Special Issue Article
Exploding head syndrome: Six new cases and review of the literature
Cephalalgia 2014, Vol. 34(10) 823–827 ! International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0333102414536059 cep.sagepub.com
Achim Frese1, Oliver Summ2 and Stefan Evers3 Abstract Background: Exploding head syndrome (EHS) is characterized by attacks of a sudden noise or explosive feeling experienced in the head occurring during the transition from wake to sleep or from sleep to wake. Methods: We present six new cases extending the clinical experience with the syndrome. We also reviewed all available cases from the scientific literature and evaluated the typical features of EHS. Results: The female to male ratio is 1.5 to 1. The median age at onset is 54. In average, one attack per day to one attack per week occurs. Some patients suffer from several attacks per night. In about half of all patients, a chronic time course can be observed but episodic or sporadic occurrence is also common. The most frequent accompanying symptoms beside the noise are fear and flashes of light. Polysomnographic studies do not reveal any specific sleep pattern associated with EHS. Tricyclic antidepressants are helpful in some patients. However, most patients do not need treatment because of the benign nature of the syndrome. Conclusion: EHS is a well-defined disease entity with a benign nature. Keywords Exploding head syndrome, headache, sleep Date received: 30 March 2014; revised: 22 April 2014; accepted: 24 April 2014
Introduction Exploding head syndrome (EHS) was first described in the medical literature in 1890, as an auditory sensory shock—‘‘a loud noise, like that of a pistol-shot, or of the crash of broken glass, or as of a bell, or a wire sharply twanged’’ (1). It was next mentioned as ‘‘snapping of the brain’’ in people suffering from melancholia, neurasthenia, and psychasthenia, occurring independently from any objective acoustic stimulation (2). Nowadays, EHS is considered a benign sleep-wake or wake-sleep transition disorder of unknown etiology. It was described as an entity for the first time in 1988 (3). The attacks are characterized by sudden loud noises described as a ‘‘bomb explosion,’’ ‘‘terrific bang,’’ or ‘‘door slamming.’’ The victim is awoken by a violent sensation of explosion in the head (‘‘an enormous roar, so loud it could kill me’’) (4). Usually, the attacks are painless, but they can be concerning or even terrifying. Because of its alarming character, EHS often is inaccurately described as a pain. The benign character and the good prognosis of the EHS are the most likely reasons why it has not become an object of more extensive neurological research. The International Classification
of Sleep Disorders has classified EHS as a parasomnia and defined diagnostic criteria, which are presented in Table 1 (5). Here, we report six further cases of EHS and try to give a complete review of all published cases to date. Furthermore, we discuss possible pathophysiological mechanisms of the syndrome.
Case reports The patients were admitted to the headache outpatient clinic, Department of Neurology, University of Mu¨nster, Germany. In all six patients, there were no pathological findings in the clinical and neurophysiological examinations including electroencephalography 1
Akademie fu¨r Manuelle Medizin, University of Mu¨nster, Germany Department of Neurology, University of Mu¨nster, Germany 3 Department of Neurology, Krankenhaus Lindenbrunn, Germany 2
Corresponding author: Achim Frese, Akademie fu¨r Manuelle Medizin, University of Mu¨nster, Von-Esmarch-Str. 50, 48149 Mu¨nster, Germany. Email: [email protected]
824
Cephalalgia 34(10)
Table 1. Criteria of exploding head syndrome according to the International Classification of Sleep Disorders (5). (a) (b) (c)
The patient complains of a sudden loud noise or sense of explosion in the head either at the wake-sleep transition or upon waking during the night. The experience is not associated with significant pain complaints. The patient rouses immediately after the event, usually with a sense of fright.
Note: In a minority of cases, a flash of light or myoclonic jerk may accompany the event.
Table 2. Demographic data, associated symptoms, and concomitant diseases of the six new exploding head syndrome patients. Patient
Sex
Age
Onset
Description (all: explosion-like feeling)
Concomitant diseases
1
M
62
years ago
Sudden loud bang
2 3 4
F F F
57 60 75
3 months ago 5 years ago 2 years ago
Flash of light Flash of light Flash of light
5
M
64
2 years ago
6
F
60
1 year ago
Electric paresthesia Mild jab-like pain Flash of light
Chronic tension-type headache Exercise headache Sexual headache Mild restless legs syndrome Mild restless legs syndrome Arterial hypertension Diabetes mellitus Obstructive sleep apnea None
(EEG), ultrasound of the brain-supplying arteries, brain imaging of the head (computed tomography (CT) or magnetic resonance imaging (MRI) scan including angiography), and laboratory investigations. Concomitant headaches were diagnosed according to the criteria of the International Headache Society (6). Data about demography, associated symptoms, and concomitant diseases are given in Table 2. All patients suffered from an explosion-like feeling in the head at the transition from wakefulness to sleep lasting for one second maximum. The sensation was gone by the time the patients were wide awake. The sensation was unpleasant and associated with an anxious feeling. Patient 1 experienced EHS nearly every evening. An external polysomnography (PSG) was unremarkable without any evidence of parasomnia or a sleep-related breathing disorder. During PSG, no attack occurred. Despite his problems falling asleep, this patient reached a score of 6 on the Epworth Sleepiness Scale (out of a possible score of 24), suggesting no increased daytime sleepiness. His chronic tension-type headache partially responded to amitriptyline (25 mg in the evening, higher doses were not tolerated because of dizziness). Amitriptyline had no significant effect on his EHS. The patient was informed about the harmlessness of EHS and did not wish any other treatment attempts. Patient 2 suffered from EHS with increasing frequency. On first examination, EHS attacks occurred one to several times each night. With amitriptyline (up to 50 mg in the evening) attack frequency significantly
Glaucoma
decreased to one to three attacks per week. Treatment caused side effects (dry mouth, dizziness) and was stopped after six weeks without exacerbation. At follow-up examination four years later, the patient reported further remission of EHS with sporadic attacks every few months. Further treatment was not necessary. Patient 3 suffered from mild EHS with infrequent attacks every few months. Patient 4 also suffered from mild EHS with infrequent attacks only once or twice a year. Obstructive sleep apnea had been diagnosed with PSG prior to EHS onset and was treated with continuous positiveairway pressure therapy for several years. Follow-up examination five years later revealed no increase of attack frequency. In patients 3 and 4, no treatment was required. Patient 5 experienced one single attack every evening. Amitriptyline (25 mg in the evening) caused almost complete remission. He was lost to follow-up after three months. Patient 6 regularly suffered from up to eight attacks per night, causing insomnia. Treatment attempts with zopiclone and bromazepam had been without success. Treatment with amitriptyline and PSG were recommended. She was lost to follow-up.
Review of the literature We performed a literature search in MedLine, Science Citation Index, and Embase with the phrase ‘‘exploding
825
Frese et al. Table 3. Demographic data of all published and cases with exploding head syndrome (missing data from some patients for some variables possible). Age at onset (years) Sex Duration (years) Time course
Situation
Symptoms
50.5 17.3 (range 12 to 84); median 54 Male Female 7.5 9.3 (range 0.1–48); median 5 Single attack or episode Sporadic (
Exploding head syndrome: Six new cases and review of the literature
Cephalalgia 2014, Vol. 34(10) 823–827 ! International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0333102414536059 cep.sagepub.com
Achim Frese1, Oliver Summ2 and Stefan Evers3 Abstract Background: Exploding head syndrome (EHS) is characterized by attacks of a sudden noise or explosive feeling experienced in the head occurring during the transition from wake to sleep or from sleep to wake. Methods: We present six new cases extending the clinical experience with the syndrome. We also reviewed all available cases from the scientific literature and evaluated the typical features of EHS. Results: The female to male ratio is 1.5 to 1. The median age at onset is 54. In average, one attack per day to one attack per week occurs. Some patients suffer from several attacks per night. In about half of all patients, a chronic time course can be observed but episodic or sporadic occurrence is also common. The most frequent accompanying symptoms beside the noise are fear and flashes of light. Polysomnographic studies do not reveal any specific sleep pattern associated with EHS. Tricyclic antidepressants are helpful in some patients. However, most patients do not need treatment because of the benign nature of the syndrome. Conclusion: EHS is a well-defined disease entity with a benign nature. Keywords Exploding head syndrome, headache, sleep Date received: 30 March 2014; revised: 22 April 2014; accepted: 24 April 2014
Introduction Exploding head syndrome (EHS) was first described in the medical literature in 1890, as an auditory sensory shock—‘‘a loud noise, like that of a pistol-shot, or of the crash of broken glass, or as of a bell, or a wire sharply twanged’’ (1). It was next mentioned as ‘‘snapping of the brain’’ in people suffering from melancholia, neurasthenia, and psychasthenia, occurring independently from any objective acoustic stimulation (2). Nowadays, EHS is considered a benign sleep-wake or wake-sleep transition disorder of unknown etiology. It was described as an entity for the first time in 1988 (3). The attacks are characterized by sudden loud noises described as a ‘‘bomb explosion,’’ ‘‘terrific bang,’’ or ‘‘door slamming.’’ The victim is awoken by a violent sensation of explosion in the head (‘‘an enormous roar, so loud it could kill me’’) (4). Usually, the attacks are painless, but they can be concerning or even terrifying. Because of its alarming character, EHS often is inaccurately described as a pain. The benign character and the good prognosis of the EHS are the most likely reasons why it has not become an object of more extensive neurological research. The International Classification
of Sleep Disorders has classified EHS as a parasomnia and defined diagnostic criteria, which are presented in Table 1 (5). Here, we report six further cases of EHS and try to give a complete review of all published cases to date. Furthermore, we discuss possible pathophysiological mechanisms of the syndrome.
Case reports The patients were admitted to the headache outpatient clinic, Department of Neurology, University of Mu¨nster, Germany. In all six patients, there were no pathological findings in the clinical and neurophysiological examinations including electroencephalography 1
Akademie fu¨r Manuelle Medizin, University of Mu¨nster, Germany Department of Neurology, University of Mu¨nster, Germany 3 Department of Neurology, Krankenhaus Lindenbrunn, Germany 2
Corresponding author: Achim Frese, Akademie fu¨r Manuelle Medizin, University of Mu¨nster, Von-Esmarch-Str. 50, 48149 Mu¨nster, Germany. Email: [email protected]
824
Cephalalgia 34(10)
Table 1. Criteria of exploding head syndrome according to the International Classification of Sleep Disorders (5). (a) (b) (c)
The patient complains of a sudden loud noise or sense of explosion in the head either at the wake-sleep transition or upon waking during the night. The experience is not associated with significant pain complaints. The patient rouses immediately after the event, usually with a sense of fright.
Note: In a minority of cases, a flash of light or myoclonic jerk may accompany the event.
Table 2. Demographic data, associated symptoms, and concomitant diseases of the six new exploding head syndrome patients. Patient
Sex
Age
Onset
Description (all: explosion-like feeling)
Concomitant diseases
1
M
62
years ago
Sudden loud bang
2 3 4
F F F
57 60 75
3 months ago 5 years ago 2 years ago
Flash of light Flash of light Flash of light
5
M
64
2 years ago
6
F
60
1 year ago
Electric paresthesia Mild jab-like pain Flash of light
Chronic tension-type headache Exercise headache Sexual headache Mild restless legs syndrome Mild restless legs syndrome Arterial hypertension Diabetes mellitus Obstructive sleep apnea None
(EEG), ultrasound of the brain-supplying arteries, brain imaging of the head (computed tomography (CT) or magnetic resonance imaging (MRI) scan including angiography), and laboratory investigations. Concomitant headaches were diagnosed according to the criteria of the International Headache Society (6). Data about demography, associated symptoms, and concomitant diseases are given in Table 2. All patients suffered from an explosion-like feeling in the head at the transition from wakefulness to sleep lasting for one second maximum. The sensation was gone by the time the patients were wide awake. The sensation was unpleasant and associated with an anxious feeling. Patient 1 experienced EHS nearly every evening. An external polysomnography (PSG) was unremarkable without any evidence of parasomnia or a sleep-related breathing disorder. During PSG, no attack occurred. Despite his problems falling asleep, this patient reached a score of 6 on the Epworth Sleepiness Scale (out of a possible score of 24), suggesting no increased daytime sleepiness. His chronic tension-type headache partially responded to amitriptyline (25 mg in the evening, higher doses were not tolerated because of dizziness). Amitriptyline had no significant effect on his EHS. The patient was informed about the harmlessness of EHS and did not wish any other treatment attempts. Patient 2 suffered from EHS with increasing frequency. On first examination, EHS attacks occurred one to several times each night. With amitriptyline (up to 50 mg in the evening) attack frequency significantly
Glaucoma
decreased to one to three attacks per week. Treatment caused side effects (dry mouth, dizziness) and was stopped after six weeks without exacerbation. At follow-up examination four years later, the patient reported further remission of EHS with sporadic attacks every few months. Further treatment was not necessary. Patient 3 suffered from mild EHS with infrequent attacks every few months. Patient 4 also suffered from mild EHS with infrequent attacks only once or twice a year. Obstructive sleep apnea had been diagnosed with PSG prior to EHS onset and was treated with continuous positiveairway pressure therapy for several years. Follow-up examination five years later revealed no increase of attack frequency. In patients 3 and 4, no treatment was required. Patient 5 experienced one single attack every evening. Amitriptyline (25 mg in the evening) caused almost complete remission. He was lost to follow-up after three months. Patient 6 regularly suffered from up to eight attacks per night, causing insomnia. Treatment attempts with zopiclone and bromazepam had been without success. Treatment with amitriptyline and PSG were recommended. She was lost to follow-up.
Review of the literature We performed a literature search in MedLine, Science Citation Index, and Embase with the phrase ‘‘exploding
825
Frese et al. Table 3. Demographic data of all published and cases with exploding head syndrome (missing data from some patients for some variables possible). Age at onset (years) Sex Duration (years) Time course
Situation
Symptoms
50.5 17.3 (range 12 to 84); median 54 Male Female 7.5 9.3 (range 0.1–48); median 5 Single attack or episode Sporadic (
