Predicting the location of mouth motor cortex in patients with brain tumors by using somatosensory evoked field measurements.
OBJECTIVE
Before resective brain surgery, localization of the functional regions is necessary to minimize postoperative deficits. The face area has been relatively difficult to map noninvasively by using functional imaging techniques. Preoperative localization of face somatosensory cortex with magnetoencephalography (MEG) may allow the surgeon to predict the location of mouth motor areas.


METHODS
The authors compared the location of face somatosensory cortex obtained with somatosensory evoked fields during preoperative MEG with the mouth motor areas identified during intraoperative electrocortical stimulation (ECS) mapping in 13 patients undergoing resection of brain tumor.


RESULTS
In this group of patients, ECS mouth motor sites were usually anterior and lateral to MEG localizations of lip somatosensory cortex. The consistent quantitative relationship between results of these two mapping procedures allows the practitioner to predict the location of mouth motor cortex based on noninvasive preoperative MEG measurements.


CONCLUSIONS
Based on this result, the authors suggest that somatosensory mapping using MEG can be used to guide intraoperative mapping and neurosurgical planning.
Kirsch
Heidi E
HE
University of California San Francisco Epilepsy Center, Department of Neurology, USA.
Zhu
Zhao
Z
Honma
Susanne
S
Findlay
Anne
A
Berger
Mitchel S
MS
Nagarajan
Srikantan S
SS
D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005910:Glioma / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009055:Mouth / Q000503:physiopathology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies