Abstract

Background and Objectives: Dysplasia of lateral semicircular canal (LSCC) is the most common inner ear malformation, because LSCC is the last single structure to be formed during inner ear embryogenesis. There have been several case reports about the LSCC anomaly which showed clinical spectrum ranging from no symptom to severe sensorineural hearing loss. The authors investigated the clinical characteristics of 7 patients with LSCC dysplasia. Materials and Methods: The medical records of 7 patients who were diagnosed as LSCC dysplasia from temporal bone computed tomography were retrospectively reviewed. We analysed the findings of history taking, pure tone audiometry, speech audiometry, and caloric tests. Results: The LSCC dysplasia was observed in all of 7 patients in which 5 showed unilaterally confined LSCC dysplasia, 1 showed bilaterally confined LSCC dysplasia, and 1 exhibited bilateral LSCC dysplasia combined with bilateral posterior semicircular canal dysplasia. From 7 patients, hearing loss was chief complaint only in 2 patients. Pure tone audiometry revealed sensorineural hearing loss in one patient, and conductive hearing loss in the other patient. Two patients complained of whirling type vertigo, and 3 complained of nonspecific dizziness. Conclusion: The patients with LSCC dysplasia may show variable symptoms such as sensorineural hearing loss, conductive hearing loss, vertigo and nonspecific dizziness.

• Keywords: Lateral semicircular canal;Congenital malformation;Hearing loss;Vertigo;Dizziness;