頭頂葉障害と眼球運動

Abstract

Thirty-three cases of unilateral parietal lobe lesions were studied. Eye movements were observed and recorded by electronystagmography (ENG). The lesions were confirmed neuroradiologically.1. Unilateral lesions in the superior part of the parietal lobe produce asymmetric optokinetic nystagmus and saccadic pursuit movements to the side of the lesion. This means a reduction in the slow phase of nystagmus to the side of the lesion. Therefore, the optokinetic nystagmus to the side of the lesion is better than that to the normal side. The visual suppression of caloric nystagmus is normal in these lesions.2. Unilateral lesions in the inferior part of the parietal lobe also produce asymmetric optokinetic nystagmus. The optokinetic nystagmus to the side of the lesion is better than that to the normal side; however, the optokinetic nystagmus to the side of the lesion itself showes poor response. The pursuit eye movements are saccadic on both sides. The quick eye movements to the normal side are impaired and those to the side of the lesion are normal or slightly impaired. The pursuit movements are bilaterally impaired and the pursuit movements to the side of the lesion are more strongly impaired than those to the normal side. Visual suppression is reduced or abolished bilaterally.