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Motor evoked potential monitoring during surgery of middle cerebral artery aneurysms: a cohort study
Qi Yue1, Wei Zhu1, Yuxiang Gu1
1Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China.
Background:
Motor evoked potential (MEP) monitoring has been widely used in brain or spine surgery to recognize potential damage of the pyramidal motor system. However, its ability to detect ischemic injury during middle cerebral artery (MCA) aneurysm surgery remains unclear. A prospective cohort study was designed to evaluate MEP changes during MCA aneurysm surgery.
Methods:
From January 2009 to August 2011, 89 patients underwent MCA aneurysm surgery and were prospectively divided into 2 groups: MEP monitoring group and control group. Based on an amplitude decrement of >50% or loss, a 2-stage warning criterion of MEP changes was established. Concomitant somatosensory evoked potential changes were also recorded. MEP changes occurred in 15 patients, and various methods were used to avoid continued brain ischemia. Indocyanine green angiography and Doppler ultrasonography were performed if needed. A head computed tomography scan was performed immediately and the day after the operation.
Results:
At discharge, neither motor status nor Glasgow Coma Scale score was significantly different between the 2 groups. However, at the latest follow-up (mean, 31.9 months), motor status of the patients in the monitoring group was better (P = 0.037). MEP monitoring was identified as an independent prognostic factor for motor outcome in long-term results by multivariate analysis (P = 0.042). Both wave loss and >50% amplitude decrement of MEP monitoring showed good predictive value when used as part of a 2-stage warning criterion.
Conclusions:
MEP monitoring is reliable for evaluation of the ischemic status of the pyramidal motor system during MCA aneurysm surgery and can improve surgical outcomes when used appropriately.
Insights
Motor evoked potential (MEP) monitoring reliably detects pyramidal tract damage during middle cerebral artery (MCA) aneurysm surgery. This technique improves long-term motor outcomes by enabling timely interventions to prevent brain ischemia.
Area of Science:
- Neurosurgery
- Neurology
- Intraoperative Monitoring
Background:
- Motor evoked potential (MEP) monitoring is standard for brain/spine surgery.
- Its efficacy in detecting ischemic injury during middle cerebral artery (MCA) aneurysm surgery is not well-established.
- A prospective study evaluated MEP changes during MCA aneurysm surgery.
Purpose of the Study:
- To evaluate the utility of MEP monitoring in detecting ischemic injury during MCA aneurysm surgery.
- To assess the impact of MEP monitoring on surgical outcomes.
- To determine if MEP changes predict long-term motor function.
Main Methods:
- A prospective cohort study of 89 patients undergoing MCA aneurysm surgery.
- Patients were divided into MEP monitoring and control groups.
- A 2-stage warning criterion for MEP changes (amplitude decrement >50% or loss) was used, with somatosensory evoked potentials also recorded.
Main Results:
- No significant difference in motor status or Glasgow Coma Scale score at discharge between groups.
- Patients in the MEP monitoring group showed better motor status at long-term follow-up (mean 31.9 months).
- MEP monitoring (wave loss or >50% amplitude decrement) was an independent prognostic factor for motor outcome.
Conclusions:
- MEP monitoring is a reliable tool for assessing pyramidal motor system ischemic status during MCA aneurysm surgery.
- Appropriate use of MEP monitoring can lead to improved surgical outcomes.
- MEP monitoring aids in preventing continued brain ischemia and improving long-term motor function.
