Evidence for a wide distribution of negative motor areas in the perirolandic cortex.
OBJECTIVE
The perirolandic regions were studied by extensive electrical stimulation to clarify the topography and somatotopic distribution of negative motor areas (NMAs) and examine the clinical significance of these areas.


METHODS
We evaluated the cortical function elicited by electrical stimulation in 30 patients with tumors or intractable epilepsy. The somatotopic distribution of NMAs was examined by localizing these regions using Talairach's bicommissural reference system. NMAs within the lesions of two patients were removed under local anesthesia.


RESULTS
We obtained negative motor responses following the stimulation of 30 electrodes in 15 patients. On the lateral brain surface, the majority of NMAs for the upper extremities were distributed broadly throughout the premotor cortex, while NMAs for the tongue were only found in the inferior frontal gyrus of the dominant hemisphere. During removal of the NMAs within the lesions of two patients, we documented transient hand clumsiness in one patient.


CONCLUSIONS
NMAs were widely distributed throughout the perirolandic area, as well as the previously reported regions in the inferior frontal gyrus. These areas likely function in the control of skilled movements; dysfunction of such movements transiently follows resection of these regions, but is subsequently well compensated for after surgery.


CONCLUSIONS
The localization and consequences of resection of NMAs suggests their clinical significance in motor control.
Mikuni
Nobuhiro
N
Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. mikunin@kuhp.kyoto-u.ac.jp
Ohara
Shinji
S
Ikeda
Akio
A
Hayashi
Naoki
N
Nishida
Namiko
N
Taki
Junya
J
Enatsu
Rei
R
Matsumoto
Riki
R
Shibasaki
Hiroshi
H
Hashimoto
Nobuo
N
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000503:physiopathology; D004558:Electric Stimulation / Q000379:methods; D004566:Electrodes; D004827:Epilepsy / Q000503:physiopathology; D019054:Evoked Potentials, Motor / Q000502:physiology* / Q000528:radiation effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology* / Q000528:radiation effects; D009433:Neural Inhibition / Q000502:physiology* / Q000528:radiation effects