Vestibular deficits correlating to dizziness handicap inventory score, hearing loss, and tumor size in a Danish cohort of vestibular schwannoma patients

OBJECTIVE: To test the degree of vestibular end-organ dysfunction by means of contemporary vestibular testing and examine to which extend these findings correlate to the hearing loss, tumor size, and dizziness handicap registered in vestibular schwannoma patients. SETTING: Tertiary referral center. PATIENTS: Eighty-nine patients diagnosed with unilateral vestibular schwannoma. INTERVENTION(S): Patients were evaluated by means of the Dizziness Handicap Inventory (DHI), magnetic resonance imaging scan as well as an extensive audiovestibular test-battery including pure-tone audiometry, ocular vestibular evoked myogenic potentials, cervical vestibular evoked myogenic potentials, and video head impulse test of all six semicircular canals. MAIN OUTCOME MEASURE(S): Patients were divided into four groups according to their number of dysfunctional vestibular end-organs. These groups were subsequently analyzed for differences in DHI score, pure-tone average, and tumor size. The group of patients with zero abnormal vestibular test results was used as index group. RESULTS: For the group with three or more abnormal vestibular test results it was possible to find a statistical significant increase in both DHI score, pure-tone average, and tumor size. This was only found for the latter two parameters in the group with dysfunction of two vestibular end-organs. It was not possible to detect any statistical significant differences in the group with only one dysfunctional end-organ. CONCLUSIONS: Substantial loss of vestibular function is correlated to a higher degree of dizziness-induced handicap, hearing loss, and tumor size in vestibular schwannoma patients. Tumor size and audiometry may potentially be used as rough markers of residual vestibular function.