Role of intraoperative neurophysiological monitoring during spinal deformity surgery

Abstract

Background: Intraoperative Neurophysiological Monitoring (IONM) is used in complicated spine surgeries, such as scoliosis and others which have the possibility of intraoperative and postoperative neurological complications. Multimodal IONM (MIOM) is more effective than a single modality for detection of intraoperative spinal cord injury. So, we evaluated the role of MIOM during the spinal deformity surgery.Materials and methods: This study was conducted on 25 patients suffering from spinal deformity. During surgery, Motor evoked potential (MEP) stimulation was performed using corkscrew needle electrodes inserted in the C3-C4 position of the 10-20 system and recording needle electrodes were inserted in the appropriate muscles. Somatosensory evoked potentials (SSEPs) were recorded from corkscrew electrodes placed in the scalp after stimulation of the median nerve at the wrist and the posterior tibial nerve at the ankle.Results: eight males (32%) and 17 females (68%) were included in the study, their ages ranged from 8-29 year with a mean (14.5 ± 4.8 year). Seven patients had congenital scoliosis (28%), 14 had idiopathic scoliosis (56%), 3 patients had kyphoscoliosis (12%), and 1 patient with neuromuscular scoliosis (4%). Hypotension, manipulation around the cord, presence of kyphosis, rigidity of the curve, removal of hemivertebrae, double curve, and manipulation around the apex affect MEP. Neurophysiological monitoring events observed in this study were classified into three categories: true positive, transient true positive, and transient false positive.Conclusion: The use of intraoperative neurophysiological monitoring reduces the incidence of complications to the nervous systems after surgery.