Have you ever been woken up by a loud and startling noise, felt like an explosion had taken place inside your head, and then found that all was quiet and still around you? If so, you might have exploding head syndrome.

Obviously, in this situation your head doesn't really explode. The syndrome is named after the uncomfortable sensation that some people feel, sometimes as they are in the process of falling asleep.

Researchers at Washington State University looked into the phenomenon after realizing how little information had been collected on it. The university researchers interviewed 211 undergraduate students and discovered that 18 percent, or roughly one out of five students, had experienced loud noises inside their heads. That drastically contradicted previous smaller studies that had suggested that the syndrome was rare and found mostly in people over 50 years old.

“I didn’t believe the clinical lore that it would only occur in people in their 50s,” said Brian Sharpless, an assistant professor at Washington State University and director of the psychology clinic. “That didn’t make a lot of biological sense to me.”

As if exploding head syndrome wasn’t strange enough, about one-third of the students who experienced it also had gone through isolated sleep paralysis, another bizarre sensation during which a person cannot move or speak while waking up. Those who suffer from this condition sometimes dream with their eyes open. The researchers believe that the reason those who experience exploding head syndrome are more likely to experience isolated sleep paralysis is because both disorders are tied to the brainstem’s reticular formation.

Since exploding head syndrome is prone to happen when someone is falling asleep, the researchers hypothesize that the jarring experience is connected to the brain shutting down. Sharpless compares the brain to a computer shutting down with motor, auditory and visual neurons powering off one by one. Rather than turning off like they are supposed to, the auditory neurons are believed to fire at the same time, causing the loud sounds.

“That’s why you get these crazy-loud noises that you can’t explain, and they’re not actual noises in your environment,” he added.

Real or not, the sudden burst of sound can be quite alarming. Some who are afflicted believe that they have experienced a seizure or bleeding in the brain.

Explaining aliens and other oddities

Sharpless also believes that certain conspiracy theories (think alien abductions) can be tied to the disorder.

“Some people have worked these scary experiences into conspiracy theories and mistakenly believe the episodes are caused by some sort of directed-energy weapon,” said Sharpless.

Those with isolated sleep paralysis may believe they are seeing real things since their eyes are open, even though they are just experiencing a waking dream. Sharpless thinks that could explain those who were certain they saw otherworldly beings such as witches or demons during the Middle Ages.

According to the researchers, due to the fear and uncertainty that surrounds these disorders, some people don’t even tell their spouse.

At the moment there is no cure. “Unfortunately for this minority of individuals, no well-articulated or empirically supported treatments are available, and very few clinicians or researchers assess for it,” explained Sharpless.

Treatments or not, many found the simple act of having a diagnosis to be a relief. “There’s the possibility that just being able to recognize it and not be afraid of it can make it better.”

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What is exploding head syndrome?
Odd sensation is relatively common and may be linked to sleep paralysis and open-eyed dreaming.