Intraoperative neurophysiologic monitoring (IONM) is a technique that is directly aimed at reducing the risk of neurological deficits after operations that involve the nervous system. IONM is a technique that has evolved during the last two decades; it makes use of recordings of electrical potentials from the nervous system during surgical operations.  The use of IONM offers a possibility to detect injuries before they become so severe they cause deficits after the operation. Introduction of IONM has reduced the risk of debilitating deficits such as muscle weakness, paralysis, hearing loss, and other loss of normal body functions. IONM is normally performed by technologists supervised by a physiologist, or a neurologist. Technologists are not permitted to make interpretations of recorded potentials and give information to the surgeon; the supervising physiologist does that. It is necessary to have certification to do IONM. Similar techniques as used in IONM are now used in a few kinds of operations for guiding the surgeon in an operation to help obtain the best results.

modalities of testing

EEG    (Electroencephalogram)

SSEP   (Somatosensory Evoked Potentials)

tcMEP (Transcranial Motor Evoked Potentials)

BAEP   (Brainstem Auditory Evoked Potentials)

EMG    (Electromyography)

NAP     (Nerve Action Potential)

Direct Cortical Stimulation

Direct Subcortical Stimulation

Awake Testing