Evolution in the Findings of Head-Impulse Tests During the Attacks of Meniere's Disease

Abstract

Objective:To determine the vestibulo-ocular reflex (VOR) performance during the attacks of Meniere's disease (MD) using video head-impulse tests (video-HITs) according to each ictal phase.Study Design:Retrospective case series review.Methods:We analyzed the results of video-HITs in 24 patients with unilateral definite MD during and between the attacks.Results:The head impulse gain of the VOR was usually normal (81%, 39 of the 48 semicircular canals [SCCs] in 16 patients) in the affected ear during the irritative or recovery phase, and did not differ from that for each SCC between the attacks (horizontal [HCs], p=0.412; anterior [ACs], p=0.920; posterior canals [PCs], p=0.477). During the paretic phase, however, the head impulse gains of the VOR were equally normal (22/42, 52%) or decreased (20/42, 48%) for the affected ear (42 SCCs in 14 patients). The gains for the HCs were lower during the paretic phase than those between the attacks in the affected ear, while those for the ACs and PCs did not differ (HCs, p=0.001; ACs, p=0.158, PCs, p=0.401). Covert saccades were more frequently observed even in the presence of normal VOR gains during the paretic phase as well.Conclusion:During the attacks of MD, HITs are usually normal during the irritative/recovery phases, but become positive in more than a half of the patients during the paretic phase. This evolution in the ictal findings of HITs may reflect characteristic ictal vestibular discharges in MD and should be considered in evaluating patients with MD according to each ictal phase during the attacks.