Technical tips: MEG and EEG with sedation

Magnetoencephalography (MEG) measures the field generated by the brain's electrical currents noninvasively. MEG is currently used for localization of epileptiform activity sources and for presurgical functional brain mapping. Such mapping with MEG requires the patients to be cooperative and lie still on their back for as long as ten minutes at a time. Hence, acquiring successful MEG in very young children, developmentally delayed individuals, and patients with skeletal abnormalities proves to be a challenge. Over the past several years, our group has undertaken research aimed at the effective use of sedation during MEG to identify epileptogenic areas and perform functional brain mapping in very young or developmentally delayed individuals. We summarize our experience of MEG data acquisition with sedation and demonstrate that epileptogenic areas can be identified and functional brain mapping can be successfully performed under sedation with propofol.