Study Finds Women Migraineurs With Aura Do Not Exhibit Altered Thalamic Volume

The pathophysiology of migraine with aura in women does not involve alteration of thalamic volume, according to a study published in NeuroImage: Clinical.

Migraine with aura presents as attacks of transient neurological symptoms including visual or somatosensory disturbances, followed by head pain. Attacks can also be associated with photo- and phonophobia.

“While the migraine aura symptoms per se are believed to be caused by a slowly propagating wave of gray matter depolarization, so called spreading depolarization (SD), it remains elusive why patients suffering from this disorder apparently are more susceptible to SD and the relation to the subsequent headache and associated symptoms is not clear,” authors wrote.

The thalamus plays a critical role in relaying and modulating sensory information traveling from the periphery to the cortex, and previous research has suggested it could play a role in disease mechanisms of migraine with and without aura. To determine if abnormalities of thalamic nuclei volumes could be identified in a large sample of migraine patients with aura specifically, researchers analyzed MRI data from 311 individuals.

The cross-sectional population-based study included 156 women with migraine with aura, 126 migraine-free matched controls, and 29 migraine aura-free co-twins from the Danish Twin Registry. The MAGeT Brain Algorithm (Method 1) and FreeSurfer-based method (Method 2) were used to assess the volume of the thalamus and its nuclei.

Linear mixed models and visual inspection of data were used to assess relations between migraine aura frequency and thalamic nuclei volumes in patients, while between-group comparisons were corrected for potential effects of age, educational level, body mass index, smoking, alcohol and hypertension.

Researchers found:

• In patients compared with controls, there were no statistically significant volume differences of the thalamic nuclei using Method 1 or Method 2 after correction for multiple comparisons
• Within the patient group, there were no indications of the thalamic nuclei volumes being dependent on the number of migraine aura attacks during the past 12 months or lifetime number of aura attacks
• Within-pair analyses showed no volume differences for any nuclei between patients and co-twins for both methods 1 and 2

“While our results indicate no abnormalities of thalamic volume in migraine patients with aura in general, we cannot rule out that such abnormalities might be present in migraine patients without aura specifically, or more severely affected migraine patients,” authors wrote.

Alteration of thalamic structures could be a consequence of repeated migraine headache attacks; however, no such correlations have been found.

In addition, a subgroup of patients (36.5%) did not experience a migraine attack in the previous year, meaning researchers may have been unable to detect potential structural thalamic abnormalities related to frequent or recent migraine attacks, marking a limitation to the study.

The results obtained in women also cannot be generalized to male patients, authors cautioned.

Reference

Hougaard A, Nielsen SH, Gaist D, et al. Migraine with aura in women is not associated with structural thalamic abnormalities. Neuroimage Clin. Published online July 25, 2020. doi:10.1016/j.nicl.2020.102361