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Neuromonitoring in surgery and anesthesia

Antoun Koht, MD
Tod B Sloan, MD, MBA, PhD
Laura B Hemmer, MD
Section Editors
Jeffrey J Pasternak, MD
Jeremy M Shefner, MD, PhD
Deputy Editor
Marianna Crowley, MD


Electrophysiologic monitoring, or neuromonitoring, is used during surgery to assess the functional integrity of the brain, brain stem, spinal cord, or peripheral nerves. The goal of monitoring is to alert the surgeon and anesthesiologist to impending injury in order to allow modification of management in time to prevent permanent damage. In some cases, neuromonitoring is used to map areas of the nervous system in order to guide management.

Neuromonitoring can include the recording of spontaneous activity (eg, electroencephalogram and spontaneous electromyogram) or evoked response to stimulus (eg, somatosensory evoked potentials, motor evoked potentials, and brainstem auditory evoked potentials). Frequently, multiple techniques are used together in order to increase the utility of monitoring and to overcome limitations of individual techniques [1,2].

Neuromonitoring has become common during many surgical procedures, often replacing intraoperative wake-up testing. Neuromonitoring is performed by a specialized team with specific expertise in the technique that is used. In most instances, no "standard of care" exists for intraoperative neuromonitoring, and techniques are chosen by the surgeon and monitoring team in order to assess or protect structures at risk (table 1).

This topic will present an overview of neuromonitoring techniques, the effects of anesthetic agents on recorded signals, and the strategy for responding to electrophysiological changes.


Electroencephalography (EEG), electromyography (EMG), somatosensory evoked potentials (SSEPs), brainstem auditory evoked potentials (BAEPs), and motor evoked potentials (MEPs) are electrophysiologic monitoring techniques that are commonly used in the operating room to improve surgical decision-making and possibly reduce neurologic complications in both adult and pediatric patients [3-23].

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Literature review current through: Nov 2017. | This topic last updated: Sep 05, 2017.
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