Jarred awakes from a sound sleep by a shotgun blast, a thunderclap... the clash of symbols, a lightning strike or the sound of every door in the house slamming." As with others who have his condition, sufferers of exploding head syndrome (EHS) wake terrified, only to realise the noise was just a figment of their imaginations.
Although no pain is associated with such an event, those afflicted with the malady will awake in "a cold sweat [with] laboured breathing and... a rapid heart rate." Believed to be related to stress, the disorder typically occurs either "just before deep sleep [or] sometimes coming out of deep sleep."
EHS generally happens in clusters "over the course of a few days [and] will then disappear for months — or years — on end." Experts agree that although events can be disturbing, the condition is "entirely benign and [some think] quite common but underreported."
First documented in 1920 as "snapping head syndrome", the condition received more serious attention in 1989 when neurologist J.M.S. Pearce examined the clinical features of 50 patients dealing with the disorder:
[Although] some start in childhood... the commonest age of onset remains middle and old age... The pattern of episodes of explosions is . . . variable. Some report 2 to 4 attacks followed by prolonged or total remission, others have more frequent attacks up to 7 in one night, for several nights each week and may then remit for several months...
Among the symptoms described by patients included flashing lights and "a curious sensation as if they had stopped breathing and had to make a deliberate effort to breathe again — an uncomfortable gasp." Although 10% of those in the study also had a history of migraines and 2% suffered from epilepsy, there was no indication that this sleep disorder was related to these conditions.
In 1991, Sachs & Svanborg made "polygraphic recordings [with] EEG, electrooculograms, and submental electromyograms (DMB)" of six patients with some interesting results:
Five of the six cases who underwent daytime polysomnography slept during parts of the recording in stages 1-2. Only two reported attacks of explosions. One patient had two attacks while she was awake and relaxed... In... her attacks there was... an alerting effect. The other case reported after the recording session that he had experienced an explosion during sleep. According to his EEG, he had not, in fact, slept at all during the recording...[i]
More recently, in a 2010 study to determine the effectiveness of topiramate (an anticonvulsant used to treat seizures), it was noted that the 39 year-old female patient's "mother and daughter have similar symptomatology, raising the possibility that [EHS] may be hereditary."
Concluding that topiramate lessened the intensity of EHS events but did not diminish its frequency, the study's authors noted that other helpful drug therapies have included clonesapam, nifedipine, flunarizine and clomipramnine. Drugs that have been unsuccessful in the treatment of EHS include amitriptyline, doxepin, trimipramine and citalopram.
In 2013, a case study of a 57-year-old man considered and ruled out a variety of potential causes of EHS:
Nocturnal headache syndromes including hypnic headache, cluster headaches, and migraine... usually cause the patient to awaken with an actual headache, which our patient did not have. Similarly, cephalgias [intense headaches] occurring from... space occupying lesions, or obstructive sleep apnea [were not found]... Nocturnal seizures are prone to occur in the non-rapid eye movement sleep, but patients are mostly amnestic about the seizures... our patient had a clear recollection of the events... and with a normal EEG...
The authors of the 2013 study opined that possible explanations for EHS include:
A sudden movement of a middle ear component of the Eustachian tube, or perhaps a brief temporal lobe complex partial seizure (though EEG studies have generally been reported as normal). There is a correlation with stress or extreme fatigue. EHS has been linked to rapid withdrawal from benzodiazepines and selective serotonin reuptake inhibitors (which our patient was not taking).
- According to the Centres for Disease Control (CDC), between 50 and 70 million adults in the United States suffer from either a "sleep or wakefulness disorder."
- In a 2009 study of unhealthy and other sleep behaviours, of the nearly 75,000 adults surveyed, over 35% slept less than seven hours each night. More shockingly: "37.9% reported unintentionally falling asleep during the day at least once in the preceding month, and 4.7% reported nodding off or falling asleep while driving at least once in the preceding month."
- It is estimated that "drowsy driving" is the cause of over 1,500 deaths and about 40,000 other injuries each year in the U.S.
Melissa writes for the wildly popular interesting fact website TodayIFoundOut.com. To subscribe to Today I Found Out's "Daily Knowledge" newsletter,click here or like them on Facebook here. You can also check 'em out on YouTube here.