FUNCTIONAL MAGNETIC-RESONANCE-IMAGING OF SENSORY AND MOTOR CORTEX - COMPARISON WITH ELECTROPHYSIOLOGICAL LOCALIZATION

Functional magnetic resonance (MR) imaging was performed using a 1.5-t esla MR system to localize sensorimotor cortex. Six neurologically nor mal subjects were studied by means of axial gradient-echo images with a motor task and one or more sensory tasks: 1) electrical stimulation of the median nerve; 2) continuous brushing over the thenar region; an d 3) pulsed now of compressed air over the palm and digits. An increas ed MR signal was observed in or near the central sulcus, consistent wi th the location of primary sensory and motor cortex. Four patients wer e studied using echo planar imaging sequences and motor and sensory ta sks. Three patients had focal refractory seizures secondary to a lesio n impinging on sensorimotor cortex. Activation seen on functional MR i maging was coextensive with the location of the sensorimotor area dete rmined by evoked potentials and electrical stimulation. Functional MR imaging provides a useful noninvasive method of localization and funct ional assessment of sensorimotor cortex.