**History/Background and/or General Information**

Short-latency somatosensory evoked potentials (SEPs) represent early
electrophysiologic responses of the somatosensory pathways to stimulation.
Somatosensory testing involves the application of multiple brief electrical
stimuli over peripheral nerves (e.g., the median, peroneal, and tibial nerves)
and recording the evoked potentials over proximal portions of the nerves
stimulated, the plexus, spine and/or scalp. These readings are then averaged
by a computer and can be traced and recorded in the form of waveforms. A
physician trained in interpreting clinical evoked potential studies then
interprets these waveforms. The waveforms obtained should be described and the
peak latencies, interpeak intervals (when appropriate), and amplitudes of the
significant components detailed. The nerves most commonly stimulated are the
median nerve at the wrist for testing in the upper extremity, and the common
peroneal nerve (CPN) at the knee and the posterior tibial nerve at the ankle
for the lower extremity.

**Covered Indications**

The use of short-latency somatosensory evoked potentials will be considered to
be medically reasonable and necessary to assist in the diagnosis of certain
neuropathologic states (as described below) in order to provide information
for treatment and for intraoperative testing during spinal surgeries in which
there is risk of additional nerve or spinal cord injury.

SEPs are used to evaluate the more proximal segments of nerves and the
integrity of the central somatosensory pathways when slowing of conduction
through the brain and/or brainstem, spinal cord, and/or peripheral nerves is
suspected. This would include conditions such as multiple sclerosis, cervical
spondylosis with myelopathy, coma, spinal cord trauma, hereditary and
idiopathic peripheral neuropathies, inflammatory and toxic neuropathies,
myoclonus, Friedreich's ataxia, syringomyelia, spinal cord tumors, spinal
stenosis and other conditions where there is spinal cord compression.

**Limitations**

SEP studies are appropriate only when a detailed clinical history and
neurologic examination and imaging studies, and EMG/Nerve Conduction studies
have failed to provide adequate information for a specific treatment plan.

As published in the CMS IOM Publication 100-08, _Medicare Program Integrity
Manual_ , Chapter 13, Section 13.5.4, an item or service may be covered by a
contractor LCD if it is reasonable and necessary under the Social Security Act
Section 1862 (a)(1)(A). Contractors shall determine and describe the
circumstances under which the item or service is considered reasonable and
necessary.

**Provider Qualifications**

SEP studies are covered when performed by providers of neurology services or
other providers who have specialized training and expertise in performing and
interpreting this test. Such training should include adequate educational
experience in the following:

  * The influences of stimulus parameters and other experimental variables on the responses that are recorded.
  * Existing knowledge of the anatomic structures and neurophysiologic events underlying the generation of evoked potentials.
  * The clinical significance and pathologic correlates of dysfunctional neural pathways demonstrated by evoked potentials alterations.
  * Relevant normative data and statistics. 

Training and expertise must have been acquired within the framework of an
accredited residency and/or fellowship program in the applicable
specialty/subspecialty. If this skill has been acquired as continuing medical
education, the courses must be comprehensive, offered or sponsored or endorsed
by an academic institution in the United States and/or by the applicable
specialty/subspecialty society in the United States, and designated by the
American Medical Association (AMA) as Category 1 Credit.