体感诱发电位在椎管内占位显微手术中的监测

对28例椎管内占位手术患者行体感诱发电位(SEP)全程监测,包括脊髓SEP(SSEP)及皮质SEP(CSEP).2例Frankel A级髓外肿瘤患者,术前无SEP,手术结束时出现SEP波形,术后短期内神经功能有一定程度恢复.2例Frankel B、C级髓内肿瘤患者,术中SEP波幅下降超过40％,潜伏期延长超过5％,术中及时暂停手术操作,术后出现神经功能轻度可逆性损害.12例D、E级髓内肿瘤患者,8例术中SEP波幅下降接近或达到50％,潜伏期延长接近或达到7％;另4例SEP轻度下降,均在安全范围内,术后脊髓功能无损害加重.说明椎管内占位病变在行髓内肿瘤切除时最易引发SEP波幅降低及潜伏期延长;脊髓手术时行SSEP和CSEP联合监测可及时准确地反映脊髓功能的变化,指导术者操作,并可初步判断预后.

Monitoring of somatosensory evoked potential in microsurgery of spinal tumors

Somatosensory evoked potential(SEP) monitoring was performed intraoperatively in 28 patients with extramedullary or intramedullary tumors.Dissection of intramedullary tumor usually leads to decrease of amplitude and increase of latency in SEP. SEP reappeared at the end of operation in 2 cases of Frankel A grade extramedullary tumors whose SEP disappeared during operation with functional recovering to some degree. In 2 cases of Frankel B and C grade intramedullary tumors, the amplitude of SEP decreased by more than 40% and the latent period in SEP increased by more than 5% during operation,and the surgical procedure was paused for a while.There was slight reversible injury of nerve post operatively. In 8 of 12 cases of Frankel D and E grade intramedullary tumors, the amplitude of SEP descended nearly by 50% and elongation of latency in SEP was about 7% during surgery. SEP was reduced lightly in other 4 cases and all achieved good recovery. Intraoperative monitoring of spinal SEP and cortex SEP can reflect the change of spinal function, reduce post operative complication, and predict prognosis.