Contralateral Hyperactive Caloric Response in Unilateral Labyrinthine Weakness

Abstract

In a series of 600 patients, 10 showed unilateral hyperactive caloric responses without a trivial explanation such as spontaneous nystagmus or directional preponderance. All 10 had unilateral weakness on the contralateral side, which was accompanied in 9 by cochlear hearing loss. It is assumed that the phenomenon of unilateral hyperreactivity in these cases can be explained by release from commissural inhibition on the basis of temporary vestibular decompensation.