ROLE OF MOTOR EVOKED POTENTIAL IN THE PREDICTABILITY OF SURGICAL RESULTS OF HERNIATED DISC INDUCED CERVICAL MYELOPATHY UNDER DIFFERENT ANESTHETIC TECHNIQUES

Abstract

Intraoperative (MEPs) application provides a method for monitoring the functional integrity of motor pathways. However, these potentials are sensitive to suppressive effect by most anesthetic agents. The aim of this work is to evaluate the role of TceMEPs in predicting motor system affection and surgical outcome during anterior cervical microdiscectomy operations and comparing the outcome under two anesthetic regimens (propofol-fentanyl) versus (sevoflurane-N20). This study included 60 patients divided into two groups (I, II). Anesthetic plane was induction by propofol and use of atracurium for intubation and muscle relaxation in predetermined doses. Maintenance of anesthesia in group (I) was by (propofol-fentanyl) infusion and in group II by (sevoflurane-N20). During operation TceMEPs monitoring with myogenic recoding of (CMAPs) from the four limbs was done. The stimuli and so the recordings of (CMAPs) would be collected at five different time intervals; (before induction, after induction, during surgical • manipulations, after completion of surgery, after reversal of muscle relaxants). By comparing between 1st and 2"ct reading in both groups, we could detect the effect of used anesthetics on (CMAPs). By comparing "'••t the 2"ct, 3'ct and 4th readings, we could detect the effect of surgical maneuvers (CMAPs) and hence the functional integrity of motor segment at risk. Finally, we conclude that; (CMAPs) recorded under (sevoflurane­ N20). anesthesia had statistically significant lower amplitude than that recorded during (propofol-fentanyl) one, whereas both regimens had minimal non-significant prolongation of latencies. However, multipulse