scholarly journals Unilateral Horizontal Semicircular Canal Malformation Causing Recurrent Vertigo

2018 ◽  
Vol 32 (2) ◽  
pp. 58-59
Author(s):  
Nathaniel W. Yang
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Temporal Bone ◽  
Semicircular Canal ◽  
Lateral Semicircular Canal ◽  
Vestibular Loss ◽  
Vestibular Neurectomy ◽  
Horizontal Semicircular Canal ◽  
Ear Malformations ◽  
Vestibular Symptoms

A 62-year-old man consulted for recurrent episodes of vertigo lasting from seconds to several minutes. The vertigo was variably described as spinning, lateral swaying, and a feeling of being “unsure of his position in space.” These episodes were noted to have begun when the patient was still in his 20’s. Standard pure tone audiometry revealed a mild-to-moderate downsloping mixed hearing loss in the left ear. Bithermal caloric testing indicated the presence of a significant left-sided peripheral vestibular loss. Due to the fact that the vertigo episodes presented relatively early in life, the possibility of a congenital inner ear malformation was considered as a cause for his symptoms.  Computerized tomographic (CT) imaging of the temporal bone was performed. This clearly showed the left horizontal semicircular canal lacking a central bony island. (Figure 1 and 2) The cochlea, superior and posterior semicircular canals, vestibular and cochlear aqueducts, and ossicular chain were grossly normal. A malformation of the horizontal or lateral semicircular canal is one of the most common inner ear malformations, as it is the last vestibular structure to be formed during inner ear embryogenesis. As such, it may occur in isolation or may be associated with other vestibular, cochlear, or middle ear malformations.1,2  Although vertigo and dizziness are symptoms to be expected in such a condition, existing data indicates that it may be totally asymptomatic, or it may also present as a sensorineural, conductive, or mixed type of hearing loss.1,3   Radiologic imaging is of prime importance in diagnosing such conditions, especially when auditory and/or vestibular symptoms manifest early in life. This case perfectly illustrates the need for such studies, as the patient went undiagnosed for more than forty years!             No definitive statements can be gleaned from existing medical literature with respect to treatment. However, in patients with debilitating vestibular symptoms, management with modalities that selectively target the vestibular system, but spare the auditory system, such as vestibular neurectomy and trans-tympanic aminoglycoside therapy appear to be reasonable options.   References   Johnson J, Lalwani AK. Sensorineural and conductive hearing loss associated with lateral semicircular canal malformation. Laryngoscope 2000 Oct;110(10):1673–1679. DOI:10.1097/00005537-200010000-00019 PMID: 11037823   Casselman JW, Delanote J, Kuhweide R, van Dinther J, De Foer B, Offeciers EF. Congenital malformations of the temporal bone. In: Lemmerling M, De Foer B, editors. Temporal bone imaging. Berlin Heidelberg: Springer-Verlag; 2015, pp. 120-154.   Kim CH, Shin JE, Lee YJ, Park HJ. Clinical characteristics of 7 patients with lateral semicircular canal dysplasia. Res Vestib Sci 2012;11(2):64-68.

scholarly journals Audiological and Vestibular Functions in Patients With Lateral Semicircular Canal Dysplasia and Aplasia

2020 ◽  
Vol 13 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Sang Hyun Kwak ◽  
Min Ki Kim ◽  
Sung Huhn Kim ◽  
Jinsei Jung
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Pure Tone ◽  
Lateral Semicircular Canal ◽  
Vestibular Loss ◽  
Horizontal Canal ◽  
Canal Paresis ◽  
Bilateral Hearing Loss ◽  
Ear Anomalies

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.

Partial Duplication of the Lateral Semicircular Canal—A Novel Anatomical Malformation in a Child with Barakat Syndrome

2021 ◽  
Author(s):  
Varun Kannan ◽  
Brandon Tran
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Sensorineural Deafness ◽  
Anatomical Variations ◽  
Lateral Semicircular Canal ◽  
Partial Duplication ◽  
Posterior Limb ◽  
Ear Malformations ◽  
Ear Anomalies

AbstractSeveral 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.

Bilateral, isolated, lateral semicircular canal malformation without hearing loss

2008 ◽  
Vol 122 (8) ◽  
pp. 858-860 ◽  
Author(s):  
I Dallan ◽  
S Berrettini ◽  
E Neri ◽  
A P Casani
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Semicircular Canal ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Lateral Semicircular Canal ◽  
Normal Limits ◽  
Dimensional Reconstruction ◽  
Ear Malformations ◽  
Molecular Aspects

AbstractHypothesis: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.

Establishment of Normative Cochlear and Vestibular Measurements to Aid in the Diagnosis of Inner Ear Malformations

2003 ◽  
Vol 128 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Derk Purcell ◽  
Jacob Johnson ◽  
Nancy Fischbein ◽  
Anil K. Lalwani
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Semicircular Canal ◽  
Visual Inspection ◽  
Lateral Semicircular Canal ◽  
Inner Ear Malformations ◽  
Routine Measurement ◽  
Temporal Bone Ct ◽  
Ear Malformations ◽  
Vertical Height

OBJECTIVE: We sought to establish normative measurements of the inner ear using computed tomography (CT) of the temporal bone to aid in the diagnosis of inner ear malformations. STUDY DESIGN AND SETTING: Prospective measurements of the inner ear structures were made on axial and coronal temporal bone CT scans on 15 patients with normal hearing and 15 patients with sensorineural hearing loss. RESULTS: The vertical height of the cochlea on coronal scan and the size of the central bony island within the lateral semicircular canal on axial scan along with visual inspection identified 7 inner ear abnormalities in 6 patients: 5 cases of lateral semicircular canal dysplasia and 2 cases of cochlear hypoplasia. In contrast, visual inspection alone identified only 4 of the 7 abnormalities. CONCLUSIONS AND SIGNIFICANCE: Routine measurement of the cochlear height and bony island of the lateral semicircular canal, in conjunction with visual inspection of CT images, will increase recognition of common inner ear malformations.

scholarly journals Concomitant Dehiscences of the Temporal Bone: A Case-Based Study

2020 ◽  
pp. 014556132097378
Author(s):  
Maurizio Barbara ◽  
Valerio Margani ◽  
Anna Voltattorni ◽  
Simonetta Monini ◽  
Edoardo Covelli
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Temporal Bone ◽  
Conductive Hearing Loss ◽  
Acoustic Energy ◽  
Superior Semicircular Canal Dehiscence ◽  
Local Bone ◽  
Tegmen Tympani ◽  
Vestibular Symptoms ◽  
Conductive Hearing

Otic capsule dehiscences create a pathological third window in the inner ear that results in a dissipation of the acoustic energy consequent to the lowered impedance. Superior semicircular canal dehiscence (SSCD) was identified by Minor et al in 1998 as a syndrome leading to vertigo and inner ear conductive hearing loss. The authors also reported the relation between the dehiscence and pressure- or sound-induced vertigo (Tullio’s phenomenon). Prevalence rates of SSCD in anatomical studies range from 0.4% to 0.7% with a majority of patients being asymptomatic. The observed association with other temporal bone dehiscences, as well as the propensity toward a bilateral or contralateral “near dehiscence,” raises the question of whether a specific local bone demineralization or systemic mechanisms could be considered. The present report regard a case of a patient with a previous episode of meningitis, with a concomitant bilateral SSCD and tegmen tympani dehiscence from the side of meningitis. The patient was affected by dizziness, left moderate conductive hearing loss, and pressure/sound-induced vertigo. Because of disabling vestibular symptoms, the patient underwent surgical treatment. A middle cranial fossa approach allowed to reach both dehiscences on the symptomatic side, where bone wax and fascia were used for repair. At 6 months from the procedure, hearing was preserved, and the vestibular symptoms disappeared.

Computerized Tomography in Hearing Loss and DIsequilibrium States

1981 ◽  
Vol 89 (5) ◽  
pp. 861-866 ◽  
Author(s):  
William N. Hanafee
Keyword(s):  
Hearing Loss ◽  
Contrast Agent ◽  
Inner Ear ◽  
Computerized Tomography ◽  
Semicircular Canal ◽  
Internal Auditory Canal ◽  
Ct Scanning ◽  
Ct Scans ◽  
Horizontal Semicircular Canal

Computerized tomographic (CT) scanning for intracanalicular tumors requires air as a contrast agent within the internal auditory canal and special computer manipulations of the image to visualize small tumors. The same computer manipulations of CT scans provide detail of the middle and inner ear structures not available by non-CT tomographic techniques. The demonstration of horizontal semicircular canal fistula is one area in which CT scanning is clearly superior. Some pitfalls of the technique and interpretation of it will be discussed.

scholarly journals Cystic Cochleovestibular Malformation (Incomplete Partition Type 1)

2010 ◽  
Vol 25 (1) ◽  
pp. 41-42 ◽  
Author(s):  
Nathaniel W. Yang
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Temporal Bone ◽  
Cochlear Implantation ◽  
Type I ◽  
Profound Hearing Loss ◽  
Increased Risk ◽  
Ear Malformations ◽  
Temporal Bone Imaging ◽  
Incomplete Partition

A 5-year old female with bilateral profound hearing loss underwent computerized tomographic imaging of the temporal bone as part of the work-up to determine the etiology of her deafness, and to delineate middle and inner ear anatomy prior to cochlear implantation. The examination revealed an inner ear malformation which, based on the newest classification of cochleovestibular malformations by Sennaroglu and Saatci, is called an incomplete partition type I (IP-1) or cystic cochleovestibular malformation. This condition is characterized by (1) a cochlea that is lacking the entire modiolus and cribriform area, resulting in a cystic appearance, and (2) a large cystic vestibule.1   Temporal bone imaging is among the most useful examinations in the etiological investigation of idiopathic sensorineural hearing loss in children, with up to 30%2 of the imaging studies showing an abnormality. The detection of inner ear malformations is important, as some abnormalities are associated with an increased risk of meningitis or progressive hearing loss following head trauma.3 Likewise, the approach to cochlear implantation may be influenced by the type of malformation. In this particular patient, the use of a cochlear implant with a full-band electrode design may be more appropriate, as the location of the neural elements within the cystic cochlea is not definitely known.

scholarly journals MRI Evaluation of Vestibular Endolymphatic Space in Patients with Isolated Cystic Lateral Semicircular Canal Malformation

2021 ◽  
Vol 2 (1) ◽  
pp. 3
Author(s):  
Víctor Manuel Suárez-Vega ◽  
Pablo Domínguez ◽  
Nicolás Pérez-Fernández
Keyword(s):  
Hearing Loss ◽  
Semicircular Canal ◽  
Endolymphatic Hydrops ◽  
Inversion Recovery ◽  
Lateral Semicircular Canal ◽  
3D Inversion ◽  
Bony Labyrinth ◽  
Ear Malformations ◽  
Mri Evaluation ◽  
Endolymphatic Space

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.

scholarly journals Comparative Study of Preoperative Radiological Findings with Intraoperative Surgical Findings in Squamosal Type of Chronic Otitis Media

2021 ◽  
Vol 10 (25) ◽  
pp. 1862-1865
Author(s):  
Sanjana Pradeep ◽  
Swaroop Dev ◽  
Jyothi Swarup Raju ◽  
Shravya Pasunuti
Keyword(s):  
Temporal Bone ◽  
Otitis Media ◽  
Semicircular Canal ◽  
Chronic Otitis Media ◽  
Sigmoid Sinus ◽  
Lateral Semicircular Canal ◽  
High Resolution Computed Tomography ◽  
Tissue Mass ◽  
Hrct Temporal Bone ◽  
A Prospective Study

BACKGROUND Chronic otitis media (COM) of squamosal type is associated with cholestatoma with potential complications. Clinical examination and high resolution computed tomography (HRCT) scans are necessary to assess the disease site and extension. The purpose of the study was to compare the preoperative HRCT findings with the intraoperative surgical findings in squamosal type of chronic otitis media as well as various parameters in HRCT temporal bone and intraoperative findings. METHODS A prospective study was conducted on 30 patients aged between 18 and 60 years of both the genders who presented with chronic otitis media squamosal type, for a period of 22 months who attended the outpatient department of ENT. RESULTS HRCT findings and intraoperative findings were compared and results were analysed. Facial canal erosion (P - 0.0031), tegmen plate erosion (P - 0.0001), sigmoid sinus plate erosion (P - 0.002) were found to be statistically significant. Lateral semicircular canal fistula (P - 0.36) and ossicular status malleus (P - 1.000), incus (P - 0.949), stapes suprastructure (P - 0.984), and stapes footplate erosion (P - 0.977) were found to be statistically insignificant. CONCLUSIONS In our study, HRCT imaging for COM squamosal type, accurately depicted the soft tissue mass, erosion of tegmen plate, sigmoid sinus plate, scutum, lateral semicircular canal fistula, incus and suprastructure of stapes erosion and the same were found intraoperatively as well. Our study showed good comparison between the preoperative HRCT scans and the surgical findings in cholesteatoma cases. HRCT is confirmed to be valuable in the diagnosis and in guiding the surgical management of cholesteatoma. KEY WORDS Chronic Otitis Media, Cholesteatoma, HRCT Temporal Bone, Modified Radical Mastoidectomy

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