Cerebral contribution to the visual suppression of vestibular nystagmus.

Thirty-two patients with cerebral lesions were examined to locate cerebral areas involved in visual suppression. Visual suppression was reduced or abolished when the lesions were in the parietal lobe, especially in the dorsoposterior region. This part of the parietal lobe seems to modify visual suppression of caloric nystagmus that is mediated by the flocculus and nodulus of the cerebellum as well as the pons. In patients with frontal lobe lesions including the parietal lobe, visual suppression was reduced or abolished. Thus, the parietal lobe is important for this visual suppression mechanism.