Preoperative magnetic source imaging for XXXX surgery: a quantitative comparison with intraoperative sensory and motor mapping.

@entity1 @entity1313
OBJECT: The aim of this study was to compare quantitatively the methods of preoperative magnetic source (MS) imaging and intraoperative electrophysiological cortical mapping (ECM) in the localization of sensorimotor cortex in @entity1 with intraaxial @entity1313 . METHODS: Preoperative magnetoencephalography (MEG) was performed while @entity1 received painless tactile somatosensory stimulation of the lip, hand, and foot. The early somatosensory evoked field was modeled using a single equivalent current dipole approach to estimate the spatial source of the response. Three-dimensional magnetic resonance image volume data sets with fiducials were coregistered with the MEG recordings to form the MS image. These individualized functional brain maps were integrated into a neuronavigation system. Intraoperative mapping of somatosensory and/or motor cortex was performed and sites were compared. In two subgroups of @entity1 we compared intraoperative somatosensory and motor stimulation sites with MS imaging-based somatosensory localizations. Mediolateral projection of the MS imaging source localizations to the cortical surface reduced systematic intermodality discrepancies. The distance between two corresponding points determined using MS imaging and ECM was 12.5 +/- 1.3 mm for somatosensory-somatosensory and 19 +/- 1.3 mm for somatosensory-motor comparisons. The observed 6.5 mm increase in site separation was systematically demonstrated in the anteroposterior direction, as expected from actual anatomy. In fact, intraoperative sites at which stimulation evoked the same @entity1 response exhibited a spatial variation of 10.7 +/- 0.7 mm. CONCLUSIONS: Preoperative MS imaging and intraoperative ECM show a favorable degree of quantitative correlation. Thus, MS imaging can be considered a valuable and accurate planning adjunct in the treatment of @entity1 with intraaxial @entity1313 .
