title: Magnetoencephalography of epilepsy with a microfabricated atomic magnetrode.
abstract: Magnetoencephalography has long held the promise of providing a noninvasive tool for localizing epileptic seizures in humans because of its high spatial resolution compared with the scalp EEG. Yet, this promise has been elusive, not because of a lack of sensitivity or spatial resolution but because the large size and immobility of present cryogenic (superconducting) technology prevent long-term telemetry required to capture these very infrequent epileptiform events. To circumvent this limitation, we used Micro-Electro-Mechanical Systems technology to construct a noncryogenic (room temperature) microfabricated atomic magnetometer ("magnetrode") based on laser spectroscopy of rubidium vapor and similar in size and flexibility to scalp EEG electrodes. We tested the magnetrode by measuring the magnetic signature of epileptiform discharges in a rat model of epilepsy. We were able to measure neuronal currents of single epileptic discharges and more subtle spontaneous brain activity with a high signal-to-noise ratio approaching that of present superconducting sensors. These measurements are a promising step toward the goal of high-resolution noninvasive telemetry of epileptic events in humans with seizure disorders.
authors.affiliation: Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305.
authors.forename: Orang
authors.identifier: http://orcid.org/0000-0001-5932-194X
authors.initials: O
authors.lastname: Alem
authors.affiliation: Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309, and.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Benison
authors.affiliation: Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309, and dbarth@psych.colorado.edu.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Barth
authors.affiliation: Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305.
authors.forename: John
authors.initials: J
authors.lastname: Kitching
authors.affiliation: Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309, and Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305.
authors.forename: Svenja
authors.initials: S
authors.lastname: Knappe
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology*; D015225:Magnetoencephalography / Q000379:methods*; D060306:Magnetometry / Q000379:methods*; D008297:Male; D055616:Microtechnology / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley
keywords: MEG; atomic; epilepsy; magnetomoeter; seizure