Comparison of glucose metabolism and cerebral blood flow during cortical motor activation

Regions of cerebral cortex activated in normal subjects making simple, repetitive, voluntary wrist movements were studied with positron emission tomography (PET). The regional cerebral metabolic rate of glucose utilization was studied with 2 [¹⁸F]fluoro-2-deoxy-D-glucose (FDG), and regional cerebral blood flow was studied with ¹⁵O-labeled water. No significant activation was found with the cerebral metabolic rate studies. Studies of regional cerebral blood flow showed significant activation of the contralateral sensorimotor cortex region of 42%, of the ipsilateral sensorimotor cortex region of 19%, and of the medial frontal cortex of 30% compared with the resting state. Increases in blood flow in the contralateral sensorimotor cortex and medial frontal cortex were visible on every activated scan. Measurement of regional cerebral blood flow seems to be more sensitive than regional cerebral metabolic rate of glucose utilization for studying cortical activation with voluntary movement.