Microstructural and network abnormalities in headache

The objective of this review is to give an overview of recent advances regarding structural changes and altered neural connectivity associated with chronic headache syndromes, focusing on migraine.

In conjunction with a recent boost of studies investigating exercise dependent neuroplasticity and reorganization of the brain, a number of new findings concerning structural abnormalities in migraine patients have been produced. MRI studies have explored structural changes not only across cohorts (e.g. headache patients and controls) but also longitudinally over time, making use of a variety of tools, such as voxel-based morphometry, cortical thickness analysis and, very recently, connectivity analysis. As certain abnormalities have repeatedly been found in migraineurs, the relation between structural deficits and functional impairment is increasingly a matter of debate.

Owing to novel neuroimaging approaches and evaluation methods, a range of possibilities for exploring brain differences between migraine patients and healthy subjects have become available. These include both regional structural alterations and network connectivity changes. Despite methodological advances, most studies involve still small populations and results are often inconclusive. Future work should clearly involve larger cohorts and combine different techniques to help us better understand the diagnostic implications.