PAPER 193: MEP/SSEP MONITORING IN SPINAL DEFORMITY SURGERY: INCIDENCE AND FACTORS LEADING TO SIGNIFICANT ELECTROPHYSIOLOGIC EVENTS

Abstract

Purpose: Despite advances in surgical technique, neurological injury remains a potentially devastating complication of spinal deformity correction surgery. The purpose of the study is to describe surgical and patient factors associated with “electrophysiologic (EP) events” and neurogenic deficits.

Method: A retrospective chart review, looking at “EP events” during surgery, was conducted on 162 patients who received surgical treatment of their pediatric spine deformity from 1999 to 2004.

Results: Ninety three percent of cases (n=151) were successfully monitored by either somatosensory evoked potential (SEP) or motor evoked potential (MEP) monitoring. All three neurologic deficits that occurred in this study cases were successfully detected by EP monitoring (0.02%, p=.002). In those 151 cases that were successfully monitored, “EP events” were occured in twenty (13.2%) cases. The most common cause was systemic change (45%) and curve correction (40%). In those 20 cases, when corrective actions were made (n=15) “EP events” reversed to baseline values in all cases. When no corrective actions were taken (N=5) there was no reversals of “EP events” to baseline. Patients with kyphosis had a trend toward significantly higher rates of “EP events” (p=.174) and patients who had cardiopulmonary comorbidities had significantly higher rates of “EP events” (p=.007).

Conclusion: Consistent with existing literature, the EP monitoring was successful in the vast majority of deformity surgeries. “EP events” were able to be reversed with corrective action and to predict neurologic deficits. Our study found that patients with kyphosis and/or cardiopulmonary comorbidities have higher risk of significant “EP events” during the surgeries.