Magnetoencephalographic fields from patients with spontaneous and induced migraine aura

We investigate and characterize the magnetoencephalographic waveforms from patients during spontaneous and visually induced migraine aura. Direct curr ent neuromagnetic fields were measured during spontaneous onset of migraine auras in 4 migraine patients, and compared with recordings from 8 migraine -with-aura patients and 6 normal controls during visual stimulation of the occipital cortex. Complex direct current magnetoencephalographic shifts, si milar in waveform, were observed in spontaneous and visually induced migrai ne patients; but not in controls. Two-dimensional inverse imaging showed mu ltiple cortical areas activated in spontaneous and visually induced migrain e aura patients. In normal subjects, activation was. only observed in the p rimary visual cortex. Results support a spreading, depression-like neuroele ctric event occurring during migraine aura that can arise spontaneously or be visually triggered in widespread regions of hyperexcitable occipital cor tex.