Background: White matter alterations have been observed in patients with migraine. However, no microstructural white matter alterations have been found particularly in episodic or chronic migraine patients, and there is limited research focused on the comparison between these two groups of migraine patients. Methods: Fifty-one healthy controls, 55 episodic migraine patients and 57 chronic migraine patients were recruited and underwent brain T1-weighted and diffusion-weighted MRI acquisition. Using Tract-Based Spatial Statistics (TBSS), fractional anisotropy, mean diffusivity, radial diffusivity and axial diffusivity were compared between the different groups. On the one hand, all migraine patients were compared against healthy controls. On the other hand, patients from each migraine group were compared between them and also against healthy controls. Correlation analysis between clinical features (duration of migraine in years, time from onset of chronic migraine in months, where applicable, and headache and migraine frequency, where applicable) and Diffusion Tensor Imaging measures was performed. Results: Fifty healthy controls, 54 episodic migraine and 56 chronic migraine patients were finally included in the analysis. Significant decreased axial diffusivity (p < .05 false discovery rate and by number of contrasts corrected) was found in chronic migraine compared to episodic migraine in 38 white matter regions from the Johns Hopkins University ICBM-DTI-81 White-Matter Atlas. Significant positive correlation was found between time from onset of chronic migraine and mean fractional anisotropy in the bilateral external capsule, and negative correlation between time from onset of chronic migraine and mean radial diffusivity in the bilateral external capsule. Conclusions: These findings suggest global white matter structural differences between episodic migraine and chronic migraine. Patients with chronic migraine could present axonal integrity impairment in the first months of chronic migraine with respect to episodic migraine patients. White matter changes after the onset of chronic migraine might reflect a set of maladaptive plastic changes.

Background Headache is a frequent symptoms of coronavirus disease 2019 (COVID-19). Its long-term evolution remains unknown. We aim to evaluate the long-term duration of headache in patients that presented headache during the acute phase of COVID-19. Methods This is a post-hoc multicenter ambisective study including patients from six different third-level hospitals between 1 March and 27 April 2020. Patients completed 9 months of neurological follow-up. Results We included 905 patients. Their median age was 51 (IQR 45–65), 66.5% were female, and 52.7% had a prior history of primary headache. The median duration of headache was 14 (6–39) days; however, the headache persisted after 3 months in 19.0% (95% CI: 16.5–21.8%) and after 9 months in 16.0% (95% confidence interval: 13.7–18.7%). Headache intensity during the acute phase was associated with a more prolonged duration of headache (Hazard ratio 0.655; 95% confidence interval: 0.582–0.737). Conclusion The median duration of headache was 2 weeks, but in approximately a fifth of patients it became persistent and followed a chronic daily pattern.