[Bilateral loss of the horizontal vestibulo-ocular reflex in Wernicke encephalopathy - a specific and early clinical sign].

Wernicke encephalopathy is a condition in which thiamine deficiency causes cognitive dysfunction, ataxia and eye motor abnormalities. The condition is potentially reversible if treated with high doses of intravenous thiamine (vitamin B1). The video head impulse test, in which the vestibulo-ocular reflex is tested, can reveal an early specific sign of selective dysfunction in the medial vestibular nuclei by demonstrating selective dysfunction of the horisontal vestibulo-ocular reflex. We present two cases with clinical and neuroradiological findings consistent with Wernicke encephalopathy where such oculomotor findings were detected.