Importance of High-Frequency Vestibular Function in the Prognosis of Bilateral Vestibulopathy

OBJECTIVES: The aim of this study was to investigate whether preserved vestibular function in the high-frequency range influences the prognosis of patients with bilateral vestibulopathy (BVP) after vestibular rehabilitation. METHODS: Twenty-four patients followed up with vestibular rehabilitation were recruited. The enrolled patients were divided into two groups according to the preservation of the high-frequency vestibulo-ocular reflex (VOR) based on the video head impulse test (vHIT). The results of computerized dynamic posturography and the Dizziness Handicap Inventory (DHI) survey collected at baseline and at the 6-month follow-up after vestibular rehabilitation therapy were analyzed. RESULTS: Both groups showed significantly increased composite and DHI scores after follow-up with vestibular rehabilitation. The group with preserved high-frequency VOR showed a better composite score (P=0.064) and vestibular score (P= 0.008) than the group with lost high-frequency VOR at the 6-month follow up. The DHI score significantly decreased only in the group with lost high-frequency VOR (P=0.047). Among the three vestibular function tests (caloric test, rotary chair test, and vHIT) used to diagnose BVP, only vHIT showed a significant correlation (P=0.015) with a favorable prognosis (composite score ≥70). CONCLUSION: Better treatment outcomes are likely in patients with BVP with preserved vestibular function in response to high-frequency stimulation, as measured by the vHIT.