Is There an Anatomic Basis for Exploding Head Syndrome?

Image courtesy of David Castillo Dominici at FreeDigitalPhotos.net

Exploding head syndrome is defined as "a sudden loud noise or an exploding sensation in the head, either at the wake-sleep transition or upon waking at night, and abrupt arousal or fright after the event." Exploding head syndrome or EHS is thought to be due to a neurologic or psychiatric disorder, but I've always wondered if there's actually an anatomic explanation that can be physically corrected resulting in cure.

I probably see at least one patient a year with this same constellation of symptoms... exploding or loud clicking or gunshot-like "sound" that occurs somewhere in the center of the head that usually occurs right about the moment when they just fall asleep. The real question in EHS is whether this sound is "real" or imagined.

Currently, the thought is that it is imagined... but I don't believe anybody has actually taken the time to truly document if that's the case. It would simply require placing several microphones taped all around the head and hitting the record button before going to bed. Should the sound be "heard," do a playback of all the recordings and see if the microphones picked up anything...

And as it so happens... I've had a handful of patients where they have actually recorded a sound using a variety of devices. And by golly, there is a sound. And boy is it prominent and from an examination standpoint, depressingly brief.

So... if EHS actually has a physical anatomic basis, exactly where is this sound produced?

I have proposed to a few of these patients to undergo a sedated endoscopy. This procedure which I normally perform for snoring and obstructive sleep apnea would seem to be the ideal test to try and find the source of the EHS sound. So far, none have taken me up on this offer due to a few problems:

1) Insurance coverage
2) The sound does not always happen when falling asleep
3) Concern that I may miss it since I may not necessarily be able to hear it if it happens and correlate it with endoscopic findings

To maximize the possibility of a successful sedated endoscopy in order to diagnose the source of the sound production...

I am publicly requesting any and all patients with EHS to do the following:

1) Document whether a sound is truly produced (by taping numerous small microphones all around the head)
2) Determine which microphone taped in what location obtained the clearest and loudest recording of the sound
3) Go see an ENT who performs sedated endoscopy

From my (ENT) side when performing a sedated endoscopy to evaluate EHS, I would place the endoscope in the nasopharynx region which is as close to a central head location as possible. A microphone would be placed where the patient states obtained the clearest recording of "the sound."

An anesthesiologist would than very slowly and gently put the patient to sleep using propofol. With the microphone hooked up to a speaker set to the highest volume, everybody in the room would listen for "the sound" while I will be examining the nasopharynx for anything that occurs at the same time that may explain what produced the sound.

My thought is that the sound is produced by the soft palate "clicking" against the back wall of the throat. Also possible is that the tongue clicks against the roof of the mouth or against the back wall of the throat or epiglottis.

However, I see these patients so rarely, that I'm not sure such interventions/testing is feasible/possible even if a sedated examination was performed.

First, it would take many sleep/wake cycles to look in each possible anatomic location. Each sleep/wake cycle may not necessarily produce "the sound." There is a risk/cost with repeated anesthesia all performed in one sitting.

All these issues/problems would need to be discussed with the patient, but by golly, wouldn't it be wonderful if "the sound" was documented both on microphone with corresponding endoscopic explanation for "the sound"???

As such, an experiment of sorts can be performed by such patients at home when they start experiencing EHS with documented sound production. My proposal would be to:

1) Wear an oral appliance that may change the jaw, tongue, palate dynamics to such a point that it may stop EHS. If a patient is a mouth-breather, wear a chin strap to enforce mouth-closure which does help move the tongue into a more normal position.
2) Use a CPAP machine at the lowest possible setting to prevent the soft palate from abutting the back wall of the throat.

Anybody have any thoughts???