Clinical characteristics associated with isolated unilateral utricular dysfunction ★

PurposeThe ocular vestibular evoked myogenic potential (oVEMP) represents the sound-induced activation of extraocular muscles and is believed to originate from the utricle and superior vestibular nerve. Isolated unilateral oVEMP abnormalities with otherwise normal balance function test (BFT) results have not yet been characterized in a large patient series, and their clinical significance remains unclear.Materials and MethodsRetrospective review of adult patients with vestibular complaints at a tertiary academic neurotologic referral center was performed. Patients with isolated unilateral oVEMP abnormalities were identified. The prevalence of vestibular symptoms and results of the Dizziness Handicap Inventory (DHI) and Hospital Anxiety and Depression Scale (HADS) were compared between these patients and those with normal BFT results.ResultsThirty-one adult patients with isolated unilateral oVEMP abnormalities were identified (71% female, mean age 48 ± 14 years). Presenting complaints included vertigo in 53%, non-vertiginous dizziness in 68%, postural instability in 52%, and swaying/rocking sensation in 13%. Significant differences were observed in the percentage of patients with postural instability (p = 0.046) and swaying/rocking sensation (p = 0.04) when comparing the abnormal oVEMP group to patients with a normal BFT battery. No differences were observed when comparing other symptoms, age, gender, diagnoses, and DHI/HADS scores between groups.ConclusionThis is the largest series to date reporting on patients with isolated unilateral oVEMP abnormalities. Our results suggest this population may demonstrate an increased prevalence of postural instability and swaying/rocking sensation. Other measures of postural stability may further characterize the vestibular impairments associated with isolated unilateral utricular dysfunction.