Cortical organization of voluntary motor activity as revealed by measurement of regional cerebral blood flow.

Regional cerebral blood flow (rCBF) was measured in conjunction with carotid angiography using the intra-arterial xenon-133 injection method. Measurements were made in 9 patients in the left hemisphere and in 6 patients in the right hemisphere. It was confirmed that there was no significant differences in the blood flow, in either the right or the left hemisphere, between measurements taken while patients carried out various types of voluntary activity and preceding measurements of total mean hemisphere blood flow taken during rest. However, the pattern of flow distribution changed significantly during various types of voluntary motor activity, In general, the contralateral Rolandic motor and sensory areas were activated during execution of voluntary movements. The supplementary motor area appears to play a major role in the integration of information from various cortical regions; such integration is, of course, necessary in the preparation of the ultimate motor action.