Spatio-temporal Imaging of Cortical Desynchronization in Migraine Visual Aura: A Magnetoencephalography Case Study
Article first published online: 12 MAR 2004
Headache: The Journal of Head and Face Pain
Volume 44, Issue 3, pages 204–208, March 2004
How to Cite
Hall, S. D., Barnes, G. R., Hillebrand, A., Furlong, P. L., Singh, K. D. and Holliday, I. E. (2004), Spatio-temporal Imaging of Cortical Desynchronization in Migraine Visual Aura: A Magnetoencephalography Case Study. Headache: The Journal of Head and Face Pain, 44: 204–208. doi: 10.1111/j.1526-4610.2004.04048.x
- Issue published online: 12 MAR 2004
- Article first published online: 12 MAR 2004
- Accepted for publication November 10, 2003.
- scintillating scotoma;
- visual aura;
- cortical oscillations;
- event-related desynchronization
Objective.—To determine cortical oscillatory changes involved in migraine visual aura using magnetoencephalography (MEG).
Background.—Visual aura in the form of scintillating scotoma precedes migraine in many cases. The involvement of cortical spreading depression within striate and extra-striate cortical areas is implicated in the generation of the disturbance, but the details of its progression, the effects on cortical oscillations, and the mechanisms of aura generation are unclear.
Methods.—We used MEG to directly image changes in cortical oscillatory power during an episode of scintillating scotoma in a patient who experiences aura without subsequent migraine headache. Using the synthetic aperture magnetometry method of MEG source imaging, focal changes in cortical oscillatory power were observed over a 20-minute period and visualized in coregistration with the patient's magnetic resonance image.
Results.—Alpha band desynchronization in both the left extra-striate and temporal cortex persisted for the duration of reported visual disturbance, terminating abruptly upon disappearance of scintillations. Gamma frequency desynchronization in the left temporal lobe continued for 8 to 10 minutes following the reported end of aura.
Conclusions.—Observations implicate the extra-striate and temporal cortex in migraine visual aura and suggest involvement of alpha desynchronization in generation of phosphenes and gamma desynchronization in sustained inhibition of visual function.