Magnetoencephalography for Clinical Pediatrics: Recent Advances in Hardware, Methods, and Clinical Applications

Abstract

Advancements in magnetoencephalography (MEG) present new opportunities for clinical pediatric centers faced with the challenge of offering a sensitive diagnostic evaluation for epilepsy in infants and young children. A noninvasive brain imaging method, which measures the magnetic fields generated by the electrical activity of the human brain, MEG provides significant advantages that make it particularly suitable for pediatric use. First, patient preparation is quick and easy and, unlike functional magnetic resonance imaging/magnetic resonance imaging, operates silently. As such, brain activity can be measured in a much more child-friendly environment. Second, although similar to electroencephalography in providing millisecond temporal resolution of neural activity, MEG offers advantages over electroencephalography in superior spatial resolution given the sensitivity of MEG to intracellular neural currents and the relative “transparency” of magnetic fields to biological tissues. Finally, when combined with magnetic resonance imaging, MEG data contribute unique information to the evaluation and localization of foci beyond that obtained with other neuroimaging technologies. As an example, the utility of MEG has been shown in determining irritative onset zones associated with epileptiform activity and for the functional mapping of nearby eloquent areas. This article reviews MEG theory along with new methods and technological advances, which result in improvements in pediatric epilepsy care. After a brief introduction to MEG technology, recent hardware developments (optimized for pediatrics), improved signal processing methods, and technological developments are reviewed. Next, two clinical case studies are presented to provide examples of MEG source localization methods applied to identify epileptogenic foci in pediatrics and compare established and recently developed analysis methods. We conclude that MEG is a unique and powerful imaging method for epilepsy treatment and patient care, increasingly a focal point in medical settings aiming to excel in the treatment of epilepsy both for diagnostics and surgical outcomes with near-future pediatric MEG system also providing optimal clinical assessments in infants and young children.