Sleep-related and non-sleep-related migraine: interictal sleep quality, arousals and pain thresholds

The Glymphatic System and its Relationship to Migraine

PURPOSE OF REVIEW

We aim to critically review animal and human studies of the glymphatic system in migraine and propose a model for how the glymphatic system may function in migraine, based on the available evidence.

RECENT FINDINGS

Early studies in animal models report migraine attacks temporarily disrupt glymphatic flow. Human imaging studies suggest chronic migraine may be associated with alterations in glymphatic system function, albeit with conflicting results. Presently, it remains unknown whether repetitive migraine attacks or frequent nights of insomnia impair glymphatic system function over time in those with migraine, and whether alterations in glymphatic function could contribute to worsening migraine disability or risk for cognitive disease. Longitudinal studies of glymphatic function in patients with migraine and insomnia, with inclusion of cognitive assessments, may be informative.

Sleep Symptoms in Migraine

PURPOSE OF REVIEW

To review replicated and highlight novel studies of sleep in children and adults with episodic and chronic migraine.

RECENT FINDINGS

Attack-related sleep symptoms are most common in the prodrome and may represent early activation of the hypothalamus rather than migraine triggers. Interictally, patients with migraine report poor sleep quality and high rates of insomnia symptoms. Cognitive behavioral therapy for insomnia in adults and adolescents with chronic migraine and comorbid insomnia results in significant improvement on their headache burden. Thus far, objective studies report that migraine per se is a not associated with sleep apnea. At the present time, there is minimal evidence that migraine is under circadian influence. The current body of evidence suggests that the insomnia symptoms and poor sleep quality commonly reported by patients with migraine are not attack-related but occur interictally and are a marker of worsening disease. The development of clinical guidelines to approach sleep symptoms and expansion of CBT-I trials in those with episodic migraine would be clinically valuable.

Orexins and primary headaches: an overview of the neurobiology and clinical impact

INTRODUCTION

Primary headaches, including migraines and cluster headaches, are highly prevalent disorders that significantly impact quality of life. Several factors suggest a key role for the hypothalamus, including neuroimaging studies, attack periodicity, and the presence of altered homeostatic regulation. The orexins are two neuropeptides synthesized almost exclusively in the lateral hypothalamus with widespread projections across the central nervous system. They are involved in an array of functions including homeostatic regulation and nociception, suggesting a potential role in primary headaches.

AREAS COVERED

This review summarizes current knowledge of the neurobiology of orexins, their involvement in sleep-wake regulation, nociception, and functions relevant to the associated symptomology of headache disorders. Preclinical reports of the antinociceptive effects of orexin-A in preclinical models are discussed, as well as clinical evidence for the potential involvement of the orexinergic system in headache.

EXPERT OPINION

Several lines of evidence support the targeted modulation of orexinergic signaling in primary headaches. Critically, orexins A and B, acting differentially via the orexin 1 and 2 receptors, respectively, demonstrate differential effects on trigeminal pain processing, indicating why dual-receptor antagonists failed to show clinical efficacy. The authors propose that orexin 1 receptor agonists or positive allosteric modulators should be the focus of future research.

The Effect of Melatonin on Sleep Disorders in Children with Cerebral Palsy A Randomized Clinical Trial

Objectives

Cerebral palsy (CP) is one of the most common causes of serious physical disability in childhood and is a persistent movement disorder before the age of three. This disorder can negatively affect both the child and their family. In recent years, the use of melatonin as a safe, effective, and cheap drug has been expanding in improving the sleep disorders of these children. Therefore, this study aimed to investigate melatonin's effect on sleep disorders in children with CP.

Materials & Methods

This double-blind clinical trial was conducted on children aged 2 to 12 years with CP who were referred to the pediatric neurology clinic for sleep problems. The participants were included in the study by convenience sampling. After obtaining informed consent from parents, patients were divided randomly into two intervention (melatonin) and control (placebo) groups. In the intervention group, patients received oral melatonin tablets, and in the control group, patients received a placebo (3 mg oral lactose) 30 minutes before going to sleep.

Results

The results of this study showed no significant relationship between age and gender with sleep disorders in children with CP (P>0.05). A significant effect of melatonin on sleep disorders was found in children with CP. The greatest effect of melatonin is the time required to start falling asleep. Melatonin was associated with decreased time needed to fall asleep and increased sleep duration.

Conclusion

The results of the study demonstrated that sleep disorders are prevalent among children with CP. Therefore, proper and timely treatment of these children is crucial. According to the present study's findings, melatonin effectively improves the time of falling asleep and these children's sleep duration.

Sleep Symptoms and Disorders in Episodic Migraine: Assessment and Management

PURPOSE OF REVIEW

We review research on sleep symptoms and disorders in patients with episodic migraine and propose a framework for evaluating sleep symptoms in this patient population.

RECENT FINDINGS

Patients with episodic migraine consistently report poorer sleep on validated self-reports compared to those without migraine. In polysomnographic studies, children with migraine have objectively shorter sleep duration and lower percentage of REM sleep interictally. Prospective actigraphy studies in adults and children suggest that there are no significant changes in sleep duration, efficiency, or quality in the night before or after a migraine attack. The relationship between sleep and migraine is multifaceted. Patients with episodic migraine report poorer sleep and have higher risk of some sleep disorders, including insomnia, sleep-related bruxism, and restless legs syndrome. Sleep screening questions may be incorporated into headache evaluations. Care should be taken to avoid headache medications that may exacerbate sleep symptoms. Evidence-based treatments for insomnia may be initiated while patients await CBT-I. Further studies are needed to assess whether treatment of comorbid sleep disorders results in improvement in migraine-related burden in those with episodic migraine.

Cyclic changes of sensory parameters in migraine patients

BACKGROUND

Migraine shows a cyclic pattern with an inter-ictal-, a pre-ictal, an ictal- and a post-ictal phase. We aimed to examine changes in psychophysical parameters during the migraine cycle.

METHODS

The perception of nociceptive and non-nociceptive stimuli and an electrically induced axon-reflex-erythema were assessed in 20 healthy controls and 14 migraine patients on five consecutive days according to different phases of the migraine cycle. Pain was rated three times during a 10-second electrical stimulus. The size of the axon-reflex-erythema was determined using laser-Doppler-imaging. Intensity and hedonic estimates of odours presented by Sniffin' Sticks were rated.

RESULTS

In healthy controls, no significant changes over the test days were observed. In migraine patients pain thresholds at the head decreased with an ictal minimum. Less habituation after five seconds of stimulation at the head was found pre-ictally, whereas reduced habituation to 10-second electrical stimulation was present in all phases. The axon-reflex-erythema size showed an inter-ictal-specific minimum at the head. odours were perceived ictally as more unpleasant and intense.

CONCLUSIONS

Somatosensory functions, pain thresholds and habituation as predominantly central parameters, axon-reflex-erythema as a peripheral function of trigeminal neurons and odour perception as a predominantly extra-thalamic sensation change specifically over the migraine cycle indicating complex variations of neuronal signal processing.

Pain thresholds and suprathreshold pain after sleep restriction in migraine - A blinded crossover study

OBJECTIVE

There is an unexplained association between disturbed sleep and migraine. In this blinded crossover study, we investigate if experimental sleep restriction has a different effect on pain thresholds and suprathreshold pain in interictal migraineurs and controls.

METHODS

Forearm heat pain thresholds and tolerance thresholds, and trapezius pressure pain thresholds and suprathreshold pain were measured in 39 interictal migraineurs and 31 healthy controls after two consecutive nights of partial sleep restriction and after habitual sleep.

RESULTS

The effect of sleep restriction was not significantly different between interictal migraineurs and controls in the primary analyses. Pressure pain thresholds tended to be lower (i.e., increased pain sensitivity) after sleep restriction in interictal migraineurs compared to controls with a 48-hour preictal-interictal cut-off (p = 0.061). We found decreased pain thresholds after sleep restriction in two of seven migraine subgroup comparisons: heat pain thresholds decreased in migraineurs with lower pain intensity during attacks (p = 0.005) and pressure pain thresholds decreased in migraineurs with higher severity of photophobia during attacks (p = 0.031). Heat pain thresholds tended to decrease after sleep restriction in sleep-related migraine (p = 0.060). Sleep restriction did not affect suprathreshold pain measurements in either group.

CONCLUSION

This study could not provide strong evidence for an increased effect of sleep restriction on pain sensitivity in migraineurs compared to healthy controls. There might be a slightly increased effect of sleep restriction in migraineurs, detectable using large samples or more pronounced in certain migraine subgroups.

Subjective Sleep Quality and Sleep Architecture in Patients With Migraine: A Meta-analysis

Background and Objectives

Sleep disturbance is often associated with migraine. However, there is a paucity of research investigating objective and subjective measures of sleep in patients with migraine. This meta-analysis aims to determine whether there are differences in subjective sleep quality measured using the Pittsburgh Sleep Quality Index (PSQI) and objective sleep architecture measured using polysomnography (PSG) between adult and pediatric patients and healthy controls.

Methods

This review was preregistered on PROSPERO (CRD42020209325). A systematic search of 5 databases (Embase, MEDLINE, Global Health, APA PsycINFO, and APA PsycArticles, last searched on December 17, 2020) was conducted to find case–control studies that measured PSG or PSQI in patients with migraine. Pregnant participants and those with other headache disorders were excluded. Effect sizes (Hedges g) were entered into a random effects model meta-analysis. Study quality was evaluated with the Newcastle Ottawa Scale and publication bias with the Egger regression test.

Results

Thirty-two studies were eligible, of which 21 measured PSQI or Migraine Disability Assessment Test in adults, 6 measured PSG in adults, and 5 measured PSG in children. The overall mean study quality score was 5/9; this did not moderate any of the results and there was no risk of publication bias. Overall, adults with migraine had higher PSQI scores than healthy controls (g = 0.75, p < 0.001, 95% confidence interval [CI] 0.54–0.96). This effect was larger in those with a chronic rather than episodic condition (g = 1.03, p < 0.001, 95% CI 0.37–1.01; g = 0.63, p < 0.001, 95% CI 0.38–0.88, respectively). For polysomnographic studies, adults and children with migraine displayed a lower percentage of rapid eye movement sleep (g = −0.22, p = 0.017, 95% CI −0.41 to −0.04; g = −0.71, p = 0.025, 95% CI −1.34 to −0.10, respectively) than controls. Pediatric patients displayed less total sleep time (g = −1.37, p = 0.039, 95% CI −2.66 to −0.10), more wake (g = 0.52, p < 0.001, 95% CI 0.08–0.79), and shorter sleep onset latency (g = −0.37, p < 0.001, 95% CI −0.54 to −0.21) than controls.

Discussion

People with migraine have significantly poorer subjective sleep quality and altered sleep architecture compared to healthy individuals. Further longitudinal empirical studies are required to enhance our understanding of this relationship.

Differentiating migraine, cervicogenic headache and asymptomatic individuals based on physical examination findings: a systematic review and meta-analysis

BACKGROUND

Migraine and cervicogenic headache (CGH) are common headache disorders, although the large overlap of symptoms between them makes differential diagnosis challenging. To strengthen differential diagnosis, physical testing has been used to examine for the presence of musculoskeletal impairments in both conditions. This review aimed to systematically evaluate differences in physical examination findings between people with migraine, CGH and asymptomatic individuals.

METHODS

The databases MEDLINE, PubMed, CINAHL, Web of Science, Scopus, EMBASE were searched from inception until January 2020. Risk of bias was assessed with the Downs and Black Scale for non-randomized controlled trials, and with the Quality Assessment of Diagnostic Accuracy Studies tool for diagnostic accuracy studies. When possible, meta-analyses with random effect models was performed.

RESULTS

From 19,682 articles, 62 studies were included in this review and 41 were included in the meta-analyses. The results revealed: a) decreased range of motion [°] (ROM) on the flexion-rotation test (FRT) (17.67, 95%CI:13.69,21.65) and reduced neck flexion strength [N] (23.81, 95%CI:8.78,38.85) in CGH compared to migraine; b) compared to controls, migraineurs exhibit reduced flexion ROM [°] (- 2.85, 95%CI:-5.12,-0.58), lateral flexion ROM [°] (- 2.17, 95% CI:-3.75,-0.59) and FRT [°] (- 8.96, 95%CI:-13.22,-4.69), reduced cervical lordosis angle [°] (- 0.89, 95%CI:-1.72,-0.07), reduced pressure pain thresholds over the cranio-cervical region [kg/cm²], reduced neck extension strength [N] (- 11.13, 95%CI:-16.66,-5.6) and increased activity [%] of the trapezius (6.18, 95%CI:2.65,9.71) and anterior scalene muscles (2.87, 95%CI:0.81,4.94) during performance of the cranio-cervical flexion test; c) compared to controls, CGH patients exhibit decreased neck flexion (- 33.70, 95%CI:-47.23,-20.16) and extension (- 55.78, 95%CI:-77.56,-34.00) strength [N].

CONCLUSION

The FRT and neck flexion strength could support the differential diagnosis of CGH from migraine. Several physical tests were found to differentiate both headache types from asymptomatic individuals. Nevertheless, additional high-quality studies are required to corroborate these findings.

STUDY REGISTRATION

Following indications of Prisma-P guidelines, this protocol was registered in PROSPERO on 21/05/2019 with the number CRD42019135269 . All amendments performed during the review were registered in PROSPERO, indicating the date and what and why was changed.

Melatonin Moderates the Triangle of Chronic Pain, Sleep Architecture and Immunometabolic Traffic

Preclinical as well as human studies indicate that melatonin is essential for a physiological sleep state, promotes analgesia and is involved in immunometabolic signaling by regulating neuroinflammatory pathways. Experimental and clinical neuromodulation studies for chronic pain treatment suggest that neurostimulation therapies such as spinal cord stimulation, vagus nerve stimulation and dorsal root ganglion stimulation have an impact on circulating inflammatory mediators in blood, cerebrospinal fluid and saliva. Herein, we provide an overview of current literature relevant for the shared pathways of sleep, pain and immunometabolism and elaborate the impact of melatonin on the crossroad of sleep, chronic pain and immunometabolism. Furthermore, we discuss the potential of melatonin as an adjunct to neurostimulation therapies. In this narrative review, we addressed these questions using the following search terms: melatonin, sleep, immunometabolism, obesity, chronic pain, neuromodulation, neurostimulation, neuroinflammation, molecular inflammatory phenotyping. So far, the majority of the published literature is derived from experimental studies and studies specifically assessing these relationships in context to neurostimulation are sparse. Thus, the adjunct potential of melatonin in clinical neurostimulation has not been evaluated under the umbrella of randomized-controlled trials and deserves increased attention as melatonin interacts and shares pathways relevant for noninvasive and invasive neurostimulation therapies.

Migraine Is More Than Just Headache: Is the Link to Chronic Fatigue and Mood Disorders Simply Due to Shared Biological Systems?

Migraine is a symptomatically heterogeneous condition, of which headache is just one manifestation. Migraine is a disorder of altered sensory thresholding, with hypersensitivity among sufferers to sensory input. Advances in functional neuroimaging have highlighted that several brain areas are involved even prior to pain onset. Clinically, patients can experience symptoms hours to days prior to migraine pain, which can warn of impending headache. These symptoms can include mood and cognitive change, fatigue, and neck discomfort. Some epidemiological studies have suggested that migraine is associated in a bidirectional fashion with other disorders, such as mood disorders and chronic fatigue, as well as with other pain conditions such as fibromyalgia. This review will focus on the literature surrounding alterations in fatigue, mood, and cognition in particular, in association with migraine, and the suggested links to disorders such as chronic fatigue syndrome and depression. We hypothesize that migraine should be considered a neural disorder of brain function, in which alterations in aminergic networks integrating the limbic system with the sensory and homeostatic systems occur early and persist after headache resolution and perhaps interictally. The associations with some of these other disorders may allude to the inherent sensory sensitivity of the migraine brain and shared neurobiology and neurotransmitter systems rather than true co-morbidity.

[Anxiety disorders as a risk factor for sleep disorders and headaches]

Anxiety and related sleep disorders are a problem in modern society. Sleep disorders cover more than 45% of the world's population and have become a global health problem in recent decades. Numerous studies have shown an association of sleep disorders with pain, depression, and anxiety, as well as a causal relationship between chronic pain and sleep deficits. Patients with headaches are at a higher risk of mood and anxiety disorders than people in the general population; these results are particularly noticeable for patients with chronic daily headache as well as medication overuse headache. This interaction between mood/anxiety problems and medication overuse may be an important factor in chronification of episodic headache. Detection and treatment of comorbid diseases will not only provide better results, but also improve the quality of life of patients. In the treatment of this category of patients, it is possible to use noofen, which improves sleep, cognitive functions, and reduces headache.

Digital Cognitive Behavioral Therapy for Insomnia in Women With Chronic Migraines

OBJECTIVE/BACKGROUND

Insomnia commonly co-occurs with chronic migraines (CM). Non-pharmacological treatments for insomnia in CM patients remain understudied. This is a proof-of-concept study, which aims to evaluate the feasibility, acceptability, and preliminary efficacy of a digital cognitive behavioral therapy for insomnia (dCBT-I) for individuals with CM and insomnia (CM-I) in the United States.

METHODS

We recruited 42 females with CM-I symptoms from a U.S.-based observational cohort and from the general population via advertisements. Within a multiple baseline design, participants were randomized to receive dCBT-I after 2, 4, or 6 weeks of completing baseline sleep diaries. DCBT-I was scrutinized against benchmarks for completion rates (≥90% to complete dCBT-I), acceptability (≥80% to find dCBT-I acceptable), and posttreatment changes in insomnia symptoms (≥50% indicating a clinically relevant improvement in their insomnia symptoms). As a secondary measure, we also reported percentage of individuals reverting to episodic migraines.

RESULTS

Out of 42 randomized, 35 (83.3%) completed dCBT-I within the 12 weeks provided. Of these completers, 33 (94.3%) reported being satisfied (n = 16) or very satisfied (n = 17) with treatment. Additionally, 65.7% of completers responded to treatment as per universally accepted criteria for insomnia. Lastly, 34% of completers reverted from CM to episodic migraine.

CONCLUSION

This study provides evidence for the feasibility and acceptability of dCBT-I in patients with CM-I complaints. Effects of improving insomnia and migraines were suggested. These results indicate that a randomized controlled trial is needed to determine the efficacy of dCBT-I in CM patients.

Fluctuations in local and widespread mechanical sensitivity throughout the migraine cycle: a prospective longitudinal study

BACKGROUND

People with migraine have localised (i.e., cephalic) mechanical sensitivity. There is uncertainty regarding widespread (i.e., extra-cephalic) mechanical sensitivity and variations in mechanical sensitivity throughout the migraine cycle. Therefore, this study aimed (1) to comprehensively assess mechanical sensitivity in both cephalic and extra-cephalic regions during the preictal, ictal, postictal and interictal phases; and (2) to compare these findings with mechanical sensitivity at corresponding time-points and locations in healthy participants.

METHODS

According to sample size calculations, 19 people with migraine and 19 matched healthy volunteers participated in a prospective longitudinal study. Pressure pain thresholds were evaluated in three cephalic regions (temporalis, upper trapezius and C1 paraspinal muscles) and two extra-cephalic regions (extensor carpi radialis and tibialis anterior muscle) with a digital algometer during the four phases of the migraine cycle in people with migraine and at corresponding intervals and locations in healthy participants. Linear mixed model analyses with a random intercept were used.

RESULTS

People with migraine had increased mechanical sensitivity in cephalic and extra-cephalic regions in all phases of the migraine cycle compared to healthy participants. Furthermore, this mechanical sensitivity was more severe in the preictal, ictal and postictal phase compared to the interictal phase in cephalic and extra-cephalic regions.

CONCLUSION

People with migraine have localised as well as widespread mechanical sensitivity compared to healthy participants. This sensitivity is even more pronounced immediately before, during and after a migraine attack.

Nightly sleep duration, fragmentation, and quality and daily risk of migraine

OBJECTIVE

To test the hypotheses that insufficient duration, high fragmentation, and poor sleep quality are temporally associated with migraine onset on the day immediately following the sleep period (day 0) and the following day (day 1).

METHODS

In this prospective cohort study of 98 adults with episodic migraine, participants completed twice-daily electronic diaries on sleep, headaches, and other health habits, and wore wrist actigraphs for 6 weeks. We estimated the incidence of migraine following nights with short sleep duration, high fragmentation, or low quality compared to nights with adequate sleep with conditional logistic regression models stratified by participant and adjusted for caffeine intake, alcohol intake, physical activity, stress, and day of week.

RESULTS

Participants were a mean age of 35.1 ± 12.1 years. We collected 4,406 days of data, with 870 headaches reported. Sleep duration ≤6.5 hours and poor sleep quality were not associated with migraine on day 0 or day 1. Diary-reported low efficiency was associated with 39% higher odds of headache on day 1 (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.06-1.81). Actigraphic-assessed high fragmentation was associated with lower odds of migraine on day 0 (wake after sleep onset >53 minutes, OR 0.64, 95% CI 0.48-0.86; efficiency ≤88%, OR 0.74, 95% CI 0.56-0.99).

CONCLUSION

Short sleep duration and low sleep quality were not temporally associated with migraine. Sleep fragmentation, defined by low sleep efficiency, was associated with higher odds of migraine on day 1. Further research is needed to understand the clinical and neurobiologic implications of sleep fragmentation and risk of migraine.

Widespread Pressure Pain Hyperalgesia Is Not Related to Pain in Patients with Parkinson's Disease

OBJECTIVE

Pain is one of the most frequent nonmotor impairments in Parkinson's disease (PD) and is hypothesized to be associated with altered nociceptive pain processing. Our aims were to investigate differences in widespread pressure pain sensitivity between PD patients with and without pain and healthy controls and to assess the relationship of health-related quality of life and sleep quality with pressure pain sensitivity.

METHODS

Nineteen PD patients with pain (12 men, age = 68 ± 9 years), 19 PD patients without pain (11 men, age = 69 ± 8 years), and 19 matched controls participated. Pressure pain thresholds (PPTs) were assessed bilaterally over the cervical spine, the second metacarpal, and the tibialis anterior by an assessor blinded to the subject's condition. Patients were assessed in a dopamine-medicated (ON) state. Pain intensity (numerical pain rating scale, 0-10), health-related quality of life (39-item Parkinson's Disease Questionnaire), and sleep quality (Pittsburgh Sleep Quality Index) were also assessed.

RESULTS

No significant differences existed between PD patients, with or without pain, and healthy controls on PPTs over the cervical spine, the second metacarpal, or the tibialis anterior muscle (all P > 0.3). PPTs were lower in females than in males in all groups (P < 0.01). In PD patients with pain, worse quality of sleep was associated with higher widespread pressure pain sensitivity (-0.607 < r < -0.535, P < 0.05). No other significant association was observed.

CONCLUSIONS

This study revealed no differences in widespread pressure hyperalgesia between PD patients with or without pain (ON state) and controls. Although dopamine may modulate pain responses, other mechanisms seems to also be implicated in altered nociceptive pain processing in patients with PD.

Physical therapy and migraine: musculoskeletal and balance dysfunctions and their relevance for clinical practice

BACKGROUND

Migraine is a primary headache with high levels of associated disability that can be related to a variety of symptoms and comorbidities. The role of physical therapy in the management of migraine is largely unknown. Therefore, the aim of this review is to highlight and critically discuss the current literature and evidence for physical therapy interventions in individuals with migraines.

METHODS

A narrative review of the literature was performed.

RESULTS

Physical therapists assessing and treating patients with migraine should focus on two primary aspects: (1) musculoskeletal dysfunctions, and (2) vestibular symptoms/postural control impairment. Signs and symptoms of musculoskeletal and/or vestibular dysfunctions are prevalent among individuals with migraines and different disability levels can be observed depending on the presence of aura or increment of the migraine attacks.

CONCLUSION

A proper physical examination and interview of the patients will lead to a tailored treatment plan. The primary aim regarding musculoskeletal dysfunctions is to reduce pain and sensitization, and physical therapy interventions may include a combination of manual therapy, exercise therapy, and education. The aim regarding postural control impairment is to optimize function and reduce vestibular symptoms, and interventions should include balance exercises and vestibular rehabilitation. However, consistent evidence of benefits is still lacking due to the lack of and therefore need for tailored and pragmatic clinical trials with high methodological quality.

Which Examination Tests Detect Differences in Cervical Musculoskeletal Impairments in People With Migraine? A Systematic Review and Meta-Analysis

BACKGROUND

Most patients with migraine report associated neck pain. Whether neck pain is a symptom of migraine or an indicator for associated cervical musculoskeletal impairment has not yet been determined. Physical examination tests to detect cervical impairments in people with headache have been suggested, but results have not been evaluated systematically and combined in meta-analyses.

PURPOSE

The purpose of this study was to identify musculoskeletal impairments in people with migraine and people who were healthy (healthy controls) by reviewing published data on physical examination results.

DATA SOURCES

PubMed, CINAHL, Web of Science, and the Cochrane Register of Clinical Trials were searched for studies published prior to December 2017.

STUDY SELECTION

Publications investigating physical examination procedures that are feasible for use in a physical therapy setting for patients with migraine and healthy controls were independently selected by 2 researchers.

DATA EXTRACTION

One researcher extracted the data into predesigned data extraction tables. Entries were checked for correctness by a second researcher. The Downs and Black Scale was used for risk-of-bias assessment by 2 reviewers independently.

DATA SYNTHESIS

Thirty-five studies (involving 1033 participants who were healthy [healthy controls] and 1371 participants with migraine) were included in the qualitative synthesis, and 18 were included in the meta-analyses (544 healthy controls and 603 participants with migraine). Overall, studies were rated as having a low to moderate risk of bias. Included studies reported 20 different test procedures. Combined mean effects indicated that 4 of the tests included in the meta-analyses distinguished between patients and controls: range of cervical motion, flexion-rotation, pressure pain thresholds, and forward head posture in a standing position.

LIMITATIONS

Manual joint testing and evaluation of trigger points were the 2 most frequently investigated tests not included in the meta-analyses because of heterogeneity of reporting and procedures.

CONCLUSIONS

Three tests confirmed the presence of musculoskeletal impairments in participants with migraine when combined in meta-analyses. Pressure pain thresholds added information on sensory processing. Additional tests might be useful but require standardized protocols and reporting.

Sleep Disorders and Migraine: Review of Literature and Potential Pathophysiology Mechanisms

Migraine shares a complex and poorly understood relationship with sleep. Patients consistently report poor sleep prior to migraine attacks and during them, identifying poor sleep as a migraine trigger. However, anecdotally, sleep is reported to serve a therapeutic role in terminating headache. Are the associations between migraine and sleep simply the result of various bidirectional relationships? A growing body of evidence suggests there may be a common underlying etiology as well. Our objective was to review studies of sleep and migraine from the last 2 decades utilizing validated subjective and objective measures of sleep and to explore potential mechanisms underlying this complex relationship by incorporating recent advances in neuroscience. We specifically focus on insomnia, obstructive sleep apnea, parasomnias, sleep related movement disorders, and REM sleep related disorders and their relationship to migraine. Parts of brainstem-cortical networks involved in sleep physiology are unintentionally being identified as important factors in the common migraine pathway. Recent discoveries on anatomic localization (the hypothalamus as a key and early mediator in the pathophysiology of migraine), common mediating signaling molecules (such as serotonin and dopamine), and the discovery of a new CNS waste removal system, the glymphatic system, all point to a common pathophysiology manifesting in migraine and sleep problems.

Pain Perception and Migraine

Background: It is well-known that both inter- and intra-individual differences exist in the perception of pain; this is especially true in migraine, an elusive pain disorder of the head. Although electrophysiology and neuroimaging techniques have greatly contributed to a better understanding of the mechanisms involved in migraine during recent decades, the exact characteristics of pain threshold and pain intensity perception remain to be determined, and continue to be a matter of debate.

Objective: The aim of this review is to provide a comprehensive overview of clinical, electrophysiological, and functional neuroimaging studies investigating changes during various phases of the so-called “migraine cycle” and in different migraine phenotypes, using pain threshold and pain intensity perception assessments.

Methods: A systematic search for qualitative studies was conducted using search terms “migraine,” “pain,” “headache,” “temporal summation,” “quantitative sensory testing,” and “threshold,” alone and in combination (subject headings and keywords). The literature search was updated using the additional keywords “pain intensity,” and “neuroimaging” to identify full-text papers written in English and published in peer-reviewed journals, using PubMed and Google Scholar databases. In addition, we manually searched the reference lists of all research articles and review articles.

Conclusion: Consistent data indicate that pain threshold is lower during the ictal phase than during the interictal phase of migraine or healthy controls in response to pressure, cold and heat stimuli. There is evidence for preictal sub-allodynia, whereas interictal results are conflicting due to either reduced or no observed difference in pain threshold. On the other hand, despite methodological limitations, converging observations support the concept that migraine attacks may be characterized by an increased pain intensity perception, which normalizes between episodes. Nevertheless, future studies are required to longitudinally evaluate a large group of patients before and after pharmacological and non-pharmacological interventions to investigate phases of the migraine cycle, clinical parameters of disease severity and chronic medication usage.

Pressure pain thresholds over the cranio-cervical region in headache: a systematic review and meta-analysis

BACKGROUND

Sensitivity of tissues can be measured by algometry. Decreased pressure pain thresholds over the cranio-cervical area are supposed to reflect signs of sensitization of the trigemino-cervical nucleus caudalis. A systematic review was conducted to assess the current scientific literature describing pressure pain threshold (PPT) values over the cranio-cervical region in patients with migraine, tension-type headache (TTH), and cervicogenic headache (CeH). A literature search was executed in three databases. The search strategy included the following keywords: migraine, TTH, CeH, PPT and algometry. A total of 624 papers was identified of which relevant papers were subsequently assessed for methodological quality. Twenty-two selected papers were assessed by two independent reviewers and the majority of studies scored low risk of bias on the selected items. Mean PPT values of several sites measured in the cranio-cervical region in patients with migraine, chronic TTH and CeH scored lower values compared to controls. The trapezius muscle (midpoint between vertebrae C7 and acromion) was the most frequently targeted site and showed significantly lower PPT values in adults with migraine (pooled standardized mean difference kPa: 1.26 [95%CI -1.71, -0.81]) and chronic TTH (pooled standardized mean difference kPa: -2.00 [95%CI -2.93, -1.08]). Most studies found no association between PPT values and headache characteristics such as frequency, duration or intensity. Further standardization of PPT measurement in the cranio-cervical region is recommended.

Comparison of the Quality of Sleep and Intensity of Headache between Migraine, Tension Headache, and Healthy Children

OBJECTIVES

Headache and sleep problems are commonly reported in children, and both can adversely impact the child's life. We aimed to compare the sleep quality and intensity of headache between school-age children with migraine as well as tension headache and healthy children.

MATERIALS & METHODS

In this cross-sectional study, 198 children 6-12 yr old in three groups were enrolled from Aug 2015 to Mar 2016. Migraine and tension headache groups from the Outpatient Clinic of Imam Khomeini of Hamadan, western Iran and healthy group from elementary schools were randomly selected (66 children in each group). Data were collected using demographic questionnaire, Child Sleep Habits Questionnaire (CSHQ), Numeric Scale of Pain Intensity and Wong-Baker Faces Pain Rating Scale. The data were analyzed using SPSS by descriptive statistic and multivariate ANOVA, one way ANOVA, Chi-square, Kruskal-Wallis and linear regression tests.

RESULTS

Approximately, 45.5% of children with migraine and 37.9% of them with tension headache had experienced severe headache. Only a significant relationship was seen between mean scores of headache intensity and sleep quality in migraine group (P<0.05). There was a significant difference in mean scores of sleep quality among three groups (P<0.001).

CONCLUSION

The children with migraine experienced more unsuitable sleep in duration of severe headache. Highlighting the co-morbidity between intensity of headache and sleep problem of children with migraine and tension headache is important to improve treatment strategies and to know the impact of headache on their normal life.

Insufficient sleep is prevalent among migraineurs: a population-based study

Background

Sleep disorder and sleep complaints are common in subjects with migraine. Although the association between sleep disorders and migraine has been reported, the association between perceived insufficient sleep and migraine has rarely reported. The aim of this study is to evaluate the association between insufficient sleep and migraine using the data of the Korean Headache-Sleep Study (KHSS).

Methods

The KHSS is a nation-wide cross-sectional population-based survey regarding headache and sleep for Korean adults aged 19 to 69 years. A difference of one hour or more between sleep need and average sleep time indicated insufficient sleep.

Results

Of 2,695 participants, 727 (27.0%) individuals were classified as having insufficient sleep. The prevalence of insufficient sleep among individuals with migraine (45.5%) was significantly higher compared to that among individuals with non-migraine headache (32.9%, p = 0.004) or among non-headache (20.4%, p < 0.001). Average sleep time did not differ among migraine, non-migraine headache, and non-headache groups (7.3 ± 1.2 vs. 7.2 ± 1.2 vs. 7.3 ± 1.4, p = 0.207). Multivariable logistic regression analyses demonstrated that migraine had an increased odds ratio (OR) for insufficient sleep after adjusting for sociodemographic variables, short sleep time, insomnia, poor sleep quality, anxiety, and depression (OR = 1.8, 95% confidence interval [CI] = 1. 2 – 2.7, p = 0.002).

Conclusions

The prevalence of insufficient sleep was significantly higher among migraineurs compared to that in non-migraine headache or non-headache group.

Does pain sensitivity change by migraine phase? A blinded longitudinal study

Objective

Studies suggest that pain thresholds may be altered before and during migraine headaches, but it is still debated if a central or peripheral dysfunction is responsible for the onset of pain in migraine. The present blinded longitudinal study explores alterations in thermal pain thresholds and suprathreshold heat pain scores before, during, and after headache.

Methods

We measured pain thresholds to cold and heat, and pain scores to 30 seconds of suprathreshold heat four times in 49 migraineurs and once in 31 controls. Sessions in migraineurs were categorized by migraine diaries as interictal, preictal (≤one day before attack), ictal or postictal (≤one day after attack).

Results

Trigeminal cold pain thresholds were decreased ( p = 0.014) and pain scores increased ( p = 0.031) in the ictal compared to the interictal phase. Initial pain scores were decreased ( p < 0.029), and the temporal profile showed less adaptation ( p < 0.020) in the preictal compared to the interictal phase. Hand cold pain thresholds were decreased in interictal migraineurs compared to controls ( p < 0.019).

Conclusion

Preictal heat hypoalgesia and reduced adaptation was followed by ictal trigeminal cold suballodynia and heat hyperalgesia. Our results support that cyclic alterations of pain perception occur late in the prodromal phase before headache. Further longitudinal investigation of how pain physiology changes within the migraine cycle is important to gain a more complete understanding of the pathogenic mechanisms behind the migraine attack.

Neurobiology and sleep disorders in cluster headache

Cluster headache is characterized by unilateral attacks of severe pain accompanied by cranial autonomic features. Apart from these there are also sleep-related complaints and strong chronobiological features. The interaction between sleep and headache is complex at any level and evidence suggests that it may be of critical importance in our understanding of primary headache disorders. In cluster headache several interactions between sleep and the severe pain attacks have already been proposed. Supported by endocrinological and radiological findings as well as the chronobiological features, predominant theories revolve around central pathology of the hypothalamus. We aimed to investigate the clinical presentation of chronobiological features, the presence of concurrent sleep disorders and the relationship with particular sleep phases or phenomena, the possible role of hypocretin as well as the possible involvement of cardiac autonomic control. We conducted a questionnaire survey on 275 cluster headache patients and 145 controls as well an in-patient sleep study including 40 CH-patients and 25 healthy controls. The findings include: A distinct circannual connection between cluster occurrence and the amount of daylight, substantially poorer sleep quality in patients compared to controls which was present not only inside the clusters but also outside, affected REM-sleep in patients without a particular temporal connection to nocturnal attacks, equal prevalence of sleep apnea in both patient and control groups, reduced levels of hypocretin-1 in the cerebrospinal fluid of patients and finally a blunted response to the change from supine to tilted position in the head-up tilt table test indicating a weakened sympathoexcitatory or stronger parasympathetic drive. Overall, these findings support a theory of involvement of dysregulation in hypothalamic and brainstem nuclei in cluster headache pathology. Further, it is made plausible that the headache attacks are but one aspect of a more complex syndrome of central dysregulation manifesting as sleep-related complaints, sub-clinical autonomic dysregulation and of course the severe attacks of unilateral headache. Future endeavors should focus on pathological changes which persist in the attack-free periods but also heed the possibility of long-lived, cluster-induced pathology.

The Presence of Symptoms With Comorbid Conditions in Individuals With Multiple Sclerosis (MS)

Individuals with multiple sclerosis (MS) may experience symptoms that impact comorbid conditions and quality of life (QOL). There is some evidence that symptom severity may vary in certain common health conditions in this population. We aimed to examine symptom severity in light of comorbid conditions commonly seen in individuals with MS (N = 339). Using a cross-sectional Internet survey, we found there was a significant increase in symptom severity of common symptoms of fatigue, imbalance, and weakness, specifically with presence or absence of certain comorbid conditions (depression, arthritis, migraine headaches, coronary artery disease [CAD]). These findings endorse the presence of more severe symptoms with certain comorbid conditions compared with individuals with MS who do not report having comorbid conditions. The findings support the importance of symptom management in individuals with MS who also have comorbid conditions.

Study of sleep microstructure in patients of migraine without aura

PURPOSE

Although the relationship between sleep and migraine has been widely reported, studies on sleep microstructure are few. The aim was to study and compare microstructural polysomnographic characteristics in patients of "migraine without aura" (MOA) with controls.

METHODS

Twenty-five patients of MOA and 25 age- and gender-matched healthy controls were subjected to overnight polysomnography. Microstructural sleep analysis, including arousal and cyclic alternating pattern (CAP) analysis was performed. Arousals and CAP parameters were compared between the two groups using the Mann-Whitney U test (p ≤ 0.05).

RESULTS

The overall arousal index (p = 0.528) and that during non-rapid eye movement (NREM) sleep (p = 0.503) were comparable between the two groups. However, the arousal index was lower in migraineurs during rapid eye movement (REM) sleep (p = 0.001). The overall CAP rate (p = 0.020) as well as the number of CAP cycles and sequences (p = 0.032) was lower among migraineurs. The total phase A duration (p < 0.0001) was increased, and conversely, phase B duration (p = 0.001) was decreased in migraineurs. The phase A1 duration (p = 0.036) was higher in migraineurs. Finally, phase A1 (p = 0.357) index was comparable, and conversely, A2 (p < 0.0001) and A3 (p = 0.020) indices were decreased in migraineurs.

CONCLUSIONS

This study showed a decreased REM arousability as well as a decreased overall CAP rate and CAP cycling in patients with migraine as compared to controls. This indicates that there is probably an alteration of the arousal mechanisms in patients with migraine that may facilitate the occurrence of headache paroxysms during sleep.

Sleep in cluster headache - beyond a temporal rapid eye movement relationship?

BACKGROUND AND PURPOSE

Cluster headache (CH) is a primary headache disorder characterized by severe attacks of unilateral pain following a chronobiological pattern. There is a close connection with sleep as most attacks occur during sleep. Hypothalamic involvement and a particular association with rapid eye movement (REM) sleep have been suggested. Sleep in a large, well-characterized population of CH patients was investigated.

METHODS

Polysomnography (PSG) was performed on two nights in 40 CH patients during active bout and one night in 25 age, sex and body mass index matched controls in hospital. Macrostructure and other features of sleep were analyzed and related to phenotype. Clinical headache characterization was obtained by semi-structured interview.

RESULTS

Ninety-nine nights of PSG were analyzed. Findings included a reduced percentage of REM sleep (17.3% vs. 23.0%, P = 0.0037), longer REM latency (2.0 vs. 1.2 h, P = 0.0012) and fewer arousals (7.34 vs. 14.1, P = 0.003) in CH patients. There was no difference in prevalence of sleep apnea between patients (38%) and matched controls (32%, P = 0.64) although the apnea index in patients was numerically higher (mean apnea-hypopnea index 10.75 vs. 4.93). No temporal association between nocturnal attacks (n = 45) and particular sleep stages was observed.

CONCLUSIONS

To date, this is the largest study of sleep in CH. It is demonstrated that REM sleep is affected which is in line with our current understanding of CH and hypothalamic involvement in the regulation of this sleep stage. Further, fewer arousals were found in CH patients but no association between apnea events or specific sleep stages. The findings support a central role of the hypothalamus and arousal systems in CH.

The effect of sleep restriction on laser evoked potentials, thermal sensory and pain thresholds and suprathreshold pain in healthy subjects

OBJECTIVE

Sleep restriction seems to change our experience of pain and reduce laser evoked potential (LEP) amplitudes. However, although LEP-habituation abnormalities have been described in painful conditions with comorbid sleep impairment, no study has previously measured the effect of sleep restriction on LEP-habituation, pain thresholds, and suprathreshold pain.

METHOD

Sixteen males and seventeen females (aged 18-31years) were randomly assigned to either two nights of delayed bedtime and four hours sleep (partial sleep deprivation) or nine hours sleep. The study subjects slept at home, and the sleep was measured with actigraphy both nights and polysomnography the last night. LEP, thermal thresholds and suprathreshold pain ratings were obtained the day before and the day after intervention. The investigator was blinded. ANOVA was used to evaluate the interaction between sleep restriction and day for each pain-related variable.

RESULTS

LEP-amplitude decreased after sleep restriction (interaction p=0.02) compared to subjects randomized to nine hours sleep. LEP-habituation was similar in both groups. Thenar cold pain threshold decreased after sleep restriction (interaction p=0.009). Supra-threshold heat pain rating increased temporarily 10s after stimulus onset after sleep restriction (interaction p=0.01), while it did not change after nine hours sleep.

CONCLUSION

Sleep restriction reduced the CNS response to pain, while some of the subjective pain measures indicated hyperalgesia.

SIGNIFICANCE

Since LEP-amplitude is known to reflect both CNS-pain-specific processing and cognitive attentive processing, our results suggest that hyperalgesia after sleep restriction might partly be caused by a reduction in cortical cognitive or perceptual mechanisms, rather than sensory amplification.

Headache and insomnia in population-based epidemiological studies

BACKGROUND

Several epidemiological studies on the association between primary headaches and insomnia have been published in recent years. Both disorders are frequent, and our purpose was to review results from population-based studies exploring this association.

METHODS

We performed a literature search in PubMed for "insomnia" (or sleep disturbance) and "headache" (or migraine) linked with "epidemiology." Two hundred and eight records were identified. Three longitudinal and 10 cross-sectional studies met our inclusion criteria: population-based design with at least 200 participants including a numerical estimate of the association between headache and insomnia.

RESULTS AND CONCLUSIONS

In nearly all studies, primary headaches, including migraine and tension-type headache, were significantly related to insomnia symptoms with OR estimates ranging from 1.4 to 1.7. The odds were even greater, from 2.0 to 2.6, for frequent, comorbid or severe headache. Recent large longitudinal studies from Norway found a bidirectional, possibly causal, association between headache and insomnia. However, not all studies used standardized diagnostic criteria for either headache or insomnia. Further research should use well defined and validated diagnostic criteria both for insomnia and headache types in order to improve the comparability between studies, investigate causality and clarify the relevance of the findings for clinical practice.

The relationship between sleep and headache in children: implications for treatment

BACKGROUND

The existence of a correlation and/or comorbidity between sleep disorders and headache, related to common anatomical structures and neurochemical processes, has important implications for the treatment of both conditions.

METHODS

The high prevalence of certain sleep disorders in children with migraine and the fact that sleep is disrupted in these patients highlight the importance of a specific therapy targeted to improve both conditions.

FINDINGS

The treatment of sleep disorders like insomnia, sleep apnea, sleep bruxism and restless legs syndrome, either with behavioral or pharmacological approach, often leads to an improvement of migraine. Drugs like serotoninergic and dopaminergic compounds are commonly used for sleep disorders and for migraine prophylaxis and treatment: Insomnia, sleep-wake transition disorders and migraine have been related to the serotonergic system abnormality; on the other hand prodromal symptoms of migraine (yawning, drowsiness, irritability, mood changes, hyperactivity) support a direct role for the dopaminergic system that is also involved in sleep-related movement disorders.

CONCLUSIONS

Our review of the literature revealed that, beside pharmacological treatment, child education and lifestyle modification including sleep hygiene could play a significant role in overall success of the treatment. Therefore comorbid sleep conditions should be always screened in children with migraine in order to improve patient management and to choose the most appropriate treatment.

Sleep quality and arousal in migraine and tension-type headache: the headache-sleep study

OBJECTIVES

The present paper summarizes and compares data from our studies on subjective and objective sleep quality and pain thresholds in tension-type headache (TTH), migraine, and controls.

MATERIAL AND METHODS

In a blinded controlled explorative study, we recorded polysomnography (PSG) and pressure, heat, and cold pain thresholds in 34 controls, 20 TTH, and 53 migraine patients. Sleep quality was assessed by questionnaires, sleep diaries, and PSG. Migraineurs who had their recordings more than 2 days from an attack were classified as interictal while the rest were classified as either preictal or postictal. Interictal migraineurs (n=33) were also divided into two groups if their headache onsets mainly were during sleep and awakening (sleep migraine, SM), or during daytime and no regular onset pattern (non-sleep migraine, NSM). TTH patients were divided into a chronic or episodic group according to headache days per month.

RESULTS

Compared to controls, all headache groups reported more anxiety and sleep-related symptoms. TTH and NSM patients reported more daytime tiredness and tended to have lower pain thresholds. Despite normal sleep times in diary, TTH and NSM had increased slow-wave sleep as seen after sleep deprivation. Migraineurs in the preictal phase had shorter latency to sleep onset than controls. Except for a slight but significantly increased awakening index SM, patients differed little from controls in objective measurements.

CONCLUSIONS

We hypothesize that TTH and NSM patients on the average need more sleep than healthy controls. SM patients seem more susceptible to sleep disturbances. Inadequate rest might be an attack-precipitating- and hyperalgesia-inducing factor.