Exploding Head Syndrome - a banger blogpost

Imagine you are about to doze off to sleep when a loud bang echoes inside your head. It sounds like an explosion, a sudden clap of thunder, or a firework going off, but no one else can hear it.

Exploding Head Syndrome is a puzzling and rare sleep disturbance. People with this condition will hear loud bangs or crashes or even see flashes of light just as they drift off or wake up.

Despite its dramatic name, this condition does not cause physical harm, but the fear and confusion it provokes can interfere with sleep quality and daily life.

Many people have never heard of this condition, and research into its causes and prevalence remains limited.

The study
A recent study examined a large group of Japanese government employees as part of the larger "NinjaSleep Study".

More than 1800 participants answered detailed questions about their sleep, mental health, and past medical conditions.

Among them, 46 (2.49%) reported experiencing sudden noises or sensations of explosions, with 23 (1.25%) meeting the diagnostic criteria for Exploding Head Syndrome. As it turns out, Exploding Head Syndrome is not that rare ...

The study found that those experiencing Exploding Head Syndrome were more likely to suffer from insomnia. While the exact relationship between these conditions is still uncertain, the findings suggest that sleep quality may play a role in triggering these episodes.

What we know about the disorder
Despite its dramatic name, Exploding Head Syndrome is not linked to brain damage or external sounds. Instead, it is believed to result from brief disruptions in the brain’s sleep mechanisms.

Some science indicates that as the brain shuts down for sleep, certain neural pathways misfire, creating the illusion of an explosion or bright flash. Researchers have found potential links between this syndrome and other sleep disturbances, as well as mental health conditions such as anxiety and depression.

Here are some of the hypotheses about the syndrome:

1. Brainstem misfiring and sleep-wake problems
Your brainstem's "reticular formation" helps control when you wake up and fall asleep. It controls transitions between wakefulness and sleep by regulating sensory processing and consciousness. In Exploding Head Syndrome, part of the brainstem may misfire during sleep onset or awakening, leading to abnormal sensory experiences. This could lead to sudden, loud noises that aren’t really there.

2. Sleep-transition glitches
When we fall asleep, the brain gradually "shuts down" different senses. This process might not work smoothly, especially during REM sleep (when we dream). Instead of turning off unnecessary sounds, the brain might suddenly create a loud noise out of nowhere.

3. Overactive brain signals
Some scientists believe that Exploding Brain Syndrome happens because certain brain areas are too active, almost like a mini electrical storm in the brain. This is similar to what happens in epilepsy or auditory hallucinations, where the brain can also hear things that aren’t real.

4. Hearing center malfunction
The temporal lobes in your brain help process sound. If this part of the brain isn’t working properly, it might randomly create the illusion of a loud noise. Some researchers believe abnormal electrical activity in this region could be responsible for the explosions.

5. Stress and chemical imbalances
Your brain relies on certain chemicals, like serotonin and GABA, to regulate sleep and relaxation. If these chemicals are off balance, the brain might become more prone to EHS. The body’s stress system could also play a role, making the brain more sensitive to these sudden sound bursts.

Fewer explosions please
Understanding Exploding Head Syndrome is crucial because sleep plays a vital role in mental and physical health.

Some scientists are considering advanced sleep tracking technologies, such as brain wave monitoring, to identify patterns in affected individuals. Others emphasize the need for a standard definition of the disorder to ensure consistency in future studies.

While Exploding Head Syndrome remains a mystery in many ways, increasing awareness and scientific investigation could help people struggling with this strange sleep phenomenon.

About the scientific paper:

First author:  Uyanga Tsovoosed, Japan
Published: Sleep, January 2025
Link to paper: https://academic.oup.com/sleep/advance-article/doi/10.1093/sleep/zsaf007/7951333