Neurophysiological studies may be reimbursed individually whether performed independently or in conjunction with each other.

If a provider reports any neurophysiological studies in addition to evoked response audiometry, the charges should be combined and processed under code 92585.

Magnetoencephalography (MEG) and magnetic source imaging (MSI) studies are considered experimental/investigational and are not covered. A participating, preferred, or network provider can bill the member for the denied services. Sufficient clinical trials have not been performed to define the test's effectiveness.

Intraoperative neurophysiology monitoring should be reported under procedure code 95920, regardless of the specific monitoring performed (e.g., brainstem auditory evoked response, somatosensory evoked potentials, etc.) If any of the testing codes for neurophysiological monitoring which are addressed below in the "Description" area of this policy are reported in conjunction with 95920, the services should be combined and processed under 95920 (e.g., 95925 + 95920 = 95920).

Intraoperative neurophysiology monitoring is an eligible service when it is performed inpatient by an eligible professional provider for any of the following indications:

• Acoustic neuroma
• Anterior cervical corpectomy
• Carotid endarterectomy
• Cerebral vascular aneurysms
• Cervical or thoracic myelopathy
• Dorsal rhizotomy
• Exploration of peripheral nerve neuroma
• Fracture of the spine
• Hemifacial spasm, 7th nerve decompression operation
• Herniated nucleus pulposus with spinal cord compression and wedge graft surgery following anterior cervical discectomy
• Leg lengthening procedure
• Most spinal instrumentation procedures
• Scoliosis
• Spinal arteriovenous malformation
• Spinal cord trauma
• Spinal stenosis
• Spondylolisthesis
• Spondylosis
• Syringomyelia
• Tethered cord
• Thoracic disc disease
• Trigeminal neuralgia, 5th nerve decompression operation
• Tumor of the CNS or peripheral NS
• Unstable spine

Individual consideration may be given for indications other than those above.  The physician must be performing the service in real time.  The physician may be in the O.R. suite or at a remote site with the monitoring performed via digital transmission or closed circuit television.  When digital transmission or closed circuit television is used, there must be the ability for continuous or immediate contact with the operating surgeon to ensure that information about the patient's status can be immediately communicated.

Description

Neurophysiological studies is a generic term for objective tests performed via sophisticated electronic equipment to detect various neurological dysfunctions. They include the following studies:

• Electroencephalography (EEG) - 95812-95813, 95816-95822, 95827, 95950, 95951, 95954, 95956
• Evoked response audiometry (ERA) - 92585, 92586
• Visual evoked potential (VEP) - 95930
• Central auditory testing - 92589
• Somatosensory evoked potential (SEP) testing -95925, 95926, 95927
• Central motor evoked potential study (transcranial motor stimulation) - 95928, 95929 

(The above codes represent testing performed in a nonoperative setting.)

NOTE: Evoked response audiometry (92585, 92586) can also be reported as:

• Brain stem auditory evoked response (BAER)
• Electrophysiological response audiometry
• Electrical response audiometry
• Evoked potential audiometry
• Low or high level biophysical EEG

Magnetoencephalography (95965, 95966, 95967) measures neurological activity of the brain using magnetic fields. It is used for fundamental study of the brain, and for clinical studies and assessment of patients with specific neurological disorders. MEG is a noninvasive functional imaging technique in which the weak magnetic forces associated with the electrical activity of the brain are recorded externally on the scalp. Using mathematical modeling, the recorded data are then analyzed to provide an estimated location of the electrical activity. This information can be superimposed on an anatomic image of the brain, typically an MRI, to produce a functional/anatomic image of the brain, referred to as magnetic source imaging (MSI) (S8035). The primary advantage of MSI is that while the conductivity and thus measurement of electrical activity as recorded by the EEG is altered by surrounding brain structures, the magnetic fields are not. Therefore, MSI permits a high resolution image.

Intraoperative neurophysiology monitoring is used to identify complications to the nervous system during certain surgical procedures. Evoked responses are constantly monitored for changes which could imply damage to the nervous system. The intent of this monitoring is to alert the surgeon so that he may possibly alter the surgical procedure to avoid permanent neurological damage.

NOTE:

This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.

PRN References

03/1994, Intraoperative neurophysiology testing, coding for
03/1995, Intraoperative neurophysiology monitoring, codes and reimbursement for
06/2005, Blue Shield covers real time on-site and remote-location intraoperative neurophysiological monitoring

Magnetoencephalography/Magnetic Source Imaging, MPRM, Policy 6.01.21, 02/15/2002