Hypnic headache

Epidemiology and clinical features of hypnic headache: A systematic review and meta-analysis

BACKGROUND

Hypnic headache is a neurological disorder characterized by recurrent headache attacks that occur exclusively during sleep, leading to awakening. Synthesizing the available epidemiological data might inform clinical decision-making.

METHODS

We searched PubMed and Embase for observational studies on hypnic headache published between 1 May 2004, and 22 December 2022. Two investigators independently screened titles, abstracts, and full-text articles. We performed a random-effects meta-analysis with meta-regression to estimate the prevalence of hypnic headache and its clinical features based on epidemiologic data from population-based and clinic-based studies.

RESULTS

Fourteen studies, one population-based and 13 clinic-based, met our eligibility criteria. The population-based study did not identify any people with hypnic headache. From 11 clinic-based studies, the pooled relative frequency of hypnic headache was 0.21% (95%CI, 0.13 to 0.35%; I2 = 87%) in adult patients evaluated for headache. The pooled mean age of onset was 60.5 years, with a slight female predisposition. Hypnic headache was typically bilateral (71%), pressing (73%), of moderate (38%) or severe (44%) pain intensity, and lasted about 115 minutes per attack.

CONCLUSIONS

Our data should be cautiously interpreted due to between-study heterogeneity. The identified clinical presentation of hypnic headache can guide clinical diagnosis, in addition to the International Classification of Headache Disorders.

Pediatric hypnic headache: a systematic review

Introduction

Hypnic headache (HH) is a primary headache, and it is considered a rare condition in children. The underlying mechanisms of HH are not yet fully understood. This systematic review aims to provide a comprehensive description of the clinical features of all published cases of pediatric HH. It will also discuss the differences in headache features between children and adults, the increased diagnostic sensitivity of the new diagnostic criteria (ICHD-3), potential pathophysiological hypotheses explaining the higher incidence in adults, differential diagnoses, and therapeutic options for children.

Methods

A systematic search was conducted to identify and analyze articles reporting cases of HH in patients under the age of 18. The search was performed in major medical databases including Cochrane Library, EBSCO, Embase, Medline, PubMed, Science Direct, Scopus, and Web of Science. The search covered the period from 1988 to April 2023. Relevant studies were screened for eligibility, and data extraction was performed using a standardized approach.

Results

Seven children with HH were included in the analysis. The mean age of onset for headache attacks was 10 ± 4.3 years (range 3-15 years). The average time from the start of headaches to diagnosis was 15.8 ± 25.0 months (range 1-60 months). Headache features in children differed from those observed in adult HH patients. Children experienced throbbing/pulsating pain, while adults reported dull/pressure-like pain. Children also had lower frequency and shorter duration of attacks compared to adults. The use of ICHD-3 criteria appeared to be more sensitive and inclusive for diagnosing HH in children compared to the previous ICHD-2 criteria. The association of headache attacks with sleep suggests that HH may be a primary disorder with a chronobiological origin. Hypothalamic dysfunction and melatonin dysregulation, which are more prevalent in older individuals, could potentially explain the higher incidence of HH in adults. Other primary headaches and secondary causes should be ruled out. Melatonin prophylactic therapy may be considered for pediatric patients.

Discussion

Further evaluation of the clinical features of HH in children is needed. The development of specific diagnostic criteria for pediatric cases could improve diagnostic rates and enhance the management of children with HH.

Hypnic Headache - What do we know in 2022?

BACKGROUND

Hypnic Headache, also known as "alarm clock headache", is a rare primary headache disorder. It is characterized by frequently recurring headache attacks, which only develop during sleep, especially nighttime sleep.

OBJECTIVE

This article gives a narrative review on the current knowledge about Hypnic Headache with a focus on secondary Hypnic Headache.

METHODS

Based on literature research, using Pubmed and Google Scholar, latest case reports, studies, and systematic reviews about Hypnic Headache were analyzed and summarized focusing on therapeutic options and causes of secondary Hypnic Headache.

CONCLUSION

Hypnic Headache mainly occurs in elderly patients. However, younger patients and children may also suffer from Hypnic Headache. Many different causes of secondary Hypnic Headache are described in the literature and ought to be ruled out before diagnosing primary Hypnic Headache. The pathophysiology of primary Hypnic Headache remains unclear, but a dysfunction of the hypothalamus seems to play a key role.

Emerging relevance of circadian rhythms in headaches and neuropathic pain

Circadian rhythms of physiology are the keys to health and fitness, as dysregulation, by genetic mutations or environmental factors, increases disease risk and aggravates progression. Molecular and physiological studies have shed important light on an intrinsic clock that drives circadian rhythms and serves essential roles in metabolic homoeostasis, organ physiology and brain functions. One exciting new area in circadian research is pain, including headache and neuropathic pain for which new mechanistic insights have recently emerged. For example, cluster headache is an intermittent pain disorder with an exceedingly precise circadian timing, and preliminary evidence is emerging linking several circadian components (eg, Clock and Nr1d1) with the disease. In this review, we first discuss the broad metabolic and physiological relevance of the circadian timing system. We then provide a detailed review of the circadian relevance in pain disease and physiology, including cluster headache, migraine, hypnic headache and neuropathic pain. Finally, we describe potential therapeutic implications, including existing pain medicines and novel clock-modulating compounds. The physiological basis for the circadian rhythms in pain is an exciting new area of research with profound basic and translational impact.

Hypnic headache: A review of clinical features, therapeutic options and outcomes

Background

Hypnic headache (HH), first reported in 1988, is a rare sleep-related headache disorder. In 2013 a new diagnostic criteria was proposed for HH in the International Classification of Headache Disorders, the third version beta (ICHD-3β).

Purpose

This review aimed to update the clinical characteristics, therapeutic options and clinical outcomes in patients with HH and also validate the new diagnostic criteria.

Methods

Based on a literature search in the major medical databases, we analyzed all case reports or case series on HH that have been published since the first description by Raskin. Except for symptomatic patients, all reported patients were included regardless of which diagnostic criteria were adopted. Four studies that reported the field-testing results of the ICHD-2 criteria were selected to validate the new ICHD-3β criteria.

Results

In total, 250 adult and five childhood patients are described in this review. The majority of patients were elderly and their ages of onset were typically more than 50 years old (92%). Approximately 7.7% of patients had some trigeminal autonomic features, which are not permitted in the ICHD-3β criteria. Compared with the ICHD-2 criteria, the diagnostic rate under the new criteria increased from 65% to 85% in recently reported cases. Randomized control trials both for acute and prophylactic treatment are lacking. Based on observational studies, the most effective acute treatment is caffeine and prophylactic medications in use are lithium, caffeine and indomethacin. Without treatment, the disease course is usually protracted but spontaneous remission did occur in 12 patients (4.8%). In those treated with prophylactic agents, no recurrence was noted in 43% of patients, even following withdrawal of medication.

Conclusions

The new ICHD-3β criteria are more sensitive and exhaustive for HH than the ICHD-2 criteria. Prophylactic treatment provides better outcomes; however, randomized controlled studies for treatment are needed to further verify the efficacy of the different drugs.

Pathophysiology of hypnic headache

Background

Hypnic headache (HH) is a rare primary headache disorder that is characterized by strictly sleep related headache attacks.

Purpose

The underlying pathophysiology of HH is mainly enigmatic but some clinical characteristics such as circadian rhythmicity and caffeine responsiveness may point toward possible underlying mechanisms.

Method

Current studies that deal with the pathophysiology of HH are summarized. Data on cerebral imaging, sleep, electrophysiology studies, effectiveness of drugs, and symptomatic headache types are discussed to illuminate underlying pathophysiologic mechanisms.

Conclusion

HH can be clearly differentiated by its clinical presentation as well as imaging and electrophysiological study results from other primary headaches such as migraine or cluster headache. The underlying pathophysiology is still enigmatic but a hypothalamic involvement seems to be likely.

Hypnic headache

Background

Hypnic headache (HH) is a rare primary headache disorder that is characterised by strictly sleep-related headache attacks.

Purpose

Because of the low prevalence of this headache disorder, disease information is mainly based on case reports and small case series. This review summarises current knowledge on HH in regard to clinical presentation, pathophysiology, symptomatic causes and therapeutic options.

Method

We review all reported HH cases since its first description in 1988 by Raskin. Broadened diagnostic criteria were applied for patient selection that slightly deviate from the current ICHD-II criteria. Patients were allowed to describe the headache character to be other than dull. Additionally, accompanying mild trigemino-autonomic symptoms were permitted.

Conclusions

Mainly elderly patients are affected, but younger patients and even children might also suffer from HH. Headache attacks usually last between 15 and 180 minutes, but some patients report headache attacks up to 10 hours. Almost all patients report motor activity during headache attacks. Cerebral MRI and 24-hour blood pressure monitoring should be performed in the diagnostic work-up of HH. Other primary headache disorders such as migraine and cluster headache may also present with sleep-related headache attacks and should be considered first. Caffeine taken as a cup of strong coffee seems to be the best acute and prophylactic treatment option.

Hypnic headache: Response to lamotrigine in two cases

Background: Hypnic headache (HH) is a rare primary headache that occurs exclusively during sleep. Drug therapy of HH is often associated with side effects. In a few cases, antiepileptic drugs have been useful in preventing HH attacks.

Cases: We describe two patients, a man aged 57 and a woman aged 63, both with a history of duodenal ulcer and both suffering from several months of frequent and moderate headaches (at least 15 days/month), which occurred only at night and resisted treatment. Physical examination and imaging were unremarkable. Sleep polysomnography was normal in the man. In both patients, the diagnosis of HH was made on the basis of the International Classification of Headache Disorders, 2nd edition criteria. Given the prior history of duodenal ulcer and the unavailability of some drugs in Morocco, we opted for the administration of moderate doses of lamotrigine. The outcome was favourable at one year follow-up and beyond.

Conclusion: To our knowledge, the response to lamotrigine in HH cases has never been reported. Because of its safety profile and availability, lamotrigine can be an effective alternative treatment in HH.

Nociceptive blink reflex and pain-related evoked potentials in hypnic headache

Background: Central facilitation of trigeminal pain processing and deficient habituation was observed in different headache and facial pain disorders. This overactivation seems to be primarily associated with chronic pain states.

Objective: To investigate the function of the trigeminal nociceptive system in patients with hypnic headache (HH).

Methods: Fifteen HH patients according International Classification of Headache Disorders II criteria and 15 age- and gender-matched healthy controls were investigated using the nociceptive blink reflex (nBR) and trigeminal pain-related evoked potentials (PREP).

Results: nBR and PREP responses showed no significant differences comparing HH patients and healthy controls. Moreover, no habituation deficit was detected in HH patients.

Conclusion: Central facilitation and change in habituation do not seem to be a crucial part in the pathophysiology of HH despite the chronic nature of this disease. Facilitation or habituation deficit does not seem to be exclusively related to chronic pain disorders in general. Further research is needed to illuminate the pathophysiology of HH.

Hypnic headache

Hypnic headache is a rare short-lasting headache occurring exclusively during sleep in the elderly population. First described in 1988 by Raskin, this headache syndrome was adopted by the International Classification of Headache Disorders in 2004 within the "other primary headache" group (code 4.5). Since then, additional case reports and case series were published and provided data to best understand hypnic headache. This review highlights new findings to discuss the relevance of actual diagnostic criteria and the treatment approach of this nocturnal headache syndrome. We also consider hypnic headache pathophysiology that remains speculative.

Hypnic headache

Hypnic headache is a rare primary headache disorder that is characterized by exclusively sleep-related headache attacks in patients usually beyond 50 years of age. Only 174 cases have been reported in the literature so far. Owing to its low prevalence, clinical features and therapeutic options, as well as underlying pathophysiologic mechanisms, are widely unknown or being controversially discussed. The association of hypnic headache with rapid-eye movement sleep was strongly contradicted in recent articles, while an association with hypothalamic dysfunction is thought to be one important pathophysiological mechanism. Common acute, as well as prophylactic, treatment is caffeine intake, either in the form of a cup of coffee or a caffeine tablet. Lithium, indomethacin and melatonin were promoted as potent medical treatments, while almost every other drug commonly used to treat headache or other pain syndromes was reported to be effective in single case reports on hypnic headache.

Serial polysomnography in hypnic headache

BACKGROUND

Hypnic headache (HH) is a rare primary headache disorder characterized by strictly sleep-related headache attacks. Most patients are over the age of 50 and usually awake at the same time at night with dull bilateral head pain. The pathophysiology of this headache disorder is still enigmatic but association with rapid eye movement (REM) sleep and sleep-disordered breathing (SDB) has been suggested.

METHODS

Six patients with HH according to the current International Classification of Headache Disorders (ICHD-II) criteria (code 4.5) were investigated. Serial polysomnography (PSG) was performed in each patient for four consecutive nights.

RESULTS

A total of 22 HH attacks were recorded from all patients during PSG. Six of the monitored headache attacks arose from REM sleep; 16 attacks, however, arose from different non-REM (NREM) sleep stages. Five patients showed an increased apnoea/hypopnoea index (>5), indicating obstructive sleep apnoea (OSA) on some but not the majority of nights. Headache onset and occurrence of SDB were not temporally connected.

CONCLUSIONS

This prospective study shows that the onset of HH was not associated with sleep stage. These results contradict the current belief that REM sleep and SDB play a crucial role in the pathophysiology of HH.

Focus on therapy of hypnic headache

Hypnic headache (HH) is a primary headache disorder, which occurs exclusively during sleep and usually begins after 50 years of age. There are no controlled trials for the treatment of HH. We reviewed all the available papers, including 119 cases published in literature up to date, reporting the efficacy of the medications used to treat HH. Acute treatment is not recommended, since no drug proved to be clearly effective and also because the intensity and the duration of the attacks do not require the intake of a medication in most cases. As for prevention, a wide variety of medications were reported to be of benefit in HH. The drugs that were found to be effective in at least five cases are: lithium, indomethacin, caffeine and flunarizine. Lithium was the most extensively studied compound and demonstrated to be an efficacious treatment in 32 cases. Unfortunately, despite its efficacy, significant adverse effects and poor tolerability are not rare, mainly in elderly patients. Many patients reported a good response to indomethacin, but some could not tolerate it. Caffeine and melatonin treatments did not yield robust evidence to recommend their use as single preventive agents. Nevertheless, their association with lithium or indomethacin seems to produce an additional therapeutic efficacy. A course of lithium should be tried first, followed 3–4 months later by tapering. If headache recurs during tapering, a longer duration of therapy may be needed. If lithium treatment does not provide a significant response, indomethacin can be commenced as second-line approach. If these treatments prove to be ineffective or poorly tolerated, other agents, such as caffeine and melatonin, can be administered.

Clinical characteristics and therapeutic options in hypnic headache

Background: Hypnic headache (HH) is a rare primary headache disorder that is characterized by exclusively sleep-related headache attacks. Because of its low prevalence, clinical features and therapeutic options are widely unknown or under discussion.

Methods: Twenty patients with HH were examined and interviewed using a standardized questionnaire in regard to their clinical characteristics and effective treatment regimens. Data were evaluated according to current International Headache Society (IHS) diagnostic criteria. Individual treatment history and effective treatment options were compared with expected efficacy based on current literature.

Results: In conflict to current IHS criteria, 15% of patients reported trigemino-autonomic symptoms. All patients showed distinct motor behavior during their headache attacks. In acute pain attacks caffeine was most effective. Lithium, topiramate, melatonin, amitriptyline and indomethacin were sometimes useful prophylactic treatment options but were often associated with side effects.

Conclusions: Our results underline the need for modification of the IHS diagnostic criteria of HH to better reflect the actual clinical characteristics of this headache. Caffeine should be considered as first-line acute therapy. Prophylactic medical treatment should be carefully evaluated in regard to side effects in this aged patient population, as this seems to be a major concern of patients apart from pure pain reduction.

Clinical Features, Polysomnography and Outcome in Patients with Hypnic Headache

Hypnic headache is rarely reported in Asians, and the proposed International Classification of Headache Disorders (ICHD)-2 criteria have never been field-tested. We studied 17 consecutive Taiwanese patients (M/F: 9/8, mean age at onset 69.6 years) with hypnic headache from a headache clinic. Fifteen patients (88%) reported >15 headache attack days per month. Polysomnography studies done on 11 patients recorded 12 attacks in seven patients: two during rapid eye movement (REM) sleep, three during non-REM sleep and two having both. Five of the seven patients reported their headache profile during polysomnography studies. The clinical course was mostly episodic without recurrence ( n = 9, 53%), followed by relapsing/remitting ( n = 5) and chronic ( n = 3). The ICHD-2 criteria were not fulfilled in 35% (6/17) patients based on patient recall or 60% (3/5) patients based on direct questioning during polysomnography studies. The major reason was the presence of pulsatile rather than dull headache in our patients. Unlike previous studies, our study showed hypnic headache occurred equally in both REM and non-REM sleep, and most patients ran an episodic course.

Secondary "hypnic headache"

Hypnic headache is a rare form of primary headache with attacks occurring exclusively with sleep. As it is typical of the elderly, a wide range of alternative diagnosis must be considered. We present a case report of a 54-year-old woman with unsuspected secondary hypnic headache that was relieved by anti-hypertensive therapy. We reviewed the literature to evaluate the usual diagnostic workup performed in hypnic headache patients. We suggest that 24 h ambulatory blood pressure monitoring may be included in the evaluation of nocturnal headache complaints especially in the elderly, in whom essential hypertension is a very frequent comorbidity.

Uncommon primary headaches

PURPOSE OF REVIEW

The new International Classification of Headache Disorders was recently published by the International Headache Society. Several uncommon primary headaches, including some new clinical entities (e.g. hypnic headache), were included in the section on 'Cluster headache and other trigeminal autonomic neuralgias' and 'Other primary headaches'. The recent classification offers an interesting opportunity to evaluate the clinical role and to discuss the mechanisms of some of the more relevant uncommon primary headaches.

RECENT FINDINGS

Due to the low incidence of these uncommon headache forms, their diagnostic criteria, pathogenetic mechanisms and therapy are still debated. Differential diagnosis versus secondary headaches is also a crucial issue. In this review, some of the most important uncommon primary headaches are discussed in light of the most recent contributions to the literature.

SUMMARY

The review focuses on the update of the main uncommon primary headaches, intending to clarify some controversial points and to indicate some headlines for further research.

Headache and sleep

Headache and sleep have long been recognised as being interdependent due to specific causative factors. Yet, the precise understanding of the roles played by these factors in this interdependency remains elusive. Many observations have suggested a reciprocal relationship between headache and sleep; however, these hypotheses have only been partially substantiated by robust findings. Being so, additional well-designed clinical and laboratory studies are required to confirm these relationships. Nonetheless, sleep and headache are known to be related in several ways: primary headache such as migraine, cluster headache (CH) and hypnic headache (HH) can be triggered by sleep, while chronic morning headaches can be caused by sleep disorders such as sleep apnoea and insomnia. Furthermore, headache and sleep disorders can also be symptoms of other underlying pathologies. Migraine, CH and HH seems to be related to sleep stages suggesting that they may in fact be a chronobiological disorder. Patients suffering from chronic morning or nocturnal headache should be considered for the presence of possible sleep disturbances.

Non-rapid eye movement sleep parasomnias

Parasomnias are unpleasant or undesirable behavioral or experiential phenomena that occur during sleep. Once believed unitary phenomena related to psychiatric disorders, it is now clear that parasomnias result from several different phenomena and usually are not related to psychiatric conditions. Parasomnias are categorized as primary (disorders of the sleep states) and secondary (disorders of other organ systems that manifest themselves during sleep). Primary sleep parasomnias can be classified according to the sleep state of origin: rapid eye movement sleep, non-rapid eye movement sleep, and miscellaneous (those not respecting sleep state). Secondary sleep parasomnias are classified by the organ system involved.