Periaqueductal Gray Matter Dysfunction in Migraine: Cause or the Burden of Illness?

The periaqueductal gray matter (PAG) plays a key role in pain regulation. Researchers studied iron levels in the PAG in patients with episodic migraine (EM) and chronic daily headache (CDH). They used advanced MRI techniques to measure relaxation rates in the PAG, red nucleus, and substantia nigra. The study included 17 patients with EM, 17 with CDH, and 17 normal adults. Results showed that both EM and CDH groups had significantly higher R2' and R2* values compared to normal adults. However, no significant differences were found between EM and CDH groups. Positive correlations were noted between illness duration and R2' values in both groups. Additionally, lower R2' and R2* values were observed in the RN and SN of the CDH group. These findings suggest that iron homeostasis in the PAG is impaired by migraine attacks, pointing to the PAG's potential role in generating migraines. Clinical relevance: This research highlights the PAG's role in migraine development, suggesting new treatment strategies targeting iron homeostasis may benefit patients.