Exploding Head Syndrome – A puzzling parasomnia: A literature review

Although inadequate sleep among young people is well documented in the literature, anomalous sleep experiences, such as the parasomnia termed exploding head syndrome (EHS), have received little empirical attention. The current study examined the association of sleep quality, symptoms of psychological distress and other unusual sleep experiences with EHS in a sample of young adults (n=135, age M=21.77, SD=2.08). We also aimed to account for the possible effect of participant chronotype on sleep experiences. The lifetime prevalence of EHS among participants was 20.0%. Three-quarters (75.6%) of participants reported poor quality sleep according to the Pittsburgh Sleep Quality Index (PSQI). Univariate analysis showed that participants with a lifetime prevalence of EHS experienced more symptoms of anxiety and poorer sleep quality; age, gender and symptoms of depression were not significantly related to EHS. Parasomnias (OR [95% CI]=1.62 [1.02-2.57], p=.040) and action-related sleep disorders (OR [95% CI]=1.87 [1.09-3.20], p=.023) were associated with lifetime experience of EHS in a logistic regression analysis. Chronotype did not significantly impact mood, sleep quality or presence of EHS. Results suggest that EHS is more common in young people than previously considered and ought to be examined in conjunction with the presence of other unusual sleep disorders. This study provides valuable insight into young peoples' sleep experiences and key factors associated with EHS.

Exploding head syndrome (EHS) is a rare sensory parasomnia and rarely reported in China, leading to serious misdiagnosis, mistreatment, and unnecessary testing. A detailed collection of clinical symptoms and longterm polysomnography-electroencephalography monitoring is very important for diagnosis and differential diagnosis of EHS. We diagnosed a patient with EHS according to the International classification of sleep disorders, third edition diagnostic criteria. The electro-clinical feature of the patient and relevant references were analyzed in order to improve the understanding of EHS, meanwhile to prevent unnecessary testing and avoid misdiagnosis and mistreatment. Key words: Exploding head syndrome; Sleep disorders; Parasomnia; Electroencephalography; Polysomnography

Exploding Head Syndrome (EHS) is a rare parasomnia characterised by the perception of loud, abrupt auditory hallucinations during sleep-wake transitions. Even though EHS is not associated with any physical pathology, it may cause substantial sleep disturbances and interruptions. To address these questions, the present narrative review synthesises the current knowledge and consensus on the nature of EHS, including its symptoms and possible causes, existing classification systems, and available interventions. Other frequent complaints include rhythmic noises in the ears, difficulty seeing and somatic sensations, such as electrical buzzing in the head. Stress or anxiety may potentially precede an episode, and dysfunction in the brainstem reticular formation and mild temporal lobe seizures have been suggested as possible neurological causes. EHS falls under the category of parasomnias within the International Classification of Sleep Disorders Third edition (ICSD-3) and is classified as an unspecified sleep-wake disorder under the Diagnostic and Statistical Manual of Mental Disorders Fifth edition (DSM-5). Current intervention strategies are still scarce; while topiramate has been shown to lessen the intensity of symptoms, no trials on this possibility have been conducted so far. Education and reassurance may be useful in alleviating these symptoms. More studies are required to increase knowledge about the underlying processes and to establish specific therapeutic strategies. The present review alerts readers to the growing evidence for EHS, which remains a condition that is not frequently identified, and urges investigators to conduct randomised controlled therapeutic trials.

Exploding Head Syndrome (EHS) attacks are characterized by perception of sudden loud banging noises, occasionally accompanied by the sensation of a flash of light. Although these attacks themselves are usually not painful, it is reported that EHS attacks may precede migraine as auras. EHS is classified as a type of parasomnia in the International Classification of Sleep Disorders (ICSD) 3rd edition and its pathophysiology is still unclear. We describe the polysomnography (PSG) characteristics of EHS patients with special emphasis on respiratory events that were followed by EHS attacks. The subjects were consecutive 20,926 patients who presented sleep and/or wake problems at our sleep center between April 1998 and March 2013. The diagnosis of EHS was based on ICSD-3 criteria. During PSG, we instructed them to ring a bell when they noticed an attack (heard a sound). We found 5 cases (0.17%) with EHS. The mean age (2 men and 3 women) was 64.8 ± 16.4 years. Three of them had otorhinolaryngologic diseases (sudden hearing loss, deflected nasal septum and sinusitis). All five subjects rang the bell for their attacks during PSG. The events occurred during stage N1 and N2. In 2 cases, respiratory events preceded the attacks. In 1 case, respiratory effort related arousal was followed by the attack. In the other 2 cases snoring preceded the attacks. One subject noticed the attack during stage W. Various respiratory events were related to the EHS attacks. A variety of ear dysfunctions or brainstem neural dysfunction during the transition from wakefulness to sleep has been reported as the pathophysiology of EHS. Our PSG findings suggest that checking otolaryngological status on subjects and respiratory events during sleep may be helpful in understanding its pathophysiology and in choosing therapeutic strategies. None.

Introduction Mental health disorders and sleep disorders are associated with systemic inflammation, which may be a key element linking these highly co-occurring conditions to negative health outcomes. This study used national VA medical records to examine C-reactive protein (CRP) levels in Iraq/Afghanistan veterans based on presence of mental health and/or sleep disorder diagnoses. Methods We examined medical records for 16,576 Iraq/Afghanistan veterans under age 55 who had high-sensitivity CRP results reported. ICD diagnostic codes were used to compare CRP values for: a) veterans without sleep disorders or mental health diagnoses, b) veterans with mental health disorders only, c) veterans with sleep disorders only, and d) veterans with both conditions. In generalized linear models controlling for demographics, we examined the impact of diagnostic category on continuous CRP value as well as the risk of elevated CRP (>3mg/L). Results Veterans with mental health disorders (coeff=.14, p<.001) and comorbid sleep and mental health disorders (coeff=.21, p<.001) had higher continuous CRP values compared to veterans without either condition. Veterans with comorbid sleep and mental health disorders had higher continuous CRP values than veterans with sleep disorders alone (coeff=.22, p<.041); however, there were few patients in the current sample who were diagnosed with sleep disorders alone (n=401, 2.4%). Additionally, veterans with mental health disorders (ARR=1.12, p=.004) and comorbid sleep and mental health disorders (ARR=1.15, p=.001) were more likely to have CRP values >3mg/L compared to veterans without either condition. Conclusion Sleep disorders were highly likely to co-occur with mental health disorders in this sample of Iraq/Afghanistan veterans. Mental health disorders and comorbid mental health/sleep disorders were associated with elevated C-reactive protein, indicating these patients are at highest risk for negative health outcomes. Future studies should investigate directionality of relationships among sleep disruption, mental health symptoms, and inflammation. Support VA Advanced Fellowship Program in Mental Illness Research and Treatment

Exploding head syndrome (EHS) is a parasomnia characterized by the perception of loud noises, or explosions inside the head during the sleep-to-wake transition. The prevalence of EHS remains unclear. This survey aimed to elucidate the prevalence of and factors associated with EHS in this cohort. As part of the Night in Japan Home Sleep Monitoring Study (NinjaSleep study), a cross-sectional survey was conducted among government employees in Koka City, Shiga Prefecture, Japan, in 2022. Participants were queried regarding their experiences with EHS as defined in the International Classification of Sleep Disorders, 3rd Edition, including sudden loud noises or sensations of explosions, subsequent abrupt awakenings and feelings of fright. Various standardized instruments were employed to evaluate depression, anxiety, insomnia, quality of life, and fatigue. Of the 2081 employees invited to participate, 1878 completed the survey. After excluding respondents with epilepsy and incomplete responses, 1843 participants were deemed eligible for analysis. Among them, 46 (2.49%) reported experiencing sudden noises or sensations of explosions, with 23 (1.25%) meeting the diagnostic criteria for EHS. The EHS was significantly related to the scores on the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Athens insomnia scale, and Chalder fatigue scale, even after adjusting for age, sex, body mass index, and categorized mean sleep duration. This study elucidates the prevalence of EHS among the Japanese population and underscores its potential association with insomnia symptoms and various psychological factors.

Introduction Exploding head syndrome (EHS) is a rare parasomnia with unclear etiology. There are limited research studies to confirm the exact predisposing and precipitating factors for its onset and frequency. Some published case reports suggest symptomatic improvement with the treatment of comorbid obstructive sleep apnea (OSA). This case presents a patient who received automatic positive airway pressure (APAP) treatment for OSA with worsening EHS symptoms. Report of case(s) A 41-year-old male with obesity (BMI of 33) and chronic back pain complained of visual and audio sensations of explosion, vibration, and light when falling asleep and waking up in the middle of the night without any associated physical pain. These events would occur twice a month and were accompanied by waking up three to four times nightly due to loud snoring. A home sleep study (HSAT) was completed and consistent with mild obstructive sleep apnea, demonstrating a respiratory event index (REI) of 7.4 events per hour. The patient was diagnosed with exploding head syndrome and OSA. He was started on APAP therapy. At the six-week follow-up, he noted worsening frequency of EHS events to twice a week. During this time, he lost his job. At the three-month follow-up since starting APAP, he reported further worsening of his EHS episodes to three times a week. The patient was not compliant with APAP usage. The compliance data revealed average usage of 2-3 hours a night with residual AHI of 1.2/hour. Conclusion EHS is a rare disorder with unknown predisposing and precipitating factors. This patient noted worsening of his EHS after the initiation of APAP therapy for his obstructive sleep apnea. However, the patient was not fully compliant with PAP therapy. He also underwent further stressors during this period. This case raises consideration regarding the side effects of APAP therapy on the severity of EHS when treating OSA. Support (if any)

Exploding head syndrome – More than “snapping of the brain”?

Exploding head syndrome (EHS) is an under-recognized parasomnia characterized by a complaint of sudden loud noise or a sense of explosion in the head that usually occurs at sleep onset. This paper is a report of 6 patients diagnosed with EHS through a structured clinical interview and video-polysomnography (vPSG) recordings. We also reviewed the available literature that addressed the presentation and clinical and PSG characteristics of EHS. The case series included 4 men and 2 women of a mean age of 44.2 years (between 13 and 77 years). Their episodes were variable in expression, between a sudden firecracker-like explosion to a gun-shot sound, mostly as if happening inside the head. EHS is always associated with distress but never with pain. Five out of 6 patients had other sleep-related problems with a close relationship of EHS symptoms to comorbid sleep disorder manifestations and exacerbations. The vPSG recordings of 5 patients were unremarkable. An attack of EHS was documented in 1 patient, arising during stage N2 of sleep. Three patients responded well to reassurance and treatment for the comorbid sleep disorder. The other 3 patients responded well to amitriptyline (10–50 mg). EHS is a well-characterized, underrecognized hypnic parasomnia with a benign course. Amitriptyline seems to be effective in persistent cases.

SUMMARY Perceptual disturbances are common in psychiatric and neurological conditions, yet some rare, non-psychotic disorders remain poorly recognised. This review examines two such syndromes: visual snow syndrome (VSS) and exploding head syndrome (EHS). VSS is marked by continuous ‘static’ across the visual field, often accompanied by palinopsia, photophobia and entoptic phenomena. EHS involves sudden, loud auditory sensations – like explosions or crashes – occurring during transitions between sleep and wakefulness. Although distinct in modality, both share common challenges: subjective distressing symptoms, normal investigation findings, frequent misdiagnosis and psychiatric comorbidities such as anxiety, sleep dysfunction and depersonalisation. The article synthesises emerging evidence on their neurobiological underpinnings, including cortical hyperexcitability, thalamocortical dysrhythmia and impaired sensory gating, and on pharmacological and non-pharmacological treatment options. Enhancing clinical awareness and adopting a multidisciplinary approach are essential for improving diagnosis and care. This article aims to support psychiatrists in recognising, differentiating and managing these complex perceptual disorders.

To evaluate the current state of sleep medicine educational resources and training offered by US neurology residency programs. In 2010, a 20-item peer reviewed Sleep Education Survey (SES) was sent to neurology residency program directors surveying them about sleep medicine educational resources used in teaching residents. Pearson product momentum correlation was used to determine correlation of program attributes with resident interest in pursuing a career in sleep medicine. Of the programs completing the survey, 81% listed a formal sleep rotation and 24% included a forum for sleep research. A variety of innovative approaches for teaching sleep medicine were noted. Program directors noted that 5.7% residents entered sleep medicine fellowship training programs in the preceding 5 years. Programs that had a more substantial investment in sleep medicine teaching resources were more likely to report residents entering a sleep medicine training program. This is the first report providing an analysis of the current state of sleep medicine training in US Neurology Residency Programs. Our data provide evidence that investment by the residency program in sleep education may enhance the ultimate decision by the neurology trainee to pursue a career in sleep medicine.

BackgroundExploding head syndrome is a rarely reported benign sensory parasomnia that may nonetheless have significant impact on patients’ quality of life and their perceived well-being. To date, the mechanisms underlying attacks, characterised by a painless perception of abrupt, loud noises at transitional sleep-wake or wake-sleep states, are by and large unclear.Methods and resultsIn order to address the current gap in the knowledge of potential underlying pathophysiology, a retrospective case-control study of polysomnographic recordings of patients presenting to a tertiary sleep disorders clinic with exploding head syndrome was conducted. Interictal (non-attack associated) electroencephalographic biomarkers were investigated by performing macrostructural and event-related dynamic spectral analyses of the whole-night EEG. In patients with exploding head syndrome, additional oscillatory activity was recorded during wakefulness and at sleep/wake periods. This activity differed in its frequency, topography and source from the alpha rhythm that it accompanied.ConclusionBased on these preliminary findings, we hypothesise that at times of sleep-wake transition in patients with exploding head syndrome, aberrant attentional processing may lead to amplification and modulation of external sensory stimuli.

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Exploding head syndrome (EHS) is a rare syndrome associated with sleep and characterized by sudden feeling of loud noise in the head awakening the patient. According to the 3rd edition of the International Classification of Sleep Disorders (2014), EHS is regarded as parasomnia. Comorbidity of EHS and migraine is mentioned in the literature. We present a patient with EHS and migraine without aura.

To the best of our knowledge, we report here for the first time a case of exploding head syndrome (EHS) that caused repeating panic attacks. A 62-year-old woman experienced a sudden sensation of a loud noise just before going to sleep. The frequency of these episodes rapidly increased to multiple times per night, and she soon began to fear sleep, which led to the occurrence of nighttime panic attacks. She was diagnosed with EHS at our sleep clinic, and clonazepam was prescribed accompanied by reassurance about the benign nature of this syndrome. The intensity of the loud noise gradually reduced, and her fear of sleep and panic attacks disappeared at around the same time. In this report, we argue the importance of gaining further knowledge about EHS, including that about complicating psychiatric symptoms and that about its treatment.