2019 Volume 47 Issue 1 Pages 1-8
Although intraoperative motor-evoked potential (MEP) monitoring is widely performed during neurosurgical operations, there is controversy regarding the evaluation of its results. The cutoff point, sensitivity and specificity of MEP recorded during spinal operations were examined by receiver operating characteristic (ROC) analyses. In 349 spinal operations for the patients without preoperative motor palsy under transcranial (TC) MEP monitoring, amplitude reduction of 77.9% and 80.6% as cutoff points for motor palsy with and without normalization by compound muscle action potential (CMAP) after peripheral nerve stimulation, respectively gave sensitivity of 100%, and specificity of 96.8% and 96.2%. In 130 operations for the treatment of compressive spinal cord disease, cutoff points of 64.4% and 50.6% relative amplitude rate gave specificities of 90.0% and 70.0%, sensitivities of 75.8% and 88.3%, with and without CMAP normalization, respectively. In 185 operations for the treatment of compressive cauda equina nerve disease, cutoff points of 11.4% and 17.9% amplitude reduction gave specificities of 58.0% and 72.4%, sensitivities of 100% and 50.0%, with and without CMAP normalization, respectively. CMAP normalization is seemed to be effective for predicting neurological recovery after the operation for compressive spinal and spinal nerve disease.
