Migraine-related gray matter and white matter changes at a 1-year follow-up evaluation

To assess the longitudinal gray matter (GM) and white matter (WM) changes between repeated observations 1 year apart in a group of the early clinical stage of migraine patients without aura, and to explore the relationship of such structural changes with headache activity, we studied patients newly diagnosed with episodic migraine lasting 8 to 14 weeks. Optimized voxel-based morphometry and tract-based spatial statistical analyses were used to evaluate changes in GM and WM by using 3-dimensional T1-weighted and diffusion-tensor imaging, respectively. At the 1-year follow-up examination, GM reduction was observed in the dorsolateral and medial part of the superior frontal gyrus, orbitofrontal cortex, hippocampus, precuneus, and primary and secondary somatosensory cortices. No significant differences were found in the fractional anisotropy and longitudinal, radial, and mean diffusivity of WM in migraine patients without aura within a year. Negative results were found for the association between changes in headache activity parameters and GM. Our results indicated that the GM and WM changed in different pathophysiological conditions of migraine patients without aura. The WM probably evolves slowly in the course of migraine chronicity.

Our study found early involvement of GM reduction of sensory-discriminative brain regions in the pathologic process of migraine, but the WM did not exhibit significant changes in the same time interval. GM reduction in sensory-discriminative brain regions may characterize the pathophysiological features of migraine patients without aura in its early stage.