The mesial surface of the frontal lobe includes primary sensory and motor cortex for the lower limb, the supplementary sensori- motor area (SSMA), the anterior cingulate cortex and the prefrontal cortex31 (Fig. 2). The SSMA extends anteriorly approximately to the level of the genu of the corpus callosum. SSMA stimulation results in usually bilateral and proximal tonic posturing and motor re- sponses, but frequently show predominance on the contralateral side. Additionally, contralateral sensory phenomena may occur. The SSMA has a somatotopic distribution: the head and upper limbs are represented at the anterior and the lower limbs at the posterior surface of the interhemispheric region. Stimulation of the anterior portion of the SSMA results in arrest or slowing of vol- untary motor activity. Furthermore, stimulation of the cingulate gyrus near the SSMA leads to motor responses that overlap those occurring in the SSMA,32 but automatisms, namely oro-alimentary, have also been described.33