There is a transient pathologic state with atypical thalamo-cortical connectivity in patients with migraine, a new study found. Researchers investigated dynamic functional network connectivity (dFNC) of the migraine brain in 89 patients with interictal migraine and 70 healthy controls. Relationships between clinical symptoms and abnormal dFNC were evaluated. Among the findings:
- 5 dFNC brain states were identified to characterize and compare dynamic functional connectivity patterns.
- Migraineurs spent more time in a strongly interconnected between-network state, but less time in a sparsely connected state.
- Abnormal posterior thalamus dFNC with the visual cortex and the precuneus were significantly correlated with headache frequency of migraine.
Tu Y, et al. Abnormal thalamo-cortical network dynamics in migraine. [Published online ahead of print May 10, 2019]. Neurology. doi: 10.1212/WNL.0000000000007607.
One of the areas in which there has been the most progress for understanding the pathophysiology of migraine is functional imaging. A seminal N=1 study by Schulte and May (Brain 2016: 139:1987–1993) of one woman receiving functional MRI scanning every morning for one month demonstrated hypothalamic activation prior to each of 3 migraine attacks, and alteration of connectivity between the hypothalamus and the dorsal pons.They noted that the “hypothalamus shows altered functional coupling with the spinal trigeminal nuclei and dorsal rostral pons during the preictal day and the pain phase of the migraine attacks” and speculated whether the real driver of attacks are these the functional changes in hypothalamo–brainstem connectivity. In the current study, thalamo-cortico-thalamo connectivity is noted to be different in migraineurs, along with cortical to cortical alterations. Thus, the pain matrix and its connectivity with the cortex appear integral to either migraine genesis or processing.
-Stewart J. Tepper, MD, FAHS, Professor of Neurology, Geisel School of Medicine at Dartmouth, Director, Dartmouth Headache Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH