Zones in the cerebellar cortex. Their organization and potential relevance to cerebellar stimulation.

The organization of zones in the cerebellar cortex, as reflected by the arrangement of cortical efferent and afferent fibers, was reviewed with special emphasis on the anterior lobe. There is conclusive evidence for the existence of at least six, and possibly as many as nine, ipsilateral rostrocaudally oriented cortical zones, each having specific afferent and efferent connections. The topography afferent and efferent fibers of the cerebellar cortex and/or the spatial arrangement of cortical zones have not been given appropriate attention in both experimental and clinical studies dealing with focal electrical stimulation of the cerebellum. It is suggested that inattention to the relationships between electrode placement and zones in the cerebellar cortex may be partially responsible for the sometimes capricious results during and/or subsequent cerebellar cortical stimulation.