Functional loss of the horizontal doll's eye reflex following unilateral vestibular lesions.

The doll's eye reflex represents the vestibulo-ocular reflex (VOR) elicited by high-acceleration head rotation. After complete unilateral vestibular lesions, the ipsilateral, horizontal doll's eye reflex is replaced by a series of "catch-up" saccades. These cause permanent symptoms of blurred vision and dizziness during ipsilateral turns. We compared normal controls and patients with complete surgical lesions or canal paresis of up to 9 years duration via electronystagmography (ENG) to determine the usefulness of the doll's eye test as a diagnostic test for complete vestibular lesions. This test was found to be more sensitive in diagnosis of such lesions than head-shaking nystagmus, rotatory directional preponderance, and spontaneous nystagmus. It is also useful to document VOR function in patients in whom caloric irrigation is contraindicated.