Functional Magnetic Resonance Mapping Of Motor Cortex In Patients With Mass Lesions Near Primary Motor And Sensory Cortices

【Objective】Motor functional deficit may be caused by surgery resection of brain tumors around the central sulcus.To study motor cortex mapping in patients with mass lesions near primary motor and sensory cortices with fMRI,provide more helpful information for clinical treatment,especially for surgical operation.【Methods】1.Subjects:Eighteen patients with mass lesions near primary motor and sensory cortices,and 8 healthy volunteers were investigated with fMRI.Age of patients varied from 24 to 78 years,and age of volunteers varied from 22 to 29 years.2.Experimental design and Imaging methods:1) MRI was performed using a 3.0T Siemens Signa scanner which was equipped for echo-planar imaging(EPI).Images were acquired using a standard head coil.2) Functional images:blood oxygenation level dependent(BOLD) imaging was performed using a single shot T₂^* weighted gradient echo EPI sequence.Four 7mm thick slices were obtained which had the same location and orientation as the anatomical slices,and 4:16 minutes 512 images were generated(0.5 sec/image). 3) Each task paradigm consisted of twelve 20-second blocks alternating between rest and activation.The specific task was repetitive selfpaced index finger to thumb opposition with a frequency of approximately 2 Hz. Tasks were performed independently on both sides.【Result】1.volunteers:all 16 runs showed functional activation in contralateral PMSC and in hibateral SMA.The functional activation in ipsilateral PMSC is much smaller than contralateral PMSC.The functional activated areas in ipsilateral PMSC,contralateral PMSC,and hibateral SMA with the task of left index finger to thumb opposition were almost the same as those of right index finger to thumb opposition,p＜0.05.2.Patients:18 cases were examined in this study,including 3 metastatic tumor,9 meningeoma and 6 neurogliocytoma.17 patients showed functional activaton near mass lesion,and one patient with meningeoma was excluded because of heavy head movement.Of 17 patients,the functional activation of eloquent cortex was different beween 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】Successful fMRI mapping can be obtained routinely in most patients with cerebral tumors,fMRI is a valuable method for pre-operative evaluation of neurosurgical patients and probably can evaluate the muscle force preand post-operation approximately.