The condition is relatively harmless, causing people only to be startled, and it doesn’t seem linked to seizure activity or epilepsy. Owing to the fact it’s both benign and uncommon, it’s not been widely studied and so its cause remains a mystery.
A 48-year-old man was seen in December 2006. For the past several months about three to four times a month, he had been having attacks of a peculiar sensation in the head likened to the noise of an exploding bomb only at night while going off to sleep. The ‘explosion’ would wake him up and disappear completely the moment he woke up.
There was no headache and no associated symptoms such as nausea, vomiting or any visual sensation. For the past 3 months, the frequency of these sensations had increased and had been occurring nearly daily at the time of consultation. The noise occurred only once during every night, after which he could go off to sleep. His past medical history had been unremarkable and he had never suffered from any significant headache problem. General physical and neurological examination had been unremarkable. Magnetic resonance imaging (MRI) of brain with contrast had been normal. He was prescribed Flunarazine 10 mg daily. At 6 months’ follow-up he had much improved and noticed the exploding head symptom only on two occasions.
A 65-year-old man was seen in February 2007. He was hypertensive and diabetic (both well controlled on oral medication) and had been having infrequent attacks of International Headache Society migraine headache (every 2‚Äì4 months) without aura since the age of 15 years. For the past 4 months prior to consultation, every 2‚Äì3 weeks, he had been awakened while going off to sleep only during taking a daytime nap by a sudden exploding (like a bomb bursting) noise in his head lasting for only few moments.
This noise was always accompanied with jerky elevation of his right arm and a queer sensation in the right side of his chest (not arm) and again lasting only momentarily. He felt quite well on waking up and could go off to sleep again. These were never accompanied by any visual flashes and never occurred during sleep at night. These sensations were very different from his migraine headaches, which lasted for several hours and the noises were not accompanied by any nausea or vomiting.
Physical examination was normal and his blood presswure in the clinic was 136/80 mmHg. He had already had a MRI of brain with contrast, MR angiography of brain and two interictal sleep EEG recordings performed before consultation with the author, all of which were normal. A video EEG with daytime sleep recording was performed, but no event could be captured.