Magnetic stimulation of the scalp: the responses of the masseter muscles. Ii
Macaluso, G.M.; Pavesi, G.; Bonanini, M.; Mancia, D.; Gennari, P.U.
Minerva Stomatologica 39(5): 343-346
1990
ISSN/ISBN: 0026-4970 PMID: 2381395 Document Number: 351176
Magnetic stimulation of nervous elements is a new technique of investigation in intact alert man. Electromyographic responses of the masseter muscles were recorded in normal volunteers and in two patients with hemispheric or capsular lesions, both by surface and needle electrodes. In the patients "cortical" responses were absent when stimulating the affected hemisphere and present when stimulating the unaffected one. These findings suggest that the direct facilitating cortico-nuclear projections for the masseter muscle are mainly crossed. Nevertheless the presence of clear ipsilateral responses after stimulation of the unaffected hemisphere demonstrates the existence of uncrossed projections; in fact only the ipsilateral motor cortex can be the site of origin of the responses in these patients.