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

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.

2018 ◽  
Vol 32 (2) ◽  
pp. 58-59
Author(s):  
Nathaniel W. Yang

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.


Author(s):  
Varun Kannan ◽  
Brandon Tran

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.


2020 ◽  
Vol 13 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Sang Hyun Kwak ◽  
Min Ki Kim ◽  
Sung Huhn Kim ◽  
Jinsei Jung

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.


2003 ◽  
Vol 128 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Derk Purcell ◽  
Jacob Johnson ◽  
Nancy Fischbein ◽  
Anil K. Lalwani

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.


2021 ◽  
Vol 2 (1) ◽  
pp. 3
Author(s):  
Víctor Manuel Suárez-Vega ◽  
Pablo Domínguez ◽  
Nicolás Pérez-Fernández

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.


ORL ◽  
2009 ◽  
Vol 71 (6) ◽  
pp. 334-341 ◽  
Author(s):  
Fang-Lu Chi ◽  
Zhao Han ◽  
Pei-Dong Dai ◽  
Yi-Bo Huang ◽  
Ning Cong ◽  
...  

1996 ◽  
Vol 105 (4) ◽  
pp. 286-288 ◽  
Author(s):  
Laurence Laccourreye ◽  
Esther Tran BA Huy ◽  
Martine François ◽  
Philippe Narcy

Recording of bilateral evoked otoacoustic emissions in a 3-year-old girl with bilateral profound hearing loss is presented. No component of auditory-evoked brain stem potentials was recorded. Findings on computed tomography of the inner ear were within normal limits. At retest 3 months later, these results were unchanged. Explanations for this particular condition are presented together with a review of the literature.


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