Identification of Pre-and Post Central Sulcus by Functional Magnetic Resonance Imaging and Electrophysiology: Comparison in 11 Cases.

Abstract:
Introduction: We compared functional Magnetic Resonance Imaging (fMRI) maps of motor and sensory functions at risk during tumor resections with findings of intraoperative cortical electrophysiology. Methods: 11 neurosurgical candidates with lesions located in or close to the primary sensomotor cortex underwent our comprehensive fMRI battery including motor and sensory tasks to identify pre-and post- central sulcus regions. A standard echoplanar functional imaging sequence (GE 1.5T) was employed. During surgery central sulcus and primary motor areas were determined by somatosensory evoked potentials(SSEPs) recordings and by direct cortical stimulation. Functional areas were referenced to MRI scans using an frameless based stereotactic navigation system to compare these areas of activation with the fMRI results. Results: fMRI revealed pre-central sulcus in 11/11 (100%) cases and post-central sulcus was activated in 8/11 (73%) cases. SSEPs recordings elicited central sulcus in 10/11 (91%) cases, and direct cortical stimulation of pre-central sulcus provoked motor responses in 4/4 cases. When both methods reported central sulcus locations, these concurred in 10/10 (100%) cases. Conclusion: This study confirmed findings of previous reports and documents the reliability of fMRI as a technique for the preoperative identification of primary sensorymotor cortex.