Functional magnetic resonance mapping of motor cortex in patients with mass lesions near primary motor and sensory cortices

Purpose: To study motor cortex mapping in patients with mass lesions near primary motor and sensory cortices with BOLD-fMRI. Material and Methods: 18 patients with mass lesions near primary motor and sensory cortices, and 8 healthy volunteers were investigated with fMRI using a 1.5T GE Signa scanner. The specific task was repetitive selfpaced index finger to thumb opposition with a frequency of approximately 2 Hz. Each task paradigm consisted of twelve 20-second blocks alternating between rest and activation. All functional data was sent to SUN GE Advanced Workstation 4.0 for post processing. Results: 14 patients showed functional activaton near mass lesion, 4 patients failed to show, and one patient with meningeoma was excluded because of heavy head movement. Of 14 patients, the functional activation of eloquent cortex was different between the group with declination of muscle force and the group with normal muscle force, generally the activated areas of the former were more scattered, dislocated, relative smaller than that of the latter. Conclusion: fMRI is a valuable method for pre-operative evaluation of neurosurgical patients and probably can evaluate the muscle force pre- and post-operation approximateli.