RT Journal Article
SR Electronic
T1 Functional organization of human supplementary motor cortex studied by electrical stimulation
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3656
OP 3666
DO 10.1523/JNEUROSCI.11-11-03656.1991
VO 11
IS 11
A1 I Fried
A1 A Katz
A1 G McCarthy
A1 KJ Sass
A1 P Williamson
A1 SS Spencer
A1 DD Spencer
YR 1991
UL http://www.jneurosci.org/content/11/11/3656.abstract
AB The presence of somatotopic organization in the human supplementary motor area (SMA) remains a controversial issue. In this study, subdural electrode grids were placed on the medial surface of the cerebral hemispheres in 13 patients with intractable epilepsy undergoing evaluation for surgical treatment. Electrical stimulation mapping with currents below the threshold of afterdischarges showed somatotopic organization of supplementary motor cortex with the lower extremities represented posteriorly, head and face most anteriorly, and the upper extremities between these two regions. Electrical stimulation often elicited synergistic and complex movements involving more than one joint. In transitional areas between neighboring somatotopic representations, stimulation evoked combined movements involving the body parts represented in these adjacent regions. Anterior to the supplementary motor representation of the face, vocalization and speech arrest or slowing of speech were evoked. Various sensations were elicited by electrical stimulation of SMA. In some cases a preliminary sensation of “urge” to perform a movement or anticipation that a movement was about to occur were evoked. Most responses were contralateral to the stimulated hemisphere. Ipsilateral and bilateral responses were elicited almost exclusively from the right (nondominant) hemisphere. These data suggest the presence of combined somatotopic organization and left-right specialization in human supplementary motor cortex.