The Henry Ford Comprehensive Epilepsy Program got the first whole-head MEG in the Midwest. Brain activity produces very weak magnetic fields which can be detected from your scalp with a special device called a magnetometer. In essence, your brain is a very weak radio station and the MEG is a collection of very sensitive antennas. EEG recordings are usually performed at the same time as MEG studies. MEG can give us some information EEG cannot see, and vice-versa. Magnetoencephalography (MEG) is a non-invasive technique used to measure magnetic fields generated by small intracellular electrical currents in neurons of the brain. Thus MEG provides direct information about the dynamics of evoked and spontaneous neural activity and the location of their sources in the brain.
For a MEG study you will change into a hospital gown and remove all metal jewelry. You will then rest on a comfortable bed while your head is positioned inside the helmet-shaped MEG. For 2 to 4 hours, your brain waves will be recorded to help find the parts of your brain producing epileptic waves. In addition, important normal brain activity can be located, such as that for the sense of touch, by tapping on your fingertips. This information will help the surgical team plan epilepsy surgery.
MEG may be helpful in the following situations:
- It can improve the detection of potential sources of seizures by revealing the exact location of the abnormalities.
- It can help when MRI scans show a lesion but the EEG findings are not entirely consistent with the MRI information. An MEG may be able to confirm that the epileptiform discharges (the brain waves typical of epilepsy) are indeed arising from the lesion. Then a decision can be made regarding surgery.
- In patients who have brain tumors or other lesions, the MEG may be able to map the exact location of the normally functioning areas near the lesion so that surgery can be planned to minimize postoperative weakness or loss of brain function.
- In patients who have had past brain surgery, the electrical field measured by EEG may be distorted by the changes in the scalp and brain anatomy. If further surgery is needed, MEG may be able to provide necessary information without invasive EEG studies.
The MEG lab at Henry Ford Hospital is also conducting research in:
- Functional Neuroimaging studies of fundamental language and memory processing in normal subjects compared to subjects with learning disorders.
- Development of neuroimaging biomarkers for indicators of recovery from stroke.
- Investigations of the underlying mechanisms of migraine and the neurological effects of medical treatments.
- Development of neuroimaging methods to determine locations of epileptogenic areas suitable for resection.
- Localization of the cortical areas involved in tinnitus generation.
- Investigations of the neural mechanisms of driver distractions during cell phone conversations during simulated driving.
- Localization of brain regions that facilitate the control of attention and other higher executive processes in subjects with ADHD and normal controls.
- Increasing our understanding of the complex relationships between social information processing, social interaction, and social competence as well as the aberrant connectivity that underlies social dysfunction in autism.
- Understanding executive processes in subjects with corpus callosum agenesis.
- Understanding the mechanisms underlying sensory inhibition (gating), i.e., the ability of the CNS to inhibit or modulate its sensitivity to incoming irrelevant sensory input.