Exploding head syndrome
|Exploding head syndrome|
|Classification and external resources|
Exploding head syndrome (EHS), alternately termed episodic cranial sensory shock, is a benign condition in which a person hears loud "imagined" noises (such as a bomb exploding, a gunshot, or a cymbal crash) or experiences an explosive feeling[clarification needed] when falling asleep or waking up. These noises have a sudden onset, are typically brief in duration, and are often jarring for the person. Neither the cause nor the mechanism is known. Though harmless in and of themselves, episodes have been known to create distress or impairment in the lives of individuals.
Exploding head syndrome is classified as a parasomnia and a sleep-related dissociative disorder by the 2005 International Classification of Sleep Disorders and is an unusual type of auditory hallucination in that it occurs in people who are not fully awake.
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 believe that EHS episodes are not natural events, but are the effects of directed energy weapons which create an auditory effect. Thus, EHS has been worked into conspiracy theories, but there is no scientific evidence that EHS has non-natural origins.
The cause of EHS is unknown, but a number of hypotheses have been put forth (summarized in ). The most prevalent theory on the cause of EHS is 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.
As of 2014, 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, methylphenidate. 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.
There have not been sufficient studies conducted to make conclusive statements about prevalence nor who tends to suffer EHS. One study found that 13.5% of a sample of undergrads reported at least one episode over the course of their lives, with higher rates in those also suffering from sleep paralysis.
Case reports of EHS have been published since at least 1876, which Silas Weir Mitchell described as "sensory discharges" in a patient. 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.
- Goadsby, Peter J.; Sharpless, Brian A. (2016-11-01). "Exploding head syndrome, snapping of the brain or episodic cranial sensory shock?". J Neurol Neurosurg Psychiatry. 87 (11): 1259–1260. doi:10.1136/jnnp-2015-312617. ISSN 0022-3050. PMID 26833175.
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