The changing direction of nystagmus in acute Meniere's disease: pathophysiological implications. The direction(s) and pathophysiologic basis of nystagmus during an acute attack of Meniere's disease have been subject to much debate in the world literature. Clinical recordings from two patients whose nystagmus was captured near the very beginning of the acute vertiginous episode are presented. Previous clinical observations in Meniere's disease, experimental animal models concerned with initiation of peripheral nystagmus, and the phenomenon of recovery are discussed. 