Cluster headache, migraine related to the circadian system

Cluster headaches and migraine were linked to the circadian system, according to data from a meta-analysis and other research.

In 16 studies, cluster headache had a circadian pattern of attacks in 70.5% of 4,953 participants, with a sharp peak between 9 p.m. and 3 a.m. and circannual peaks in the spring and fall, reported Mark Joseph Burish, MD, PhD, of the University of Texas Health Sciences Center at Houston, and colleagues.

Migraine had a circadian pattern of attacks in 50.1% of 5,385 participants in eight studies, with a clear trough between 11 p.m. and 7 a.m. and a circadian peak from April to October, the researchers wrote in Neurology.

“These data suggest that both headache disorders are highly circadian on multiple levels, particularly cluster headaches,” Burish said in a statement.

“This reinforces the importance of the hypothalamus – the area of ​​the brain that houses the primary biological clock – and its role in cluster headache and migraine,” he said. “It also raises the question of the genetics of triggers such as changes in sleep that are known migraine triggers and which are clues to the body’s circadian rhythm.”

The findings also increase the possibility of using circadian rhythm-based treatments for headache disorders, Burish noted. “This could include both circadian-based treatments — like taking medications at certain times of the day — and treatments that cause circadian changes, which some medications can do,” he said. .

While the percentage of patients with a circadian pattern was not as high in migraine as in cluster headache, it was notable in a “disorder for which timing is not considered an important feature” , wrote Burish and his colleagues.

The chronotype was highly variable in cluster headaches and migraines. Cluster headache was associated with lower melatonin levels and higher cortisol levels compared to controls. It was also associated with two main circadian genes, CLOCK And REV-ERBα. Five of the nine cluster headache susceptibility genes were clock-gated genes (CCGs) that have a circadian expression pattern.

Migraine patients also had lower urinary melatonin levels, which decreased even more during an attack. Migraine was associated with two main circadian genes, CK1δ And RORαand 110 of 168 migraine susceptibility genes were GCCs.

A better understanding of the chronobiological factors at play in cluster headaches and migraine can influence treatment approaches, said Heidi Sutherland, PhD, and Lyn Griffiths, PhD, both of Queensland University of Technology in Australia. in an accompaniment editorial.

Interventions known to regulate sleep — such as melatonin or cognitive behavioral therapy — may be helpful for some patients susceptible to circadian misalignment or sleep disorders, the editorialists noted. Additionally, treating comorbidities that cause sleep disturbances, such as insomnia, can help manage headaches. Moreover, the chronobiological potential effects headaches and migraine medications should also be considered, Sutherland and Griffiths suggested.

The observation of circadian features of cluster headache “may not be surprising” in that it confirmed previous research, the researchers noted. “However, migraine has distinct lines of research that suggest it is also strongly associated with the circadian system,” observed Burish and co-authors. Many common migraine triggers — bright light, exercise, skipping meals, and sleep-wake changes like lack of sleep and oversleeping — are also variables that can act as circadian time cues, they pointed out.

The researchers assessed all available studies on cluster headache and migraine that contained information on the timing of headaches during the day and over the year, and performed a separate analysis of association studies. at the genome level.

One limitation was that many studies failed to define what a “circadian pattern” was, the researchers acknowledged. Some did not report medication, other disorders such as bipolar disorder or circadian rhythm issues, including shift work, they added.