Although migraine is defined by the headache and headache associated symptoms, the true beginning of a migraine attack lies in the premonitory phase and to understand the generation of attacks one needs to investigate the phase before headache starts. The premonitory phase of migraine is characterized by a well described complex of symptoms. Its duration, however, is not clearly defined and there are to date no biomarkers to help defining when this phase starts.
Here we used functional magnetic resonance imaging to elucidate the duration of the premonitory phase in spontaneous human migraine attacks. As migraine attacks are hardly predictable and thereby the premonitory phase difficult to catch, we scanned nine patients daily over a minimum period of 30 days using a well-established paradigm for functional MRI of trigeminal nociception.
Seven patients were included in the analysis thus providing cumulative data of 27 spontaneous human migraine attacks including scans before, during and after migraine pain as well as interictal scans. As a response to painful trigeminal stimulation activation of the hypothalamus was present within the last 48 hours before headache onset but not earlier.
Using hypothalamic activation as a potential marker for the premonitory phase of migraine in this unique data set, our data thus corroborate a duration of 48 hours for the premonitory phase of migraine and we suggest to apply this timely criterion in future studies when focussing on this particular phase of the migraine cycle. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.