Headaches and Circadian Rhythms

Researchers recently completed a meta-analysis of 72 headache studies and concluded that some cluster and migraine headaches are linked to a patient's circadian rhythm.  Circadian rhythms are roughly 24-hour physiological cycles, including sleep-wake patterns, hormone secretion, body temperature, and other biological functions.  These cycles occur in all lifeforms - from bacteria, plants, and animals to humans.  A human's internal circadian clock affects metabolic homeostasis and higher-order functions such that there are peak times every day for certain activities.  Thus, when the circadian rhythm is disrupted or interrupted, a patient's risk for a wide range of diseases increases.  

"Cluster headache is known to be circadian, but it was surprising how circadian migraine is," said Dr. Mark Joseph Burish, the study's lead author and the director of the Will Erwin Headache Research Center at University of Texas Health Science Center in Houston.  

Cluster headaches are a rare type of headache that can cause bursts of intense pain around an eye.  Each burst lasts for about 15 minutes, but an attack can last between one and three hours.  These attacks sometimes occur at the same time of day for up to one month at a time.  Other symptoms can also include watering of the eye, drooping eyelid, and a stuffy nose.  When it came to genetic predisposition, the studies showed that five of the nine genes associated with cluster headaches were also involved in regulating circadian rhythms.  

Migraine is a type of headache characterized by recurrent attacks of moderate to severe throbbing and pulsating pain on one side of the head; symptoms throughout the four phases of a migraine can also include nausea, vertigo, and sensitivity to light, sound, touch, or movement.  Untreated migraine attacks can last from 4 to 72 hours.  Many genes are associated with risk for migraine, and the study found 110 of the 168 genes were also tied to circadian rhythm.

In addition to circadian rhythm, the meta-analysis study also focused on two hormones: cortisol and melatonin.  "Circadian rhythms are driven by hormones," said Dr. Narayan Kissoon, a neurologist at the Mayo Clinic in Rochester, Minnesota, who specializes in headache medicine.  The hypothalamus, the area of the brain that primarily controls the biological clock, is linked to the glands that produce melatonin - which signals when it is time to sleep - and cortisol - the body's cue that it should be awake.  The scientists found that people who get migraines often produce less melatonin than people who don't get these headaches, and produce even less during a migraine attack.  People with cluster headaches had both higher cortisol levels and lower melatonin levels.

"These results raise the potential for using circadian-based treatments for headache disorders," Dr. Burish said.  He added, "This could include both treatments based on the circadian rhythm (such as taking medications at certain times of the day) and treatments that cause circadian changes, which certain medications can do."

Some things you can do to help regulate your circadian rhythm, and maybe help reduce cluster or migraine headaches, are nail down your sleep routine (go to bed and wake up at the same time each day), don't use screens right before bed, get some sunshine every day (in the morning whenever possible), don't consume caffeine in the afternoon, perform calming activities before bedtime (such as stretching or reading), and prepare for time changes or jet lag.

It is important to note that while circadian rhythms can contribute to headaches, there are many other factors involved, including genetics, environmental triggers, stress, and underlying health conditions.  Managing headaches often involves a comprehensive approach that addresses multiple factors, including sleep hygiene, stress management, trigger identification, and appropriate medical treatment.  

Headache pain, even when severe, usually is not the result of an underlying disease.  But headaches can occasionally indicate a serious underlying medical condition, so please talk with your doctor.  Even if you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.