Video-Head impulse test with little diagnostic impact in vertigo-patients

Abstract

Video-head impulse test (V-HIT) is more and more becoming a routine test in patients with vertigo, contributing information about the vestibulo-ocular reflex (VOR). According to Ewald's second law, the unilateral pathological test points to this side's peripheral organ as being diseased. The value in clinical routine is still unclear. 171 consecutive patients with vertigo that had received a V-HIT and caloric testing at presentation in an academic ENT-department were included. By chart-review, they were categorized in different groups with unilateral peripheral, central and other etiology of vertigo, irrespective of their V-HIT result. Then the latter was analyzed within the different groups with respect to Gain, Gain-Asymmetry (GA) and Catch-up Saccades (CS). Canal Paresis (CP) from caloric testing was compared to GA. In patients with unilateral peripheral disease, 31 % showed a pathological gain (< 0.8), the mean GA was 4.53 % (± 16.72 %) and 60 % had CSs. In patients with presumed or assured central etiology, these data were 28 %, -1,56 % (± 17,89 %) and 45 %. Isolated CS occurred only sporadically. CP was not correlated with GA in all groups (p = 0,114). In this study V-HIT showed little diagnostic use, especially in separating peripheral from central disease. The lacking correlation between asymmetry in caloric testing and asymmetry of V-HIT gain challenges current pathophysiological concepts of impaired VOR.