[Left motor extinction due to an ischemic lesion of the anterior limb of the internal capsule (author's transl)].

An ischemic lesion limited to the anterior limb of the internal capsule provoked a left motor neglect in a 64-year-old man. There was reduction in spontaneous mobility of the left side of the body, reversible during verbal incitations and accompanied by motor extinction. There were no perceptive disorders, or visual, somatesthetic, or auditive neglect. The importance of the motor extinction phenomenon (described by Valenstein and Heilman in a case with a lesion of similar site) is emphasized: it demonstrates the role in motor neglect of a disequilibrium in intentional activation of the hemispheres. Pathological and clinical correlations are discussed in relation to cases reported in the literature and the results of animal studies. It is suggested that motor neglect may result from interruption of connections between the median thalamic nuclei, the striatum, and the frontal cortex. Relationships between motor neglect and perceptive (attentional) neglect syndromes are discussed.