Headaches: Cluster - Risk Factors

Head Injury

Head injury may also increase the risk of cluster headaches. In one study, over 13% of patients reported a history of a head injury that caused loss of consciousness and nearly a quarter had experienced a head injury without loss of consciousness.

Sleep Apnea and Other Sleep Disorders

Cluster headaches tend occur during specific sleep stages and have been associated with several sleep disorders, including narcolepsy, insomnia, and sleep apnea.

Sleep apnea, a disorder in which a person stops breathing during the night, perhaps hundreds of times, is of particular interest. Studies have reported sleep apnea in 30% to 80% of cluster headache patients. One study suggested that in some people apneas may trigger cluster headache during the first few hours of sleep, making patients susceptible to follow-up attacks during the following midday to afternoon periods. Treating patients who have both disorders with a device called CPAP, which opens the airways, may help improve both conditions. Note: Although sleep apnea inevitably causes daytime sleepiness, most people who have it are not even aware of it.

Cluster Headache Triggers

The following are some conditions and substances that might trigger cluster attacks.

Alcohol.
High altitudes (trekking, air travel).
Bright light (including sunlight).
Exertion.
Heat (hot weather, hot baths).
Foods high in nitrites (such as bacon and preserved meats).
Certain medications (including those that cause blood vessel dilation, such as nitroglycerin, and various blood pressure medications).
Cocaine.

Triggers usually have an effect only during active cluster cycles. When the disorder is in remission, such triggers rarely set off the headaches. Of interest, however, was a case in which a man's cluster headaches were triggered only during coughing and sneezing. Treatment with indomethacin was effective in preventing the headaches.