Visual facial grasp

Some patients with degenerative neurological diseases have a release of the vestibular-ocular reflex (VOR), as detected by passive head movement during visual fixation on a moving target ("doll's eyes"maneuver). However, a positive doll's eyes sign might be induced by other defects and the purpose of this article is to describe a new ocular sign of cortical dysfunction, the visual facial grasp. We observed three patients, one with progressive supranuclear palsy (PSP), another with probable Alzheimer's disease (AD) and a third with cortico-basal degeneration (CBD) all of whom appeared to demonstrate a release of the vestibulo-ocular reflex (VOR) with passive head movements. Whereas the patient with PSP, who was unable to inhibit the VOR regardless of the visual target used probably had a true release of the VOR, the patients with AD and CBD were able to inhibit this reflex when the visual target was the examiner's moving face. These two patients also exhibited spontaneous preference for visual fixation on the examiner's face and improvement in smooth pursuit when the examiner's face was the visual target. This clinical observation suggests that the deficits in these two patients with AD and CBD were related to the emergence of a primitive stimulus-bound behavior, the visual facial grasp.