi = "10.4103/0366-6999.226895", openalex = "W2792868293", references = "michel2016isolated" } @article{doi101017s0022215120001334, author = "Abidin, Zakhirati Zainol and Zaki, Faizah Mohd and Kew, Thean Yean and Goh, Bee See and Abdullah, Asma", title = "Cochlear nerve canal stenosis and associated semicircular canal abnormalities in paediatric sensorineural hearing loss: a single centre study", year = "2020", journal = "The Journal of Laryngology \& Otology", abstract = "OBJECTIVE: This study aimed to evaluate the association between cochlear nerve canal dimensions and semicircular canal abnormalities and to determine the distribution of bony labyrinth anomalies in patients with cochlear nerve canal stenosis. METHOD: This was a retrospective study in which high-resolution computed tomography images of paediatric patients with severe-to-profound sensorineural hearing loss were reviewed. A cochlear nerve canal diameter of 1.5 mm or less in the axial plane was classified as stenotic. Semicircular canals and other bony labyrinth morphology and abnormality were evaluated. RESULTS: Cochlear nerve canal stenosis was detected in 65 out of 265 ears (24 per cent). Of the 65 ears, 17 ears had abnormal semicircular canals (26 per cent). Significant correlation was demonstrated between cochlear nerve canal stenosis and semicircular canal abnormalities (p < 0.01). Incomplete partition type II was the most common accompanying abnormality of cochlear nerve canal stenosis (15 out of 65, 23 per cent). CONCLUSION: Cochlear nerve canal stenosis is statistically associated with semicircular canal abnormalities. Whenever a cochlear nerve canal stenosis is present in a patient with sensorineural hearing loss, the semicircular canal should be scrutinised for presence of abnormalities.", url = "https://doi.org/10.1017/s0022215120001334", doi = "10.1017/s0022215120001334", openalex = "W3045589268", references = "doi101016janorl201210005, doi101016s0194599803015936, doi101258ar2010100324" } @article{doi101055s00393402738, author = "Steenerson, Kristen K. and Crane, Benjamin T. and Minor, Lloyd B.", title = "Superior Semicircular Canal Dehiscence Syndrome", year = "2020", journal = "Seminars in Neurology", abstract = "Superior canal dehiscence syndrome (SCDS) is a vestibular disorder caused by a pathologic third window into the labyrinth that can present with autophony, sound- or pressure-induced vertigo, and chronic disequilibrium among other vestibulocochlear symptoms. Careful history taking and examination in conjunction with appropriate diagnostic testing can accurately diagnose the syndrome. Key examination techniques include fixation-suppressed ocular motor examination investigating for sound- or pressure-induced eye movements in the plane of the semicircular canal. Audiometry, vestibular evoked myogenic potentials, and computed tomography confirm the diagnosis. Corrective surgical techniques can be curative, but many patients find their symptoms are not severe enough to undergo surgery. Although a primarily peripheral vestibular disorder, as first-line consultants for most dizziness complaints, neurologists will serve their patients well by understanding SCDS and its role in the differential diagnosis of vestibular disorders.", url = "https://doi.org/10.1055/s-0039-3402738", doi = "10.1055/s-0039-3402738", openalex = "W2503897659", references = "merchant2007superior" } @article{doi1010800001648920201804615, author = "Choi, BoYoon and Lee, Dong‐Han and Shin, Jung Eun and Kim, Chang‐Hee", title = "Nystagmus in patients with lateral semicircular canal dysplasia", year = "2020", journal = "Acta Oto-Laryngologica", abstract = "BACKGROUND: Dizziness is not a common symptom in the lateral semicircular canal (LSCC) dysplasia, and nystagmus findings has been rarely described in LSCC dysplasia. OBJECTIVE: To investigate the characteristics of spontaneous and positional nystagmus in patients with LSCC dysplasia. METHODS: Patterns of spontaneous and positional nystagmus of twelve patients with LSCC dysplasia, who visited our clinic with a chief complaint of dizziness, were investigated. RESULTS: LSCC dysplasia was observed unilaterally in 4, and bilaterally in 8 patients. Non-rotatory dizziness with various onset times was the most common description of dizziness, and unilateral caloric weakness was observed in 82\% of patients. Direction-fixed nystagmus, in which the direction of spontaneous nystagmus was same with that of positional nystagmus, was observed in 9 patients, and direction-changing positional nystagmus, in which the direction of nystagmus was changed from that of spontaneous nystagmus by positioning maneuvers, was observed in 3 patients, of whom down-beating or direction-changing spontaneous nystagmus was observed in one patient each. CONCLUSION: While direction-fixed horizontal nystagmus is the most commonly observed type of nystagmus in LSCC dysplasia, atypical spontaneous nystagmus, such as down-beating nystagmus or direction-changing spontaneous nystagmus, may be observed in patients with bilateral LSCC dysplasia.", url = "https://doi.org/10.1080/00016489.2020.1804615", doi = "10.1080/00016489.2020.1804615", openalex = "W3078104591", references = "doi101258ar2010100324, doi1021053ceo201901053" } @article{doi1021053ceo201901053, author = "Kwak, Sang Hyun and Kim, Min Ki and Kim, Sung Huhn and Jung, Jinsei", title = "Audiological and Vestibular Functions in Patients With Lateral Semicircular Canal Dysplasia and Aplasia", year = "2020", journal = "Clinical and Experimental Otorhinolaryngology", abstract = "OBJECTIVES: The aim of the present study was to evaluate audiologic and vestibular functions in patients with lateral semicircular canal (LSCC) dysplasia/aplasia. METHODS: We conducted a retrospective study of a patients with LSCC dysplasia and aplasia at tertiary referral center. The subjects included 15 patients with LSCC dysplasia or aplasia, with or without combined inner ear anomalies. Medical history, temporal bone computed tomography scans, pure-tone audiograms, and vestibular function test results were analyzed. RESULTS: LSCC anomaly was identified in 15 patients (20 ears). Nine patients had unilateral LSCC dysplasia only and showed a mean pure-tone average of 45.5±28.7 dB, while three patients (33.3\%) among them had normal hearing. Six patients had bilateral LSCC dysplasia/aplasia combined with other inner ear anomalies and profound bilateral hearing loss. Notably, only four out of 15 patients (26.7\%) had dizziness symptoms. On caloric test, patients with isolated LSCC dysplasia showed a 51.8\%±29.3\% level of canal paresis (eight out of nine patients showed anomalies), whereas patients with bilateral LSCC dysplasia/aplasia presented bilateral vestibular loss. One patient with isolated LSCC underwent video-head impulse test; horizontal canal gain decreased to 0.62 (17\% asymmetry) and anterior canal gain was 0.45 (52.6\% asymmetry), whereas posterior canal gain was normal. CONCLUSION: Bilateral LSCC dysplasia/aplasia is comorbid with other inner ear anomalies and presents as profound bilateral hearing loss and vestibulopathy. In contrast, isolated unilateral LSCC dysplasia presents as ipsilateral horizontal canal paresis. Hearing function in isolated LSCC dysplasia is usually, but not always, impaired with varying severity.", url = "https://doi.org/10.21053/ceo.2019.01053", doi = "10.21053/ceo.2019.01053", openalex = "W2999413397", references = "dallan2008bilateral, doi101001jamaoto20163175, doi101002jnr20652, doi101016jheares201602004, doi101016jijporl200907013, doi101016s0194599803015936, doi101016s0720048x01003771, doi101038nrdp201694, doi1010970000553720001000000019, doi101111nyas12687, doi10117700034894790884s201, doi101242dev125133, doi101258ar2010100324" } @article{doi101055s00411740366, author = "Kannan, Varun and Tran, Brandon", title = "Partial Duplication of the Lateral Semicircular Canal—A Novel Anatomical Malformation in a Child with Barakat Syndrome", year = "2021", journal = "Journal of Pediatric Neurology", abstract = "Abstract Several known genetic causes of sensorineural deafness are associated with dysplasia of inner ear structures, including the cochlea and labyrinth. Here, we present a child with Barakat syndrome and sensorineural hearing loss, found to have multiple inner ear anomalies including partial duplication of the posterior limb of the left lateral semicircular canal. To our knowledge, duplication of the semicircular canal has not previously been reported. This finding expands our understanding of the range of anatomical variations observed in congenital inner ear malformations, and further characterizes the phenotypic manifestations of Barakat syndrome.", url = "https://doi.org/10.1055/s-0041-1740366", doi = "10.1055/s-0041-1740366", openalex = "W4200372297", references = "doi101007s0040501905294y, doi1021053ceo201901053" } @article{doi103233ves200004, author = "Ward, Bryan K. and van de Berg, Raymond and Rompaey, Vincent Van and Bisdorff, Alexandre and Hullar, Timothy E. and Welgampola, Miriam S. and Carey, John P.", title = "Superior semicircular canal dehiscence syndrome: Diagnostic criteria consensus document of the committee for the classification of vestibular disorders of the Bárány Society", year = "2021", journal = "Journal of Vestibular Research", abstract = "This paper describes the diagnostic criteria for superior semicircular canal dehiscence syndrome (SCDS) as put forth by the classification committee of the Bárány Society. In addition to the presence of a dehiscence of the superior semicircular canal on high resolution imaging, patients diagnosed with SCDS must also have symptoms and physiological tests that are both consistent with the pathophysiology of a 'third mobile window' syndrome and not better accounted for by another vestibular disease or disorder. The diagnosis of SCDS therefore requires a combination of A) at least one symptom consistent with SCDS and attributable to 'third mobile window' pathophysiology including 1) hyperacusis to bone conducted sound, 2) sound-induced vertigo and/or oscillopsia time-locked to the stimulus, 3) pressure-induced vertigo and/or oscillopsia time-locked to the stimulus, or 4) pulsatile tinnitus; B) at least 1 physiologic test or sign indicating that a 'third mobile window' is transmitting pressure including 1) eye movements in the plane of the affected superior semicircular canal when sound or pressure is applied to the affected ear, 2) low-frequency negative bone conduction thresholds on pure tone audiometry, or 3) enhanced vestibular-evoked myogenic potential (VEMP) responses (low cervical VEMP thresholds or elevated ocular VEMP amplitudes); and C) high resolution computed tomography (CT) scan with multiplanar reconstruction in the plane of the superior semicircular canal consistent with a dehiscence. Thus, patients who meet at least one criterion in each of the three major diagnostic categories (symptoms, physiologic tests, and imaging) are considered to have SCDS.", url = "https://doi.org/10.3233/ves-200004", doi = "10.3233/ves-200004", openalex = "W3127116841" } @article{doi103389fneur2021741948, author = "Wu, Shuzhi and Lin, Ping and Zheng, Yanyan and Zhou, Yifei and Liu, Zhaobang and Yang, Xiaokai", title = "Measurement of Human Semicircular Canal Spatial Attitude", year = "2021", journal = "Frontiers in Neurology", abstract = "Located deep in the temporal bone, the semicircular canal is a subtle structure that requires a spatial coordinate system for measurement and observation. In this study, 55 semicircular canal and eyeball models were obtained by segmentation of MRI data. The spatial coordinate system was established by taking the top of the common crus and the bottom of the eyeball as the horizontal plane. First, the plane equation was established according to the centerline of the semicircular canals. Then, according to the parameters of the plane equation, the plane normal vectors were obtained. Finally, the average unit normal vector of each semicircular canal plane was obtained by calculating the average value of the vectors. The standard normal vectors of the and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were [-0.651, 0.702, 0.287], [0.749, 0.577, 0.324], [-0.017, -0.299, 0.954], [0.660, 0.702, 0.266], [-0.739, 0.588, 0.329], [0.025, -0.279, 0.960]. The different angles for the different ways of calculating the standard normal vectors of the right and left posterior semicircular canal, superior semicircular canal and lateral semicircular canal were 0.011, 0.028, 0.008, 0.011, 0.024, and 0.006 degrees. The technology for measuring the semicircular canal spatial attitudes in this study are reliable, and the measurement results can guide vestibular function examinations and help with guiding the diagnosis and treatment of BPPV.", url = "https://doi.org/10.3389/fneur.2021.741948", doi = "10.3389/fneur.2021.741948", openalex = "W3203684933", references = "doi101002ar22664" } @article{doi103390ohbm2010003, author = "Vega, Víctor Manuel Suárez and Domínguez, Pablo and Pérez‐Fernández, Nicolás", title = "MRI Evaluation of Vestibular Endolymphatic Space in Patients with Isolated Cystic Lateral Semicircular Canal Malformation", year = "2021", journal = "Journal of Otorhinolaryngology Hearing and Balance Medicine", abstract = "Isolated lateral semicircular canal dysplasia (LSCCD) is one of the most frequent malformations of the bony labyrinth. The aim of this study is to depict morphology and size of the vestibular endolymphatic space in patients with isolated LSCCD using a dedicated 3D high resolution MR sequence called 3D inversion recovery with REAL reconstruction (3D-REAL-IR). From January 2018 to February 2020, we reviewed 281 CT and 241 MR temporal bone studies, and 103 MR studies performed for the evaluation of endolymphatic hydrops (EH). Five patients with LSCCD were found, one of them with bilateral malformation. Three patients (four affected ears) underwent specific MR examination for the evaluation of EH, consisting of a heavily T2-weighed cisternography sequence (T2 SPACE) and a 3D inversion-recovery with REAL reconstruction. The endolymphatic volumetric ratio (ELR) was calculated as the total endolymphatic volume divided by the total lymph (vestibular) volume multiplied by 100. Hydrops MR imaging was available in four of the affected ears. ELR ranged from 22\% to 81\%. Both extremes were present in the same patient, corresponding to a patient with right unilateral Ménière’s syndrome but with bilateral LSCCD. A patient affected with hearing loss had an ELR of 33\% and the last patient with unilateral probable Ménière’s syndrome showed an ELR of 42\%. Endolymphatic hydrops imaging is feasible and can be performed on patients with inner ear malformations like LSCCD. The endolymphatic volumetric ratio could be a useful and reproducible tool in daily clinical practice.", url = "https://doi.org/10.3390/ohbm2010003", doi = "10.3390/ohbm2010003", openalex = "W3123769573", references = "doi1021053ceo201901053" } @article{doi103389fneur2022879149, author = "Gianoli, Gerard J. and Soileau, James S. and Shore, Bradley", title = "Description of a New Labyrinthine Dehiscence: Horizontal Semicircular Canal Dehiscence at the Tympanic Segment of the Facial Nerve", year = "2022", journal = "Frontiers in Neurology", abstract = "Objective: This report is a case series of patients with findings suspicious for a labyrinthine dehiscence syndrome not previously described in the medical literature. We describe the clinical and test findings in 16 patients with CT findings suspicious for dehiscence of the ampullated end of the horizontal semicircular canal at the tympanic segment of the facial nerve. Study Design: Observational case series. Setting: Neurotology vestibular referral center. Patients: To be included in this study the patients were seen at our center in 2019 and had a high-resolution CT scan with a collimation of 0.6 mm. Patients who were identified as having findings suspicious for dehiscence of bone where the facial nerve crosses the ampullated end of the horizontal semicircular canal (HSC-FND) were identified and further analyzed. Interventions: Case series retrospective record review of patient symptoms, physical findings, audiometry, vestibular testing, and CT scans was performed. CT findings of other dehiscent sites were noted. A comparison to surgically treated perilymph fistula (PLF) patients of the same period was performed. Main Outcome Measures: History and physical exam were reviewed for auditory symptoms, vestibular symptoms, and exacerbating factors. and. Audiometry and vestibular testing were reviewed to determine which tests were most likely to be abnormal. CT scans were independently graded according to degree of suspicion for HSC-FND. Finally, patients with HSC-FND as the sole dehiscence identified were compared to those who had HSC-FND plus other dehiscent sites (HSC-FND+O) and to the group of surgically treated PLF patients. Results: Of 18 patients, 16 met inclusion criteria. Nine (56\%) of those suspicious for HSC-FND had dehiscences in other parts of the labyrinth. Additional dehiscent sites included: six superior semicircular canal dehiscences (SSCD), two cochlear facial dehiscences and one cochlear carotid dehiscence. The most common auditory symptoms were autophony followed by tinnitus and aural fullness. The most common vestibular symptoms were pulsion sensation (feeling of being pushed to one side) followed by vertigo spells. The most common exacerbating factors for vertigo were straining, and sound. The most commonly abnormal vestibular test was nasal Valsalva testing, which was positive in all but one patient. Anamnesis and examination observations were similar in both groups, but the HSC-FND group were less likely to demonstrate a caloric weakness or an abnormal ECOG compared to the HSC-FND+O group. Of note, cVEMP was more often found to have lower thresholds in the HSC-FND group compared to the HSC-FND+O group. An example case is highlighted. Comparison to the PLF patients revealed statistically significant difference in the presenting symptoms of autophony, fullness and pulsion sensation. When comparing testing, HSC-FND patients were more likely to have an abnormal cVEMP and PLF patients were more likely to have asymmetric hearing. The incidence of bilateral disease was also more common among the HSC-FND patients than the PLF patients. Conclusions: A new labyrinthine dehiscence has been described to occur where the tympanic segment of the facial nerve crosses over the ampullated end of the horizontal semicircular canal. HSC-FND patients can present in a similar manner as HSC-FND+O patients with similar test findings except as mentioned above. The identification of one dehiscence such as SSCD does not preclude the presence of another dehiscence such as HSC-FND. HSC-FND could be the source of persistent symptoms post SSCD surgery as illustrated in the case presented. HSC-FND patients seem to identify themselves compared to PLF patients by a much more likely presenting symptoms of autophony, fullness, pulsion, abnormal cVEMP, bilaterality of disease, and symmetric hearing.", url = "https://doi.org/10.3389/fneur.2022.879149", doi = "10.3389/fneur.2022.879149", openalex = "W4283574959", references = "doi101002ar22664" } @article{doi1010800001648920232179661, author = "Wang, Qin and Bian, Panpan and Bai, Shengjin and Chen, Chi and Wang, Yanli and Guo, Yufen and Xu, Baicheng", title = "Research on congenital severe-to-profound sensorineural hearing loss associated with central lucency of the bony island of the lateral semicircular canal", year = "2023", journal = "Acta Oto-Laryngologica", abstract = "BACKGROUND: Central lucency of the bony island of the lateral semicircular canal (LSCC) is commonly found in patients with congenital severe-to-profound sensorineural hearing loss (SNHL). OBJECTIVE: Exploring the significance of bony island lucency of LSCC in congenital severe-to-profound SNHL patients. MATERIAL AND METHODS: Retrospective measurements of the inner ear structures were made on axial temporal bone CT scans from 182 (364 ears) congenital severe-to-profound SNHL patients and 50 (100 ears) tympanic membrane perforation (TMP) patients. RESULTS: The incidence of bony island lucency of LSCC was 46.7\% in the congenital severe-to-profound SNHL group and 0\% in the TMP group. There was a statistically significant difference in inner ear structures among congenital severe-to-profound SNHL patients with normal inner ear structure and bony island lucency of LSCC, congenital severe-to-profound SNHL patients with normal inner ear structure and no bony island lucency of LSCC, and TMP patients. The importance of the bony island lucency of LSCC was further confirmed through multiple linear regression analysis. CONCLUSIONS AND SIGNIFICANCE: Bony island lucency may have significance in congenital severe-to-profound SNHL and may be a manifestation of largely overlooked SCC malformation or hypoplasia of the inner ear.", url = "https://doi.org/10.1080/00016489.2023.2179661", doi = "10.1080/00016489.2023.2179661", openalex = "W4321996606", references = "doi101007s0040501905294y, doi1021053ceo201901053" } @article{doi101136bcr2022254068, author = "Goulioumis, Anastasios and Athanasopoulos, Michail and Kalogerakou, Kleanthi and Gyftopoulos, Kostis", title = "Lateral semicircular canal dilatation in a patient with congenital hearing loss due to α-tectorin mutation: microanatomical considerations", year = "2023", journal = "BMJ Case Reports", abstract = "gene may affect additional glycoproteins that share a high percentage of sequence similarity at the amino acid level with α-tectorin. The mutated glycoproteins differ in the hydration level of their side chains of glycosaminoglycans. Hydration level could affect the mass of the ampullary cupula of the lateral semicircular canal leading to its dilation during embryogenesis.", url = "https://doi.org/10.1136/bcr-2022-254068", doi = "10.1136/bcr-2022-254068", openalex = "W4382657607", references = "doi101016jijporl200907013" } @article{michailidou2023hearing, author = "Michailidou, Efterpi and Rüegg, Pascal Oliver and Karrer, Tanya and Korda, Athanasia and Weder, Stefan and Kompis, Martin and Caversaccio, Marco and Mantokoudis, Georgios", title = "Hearing Results after Transmastoid Superior Semicircular Canal Plugging for Superior Semicircular Canal Dehiscence: A Meta-Analysis", year = "2023", journal = "Audiology Research", abstract = "Objective: The transmastoid plugging of a superior semicircular canal is considered a safe and effective technique for the management of superior semicircular canal dehiscence (SSCD). The aim of this meta-analysis is to assess the postoperative hearing outcomes after the transmastoid plugging of the superior semicircular canal. Search method and data sources: A systematic database search was performed on the following databases until 30 January 2023: MEDLINE, Embase, Cochrane Library, Web of Science, CINAHL, ICTRP, and clinicaltrials.gov. A systematic literature review and meta-analysis of the pooled data were conducted. We also included a consecutive case series with SCDS for those who underwent transmastoid plugging treatment at our clinic. Results: We identified 643 citations and examined 358 full abstracts and 88 full manuscripts. A total of 16 studies were eligible for the systematic review and 11 studies for the meta-analysis. Furthermore, 159 ears (152 patients) were included. The postoperative mean air conduction threshold remained unchanged (mean difference, 2.89 dB; 95\% CI: −0.05, 5.84 dB, p = 0.58), while the mean bone conduction threshold was significantly worse (mean difference, −3.53 dB; 95\% CI, −6.1, −0.95 dB, p = 0.9). Conclusion: The transmastoid plugging technique for superior semicircular canal dehiscence syndrome, although minimally worsening the inner ear threshold, is a safe procedure in terms of hearing preservation and satisfactory symptom relief.", url = "https://doi.org/10.3390/audiolres13050065", doi = "10.3390/audiolres13050065", number = "5", openalex = "W4387461437", pages = "730-740", volume = "13", references = "doi101001archotol1243249, doi101007s0040500808404, doi101016jjclinepi202103001, doi1010371082989x112193, doi1010970012949220030300000023, doi10109701mlg000017832455729b7, doi101136ebmental2019300117, doi103233ves200004, doi103389fneur201700177, doi10732600034819155820111018000009" } @article{dina2024posterior, author = "Dina, Elena and Prenafeta Moreno, Mario and Martínez Arias, Àngels", title = "Posterior semicircular canal involvement in sudden hearing loss", year = "2024", journal = "Acta Otorrinolaringologica (English Edition)", url = "https://doi.org/10.1016/j.otoeng.2024.01.010", doi = "10.1016/j.otoeng.2024.01.010", number = "4", openalex = "W4391896109", pages = "269-271", volume = "75" } @article{doi103389fneur20241341812, author = "Yun, Ji Min and Kim, Sung Huhn and Bae, Seong Hoon", title = "Vestibular dysfunction in lateral semicircular canal dysplasia", year = "2024", journal = "Frontiers in Neurology", abstract = "Introduction: Lateral semicircular canal (LSCC) dysplasia is the most common inner ear malformation. The severity of dysplasia can appear in various spectrums, from a short and broad LSCC with normal or small-sized central bony island (CBI) to a single fluid-filled cavity confluent with the vestibule without CBI. However, reports on the association between LSCC dysplasia and the loss of vestibular function are still lacking. In this study, the results of vestibular function tests [caloric test and video-head impulse test (vHIT)] in patients with LSCC dysplasia were analyzed and compared between groups with and without CBI. Methods: This study retrospectively enrolled 17 patients (23 ears) who had LSCC dysplasia following computed tomography or magnetic resonance imaging and underwent vestibular function tests. Results: = 0.001 and 0.004, respectively). Discussion: LSCC dysplasia impairs VOR function, especially in the absence of CBI.", url = "https://doi.org/10.3389/fneur.2024.1341812", doi = "10.3389/fneur.2024.1341812", openalex = "W4390953059", references = "doi101258ar2010100324, doi1021053ceo201901053" } @article{doi103389fneur20241476004, author = "Hong, Sean and Wackym, P. Ashley and Murphy, Damian J. and Peci, Eran and Kiel, M. and Tucker, Aaron and Carayannopoulos, Nicolas L. and Chandrasekar, S and Suresh, Nikhil and Utku, Umut A. and Yao, Justin D. and Mowery, Todd M.", title = "Model of superior semicircular canal dehiscence: asymmetrical vestibular dysfunction induces reversible balance impairment", year = "2024", journal = "Frontiers in Neurology", abstract = "Background: Superior semicircular canal dehiscence (SSCD) is a vestibular-cochlear disorder in humans in which a pathological third mobile window of the otic capsule creates changes to the flow of sound pressure energy through the perilymph/endolymph. The primary symptoms include sound-induced dizziness/vertigo, inner ear conductive hearing loss, autophony, headaches, and visual problems. We have developed an animal model of this human condition in the Mongolian Gerbil that uses surgically created SSCD to induce the condition. A feature that is unique in this model is that spontaneous resurfacing of the dehiscence occurs via osteoneogenesis without a subsequent intervention. In this study, we completed our assessment of this model to include reversible asymmetrical vestibular impairments that interfere with balance. Methods: = 6) were trained to complete a balance beam task. They were also trained to perform a Rotarod task. After 10 days of training, preoperative ABR and c+VEMP testing was followed by a surgical fenestration of the left superior semicircular canal. Balance beam testing recommenced at postoperative day 6 and continued through postoperative day 15 at which point final ABR and c+VEMP testing was carried out. Results: Behavioral comparison of preoperative and postoperative performance show a significant decrease in Rotarod performance, increased rates of falling, and an increase in time to cross the balance beam. Impairments were the most significant at postoperative day 7 with a return toward preoperative performance by postoperative day 14. This behavioral impairment was correlated with residual impairments to auditory thresholds and vestibular myogenic amplitudes at postoperative day 14. Conclusion: These results confirm that aberrant asymmetric vestibular output in our model of SSCD results in reversible balance impairments. The level of these behavioral impairments is directly correlated with severity of the vestibular dysfunction as we have previously reported for peripheral ear physiology and cognition.", url = "https://doi.org/10.3389/fneur.2024.1476004", doi = "10.3389/fneur.2024.1476004", openalex = "W4403806814", references = "michailidou2023hearing" } @article{doi1010800001648920252449593, author = "Benoit, Charlotte and Hautefort, Charlotte and Vérillaud, Benjamin and Herman, Philippe and Kania, R.", title = "Transmastoid superior semicircular canal dehiscence plugging: VHIT findings", year = "2025", journal = "Acta Oto-Laryngologica", abstract = "BACKGROUND: Superior canal dehiscence syndrome (Minor's syndrome) is a condition characterized by a bony defect in the superior semicircular canal (SSCC), with treatment primarily being surgical, notably through plugging of SSCC. AIMS/OBJECTIVES: To examine the clinical outcome and postoperative VHIT findings after transmastoid plugging of the SSCC. MATERIALS AND METHODS: a transmastoid approach were included. Through a retrospective chart review and literature review, postop video head impulse test (VHIT) findings, pre and post-operative audiological/vestibular symptoms and audiograms were analyzed in a tertiary care university hospital. RESULTS: = 0.0391) Almost all patients had improvement of their preoperative symptoms. No surgical complication was noted. The literature review also highlighted safety and effectiveness of this surgical technique. CONCLUSION AND SIGNIFICANCE: Post-operative VHIT findings showed an elective deficit of the SSCC function thus confirming the surgical SSCC plugging through a trans mastoid approach.", url = "https://doi.org/10.1080/00016489.2025.2449593", doi = "10.1080/00016489.2025.2449593", openalex = "W4406423910", references = "michailidou2023hearing" } @article{doi101007s00405026100331, author = "Bhatia, Harsimran and Agarwal, Purnima and Pol, Shashikant Anil", title = "Anomalous posterior semicircular canals in congenital hearing loss: not-so-common findings in a common imaging scenario!", year = "2026", journal = "European Archives of Oto-Rhino-Laryngology", url = "https://doi.org/10.1007/s00405-026-10033-1", doi = "10.1007/s00405-026-10033-1", openalex = "W7131210334", references = "doi101016janorl201210005" }