An Often Misunderstood and Frightening Parasomnia
Exploding Head Syndrome (EHS) is a psychological condition whereby individuals are abruptly awakened by what they perceive as blaring, ear-piercing noises, such as the sound of a sonic boom, screaming people, gunfire, or explosion.
The condition is considered a hypnagogic auditory phenomenon, where sounds are heard "in the head" without auditory stimulus soon after an afflicted individual falls asleep. The harsh, frightening sounds can last for just a few seconds to a few minutes in length.
Research Reveals New Insights
While thought to be a rare parasomnia, Washington State University researchers have found that an unexpectedly high percentage of young people experience the condition.
Brian Sharpless, a Washington State University assistant professor and director of the university psychology clinic, found that nearly one in five – 18 percent – of college students interviewed for the study said they had experienced EHS at least once.
Sharpless noted the condition was so bad for some that it significantly impacted their lives.
The study is the largest of its kind, with 211 undergraduate students interviewed by psychologists or graduate students trained in recognizing the symptoms of ESD and isolated sleep paralysis. The results appear online in the Journal of Sleep Research.
More Widespread Than Previously Thought
Until now, based on smaller and less rigorous studies, some researchers have hypothesized that EHS is found mostly in people older than 50.
"I didn't believe the clinical lore that exploding head syndrome would only occur in people in their 50s," said Sharpless. "That didn't make a lot of biological sense to me."
He started to think EHS was more widespread when he reviewed the scientific literature on the disorder for the journal Sleep Medicine Reviews. In that report, he concluded the disorder was a largely overlooked phenomenon that warranted a deeper look.
Researchers suspect EHS stems from problems with the brain shutting down. When the brain goes to sleep, it acts like a computer shutting down, with motor, auditory and visual neurons turning off in stages. But instead of shutting down properly, the auditory neurons are thought to fire all at once, Sharpless said.
"That's why you get these crazy-loud noises that you can't explain, and they're not actual noises in your environment," he said.
The same part of the brain, the brain stem's reticular formation, appears to be involved in isolated sleep paralysis as well, which could account for why some people experience both maladies, he said.
The occurrences can be terrifying. EHS can lead some people to believe that they're going insane, experiencing a seizure or having a subarachnoid hemorrhage. Some individuals who experience episodes are so unnerved by the experience that they don't tell anyone, which can compound the impact of the condition.
Link to Sleep Paralysis
The research also found that approximately thirty percent of those with EHS also experienced bouts with sleep paralysis, a condition in which an individual is feels frozen and momentarily cannot move or talk when waking up.
The inability to move may last for a number of seconds or minutes. Sleep paralysis typically occurs during the REM stage of sleep, when dreams occur.
Treating Exploding Head Syndrome
Neither EHS nor sleep paralysis disorder have a well-established treatment. According to Sharpless, the minority of individuals who are affected have no well-articulated or empirically supported treatments are available – and very few clinicians or researchers assess for it, according to Sharpless.
Yet, researchers have tried different drugs that may be promising.
"One of the drugs they gave for EPS actually didn't make the noises go away," he said. "It just turned the volume down." But many people are at least relieved to get a proper diagnosis and learn that they aren't alone.