'Exploding head syndrome': Real but overlooked sleep disorder

"It's a provocative and understudied phenomenon," said Brian Sharpless, a WSU assistant professor and director of the university psychology clinic, who recently reviewed the scientific literature on the disorder for the journal Sleep Medicine Reviews. "I've worked with some individuals who have it seven times a night, so it can lead to bad clinical consequences as well."

People with the syndrome typically perceive abrupt, loud noises—door slams, fireworks, gunshots—as they are going to sleep or waking up. While harmless, the episodes can be frightening.

"Some people start to become anxious when they go into their bedroom or when they try to go to sleep," said Sharpless. "Daytime sleepiness can be another problem for people."

Some patients report mild pain. Some hear an explosion in one ear, others in both ears, and yet others within their heads. Some also see what looks like lightning or bright flashes.

Researchers do not know how widespread the problem is, but Sharpless is fielding enough reports of people with the disorder that he thinks it is more widespread than presumed. Just this week, a story on the disorder in Britain's Daily Mail prompted several people with the syndrome to contact him.

The term "exploding head syndrome" dates to a 1988 article in Lancet but it was described clinically as "snapping of the brain" in 1920. Silas Weir Mitchell, an American physician, wrote in 1876 of two men who experienced explosive-sounding "sensory discharges."

While the syndrome is recognized in the International Classification of Sleep Disorders, studies using electroencephalogram recordings have only documented the disruptions in periods of relaxed but awake drowsiness.

As with many sleep phenomena, it is largely mysterious.

"In layman's terms, our best guess is that it occurs when the body doesn't shut down for sleep in the correct sequence," said Sharpless. "Instead of shutting down, certain groups of neurons actually get activated and have us perceive the bursts of noise. Behavioral and psychological factors come into play as well, and if you have normally disrupted sleep, the episodes will be more likely to occur."

Judging from the limited scientific literature and available statistics, Sharpless said the syndrome is more common in women than men. Some medical treatments are available for it, but one possible intervention can be simply reassuring a patient that it is not a dangerous condition.