No microstructural white matter alterations in chronic and episodic migraineurs: a case-control diffusion tensor magnetic resonance imaging study.

BACKGROUND: In patients with episodic migraine (EM), diffusion tensor imaging (DTI) revealed microstructural white matter alterations in various brain regions related to pain processing. Some of these changes were correlated with migraine duration and attack frequency, suggesting that migraine is a progressive disease with proceeding structural alterations of the brain. This study aimed to identify possible microstructural white matter alterations in patients with chronic migraine (CM) using DTI. We hypothesized that alterations in DTI are more pronounced in patients with CM compared with EM.
METHODS: Individually, age- and sex-matched subjects with CM without aura, EM without aura, and healthy controls (n = 21 per group) underwent conventional head magnetic resonance imaging and DTI imaging in a 3T MRI scanner and were included in analysis. DTI data were analyzed using a tract-based spatial statistics approach. Fractional anisotropy (FA), mean diffusivity, radial diffusivity, and axial diffusivity were compared between subjects with CM and EM, CM and controls, EM and controls, as well as between all subjects with migraine (EM + CM) and controls.
RESULTS: In chronic migraineurs (mean age 49 ± 7.5 years), we did not find any statistically significant difference (P < .05, threshold-free cluster enhancement corrected for multiple comparison) in DTI-derived parameters in comparison with episodic migraineurs (FA: P > .245) and healthy controls (FA: P > .099). In contrast to previous DTI studies, we did not find alterations in DTI-derived indices in subjects with EM compared with healthy controls (FA: P > .486).
CONCLUSIONS: No microstructural white matter changes could be observed in middle-aged chronic and episodic migraineurs using DTI. CM does not seem to be a risk factor for progressive microstructural changes in DTI.