Functional localization by magnetoencephalography.

Magnetoencephalography combines the attributes of real-time millisecond temporal resolution with precise anatomic localization. In addition to characterizing spontaneous epileptiform discharges and slow wave activity, magnetoencephalography may be used to map sensorimotor, auditory, and visual functions. Magnetoencephalography functional data are registered to three-dimensional magnetic resonance imaging to provide a useful way to analyze the relationship of structure to function and to assist in surgical planning. Magnetoencephalography is noninvasive and can be done with rapid turn-around time, but it is expensive and is not optimal for all brain areas or functions. Future integration and cross-analysis of magnetoencephalography with other functional mapping modalities will likely prove to be complementary and of even greater use.