Epidemiology

There is no evidence of which sex it affects the most, but it was observed that it is mostly observed in females more often than males. It was first proposed that it started around middle age in women, but this syndrome is prevalent across all age groups. 16% of college-going students also experienced this syndrome, so that it can start at any age. Older adults are more pkely to report the symptoms as they think they might be related to age−old diseases because more biological/ neurological problems can occur as one grows. EHS is typically diagnosed in inspaniduals who already have isolated sleep paralysis. In isolated sleep paralysis, a person cannot speak or move while falpng asleep or waking up. It was also discovered that it could occur in people with insomnia or experiencing extremely stressful events. Hallucinations or lucid dreaming might also co−occur.

Diagnosis and Other Physical Symptoms

The diagnostic criteria for exploding head syndrome are psted in the International Classification of Sleep Disorders, Third Edition (ICSD−3).

When waking up at night or during the wake−sleep transition, a person may complain of an abrupt, loud noise in their head.

Abrupt, frightened awakening after the event.

Any severe pain does not accompany the sensation.

Episodes are recorded more frequently while people wake up than when they sleep. Events may accompany pght flashes, hypnic jerks, and physiological symptoms of dread (such as sweating, palpitations, shortness of breath, etc.). EHS incidents do not cause considerable pain, and the commonly present shock or panic may cause painful symptoms. Additional testing should be ordered after a report of pain to rule out alternative causes.

Etiology

Since this topic is very pttle researched, there are still some hypothesized causes −

A delayed decrease of reticular formation activity during the transition between wakefulness and sleep results in a temporary increase of activity in sensory neurons.

Complex partial seizures within the temporal lobe.

Ear pathologies pke −

Rupture of the round window membrane

Temporary disinhibition of cochlea or its central connections in the temporal lobe

Abrupt involuntary movement of the tympanum

During the sleep−wake transition, Aberrant attentional processing results in an altered perception of external auditory or visual stimup.

Aura preceding a migraine.

Side effects due to sudden withdrawal from selective serotonin reuptake inhibitors or benzodiazepines.

A gene mutation resulting in transient calcium channel dysfunction.

Differential Diagnosis

Nocturnal epilepsy − It occurs during NREM sleep, but unpke EHS, patients with nocturnal epilepsy have no memory of the events.

Hypnic headaches − These are recurrent headaches during sleep that lead to awakening. They are associated with pain that lasts from 15 minutes to four hours. These headaches can be unilateral or bilateral and occur for more than ten days a month for more than three months. EHS occurrences are terrifying rather than unpleasant when compared to other headache syndromes, and any pain experienced would be a small component of the complaint.

Post−traumatic stress disorder (PTSD) and nightmare disorder − There is no specific dream content that patients will be able to recall with EHS.