| Exploding head syndrome | |
|---|---|
| Other names | Episodic cranial sensory shock, snapping of the brain, auditory sleep start |
 | |
| Artistic depiction of flash seen from exploding head syndrome | |
| Specialty | Sleep medicine |
| Symptoms | Hearing loud noises when falling asleep or waking up |
| Duration | Short |
| Causes | Unknown |
| Differential diagnosis | Nocturnal epilepsy, hypnic headaches, nightmare disorder, PTSD |
| Treatment | Reassurance, clomipramine, calcium channel blockers |
| Prognosis | Good |
| Frequency | ~10% of people |
Exploding head syndrome (EHS) is a condition in which a person experiences unreal noises that are loud and of short duration when falling asleep or waking up. The noise may be frightening, typically occurs only occasionally, and is not a serious health concern. People may also experience a flash of light. Pain is typically absent.
The cause is unknown. Potential explanations include ear problems, temporal lobe seizure, nerve dysfunction, or specific genetic changes. Potential risk factors include psychological stress. It is classified as a sleep disorder or headache disorder. People often go undiagnosed.
There is no high quality evidence to support treatment. Reassurance may be sufficient. Clomipramine and calcium channel blockers have been tried. While the frequency of the condition is not well studied, some have estimated that it occurs in about 10% of people. Females are reportedly more commonly affected. The condition was initially described at least as early as 1876. The current name came into use in 1988.
Signs and symptoms
Individuals
with exploding head syndrome hear or experience loud imagined noises as
they are falling asleep or waking up, have a strong, often frightened
emotional reaction to the sound, and do not report significant pain;
around 10% of people also experience visual disturbances like perceiving
visual static, lightning, or flashes of light. Some people may also
experience heat, strange feelings in their torso, or a feeling of
electrical tinglings that ascends to the head before the auditory
hallucinations occur. With the heightened arousal, people experience distress, confusion, myoclonic jerks, tachycardia,
sweating, and the sensation that feels as if they have stopped
breathing and have to make a deliberate effort to breathe again.
The pattern of the auditory hallucinations is variable. Some
people report having a total of two or four attacks followed by a
prolonged or total remission, having attacks over the course of a few
weeks or months before the attacks spontaneously disappear, or the
attacks may even recur irregularly every few days, weeks, or months for
much of a lifetime.
Some individuals hold the belief that EHS episodes are not
natural events, but are the effects of directed energy weapons which
create an auditory effect.[9] Thus, EHS has been worked into conspiracy theories, but there is no scientific evidence that EHS has non-natural origins.
Causes
The cause of EHS is unknown. A number of hypotheses have been put forth with the most common being dysfunction of the reticular formation in the brainstem responsible for transition between waking and sleeping.
Other theories into causes of EHS include:
- Minor seizures affecting the temporal lobe
- Ear dysfunctions, including sudden shifts in middle ear components or the Eustachian tube, or a rupture of the membranous labyrinth or labyrinthine fistula
- Stress and anxiety
- Variable and broken sleep, associated with a decline in delta sleep
- Antidepressant discontinuation syndrome
- Temporary calcium channel dysfunction.
- PTSD
Diagnosis
Classification
Exploding head syndrome is classified under other parasomnias by the 2014 International Classification of Sleep Disorders (ICSD, 3rd.Ed.) and is an unusual type of auditory hallucination in that it occurs in people who are not fully awake.
According to ICD-10 and DSM-5 EHS is classified as either another
specified sleep-wake disorder (codes:780.59 or G47.8) or unspecified
sleep-wake disorder (codes: 780.59 or G47.9).
Treatment
As of 2018,
no clinical trials had been conducted to determine what treatments are
safe and effective; a few case reports had been published describing
treatment of small numbers of people (two to twelve per report) with clomipramine, flunarizine, nifedipine, topiramate, carbamazepine. Studies suggest that education and reassurance can reduce the frequency of EHS episodes. There is some evidence that individuals with EHS rarely report episodes to medical professionals.
Epidemiology
There have not been sufficient studies to make conclusive statements about how common or who is most often affected.
One study found that 14% of a sample of undergrads reported at least
one episode over the course of their lives, with higher rates in those
who also have sleep paralysis.
History
Case reports of EHS have been published since at least 1876, which Silas Weir Mitchell described as "sensory discharges" in a patient.
However, it has been suggested that the earliest written account of EHS
was described in the biography of the French philosopher René Descartes in 1691. The phrase "snapping of the brain" was coined in 1920 by the British physician and psychiatrist Robert Armstrong-Jones.
A detailed description of the syndrome and the name "exploding head
syndrome" was given by British neurologist John M. S. Pearce in 1989. More recently, Peter Goadsby and Brian Sharpless have proposed renaming EHS "episodic cranial sensory shock" as it describes the symptoms more accurately (including the non-auditory elements) and better attributes to Mitchell.
