SPATIAL PATTERNS OF FUNCTIONAL ACTIVATION OF THE CEREBELLUM INVESTIGATED USING HIGH-FIELD (4 T) MRI

Using single and multislice functional MRI at high held strength (4 T) we studied cerebellar activation in 12 subjects making a series of al ternating wrist flexion and extension movements against constant inert ial loads. Three spatial patterns of activation were observed: (i) par asagittal bands of activity localized primarily in the ipsilateral int ermediate and lateral zones of the cerebellar hemispheres, (ii) medio- lateral bands which in some subjects followed the contour of individua l folia and (iii) fragmented regions of activation covering extensive areas of the cerebellum. Bilateral activation of the cerebellum was ob served in all subjects with measurable activity. Mean statistically si gnificant activation intensity ranged from 2.34 to 13.54% above baseli ne.