Topography of the cortical motor hand area: prospective study with functional MR imaging and direct motor mapping at surgery.
OBJECTIVE
To localize the cortical motor hand area with functional magnetic resonance (MR) imaging and electrical stimulation at surgery and to detect changes due to central lesions.


METHODS
Fast-gradient-echo and functional MR images of the brain were acquired in four healthy volunteers and six patients with tumors in the central region before, during, and after repetitive opening and closing of the hand. Open brain surgery was performed, and the exposed cortex was stimulated.


RESULTS
At functional MR imaging, circumscribed changes in signal intensity that correlated in time with the task were seen in the central region of the contralateral brain. In the healthy volunteers, the area of change was spotlike and projected into the posterior bank of the precentral gyrus. In four of the six patients, this area was diffuse and projected into the precentral gyrus. The locations of the cortical hand area as determined with intrasurgical mapping and functional MR imaging were identical.


CONCLUSIONS
Identification of the cortical area responsible for motor hand function was similar with functional MR imaging and with direct stimulation at surgery. A space-occupying lesion can change the cortical representation of motor hand function.
Yousry
T A
TA
Department of Diagnostic Radiology, Ludwig Maximilian University, Munich, Germany.
Schmid
U D
UD
Jassoy
A G
AG
Schmidt
D
D
Eisner
W E
WE
Reulen
H J
HJ
Reiser
M F
MF
Lissner
J
J
D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000503:physiopathology / Q000601:surgery; D004292:Dominance, Cerebral / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006225:Hand / Q000294:innervation*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D011446:Prospective Studies