Another evidence for pressure transfer mechanism in incomplete partition two anomaly via enlarged vestibular aqueduct.

A female patient with unilateral enlarged vestibular aqueduct (EVA) demonstrated scala vestibuli dilatation on that side while on the contralateral side both vestibular aqueduct and scala vestibuli were normal. This important radiological finding demonstrates that modiolar defects (hence 'cystic apex') observed in Incomplete partition-II is due to pressure transfer via EVA during embryological development. Therefore, it supports the previous histopathological ideas radiologically. Depending on the patency of EVA, variety of modiolar defects may arise.

Computed tomography findings in large vestibular aqueduct syndrome.

CONCLUSIONS: Patients with large vestibular aqueduct syndrome (LVAS) have disturbed morphogenesis of bony labyrinth. Semicircular canal anomalies are common in LVAS. OBJECTIVE: To describe the additional inner ear anomalies on CT imaging in pediatric patients with LVAS, and to investigate the lateral semicircular canal (LSCC) anomalies associated with LVAS by measurement of the LSCC bony island width. PATIENTS AND METHODS: We retrospectively reviewed the digitally stored temporal bone CT imaging obtained for 23 patients with LVAS, additional inner ear anomalies were noted, and measurements of the LSCC bony island width were made on axial CT scans on the workstation. Measurements were compared to the normative data obtained from 20 patients without sensorineural hearing loss. RESULTS: Of the 23 patients (bilateral in 22 and unilateral in 1), additional inner ear malformations were identified in 21 cases presenting either singly or in combination. A small LSCC bony island (<3 mm in diameter) appeared highly typical; vestibule and LSCC anomalies were identified in 13 cases (26 ears) based on visual inspection combined with abnormal measurements. Dehiscence of the superior and/or posterior semicircular canal was identified in 19 ears, and Mondini deformity was identified in 6 ears.

Sudden sensorineural hearing loss associated with inner ear anomaly.

OBJECTIVE: This study was conducted to evaluate the frequency of inner ear anomaly in patients with sudden sensorineural hearing loss and in control subjects. STUDY DESIGN: Retrospective case review. SETTING: A tertiary referral center. PATIENTS AND INTERVENTION: We evaluated 366 patients (165 men and 201 women; age range, 3-91 yr) with sudden sensorineural hearing loss and 228 control subjects without sensorineural hearing loss using magnetic resonance imaging. Three hundred fifty-six patients had unilateral and 10 patients had bilateral sudden sensorineural hearing loss. RESULTS: Eleven (2.9%) of 376 ears with sudden sensorineural hearing loss had inner ear anomaly. Nine patients (2.5%) had inner ear anomaly associated with sudden sensorineural hearing loss, but none of the 228 control subjects had the anomaly. The current study demonstrated that the frequency of inner ear anomaly in patients with sudden sensorineural hearing loss was significantly higher than in control subjects. CONCLUSION: Our study reveals that inner ear anomaly may be associated with sudden sensorineural hearing loss in 2.5% of patients.