Brains of individuals with migraine show dynamic changes over time, in particular, increases and decreases in gray matter volume in frontotemporoparietal areas associated with nociception, according to a study recently published in Neurology. These changes were found to be associated with patients’ clinical characteristics, particularly length and severity of disease.
This cross-sectional, longitudinal study included 73 individuals with episodic migraine and 46 healthy controls age- and sex-matched. Of these, 24 individuals with migraine and 25 controls agreed to follow-up with reexamination in 4 years, which resulted in the migraine group being significantly older at follow-up. The baseline volume of cerebellar gray matter was lower in participants with episodic migraine vs control participants, but frontotemporal lobe gray matter volume was higher in individuals with migraine.
Through the follow-up period, the volume of gray matter in frontotemporoparietal regions increased in participants with migraine, particularly in those who had longer disease duration and higher frequency of migraine attacks at baseline. Participants with migraine also had a reduction in gray matter volume in visual areas, a change that was associated with more acute pain. A higher frequency of attacks at follow-up was associated with both enlarged and diminished nociceptive regions. A decrease in volume of extrastriate visual region gray matter in participants with migraine over the follow-up period showed strong associations with shorter duration of disease and lower frequency of attacks at baseline.
Gray matter volume changes were assessed via a full-brain analysis using SPM12 and a standard linear models, with 3-dimensional T1-weighted and brain T2-weighted scans collected at baseline. Limitations to this study include the fact that 8 and 25 of the patients were using preventative therapy at follow-up and at baseline, respectively, which could have influenced the results.
The researchers concluded that “the migraine brain changes dynamically over time, and different pathophysiologic mechanisms can occur in response to patients’ disease severity. The interaction between predisposing brain traits and experience-dependent responses might vary across different nociceptive and visual areas, thus leading to distinct patterns of longitudinal [gray matter] volume changes.”
Messina R, Rocca MA, Colombo B, et al. Gray matter volume modifications in migraine: A cross-sectional and longitudinal study [published online June 20, 2018]. Neurology. doi: 10.1212/WNL.0000000000005819