This document addresses non-operative uses of the following evoked potential (EP) studies:

• visual evoked potentials (VEPs);
• somatosensory evoked potentials (SSEPs or SEPs);
• motor evoked potentials (MEPs).

Evoked potentials (EPs) or evoked responses are electrical waves created in the central nervous system by peripheral stimulation of a sensory organ. EPs are used to identify abnormal central nervous system function that may not be detected clinically.

Note: This document does not address intra-operative uses for VEPs, SSEPs, or MEPs. For additional information on intra-operative evoked potentials, please see CG-SURG-104 Intraoperative Neurophysiological Monitoring.

Clinical Indications

I. Visual Evoked Potentials:

Medically Necessary:

Visual evoked potentials are considered medically necessary for the diagnosis, evaluation, or monitoring of any of the following conditions:

1. Multiple sclerosis or neuromyelitis optica, or other demyelinating disorders of the optic nerve; or
2. Suspected disorder of the optic nerve, optic chiasm or optic radiations not explained by magnetic resonance imaging, computerized tomography, infectious diseases or metabolic disorders.

Not Medically Necessary:

Visual evoked potentials are considered not medically necessary for all other uses, including but not limited to glaucoma testing and routine screening of infants.

II. Somatosensory Evoked Potentials:

Medically Necessary:

Somatosensory evoked potentials are considered medically necessary when the results will be used to guide clinical management for the following conditions:

1. Acute (within 72 hours of onset) anoxic encephalopathy; or
2. Coma following traumatic, hypoxic-ischemic and other diffuse brain injuries; or
3. Central nervous system deficit identified on clinical exam when not explained by appropriate imaging studies; or
4. Demyelinating disease (such as multiple sclerosis) when diagnosis is uncertain and clinical suspicion exists based on neurologic symptoms or cerebrospinal fluid evaluation; or
5. Myelopathy, unexplained; or
6. Spinocerebral degeneration (such as Friedreich’s ataxia); or
7. Spinal cord lesions secondary to trauma when the need for surgical intervention is uncertain; or
8. Suspected brain death.

Not Medically Necessary:

Somatosensory evoked potentials are considered not medically necessary for all other uses.

III. Motor Evoked Potentials:

Medically Necessary:

Motor evoked potentials are considered medically necessary for evaluation of suspected hysterical or factitious paralysis.

Not Medically Necessary:

Motor evoked potentials are considered not medically necessary in the non-operative setting when the above criteria are not met.