MEG (MAGNETOENCEPHALOGRAPHY)
The MEG collects magnetic signals generated by epileptiform activity. The MEG, which was first implemented at the Massachusetts Institute of Technology in the mid 1960s, is useful at identifying the “irritative zone” in patients who have frequent interictal spikes, which in many cases is where the seizures start. MEG may have some advantage over routine EEG, especially in cases where discharges arise from deep within the brain, are oriented tangential to the surface, and in cases in which the skull has a defect. MEG signals are not interfered with by the skull, scalp, or dura (layer that covers the brain). However, the recording of seizures on a routine basis is rare with MEG. The utility of this technique is still not proven, and although it could potentially add value to the evaluation, at present it is not a mandatory component of the clinical standard of care.