Somatosensory evoked potentials combined with transcranial electric motor evoked potentials in posterior spinal correction and fusion for severe kyphoscoliosis

English Keywords:Somatosensory evoked potentials  Motor evoked potentials  Severe kyphoscoliosis  Intraoperative monitoring

English Abstract:

  【Abstract】 Objectives: To evaluate the clinical values of somatosensory evoked potentials(SSEPs) combined with transcranial electric motor evoked potentials(TCeMEPs) during posterior spinal correction and fusion for severe kyphoscoliosis. Methods: A total of 69 patients with severe kyphoscoliosis(coronal or sagittal Cobb angle more than 90°) undergoing posterior spinal fusion from August 2015 to October 2017 was reviewed, the intraoperative monitoring data including SSEPs and TCeMEPs were collected in all the patients. The followings were calculated: successful rate, alert rate, positive predictive value, negative predictive value, sensitivity and specificity of the intraoperative monitorings(SSEPs, TCeMEPs, SSEPs combined with TCeMEPs). Chi-square test was used to compare the data among the groups. Results: Stable monitoring baseline of SSEPs was obtained in 58 patients, of whom 5 cases met the alarm criteria. Postoperative neurological defect was found in 2 patients, while in the other 3 patients the SSEPs recovered generally during operation with no neurological defect postoperatively. Stable monitoring baseline of TCeMEPs was obtained in 67 patients. A total of 3 cases met the alarm criteria, of whom 2 cases were true positive and 1 case was with no significant neurological defect. The success rate, alert rate, true positive rate, false positive rate, true negative rate, false negative rate, positive predictive value, negative predictive value, sensitivity and specificity of single SSEPs were 84.1%(58/69), 8.6%(5/58), 3.4%(2/58)， 5.2%(3/58), 91.4%(53/58)， 0(0/58), 40%(2/5), 100%(53/53), 100%(53/53) and 94.6%(53/56), respectively. The values for single TCeMEPs were 97.1%(67/69), 4.4%(3/67), 3.0%(2/67), 1.5%(1/67), 95.5%(64/67), 0(0/67), 66%(2/3), 100%(64/64), 100%(64/64) and 98.5%(64/65), respectively. In addition, the alert rate, true positive rate, false positive rate, true negative rate, false negative rate, positive predictive value, negative predictive value, sensitivity and specificity of SSEPs combined with TCeMEPs were 3.4%(2/58), 3.4%(2/58), 0(0/58), 96.6%(56/58) and 0(0/58), 100%, 100%, 100% and 100%, respectively. No significant differences were found among 3 groups in success rate, alert rate, true positive rate, true negative rate, false negative rate, negative predictive value, sensitivity and specificity(P>0.05). Significant differences were observed in negative positive rate and positive predictive values among 3 groups(P<0.05). Conclusions: SSEPs combined with TCeMEPs can increase the predictive values during surgical correction of severe kyphoscoliosis and further reduce the risk of neurological complication.