DESCRIPTION
Electrocorticography (ECoG) uses epidural or subdural electrode arrays to record the electroencephalogram (EEG) from the cerebral cortex. ECoG is an invasive procedure; a craniotomy is required for implantation of the electrodes. The purpose of ECoG is to localize a suspected seizure focus in the cerebral cortex for individuals who are candidates for surgery.
POLICY
Extraoperative electrocorticography for the purpose of recording seizures is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
Extraoperative electrocorticography, for other conditions/diseases or stimulation and recording in order to determine electrical thresholds of neurons as an indicator of seizure focus is considered investigational.
MEDICAL APPROPRIATENESS
Extraoperative electrocorticography, for the purpose of recording seizures is considered medically appropriate if ALL of the following criteria are met:
Debilitating seizures intractable to anti-convulsant medication
Failure of standard testing to clearly localize a seizure focus, but that does strongly indicated the presence of a focus
Suspected seizure focus located in an area of the brain that is accessible for surgery
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
ADDITIONAL INFORMATION
High frequency of recording sessions or long duration of implantation may indicate that the electrocorticography is being used for stimulation and recording to determine neuronal thresholds. EEGs that result from such sessions may show stimulation artifacts that would not occur if EEG recording were performed without stimulation. However, such stimulation artifacts can be filtered out in the recording process and, therefore, will not always be evident in the EEG.
Intra-operative electrocorticography is a long-standing technique used to map abnormal brain tissue in the motor and/or sensory cortex prior to resection of the abnormal brain tissue. As such, intra-operative electrocorticography is an integral part of surgery that might involve normal motor and/or sensory cortex.
No controlled studies were found in the published literature that validates the application of electrocorticography for other conditions/disease or stimulation and recording in order to determine electrical thresholds of neurons as an indicator of seizure focus.
SOURCES
Asano, E., Juhasz, C., Shah, A., Sood, S., & Chugani, H. T. (2009). Role of subdural electrocorticography in prediction of long-term seizure outcome in epilepsy surgery. Brain, 132 (Pt. 4), 1038-1047.
BlueCross BlueShield Association. Medical Policy Reference Manual. (2:2003). Electrocorticography (7.01.34). Retrieved March 7, 2011 from BlueWeb. (0 articles and/or guidelines listed)
Erickson, K. M., & Cole, D. J. (2007). Anesthetic considerations for awake craniotomy for epilepsy. Anesthesiology Clinics, 25 (3), 535-555.
Jafari-Khouzani, K., Elisevich, K., Patel, S., Smith, B., & Soltanian-Zadeh, H., (2010). FLAIR signal and texture analysis for lateralizing mesial temporal lobe epilepsy. NeuroImage, 49 (2), 1559-1571.
Kim, A., & Nordli, D. R. (2010). Extending high-frequency oscillation analysis to pediatric electrocorticography. Ripple effect. Neurology, 75 (19), 1666-16667.
Ray, S., Crone, N. E., Niebur, E., Franaszczuk, P. J., & Hsiao, S. S. (2008). Neural correlates of high-gamma oscillations (60-200 Hz) in macaque local field potentials and their potential implications in electrocorticography. The Journal of Neuroscience, 28 (45), 11526-11536.
U. S. Food and Drug Administration. (2009, May). Center for Devices and Radiological Health. 510(k) Premarket Notification Database. K030982. Retrieved March 7, 2011 from http://www.accessdata.fda.gov/cdrh_docs/pdf9/K090957.pdf.
van Dellen, E., Douw, L., Baaven, J. C., Heimans, J. J., Ponten, S. C., Vandertop, W. P., et al. (2009). Long-term effects of temporal lobe epilepsy on local neural networks: A graph theoretical analysis of corticography recordings. Public Library of Science One, 4 (11), e8081.
Van Gompel, J. J., Rubio, J., Cascino, G. D., Worrell, G. A., & Meyer, F. B. (2009). Electrocorticography-guided resection of temporal cavernoma: Is electrocorticography warranted and does it alter the surgical approach? Journal of Neurosurgery, 110 (6), 1179-1185. (Level 3 Evidence - Independent study)
ORIGINAL EFFECTIVE DATE: 6/1984
MOST RECENT REVIEW DATE: 4/14/2011
ID_BT
Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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