Intraoperative Neurophysiological Monitoring, by Leon K Liem

eMedicine
Liem's article on "Intraoperative Neurophysiological
monitoring", a good place for starters to know the basics of
neuromonitoring.  Author: Leon K Liem, MD, Assistant Clinical Professor, Division of Neurological Surgery, University of Hawaii, John Burns School of Medicine

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Updated: Feb 11, 2010

Introduction

This article provides an overview of the various neurophysiological monitoring techniques used intraoperatively.
Intraoperative neurophysiological monitoring has been utilized in attempts to minimize neurological morbidity from operative manipulations. The goal of such monitoring is to identify changes in brain, spinal cord, and peripheral nerve function prior to irreversible damage. Intraoperative monitoring also has been effective in localizing anatomical structures, including peripheral nerves and sensorimotor cortex, which helps guide the surgeon during dissection.
Evoked potential monitoring includes somatosensory evoked potentials (SSEP), brainstem auditory evoked potentials (BAEP), motor evoked potentials (MEP), and visual evoked potentials (VEP). Electromyography (EMG) also is used extensively during operative cases. Scalp electroencephalography (EEG) provides data for analysis in SSEP, BAEP, and VEP. Scalp EEG also can be used to monitor cerebral function during carotid or other vascular surgery. In addition, EEG recorded directly from the pial surface, or electrocorticography (ECoG), is used to help determine resection margins for epilepsy surgery, and to monitor for seizures during electrical stimulation of the brain carried out while mapping cortical function. http://emedicine.medscape.com/article/1137763-overview