Position Statements | Interoperative Electrophysiological Monitoring

Interoperative Electrophysiological Monitoring

AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves Updated Position Statement: Intraoperative Electrophysiological Monitoring

January 2018

Intraoperative somatosensory evoked potential (SSEP) and motor evoked potential (MEP) monitoring are commonly referred to as intraoperative monitoring (IOM). There is Level I evidence that IOM is a reliable diagnostic tool for assessment of spinal cord integrity during surgery. MEPs have been shown to be superior to SSEPs in the assessment of spinal cord integrity during surgery. Intraoperative MEPs have been shown to predict recovery in traumatic cervical spinal cord injury.

There is insufficient evidence (Level III) of a therapeutic benefit of IOM during spinal surgery. While IOM is generally regarded as integral to lateral spine surgery, there is insufficient evidence to support a therapeutic benefit. The cost-effectiveness of IOM has been inadequately studied.

There is no published data to suggest that IOM results in alterations of procedures, abortion of procedures, increased procedure/anesthesia time, increased procedural difficulty, or increased risk of needle-sticks for the operative team.

IOM should be performed in procedures when the operating surgeon feels that the diagnostic information is of value, such as deformity correction, spinal instability, spinal cord compression, intradural spinal cord lesions and when in proximity to peripheral nerves or roots. Spontaneous and evoked electromyography is recommended for minimally invasive lateral retroperitoneal transpsoas approaches to the lumbar spine, and may also be of utility during pedicle screw insertion.


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