1343 Not Just in Your Head: Recognizing Exploding Head Syndrome as a Sleep Disorder

Abstract Introduction Exploding head syndrome (EHS) is characterized by the perception of a sudden loud noise or explosion in the head that occurs as the patient is falling asleep or waking up, typically associated with fear. The sensation is painless, lasts a few seconds, and may be associated with a flash of light or myoclonic jerk. Report of case(s) A 63-year-old-man with diabetes and hypertension reported hearing loud clapping noises while falling asleep for the last 25 years, occurring 5-6 times weekly. He described the sounds as someone “clapping against the wall”. The sounds occurred only during the transition from wake to sleep. The noises distressed him and made it challenging for him to fall back asleep. He denied any associated pain, visions, or jerking movements. He previously worked at a refinery and worked a rotating shift, but had recently retired. His Epworth Sleepiness Scale was 2. His Insomnia Severity Index was 5. He underwent a polysomnogram with extended electromyography that showed moderate obstructive sleep apnea (OSA) with an apnea-hypopnea index of 22/hr. His brain MRI was normal. Audiologic examination found mild sensorineural hearing loss. He had no history of seizures, headache disorders, or psychiatric conditions. He was diagnosed with EHS. During a follow-up visit 6 months later, he reported that the episodes had reduced to 1-2 times weekly. He had not yet started treatment for his OSA at that time. Conclusion The pathophysiology of EHS remains unknown. EHS is an underrecognized parasomnia, with lifetime prevalence ranging from 10% to over 30%. While frightening, EHS is generally considered to be a benign and self-limited condition. There is currently no established association between EHS and OSA, nor is there a known association between hearing loss and EHS. EHS is most strongly associated with insomnia, sleep paralysis, and dissociative experiences. Treatment includes reassurance about the benign nature of the condition, and addressing sleep quality and insomnia symptoms, as poor sleep and psychological distress are associated with increased EHS frequency. We suspect that retirement from shift work (which improved his sleep) and education about the condition likely contributed to the reduction in his EHS frequency. Support (if any)