“There’s this sudden crescendo of noise, then a profound and jarring explosion of sound, electrical fizzing and a bright flash in my vision, like someone has lit a spotlight in front of my face.”
That’s how Niels Nielsen describes what it’s like to live with “exploding head syndrome” – an unpleasant and sometimes terrifying sensation. Others describe it as like a bomb going off next to their head as they fall asleep. Sometimes it occurs just once in a lifetime, for others it happens multiple times a night.
The physician Silas Weir Mitchell first described the disorder in 1876, when he described two men who suffered from what he called “sensory discharges” – the men themselves described it as hearing “loud bells” or a “gunshot” that would wake them from sleep. But despite its provocative and intriguing name, there has been relatively little research into the disorder. There's now a theory, however, that the condition and related sleep disturbances may help explain apparently unrelated cultural phenomena, specifically the origins of alien abductions, government conspiracy theories, and supernatural demons.
So what do we know about this nocturnal experience? Well, it may not be as rare as you might think. In a study published last month, 211 students were asked whether they had ever experienced the condition – 18% said yes. However, this sample is probably not reflective of its true prevalence since students are prone to lack of sleep – a factor known to increase the risk of experiencing the phenomenon.
Just how common is exploding head syndrome? (Credit: Thinkstock)
“If you have any sort of sleep disruption like insomnia or jetlag, then you might be more likely to experience the condition,” says Brian Sharpless, assistant professor of psychology at Washington State University, who led the study. “Stress and emotional tension are also associated with an increased occurrence.”
Sudden shut down
Theories about the cause of an exploding head are speculative, says Sharpless. Several ideas have been proposed, including ear disorders and partial epileptic seizures. But the most compelling theory comes from a handful of studies in which people with the condition have had their brain activity monitored overnight. These small studies suggest that there may be a burst of neural activity in the brain that coincides with the reported explosion.
Normally, when we go to sleep our body shuts down and becomes paralysed so that we don’t act out our dreams. During this transition from wake to sleep, the brain usually turns off bit by bit, says Sharpless.
However, in exploding head syndrome, there is a hiccup in the 'reticular formation' – the part of the brain responsible for overseeing this general shut-down – which results in a delay in switching off some areas.
This delay is associated with a suppression of alpha brainwaves that are normally responsible for drowsiness, and a sudden burst of neural activity in the areas of the brain responsible for processing sound. “We think the neurons are all firing at once,” he says, which results in the sensation of an explosion in your head.
Suppression of the brain's alpha waves may partly help explain the condition (Credit: SPL)
“This theory makes sense to me,” says Nielsen. “It has always felt electrical in its nature. The sensation of an explosion is accompanied with a very loud sound in both my ears, as if you’ve crossed two wires in a circuit and zapped them together.”
Sharpless says some people also feel an aura of electrical sensations that moves from the lower torso to the head, immediately before the explosion strikes. “It feels like an electric shock,” says Nielsen. “You can feel the current passing through you.”
While there is no cure-all treatment, antidepressants reduce occurrence, as do relaxation and stress-busting techniques. “You can help a lot just by reassuring a person that they’re not crazy or experiencing symptoms of a tumour or some other brain disorder,” says Sharpless.
Could reports of alien abductions be down to a quirk of the sleepy brain? (Credit: Thinkstock)
But what has this got to do with alien abductions and supernatural beings? Exploding head syndrome is often linked with sleep paralysis – people who experience one often experience the other. Sleep paralysis is another spooky sleep disorder in which you feel like you are awake but you can’t move your body. Sharpless thinks that the two could explain several apparently supernatural events.
Both sleep paralysis and exploding head syndrome appear to share an underlying problem in the transition between wakefulness and sleep. In sleep paralysis, parts of your brain are in REM sleep – the time in which we dream the most – while other parts of your consciousness have woken up. “So you get the body paralysis and the dream content of REM sleep, but you’re conscious,” says Sharpless. “It’s like having a dream while you’re awake. The scary thing is that you hear things and feel things as real as they are during the day, but what’s going on is completely hallucinatory.”
Consider the case of Haruko Matsuda (not her real name), a young Japanese woman, who often experiences sleep paralysis. She described a typical night to Sharpless: “I felt something push on my chest so I opened my eyes. I heard someone yelling… and it sounded like it was coming from right beside my ear,” she said. “I thought it was a ghost or something. It was yelling ‘I’m gonna kill you!’. I couldn’t move, and I was so scared…”
In 1781, Henry Fuseli depicted the idea of a demon sitting on a woman’s chest, in The Nightmare (Credit: Henri Fuseli/Wikipedia)
In the Middle Ages, Matsuda’s symptoms could have been attributed to male or female demons – incubi and succubi – who would sit on people’s chests and seduce them into having sexual intercourse. More recently, people apparently frozen and dazzled during the night have blamed the experience on alien abduction.
Take a look at these supernatural or alien stories, says Sharpless, and sometimes you can see hints of both sleep paralysis and exploding head syndrome. “People can sense these strange explosions in their head, and they may think they’ve had something implanted in their brain. Or they feel this surge of electricity and they think they’ve been shot by some kind of new energy weapon. They can’t move, but hear and see strange things and think they’ve been abducted.”
Nielsen, who is now a psychiatrist, says he has had episodes of exploding head syndrome every few months since he was 10 years old, and has experienced sleep paralysis twice – but his scientific mind helped prevent any anxiety over them. “I’ve always had a tendency to think about things scientifically, so even as a teenager I explained it to myself as ‘oh something electrical is happening in my brain’, without making too much out of it,” he says. “They don’t bother me at all, but if someone already has a tendency to wonder about paranormal things, I can definitely see how they could gravitate towards a supernatural explanation.”
It feels electrical... accompanied by a very loud sound