The projections from motor and premotor cortices were some of the first to be identified.72 Projections from M1 terminate almost entirely in the putamen, in the dorsolateral and central region. There are some terminals, albeit few, rostral to the anterior commissure; however, the main projection lies caudal to the anterior commissure. The caudal premotor area projects to a striatal region that is just adjacent to M1 projections. These terminals extend only slightly into the caudate nucleus. The rostral premotor areas terminate in both the caudate and putamen, bridging the two with a continuous projection. These terminals extend more rostrally than those from the motor cortex, although they do not extend into the rostral pole of the striatum. Both motor and premotor areas extend through much of the putamen caudally. This dorsolateral sector of the striatum also receives overlapping projections from parietal areas associated with somatosensory function. Furthermore, these parietal projections follow the same somatotopic organization.73 Thus, the dorsolateral striatum is linked to motor function.71 Physiological studies support this idea, demonstrating somatotopic maps and neuronal responses to specific movement.74,75 Moreover, imaging
