[Clinical manifestations and audio-vestibular functional evaluation in patients with lateral semicircular canal...

Seven patients with radiographically confirmed lateral semicircular canal malformations who visited the Department of Otorhinolaryngology Head and Neck Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between April 2013 and July 2019 were retrospectively reviewed. Among them, five cases had bilateral malformations and two were unilateral, involving a total of 12 ears, of which five ears were sensorineural hearing loss and two ears were mixed hearing loss. Glycerol test was performed in three cases (five affected ears), with positive results in three ears. Electrocochleography was performed in three cases (five affected ears), and only one affected ear was abnormal. Episodic vertigo occurred in six cases (including one case of positional vertigo), and chronic dizziness occurred in one case. Spontaneous nystagmus and abnormal caloric test results were observed in two cases. Vestibular evoked myogenic potential test was performed in four cases, with abnormalities in three cases. Video head impulse test results were normal in all three cases examined. All patients received symptomatic treatment and had good clinical control. The current study indicates that the clinical presentation and audio-vestibular function test results of patients with LSCC malformations are heterogeneous, and thus imaging studies are recommended to confirm the diagnosis. Further investigations are warranted to determine the pathogenesis of this malformation and the underlying mechanisms of inner ear functional impairment.