Magnetoencephalography (MEG), recording and analysis; for spontaneous brain magnetic activity (eg, epileptic cerebral cortex localization)
CPT4 code
Name of the Procedure:
Magnetoencephalography (MEG)
Summary
Magnetoencephalography (MEG) is a non-invasive medical test that records and analyzes the magnetic fields produced by brain activity. It is primarily used to identify areas of the brain responsible for functions such as reading, sensing, or movement and to localize regions involved in epilepsy.
Purpose
MEG is used to localize areas of the brain that are involved in specific functions or where abnormalities, such as epileptic activity, occur. The goal is to provide precise information for diagnosis and treatment planning, including pre-surgical mapping for epilepsy or brain tumors.
Indications
- Suspected epilepsy or other seizure disorders
- Pre-surgical planning for epilepsy or brain tumor resection
- Mapping brain functions for research or clinical purposes
- Unexplained neurological symptoms
Preparation
- No specific fasting is required.
- Patients should avoid caffeine and any other stimulants on the day of the test.
- Remove any metal objects or jewelry before the procedure.
- Diagnostic tests like MRI may be conducted beforehand to complement MEG results.
Procedure Description
- The patient sits or lies down in a quiet room.
- A special cap with sensors is placed on the patient’s head to detect magnetic fields.
- The patient is asked to remain still and may be given tasks to perform (e.g., reading or moving specific body parts).
- The sensors detect and measure the magnetic fields produced by brain activity.
- The data is captured and analyzed by a computer to create detailed maps of brain activity.
Duration
The entire procedure typically takes about 1 to 2 hours.
Setting
MEG is performed in a specialized lab within a hospital or outpatient clinic equipped with MEG technology.
Personnel
- Neurologist or neurophysiologist
- MEG technologist or technician
- Radiologist (for data interpretation)
- Additional healthcare staff for patient support
Risks and Complications
- MEG is non-invasive and generally very safe.
- Rare risks include discomfort from holding still for prolonged periods or anxiety from the procedure itself.
- There are no known significant complications because the technology does not involve radiation.
Benefits
- Highly accurate localization of brain functions and epileptic regions.
- Non-invasive and painless.
- Provides critical information for surgical planning and treatment changes.
Recovery
- No recovery time needed.
- Patients can resume normal activities immediately after the procedure.
- Follow-up appointments may be scheduled to discuss results.
Alternatives
- Electroencephalography (EEG): Uses electrical activity instead of magnetic fields but may be less precise.
- Functional MRI (fMRI): Captures brain activity through blood flow changes, requiring more extensive infrastructure.
- Positron Emission Tomography (PET): Provides functional imaging but involves radioactive tracers.
Patient Experience
- Patients should feel comfortable throughout the procedure, experiencing no pain.
- Some may feel anxious about remaining still but will be supported by staff.
- Post-procedure, patients can return to their daily activities with no downtime.