Cervical Spondylotic Myelopathy Intraoperative Somatosensory Evoked Potential Changes And The Curative Effect Relationship,

Objective:To measure CSM(Cervical Spondylotic Myelopathy) patients' SEP(somatosensory-evoked potential) in the operation and record the data, investigate the relationship between SEP and patients' recovery and relationship between SEP and effect of operation.Methods: Randomly selected 29 CSM patients treated with anterior cervical diskectomy and fusion with autogenous iliac crest graft enhanced by anterior plate system for cervical spondylotic myelopathy, monitored and recorded the SEP data with Medelec Synergy made by british oxford company from the beginning of operation to the end of operation. The data included basic line, latency(Lat), amplitude(Amp), shape change of P15 and N20 waves. Basic line is SEP at the beginning of operation. Lat is the time in which SEP get to the Max, measured with mS. Amp is the Max value of SEP, measured with uV. According to SEP data change, divided patients between A group(SEP data changed better) and B group(SEP data had no change). Separately recorded all patients' JOA values before operation and 1 week, 2 weeks, 4 weeks after operation. JOA values 1 week and 2 weeks after operation are spcially important. Then analyzed JOA values by statistical methods. investigate the relationship between SEP and patients' recovery and relationship between SEP and effect of operation.Results: There were 17 patients in A group. Compared with the data at the beginning of operation, SEP changed better markedly at the end of operation. A group's arms Amp increased 60%-157%, Lat shortened 13%-27%. 12 cases' arms amp increased over 70%. 8 cases' arm Lat shortened over 15%. Patients in A group got good recovery. There were 12 patients in B group. Bgroup's arms Amp increased lower 30%, Lat shortened lower 10%. 6 cases got no change. In operation 4 cases' arms Lat lengthened over 10% or Amp reduced over 50%. But at the end of operation this 4 cases' arms Lat and Amp got to common level.The recorder did not know Patients' information,when they recorded the Patients' JOA values. So, the record would be true and believable. JOA values in A group were all higher than in B group. According to JOA values 2 weeks after operation, calculated the rate of recovery. Recovery rate over 50% is good; lower 50% is common. In A group good recovery rate was 94.1%; average recovery rate was (74.1±12.79)%. In B group good recovery rate was 41.7%; average recovery rate was(50.35±16.37)%. And the result of analyzing all values by statistical methods(P<0.05)proved patients' recovery and operations' effect in A group was better than in B group.Conclusion:There is a strong relationship between SEP and CSM patient's clinical symptom. SEP data change can be used as one of the targets in forecasting CSM patients' recovery and effect of operation in the short term.