Application Of Intraoperative Evoked Potential Monitoring In Neurosurgery

Objective: To primarily valuate the clinical application of somatosensory evoked potential monitoring in neurosurgical surgery.Methods: Operations on 54 cases of neurosurgical patients were performed, with real-time somatosensory evoked potential (SEP) monitoring. If SEP waveforms changed significantly, operations were modified or even stopped. The detailed changes of SEP waveforms were classified as follows: TypeⅠ, no change; TypeⅡ, change that reverts to baseline; TypeⅢ, change that does not revert to baseline; TypeⅣ, complete flattening of the SEP waveform without improvement. Individual deterioration of motor function corresponding to different intraoperative SEP changes was valuated postoperatively.Results: 36 patients demonstrated TypeⅠSEP waveforms, only 2 of whom had decreased muscle strength. 7 patients demonstrated TypeⅡSEP waveforms, and no patients had postoperative motor deficits. 5 patients demonstrated TypeⅢSEP waveforms, all of them had postoperative motor deficits. 6 patients demonstrated TypeⅣSEP, 5 of whom behaved hemiplegia. The rate of myodynamia deterioration in the group with normal SEPs was significantly lower than that in the group with unrecovered abnormal SEPs.Conclusion: During neurosurgical procedures, dynamic monitoring of SEPs can detect real time neurological deficits, which is beneficial for surgeons to timely protect related function. Moreover, SEP changes are helpful to predict postoperative motor function. Objective: To explore the clinical application of neuronavigation, diffusion tensor imaging (DTI) together with intraoperative monitoring of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) during surgery on intracranial tumors.Methods: Preoperative DTI was performed on 27 patients with brain tumors to obtain pyramidal tracts imaging. Afterwards, the spatial relationship between fiber bundle and brain tumors was studied. Besides, neuronavigation was applied intraoperatively to guide the resection of brain tumors. Moreover, SEP and MEP intraoperative monitoring was performed on 15 cases in the study group, not on the left 12 cases in the control group.Results: Before surgery pyramidal tracts were reconstructed successfully by DTI in all 27 patients, among which normal tracts were demonstrated in 13 cases, simple displacement in 11 cases and disruption or loss in 3 cases. Total resection was achieved in 21 patients, while subtotal resection was achieved in 6 patients. In the study group, SEPs and MEPs were normal in 12 patients. However, complete disappearance of SEP waveform was observed in 3 patients (2 also with disappeared MEP waveform). The rate of myodynamia deterioration in the study group was significantly lower than that in the control group.Conclusion: The combination application of modern techniques like neuronavigation, DTI and SEP/MEP monitoring in neurosurgical operations on intracranial neoplasms is beneficial to protect motor function and therefore improve the postoperative quality of life.