Sleep quality, arousal and pain thresholds in migraineurs: a blinded controlled polysomnographic study

Quantifying sensory thresholds along the migraine cycle: An exploratory longitudinal study

BACKGROUND

To date, a number of studies on migraine have cross-sectionally evaluated sensory sensitivity with aversion thresholds/scores along the migraine cycle, reporting a decreased tolerance to sensory stimuli in different sensory modalities. Our hypothesis was that patients with migraine would exhibit heightened sensitivity to sound, light, touch and smell on days where they reported greater headache intensity.

METHODS

This is an exploratory, longitudinal study, carried out over the course of 27 days. Aversion thresholds or scores to sound, light, touch and smell were quantified in six patients with migraine (11.33 ± 6.53 headache days/month).

RESULTS

Patients reported an increased sensitivity to light (padj = 0.0297), touch (padj = 0.0077), and smell (padj = 0.0201) on days with higher headache intensity. However, a greater sensitivity to sound on days with higher headache intensity was only reported when anxiety levels were high (padj = 1.4e-06). Interestingly, variable levels of tolerance to bothersome light over time can also influence the correlation between light sensitivity and headache intensity (padj = 1.4e-06).

CONCLUSIONS

Based on the present findings, future longitudinal studies evaluating sensory threshold changes along the migraine cycle in patients with migraine should account for the increased tolerance to bothersome light over time as well as the effect of anxiety on auditory sensitivity.

Understanding the Biological Relationship between Migraine and Depression

Migraine is a highly prevalent neurological disorder. Among the risk factors identified, psychiatric comorbidities, such as depression, seem to play an important role in its onset and clinical course. Patients with migraine are 2.5 times more likely to develop a depressive disorder; this risk becomes even higher in patients suffering from chronic migraine or migraine with aura. This relationship is bidirectional, since depression also predicts an earlier/worse onset of migraine, increasing the risk of migraine chronicity and, consequently, requiring a higher healthcare expenditure compared to migraine alone. All these data suggest that migraine and depression may share overlapping biological mechanisms. Herein, this review explores this topic in further detail: firstly, by introducing the common epidemiological and risk factors for this comorbidity; secondly, by focusing on providing the cumulative evidence of common biological aspects, with a particular emphasis on the serotoninergic system, neuropeptides such as calcitonin-gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), substance P, neuropeptide Y and orexins, sexual hormones, and the immune system; lastly, by remarking on the future challenges required to elucidate the etiopathological mechanisms of migraine and depression and providing updated information regarding new key targets for the pharmacological treatment of these clinical entities.

Narrative review: pathogenesis, diagnosis, and treatment of sleep-related painful erection

Objective

Through critical analysis and comprehensive review of the limited literature, this paper can help clinicians better identify the pathophysiology of sleep-related painful erections (SRPE) and provide direction for future treatment research.

Background

Patients with SRPE will be awakened by painful erections during sleep, which affects their sleep process and general health. At present, literatures of experimental and clinical research on SRPE disease are limited, as well as long-term reports on its pathogenesis and clinical management.

Methods

We use the PubMed database to obtain sleep-related peer erection literature. The search terms used include sleep, painful, penis and erection. After rigorous screening, the search returned 21 references published between 1987 and 2021.

Conclusions

The main cause of SRPE is obstructive sleep apnea (OSA) syndrome, psychological and spiritual factors, androgen elevation, neuroendocrine regulation and threshold of pain in the REM phase. The combination of multiple medications is the most effective approach to treat sleep-pain-related erections. The combination of CPAP, REM inhibitors and Baclofen has significant effect on SRPE caused by OSA syndrome. This article provides effective support and strategies for doctors to manage SRPE patients through a comprehensive analysis of the pathogenesis mechanism and clinical treatment strategies of SRPE.

Administration in Efficacy of Melatonin Reducing Headaches in Children With Migraines and Sleep Disorders: A Randomized Clinical Trial Study

Objectives

Migraine headache after tension headache is the most common primary headache in children, and sleep disorders can aggravate the symptoms. Melatonin has been proposed in some studies for prophylaxis of migraine headaches. This study aimed to evaluate melatonin's effect on migraine symptoms in children with migraine headaches and sleep disorders.

Materials & Methods

In this randomized clinical trial study, all 30 children aged 5 to 15 years with migraine headaches and sleep disorders were referred to the Pediatric Neurology Clinic and enrolled. Patients were randomly divided into two equal groups; the intervention group was treated with melatonin (3 mg daily) and propranolol (1 mg/kg daily), and the control group was treated with propranolol alone (1 mg/kg daily). The severity of the migraine headaches was assessed with PEDMIDAS and a five-point Likert scale. The children's sleep habits questionnaire (CSHQ) assessed children's sleep disorders. The ANOVA and linear regression methods were used to analyze and compare the findings between the groups.

Results

Out of 30 children participating in the study, 9 were girls, and 21 were boys. The number of daily headaches one month (P = 0.02) and four months (P = 0.03) after treatment was significantly lower in the melatonin group compared to the control group. Regarding sleep quality, there was no significant difference between the two groups.

Conclusion

Melatonin and propranolol could better alleviate migraine headaches than propranolol alone in children.

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.

Pain sensitivity in men who have never experienced a headache: an observer blinded case control study

Background

Headache affects 90–99% of the population. Based on the question “Do you think that you never ever in your whole life have had a headache?” 4% of the population say that they have never experienced a headache. The rarity of never having had a headache suggests that distinct biological and environmental factors may be at play. We hypothesized that people who have never experienced a headache had a lower general pain sensitivity than controls.

Methods

We included 99 male participants, 47 headache free participants and 52 controls, in an observer blinded nested case-control study. We investigated cold pain threshold and heat pain threshold using a standardized quantitative sensory testing protocol, pericranial tenderness with total tenderness score and pain tolerance with the cold pressor test. Differences between the two groups were assessed with the unpaired Student’s t-test or Mann-Whitney U test as appropriate.

Results

There was no difference in age, weight or mean arterial pressure between headache free participants and controls. We found no difference in pain detection threshold, pericranial tenderness or pain tolerance between headache free participants and controls.

Conclusion

Our study clearly shows that freedom from headache is not caused by a lower general pain sensitivity. The results support the hypothesis that headache is caused by specific mechanisms, which are present in the primary headache disorders, rather than by a decreased general sensitivity to painful stimuli.

Trial registration

Registered at ClinicalTrials.gov (NCT04217616), 3rd January 2020, retrospectively registered.

Has the Phase of the Menstrual Cycle Been Considered in Studies Investigating Pressure Pain Sensitivity in Migraine and Tension-Type Headache: A Scoping Review

OBJECTIVE

The aim of this scoping review was to identify if the phase of the menstrual cycle was considered in observational studies comparing pressure pain sensitivity between women with migraine or tension-type headache (TTH) and headache-free women.

METHODS

A systematic electronic literature search in PubMed, Medline, Web of Science, Scopus, and CINAHL databases was conducted. Observational studies including one or more groups with TTH and/or migraine comparing pressure pain thresholds (PPTs) were included. The methodological quality (risk of bias) was assessed with the Newcastle-Ottawa Scale. Authors, objectives, inclusion/exclusion criteria, size sample, female sample, tool to assess PPTs, mean age, and the use of any medication were extracted and analyzed independently by two authors.

RESULTS

From a total of 1404 and 1832 identified articles for TTH and migraine, 30 and 18 studies satisfied the criteria and were included. Nineteen (63.4%) studies assessing TTH patients and eleven (61.1%) assessing migraine patients showed a high risk of bias. The most common flaws were attributed to improper selection of control and control over other additional factors. Based on the systematic review, just one study including TTH and one including migraine patients considered the menstrual cycle.

CONCLUSION

The results of this scoping review identified that the phase of the menstrual cycle has been rarely considered in studies investigating sensitivity to pressure pain in primary headaches, such as TTH or migraine, although there is evidence showing the relevance of the phase of the menstrual cycle in pain perception.

Nightmares in Migraine: A Focused Review

Nightmares usually occur during the sleep phase of rapid eye movement (REM) and are associated with some physical symptoms, including sweating, shortness of breath, and lower limb movements. Emotions of fear, anger, shame, and sadness may also accompany nightmares. These symptoms can occur during dreaming, upon awakening, or later when the dream experience is recollected. Nightmares may sporadically occur for everyone, but nightmare disorders are associated with features of impaired mental and physical health and require professional medical treatment. The occurrence of nightmares with several disorders has been reported in the literature, but in migraines it has only been investigated in a small number of studies. Considering the existing relationship between sleep disorders and migraine, the occurrence of nightmares in migraine can negatively affect this association and elevate the risk of depression and anxiety. This, in turn, further reduces the quality of life of affected individuals. Hence, expanding the knowledge on the link between nightmares and migraine, promoting an acceptable quantity and quality of sleep through pharmacological and nonpharmacological interventions in the management of nightmares in migraine, and further scientific investigation of the biopsychosocial mechanisms underlying the link, will be highly valuable for optimal care. This focused review, therefore, gives a brief overview of the current understanding of nightmares in migraine to highlight the open questions and value of further research. The ultimate goal is to contribute to timely recognition and sufficient action to offer beneficial outcomes for affected patients.

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.

Exploratory study to understand association of emotional comorbidities and sleep with migraine

BACKGROUND

Migraine is often associated with psychiatric and emotional co-morbidities. Several studies have shown association of sleep problems and/or emotional co-morbidities among migraineurs. However, less is known about the association of migraine disability with sleep and emotional co-morbidities.

OBJECTIVE

To explore the association of emotional co-morbidities and sleep quality with migraine disability among migraineurs in the central part of India.

METHODS AND MATERIAL

A cross-sectional study enrolling 132 patients of migraine was conducted at a tertiary care centre. They were evaluated for migraine disability by Migraine Disability Assessment Test (MIDAS), emotional co-morbidities by depression, anxiety, stress scale (DASS-21) and sleep quality by Pittsburgh Sleep Quality Index (PSQI).

RESULT

Mean age of participants was 32.9 ± 9.8 and 83.3% (n = 110) were females. Fourty seven percentage(n = 62) patients reported moderate to severe disability on MIDAS. Anxiety was most frequent (n = 87; 65.9%) emotional co-morbidity followed by depression (n = 70;53%) and stress (n = 52;39.4%). Severity of emotional co-morbidities increased while sleep quality deteriorated with increasing migraine disability. However, migraine frequency had positive correlation only with sleep quality. Stress showed a linear relationship with migraine disability at highest second-third decile of MIDAS.

CONCLUSION

Migraineurs in central India have higher emotional co-morbidities. These co-morbidities increased and sleep quality deteriorated with increasing migraine disability. Frequency of migraine has no association with emotional co-morbidities. Linear association of stress at higher migraine disability prompts possible role of stress management to break the complex relationship between stress and migraine.

Spatial aspects of pain modulation are not disrupted in adolescents with migraine

OBJECTIVE

To compare spatial pain modulation capabilities between adolescents with and without migraine.

BACKGROUND

Conditioned pain modulation (CPM) responses at the leg are similar in adolescents with versus without migraine. However, the anatomical region of testing may affect spatial pain modulation capabilities as differences in nociceptive processing between patients with migraine and healthy controls are found in local areas that are near the site of clinical pain but not in nonlocal areas. This study aimed to examine spatial pain modulation capabilities tested by the CPM paradigm using test stimulus applied to a local body area.

METHODS

Nineteen adolescents with migraine (age 14.9 ± 2.3, mean ± SD; 16 female) and 20 healthy adolescents (age 13.8 ± 2.5, mean ± SD; 16 female) completed this case-control study at Cincinnati Children's Hospital Medical Center. Pressure pain thresholds (PPT) were assessed at the trapezius before and during immersion of the foot in a cold water bath (8°C).

RESULTS

In the migraine group (146.0 ± 79.1, mean ± SD), compared to healthy controls (248.0 ± 145.5, mean ± SD), significantly lower PPT (kilopascal) values were found (estimate = 124.28, 95% CI: 58.98, 189.59, p < 0.001; effect size: d = 1.40). No differences between the groups were found for pain intensity and unpleasantness ratings of cold-water immersion nor the CPM response.

CONCLUSIONS

This study found altered ascending nociceptive processing of mechanical stimuli at the neck in adolescents with migraine. However, endogenous pain modulatory mechanisms were functional and not altered. In light of other studies, impairments in inhibitory control may not be involved in migraine pathophysiology in pediatric patients regardless of stimulus location.

Pain sensitivity in young adults with juvenile idiopathic arthritis: a quantitative sensory testing study

BACKGROUND

To study for the first-time, pain perception, pain sensitivity, and self-reported pain in young adults with long disease duration of juvenile idiopathic arthritis (JIA) compared with controls.

METHODS

Children from Central Norway diagnosed with JIA between 1997 and 2004 were included consecutively in a population-based prospective study. Children with onset 1997-2000 were part of the Nordic JIA cohort. Controls were age- and sex-matched. In 2015-2017, study visits with investigator-blinded quantitative sensory testing (QST) comprising cold and warm detection thresholds (CDT/WDT), cold and heat pain thresholds (CPT/HPT), pressure pain threshold (PPT), and a suprathreshold heat pain test were performed. We constructed separate multilevel models for each variable of detection and pain thresholds with interaction between groups and site adjusted for the effect of age and sex.

RESULTS

Among 96 young adults with JIA, 71% were female, median age was 22.7 years, disease duration was 16.1 years, and 47% had oligoarticular disease. Among 109 controls, 71% were female, and median age was 23.5 years. Participants with JIA had lower pressure pain thresholds (PPTs) (95% CI) compared to controls, upper limb 888 (846,930) versus 1029 (999,1059) kPa and lower limb 702 (670,734) versus 760 (726,794) kPa. Participants with inactive disease had the lowest PPTs and cold pain thresholds (CPTs), compared to those in remission off medication and those with active disease. Minor differences were found regarding CDT/WDT and CPT/HPT in JIA compared to controls. The median (IQR) temperature needed to evoke pain = 6 on a 0-10 numeric rating scale (NRS) in the suprathreshold heat pain tests were lower in JIA than in controls (46 °C (45-47 °C) versus 47 °C (46-48 °C)). We found no associations between self-reported pain and pain thresholds.

CONCLUSIONS

Our results indicate for the first time that young adults with long disease duration of JIA may have altered pain perception and sensitivity compared to controls. A clinical implication may be the importance of early treatment to quickly achieve pain-free remission and avoid long-term pain sensitization.

Sleep Disorders and Headache: A Review of Correlation and Mutual Influence

The review is devoted to the complex relationship between headache and sleep disorders. The shared neuroanatomical structures of the nervous system involved in pain perception and sleep are shown, and mechanisms of comorbidity between headaches and sleep disorders are considered. Various types of headaches in the continuum of the sleep–wake cycle are described. Both pharmacological and non-pharmacological approaches to treatment are examined in detail, with the biochemical basis of the drug action.

Migraine understood as a sensory threshold disease

Migraine encompasses a broader spectrum of sensory symptoms than just headache. These "other" symptoms, eg, sensory phobias, cognitive and mood changes, allodynia, and many others indicate an altered sensitivity to sensory input which can be measured, in principle, by quantifying sensory threshold changes longitudinally over time. Photophobia, for example, can be quantified by investigating the discomfort thresholds towards the luminance of light. The aim of this review is to look into how thresholds change in patients with migraine. We performed a PubMed search up to June 2018 targeting all peer-reviewed articles evaluating the changes in threshold, sensory phobia, or sensitivity in patients with migraine. Migraineurs, in general, exhibit lower sensory thresholds compared with healthy controls. These threshold changes seem to follow the different phases during a migraine cycle. In general, thresholds reach a nadir when the headache starts (the ictal phase), rise after the headache ends, and then gradually descend towards the next attack. The sensory modality of measurement-mechanical, thermal, or nociceptive-and the location of measurement-trigeminal vs somatic dermatome-also influence the sensory threshold. Functional imaging studies provide evidence that the hypothalamo-thalamo-brainstem network may be the driving force behind the periodic threshold changes. In summary, there is evidence in the literature that migraine could be understood as a periodic sensory dysregulation originating from the brain. Nevertheless, the interstudy discrepancy is still high due to different study designs and a lack of focus on distinct migraine phases. Further well-designed and harmonized studies with an emphasis on the cyclic changes still need to be conducted.

Convergent and Discriminant Validity of the Serbian Version of the Central Sensitization Inventory

OBJECTIVES

The goal of the present study was to explore additional evidence of validity of the Serbian version of the Central Sensitization Inventory (CSI), a patient-reported outcome measure of symptoms that have been found to be associated with central sensitization (CS). The CSI has been found to be psychometrically sound, and has demonstrated evidence of convergent and discriminant validity in numerous published studies and in multiple languages.

METHODS

CSI data were collected from 399 patients with chronic pain who had various diagnoses and from 146 pain-free controls. In addition, the patient sample completed a battery of validated patient-reported outcome measures of sleep problems, cognitive problems, pain catastrophizing, pain-related fear-avoidance, decreased quality of life, and decreased perception of social support. Six patient subgroups were formed, with presumably different levels of CS (including those with fibromyalgia, multiple pain sites, and localized pain sites).

RESULTS

Significant differences were found in total CSI scores among the controls and patient subgroups. Those with fibromyalgia and multiple pathologies scored highest and the control subjects scored lowest. Other patient-reported CS-related symptom dimensions were significantly correlated with total CSI scores. When the patients were divided into CSI severity subgroups (from subclinical to extreme), the severity of these other symptom dimensions increased with the severity of CSI scores.

CONCLUSIONS

The current study successfully demonstrated additional evidence of the convergent and discriminant validity of the Serbian version of the CSI.

Mechanical punctate pain threshold is associated with headache frequency and phase in patients with migraine

Objective

Previous studies regarding the quantitative sensory testing are inconsistent in migraine. We hypothesized that the quantitative sensory testing results were influenced by headache frequency or migraine phase.

Methods

This study recruited chronic and episodic migraine patients as well as healthy controls. Participants underwent quantitative sensory testing, including heat, cold, and mechanical punctate pain thresholds at the supraorbital area (V1 dermatome) and the forearm (T1 dermatome). Prospective headache diaries were used for headache frequency and migraine phase when quantitative sensory testing was performed.

Results

Twenty-eight chronic migraine, 64 episodic migraine and 32 healthy controls completed the study. Significant higher mechanical punctate pain thresholds were found in episodic migraine but not chronic migraine when compared with healthy controls. The mechanical punctate pain thresholds decreased as headache frequency increased then nadired. In episodic migraine, mechanical punctate pain thresholds were highest ( p < 0.05) in those in the interictal phase and declined when approaching the ictal phase in both V1 and T1 dermatomes. Linear regression analyses showed that in those with episodic migraine, headache frequency and phase were independently associated with mechanical punctate pain thresholds and accounted for 29.7% and 38.9% of the variance in V1 ( p = 0.003) and T1 ( p < 0.001) respectively. Of note, unlike mechanical punctate pain thresholds, our study did not demonstrate similar findings for heat pain thresholds and cold pain thresholds in migraine.

Conclusion

Our study provides new insights into the dynamic changes of quantitative sensory testing, especially mechanical punctate pain thresholds in patients with migraine. Mechanical punctate pain thresholds vary depending on headache frequency and migraine phase, providing an explanation for the inconsistency across studies.

Formalin-induced and neuropathic pain altered time estimation in a temporal bisection task in rats

Time perception is an important ability that is related closely to humans’ and animals’ daily activities. It can be distorted by various emotional states. In human studies, experimental pain has been shown to prolong the perception of time. However, related animal studies are lacking. In this study, we used a temporal bisection task to investigate how acute inflammatory pain (induced by hind-paw formalin injection) and chronic neuropathic pain [induced by spinal nerve ligation (SNL)] affected time perception in rats. Rats were trained to recognize “short” (1200-ms) and “long” (2400-ms) anchor-duration pure tones and were rewarded for corresponding lever presses. During testing, rats perceived a series of intermediate-duration and anchor-duration pure tones, and selected levers corresponding to the “short” and “long” tones. After formalin injection, rats gave more “long” lever-press responses than after saline injection. The point of subjective equality after formalin injection also increased, suggesting that formalin-induced acute pain extended time perception. In contrast, rats that had undergone SNL gave fewer “long” lever-press responses compared with the sham surgery group. This animal study suggests that formalin-induced pain and neuropathic pain may have different effects on time perception.

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.

Increased pain sensitivity but normal pain modulation in adolescents with migraine

Inhibitory pain modulation has been reported to be deficient in adults across different types of chronic pain, including migraine. To determine whether a similar phenomenon occurs in youth, we performed a quantitative sensory testing investigation in adolescents with migraine (N = 19). These patients were compared to healthy adolescents with (Fam-His; N = 20) or without (Healthy; N = 29) a family history of migraine (eg, first-degree relative with migraine). Subjects were first familiarized with the stimuli and visual analogue rating scales using graded noxious stimuli (0°C, 43-49°C range). These data were used to explore potential pain sensitivity differences between the groups. Pain inhibition was assessed by conditioned pain modulation (CPM), which used both suprathreshold heat pain (heat CPM) and pressure pain thresholds (pressure CPM) as the test stimuli before and during cold-water immersion (8°C). In response to the graded heat stimuli, Fam-His participants reported higher pain intensity ratings compared with patients with migraine, who in turn reported higher pain intensity ratings than the healthy controls (F = 3.6, [df = 2, 459], P = 0.027). For heat and pressure CPM, there was no significant group difference in the magnitude of CPM responses. Thus, adolescents with migraine and healthy adolescents have similar inhibitory pain modulation capability, despite having marked differences in pain sensitivity. Although Fam-His participants are asymptomatic, they demonstrate alterations in pain processing, which may serve as markers for prediction of migraine development.

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.

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.

Characterization of migraineurs presenting interictal widespread pressure hyperalgesia identified using a tender point count: a cross-sectional study

BACKGROUND

Migraineurs exhibit pain hypersensitivity throughout the body during and between migraine headaches. Migraine is classified as a central sensitivity syndrome, typified by fibromyalgia showing widespread pressure hyperalgesia determined by a tender point. This study was performed to examine whether: 1) there is a subgroup of episodic migraineurs with widespread pressure hyperalgesia during and between attacks; 2) if such a subgroup exists, what is the prevalence and what is the difference between groups with interictal widespread hyperalgesia and acute allodynia regarding the demographic and clinical characteristics of migraine.

METHODS

This was a cross-sectional study. A total of 176 consecutive episodic migraineurs and 132 age- and sex-matched controls were recruited. The presence of widespread pressure hyperalgesia was investigated using manual tender point survey. To classify a subject's response as widespread pressure hyperalgesia, the cutoff value for responders was defined as the positive tender point count below which 95% of controls responded.

RESULTS

Based on the number of positive tender points in controls, the cutoff value of tender point count for pressure hyperalgesia responders was 7. Of the 176 subjects, interictal widespread pressure hyperalgesia and acute allodynia were observed in 74 (42%) and 115 (65.3%) patients, respectively. Univariate analysis indicated that risk factors associated with interictal widespread pressure hyperalgesia were female gender, younger age at migraine onset, higher frequency of migraine attacks, severe headache impact, cutaneous allodynia and depression. Multivariate logistic regression analysis confirmed that independent risk factors associated with interictal widespread pressure hyperalgesia were female gender, higher frequency of migraine attack and younger age at onset.

CONCLUSION

Interictal widespread pressure hyperalgesia was common (42%) in the episodic migraineurs and was associated with younger age at onset, female gender, and higher frequency of headache, but not duration of migraine illness. Presence of interictal widespread pressure hyperalgesia is assumed to be an indicator of genetic susceptibility to migraine attacks. We expect that a tender point count, as an alternative to quantitative sensory testing, will become useful as a diagnostic indicator of interictal hyperalgesia in migraineurs to predict susceptibility to migraine attacks and to permit tailored treatment.

Habituation of laser-evoked potentials by migraine phase: a blinded longitudinal study

Background

Migraineurs seem to have cyclic variations in cortical excitability in several neurophysiological modalities. Laser-evoked potentials (LEP) are of particular interest in migraine because LEP specifically targets pain pathways, and studies have reported different LEP-changes both between and during headaches. Our primary aim was to explore potential cyclic variations in LEP amplitude and habituation in more detail with a blinded longitudinal study design.

Methods

We compared N1 and N2P2 amplitudes and habituation between two blocks of laser stimulations to the dorsal hand, obtained from 49 migraineurs with four sessions each. We used migraine diaries to categorize sessions as interictal (> one day from previous and to next attack), preictal (< one day before the attack), ictal or postictal (< one day after the attack). Also, we compared 29 interictal recordings from the first session to 30 controls.

Results

N1 and N2P2 amplitudes and habituation did not differ between preictal, interictal and postictal phase sessions, except for a post hoc contrast that showed deficient ictal habituation of N1. Habituation is present and similar in migraineurs in the interictal phase and controls.

Conclusions

Hand-evoked LEP amplitudes and habituation were mainly invariable between migraine phases, but this matter needs further study. Because hand-evoked LEP-habituation was similar in migraineurs and controls, the present findings contradict several previous LEP studies. Pain-evoked cerebral responses are normal and show normal habituation in migraine.

Electronic supplementary material

The online version of this article (10.1186/s10194-017-0810-6) contains supplementary material, which is available to authorized users.

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.

Altered functional connectivity of amygdala underlying the neuromechanism of migraine pathogenesis

Background

The amygdala is a large grey matter complex in the limbic system, and it may contribute in the neurolimbic pain network in migraine. However, the detailed neuromechanism remained to be elucidated. The objective of this study is to investigate the amygdala structural and functional changes in migraine and to elucidate the mechanism of neurolimbic pain-modulating in the migraine pathogenesis.

Methods

Conventional MRI, 3D structure images and resting state functional MRI were performed in 18 normal controls (NC), 18 patients with episodic migraine (EM), and 16 patients with chronic migraine (CM). The amygdala volume was measured using FreeSurfer software and the functional connectivity (FC) of bilateral amygdala was computed over the whole brain. Analysis of covariance was performed on the individual FC maps among groups.

Results

The increased FC of left amygdala was observed in EM compared with NC, and the decreased of right amygdala was revealed in CM compared with NC. The increased FC of bilateral amygdala was observed in CM compared with EM. The correlation analysis showed a negative correlation between the score of sleep quality (0, normal; 1, mild sleep disturbance; 2, moderate sleep disturbance; 3, serious sleep disturbance) and the increased FC strength of left amygdala in EM compared with NC, and a positive correlation between the score of sleep quality and the increased FC strength of left amygdala in CM compared with EM, and other clinical variables showed no significant correlation with altered FC of amygdala.

Conclusions

The altered functional connectivity of amygdala demonstrated that neurolimbic pain network contribute in the EM pathogenesis and CM chronicization.

What Factors Contribute to Headache-Related Disability in Teens?

BACKGROUND

Our aim was to describe the relationship between risk factors, such as stress, depression, and anxiety, and potentially protective factors against pediatric headache-related disability, such as mindfulness, resilience, and self-compassion, and to determine teens' interest in mind-body skills training to help reduce headache-related disability.

METHODS

This was a cross-sectional survey among adolescents seen in an academic neurology clinic reporting four or more headaches monthly using standardized instruments to determine the relationship between putative risk and protective factors as well as physiologic markers of inflammation and vagal tone and headache-related disability.

RESULTS

Among the 29 participants, 31% were male, the average age was 14.8 years, average headache frequency was 11.6 per month, and the most commonly reported trigger was stress (86%). The only risk or protective factor significantly associated with headache-related disability was depression (r = 0.52, P = 0.004). Depression was negatively correlated with mindfulness, resilience, and self-compassion (P < 0.01 each) and positively correlated with stress, sleep disturbance, and anxiety (P < 0.01 each). Biomarkers of vagal tone and inflammation were correlated with each other but not with headache-related disability or depression. There was strong interest in learning skills like slow, deep breathing practices supported by a smart phone application to reduce stress and the negative impact of headaches on daily life.

DISCUSSION

Among teens with frequent migraine headaches, depression is the strongest risk factor for headache-related disability. Stress is viewed as a headache trigger, and teens reported wanting to learn simple stress management strategies supported by a smart phone application to help reduce headache-related disability.

Cervical non-invasive vagus nerve stimulation (nVNS) for preventive and acute treatment of episodic and chronic migraine and migraine-associated sleep disturbance: a prospective observational cohort study

Background

The debilitating nature of migraine and challenges associated with treatment-refractory migraine have a profound impact on patients. With the need for alternatives to pharmacologic agents, vagus nerve stimulation has demonstrated efficacy in treatment-refractory primary headache disorders. We investigated the use of cervical non-invasive vagus nerve stimulation (nVNS) for the acute treatment and prevention of migraine attacks in treatment-refractory episodic and chronic migraine (EM and CM) and evaluated the impact of nVNS on migraine-associated sleep disturbance, disability, and depressive symptoms.

Methods

Twenty patients with treatment-refractory migraine were enrolled in this 3-month, open-label, prospective observational study. Patients administered nVNS prophylactically twice daily at prespecified times and acutely as adjunctive therapy for migraine attacks. The following parameters were evaluated: pain intensity (visual analogue scale [VAS]); number of headache days per month and number of migraine attacks per month; number of acutely treated attacks; sleep quality (Pittsburgh Sleep Quality Index [PSQI]); migraine disability assessment (MIDAS); depressive symptoms (Beck Depression Inventory® [BDI]); and adverse events (AEs).

Results

Of the 20 enrolled patients, 10 patients each had been diagnosed with EM and CM. Prophylaxis with nVNS was associated with significant overall reductions in patient-perceived pain intensity; median (interquartile range) VAS scores at baseline versus 3 months were 8.0 (7.5, 8.0) versus 4.0 (3.5, 5.0) points (p < 0.001). Baseline versus 3-month values (mean ± standard error of the mean) were 14.7 ± 0.9 versus 8.9 ± 0.8 (p < 0.001) for the number of headache days per month and 7.3 ± 0.9 versus 4.5 ± 0.6 (p < 0.001) for the number of attacks per month. Significant improvements were also noted in MIDAS (p < 0.001), BDI (p < 0.001), and PSQI global (p < 0.001) scores. No severe or serious AEs occurred.

Conclusion

In this study, treatment with nVNS was safe and provided clinically meaningful decreases in the frequency and intensity of migraine attacks in patients with treatment-refractory migraine. Improvements in migraine-associated disability, depression, and sleep quality were also noted.

Sleep disturbances among pregnant women with history of migraines: A cross-sectional study

BACKGROUND

Migraine is associated with sleep disturbances in men and non-pregnant women. However, relatively little is known about sleep disturbances among pregnant migraineurs. We investigated sleep disturbances among pregnant women with and without history of migraine.

METHODS

This cross-sectional study was conducted among 1324 women who were recruited during early pregnancy. Migraine diagnoses were based on the International Classification of Headache Disorders-II criteria. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used to evaluate sleep-related characteristics including sleep duration, sleep quality, excessive daytime sleepiness, and other sleep traits. Multivariable logistic regression procedures were used to estimate adjusted odds ratios (AORs) and 95% confidence intervals (CIs).

RESULTS

Migraineurs were more likely than non-migraineurs to report short sleep duration (<6.5 hours) (AOR = 1.47, 95% CI 1.07-2.02), poor sleep quality (PSQI>5) (AOR = 1.73, 95% CI 1.35-2.23), and daytime dysfunction due to sleepiness (AOR = 1.51, 95% CI 1.12-2.02). Migraineurs were also more likely than non-migraineurs to report taking sleep medication during pregnancy (AOR = 1.71, 95% CI 1.20-2.42). Associations were generally similar for migraine with or without aura. The odds of sleep disturbances were particularly elevated among pre-pregnancy overweight migraineurs.

CONCLUSION

Migraine headache and sleep disturbances are common comorbid conditions among pregnant women.

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.

Sleep features and central sensitization symptoms in primary headache patients

BACKGROUND

Association between sleep disorders and headache is largely known. The aim of the present study was to evaluate sleep quality and quantity in a large cohort of primary headache patients, in order to correlate these scores with symptoms of central sensitization as allodynia, pericranial tenderness and comorbidity with diffuse muscle-skeletal pain.

METHODS

One thousand six hundreds and seventy primary headache out patients were submitted to the Medical Outcomes Study (MOS) within a clinical assessment, consisting of evaluation of frequency of headache, pericranial tenderness, allodynia and coexistence of fibromyalgia syndrome (FM).

RESULTS

Ten groups of primary headache patients were individuated, including patients with episodic and chronic migraine and tension type headache, mixed forms, cluster headache and other trigeminal autonomic cephalalgias. Duration but not sleep disturbances score was correlated with symptoms of central sensitization as allodynia and pericranial tenderness in primary headache patients. The association among allodynia, pericranial tenderness and short sleep characterized chronic migraine more than any other primary headache form. Patients presenting with FM comorbidity suffered from sleep disturbances in addition to reduction of sleep duration.

CONCLUSION

Self reported duration of sleep seems a useful index to be correlated with allodynia, pericranial tenderness and chronic headache as a therapeutic target to be assessed in forthcoming studies aiming to prevent central sensitization symptoms development.

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.

Real-time sharing and expression of migraine headache suffering on Twitter: a cross-sectional infodemiology study

BACKGROUND

Although population studies have greatly improved our understanding of migraine, they have relied on retrospective self-reports that are subject to memory error and experimenter-induced bias. Furthermore, these studies also lack specifics from the actual time that attacks were occurring, and how patients express and share their ongoing suffering.

OBJECTIVE

As technology and language constantly evolve, so does the way we share our suffering. We sought to evaluate the infodemiology of self-reported migraine headache suffering on Twitter.

METHODS

Trained observers in an academic setting categorized the meaning of every single "migraine" tweet posted during seven consecutive days. The main outcome measures were prevalence, life-style impact, linguistic, and timeline of actual self-reported migraine headache suffering on Twitter.

RESULTS

From a total of 21,741 migraine tweets collected, only 64.52% (14,028/21,741 collected tweets) were from users reporting their migraine headache attacks in real-time. The remainder of the posts were commercial, re-tweets, general discussion or third person's migraine, and metaphor. The gender distribution available for the actual migraine posts was 73.47% female (10,306/14,028), 17.40% males (2441/14,028), and 0.01% transgendered (2/14,028). The personal impact of migraine headache was immediate on mood (43.91%, 6159/14,028), productivity at work (3.46%, 486/14,028), social life (3.45%, 484/14,028), and school (2.78%, 390/14,028). The most common migraine descriptor was "Worst" (14.59%, 201/1378) and profanity, the "F-word" (5.3%, 73/1378). The majority of postings occurred in the United States (58.28%, 3413/5856), peaking on weekdays at 10:00h and then gradually again at 22:00h; the weekend had a later morning peak.

CONCLUSIONS

Twitter proved to be a powerful source of knowledge for migraine research. The data in this study overlap large-scale epidemiological studies, avoiding memory bias and experimenter-induced error. Furthermore, linguistics of ongoing migraine reports on social media proved to be highly heterogeneous and colloquial in our study, suggesting that current pain questionnaires should undergo constant reformulations to keep up with modernization in the expression of pain suffering in our society. In summary, this study reveals the modern characteristics and broad impact of migraine headache suffering on patients' lives as it is spontaneously shared via social media.

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.

Polysomnographic investigation of sleep and respiratory parameters in women with temporomandibular pain disorders

STUDY OBJECTIVES

Temporomandibular pain disorders (TMD) and myofascial pain were linked to increased prevalence of insomnia and obstructive sleep apnea (OSA) on clinical grounds. However, the literature lacks an accurate polysomnographic (PSG) characterization of sleep abnormalities associated with TMD, given that prior studies included small or uncontrolled samples of TMD patients. The present investigation aims to objectively evaluate measures of sleep and respiratory disturbance in a large representative sample of TMD cases in comparison with matched controls.

METHODS

Sleep, respiration, and limb movements were measured using a 2-night attended PSG protocol in 170 women-124 TMD cases with myofascial pain and 46 demographically matched controls. The second night data were compared between the groups using ANCOVAs. In TMD cases, the relationship between pain ratings and sleep parameters was analyzed using multiple regressions.

RESULTS

In comparison to healthy controls, TMD cased evidenced a significant increase in stage N1 sleep (12.2% ± 7.6% vs. 9.2% ± 5.0%, p = 0.03), which was only mild relative to normative values. TMD cases also demonstrated mild but significant elevations in arousals associated with all types of respiratory events (6.0/h ± 6.1 vs. 3.5/h ± 3.3 p = 0.02) and in respiratory effort related arousals (RERAs, 4.3/h ± 4.3 vs. 2.6/h ± 2.7, p = 0.02). Myofascial pain predicted a lower sleep efficiency (p = 0.01), more frequent awakenings (p = 0.04), and higher RERA index (p = 0.04) among TMD cases.

CONCLUSIONS

Myofascial pain in TMD is associated with mild elevation in sleep fragmentation and increased frequency of RERA events. Further research is required to evaluate the clinical significance of these findings.

Histamine in migraine and brain

BACKGROUND

Histamine has been studied in both health and disease since the initial description a century ago. With its vasodilative effect, it was suggested early on to be involved in the pathophysiology of migraine. Over the past 25 years, much has been learned about histamine as a neurotransmitter in the central nervous system. The role of this neurotransmitter system in migraine has not been previously reviewed.

OBJECTIVE

Discuss a potential role of the brain histaminergic system in migraine.

METHODS

Unstructured literature search with a no specific hypothesis-driven approach.

RESULTS

There is substantial evidence that systemically given histamine may elicit, maintain, and aggravate headache. The mechanisms for this are not known, and histamines do not penetrate the blood-brain barrier (BBB). However, circulating histamine may influence hypothalamic activity via the circumventricular organs that lack BBB. In the rat, prolonged activation of meningeal nociceptors induced by dural mast cell degranulation has been observed. Subcutaneous injections of N-alpha-methyl histamine, a catabolite of histamine with high affinity to the histamine H3 receptor, probably have some migraine preventive effect. A negative feedback on histamine release from mast cells in proximity to C-fiber endings has been a postulated mechanism. Most antihistamines have shown to be ineffective as acute medication for migraine. Two centrally acting potent H1 receptor antagonists (cinnarizine and cyproheptadine) have been reported to be efficacious in preventing migraine. However, the proof for this is limited, and their efficacy has been ascribed other actions than the antihistaminergic. In general, lack of specificity and side effects limit the potential use of centrally acting H1 and H2 antagonists. Brain histamine is synthesized by neurons that are restricted to the posterior basal hypothalamus, more specific to the tuberomamillary nucleus (TMN), and that project practically to the whole central nervous system. The posterior hypothalamus is a suspected locus in quo in several primary headaches. Recently, a positron emission tomography study performed in the prodromal phase of migraine attacks supported the idea of initial involvement of this area. In another recent study, the thalamic nuclei receiving trigeminal output was also shown to have direct connections with the ventral TMN. The central histaminergic system plays an important role in the complex sleep-wake cycle, promoting cortical excitability during wakening and attention, and it consolidates the wake state. The period of the day, in the evenings and during the night, when there is reduced susceptibility for migraine attacks corresponds with less central histaminergic firing. Activation of both the H3 and the H4 receptor promotes inhibitory actions on neurons. The H3 receptor causes autoinhibition of the histaminergic neurons themselves, and centrally acting H3 receptor agonist prodrugs have shown to both inhibit neurogenic inflammation in dura, to induce sleep, and to produce antinociception. There are no registered ongoing studies on H3 and H4 receptor ligands in migraine.

CONCLUSION

The role of the central histaminergic system in migraine is largely unexplored, but findings from preclinical research may be linked to several aspects of the disorder. The histaminergic system of the brain may play an important role, especially in the initial phase of an attack, and histamine H3 and H4 receptor ligands may potentially have migraine prophylactic properties. However, the basis for this is still circumstantial, and the evidence is lacking.

Sleep quality, arousal and pain thresholds in tension-type headache: a blinded controlled polysomnographic study

INTRODUCTION

We aimed to compare subjective and objective sleep quality in tension-type headache (TTH) patients and to evaluate the relationship between sleep quality and pain thresholds (PT) in controls and TTH patients.

METHODS

A blinded cross-sectional study where polysomnography (PSG) and PT (to pressure, heat and cold) measurements were done in 20 patients with TTH (eight episodic (ETTH) and twelve chronic (CTTH) TTH) and 29 healthy controls. Sleep diaries and questionnaires were applied.

RESULTS

TTH patients had more anxiety ( P = 0.001), insomnia ( P < 0.0005), daytime tiredness ( P < 0.0005) and reduced subjective sleep quality ( P < 0.0005) compared to healthy controls. Sleep diaries revealed more long awakenings in TTH ( P = 0.01) but no total sleep-time differences. TTH patients had more slow-wave sleep ( P = 0.002) and less fast arousals ( P = 0.004) in their PSGs. CTTH subjects had lower pressure PT ( P = 0.048) and more daytime sleepiness than the controls ( P = 0.039). Among TTH lower cold PT (CPT) correlated inversely with light sleep (N1) ( R  = -0.49, P = 0.003) while slow arousals correlated inversely with headache-frequency ( R  = -0.64, P = 0.003).

CONCLUSIONS

We hypothesize that TTH patients need more sleep than healthy controls and might be relatively sleep deprived. Inadequate sleep may also contribute to increased pain sensitivity and headache frequency in TTH.

Do nocturnal headaches matter? A prospective diary study on subjective sleep parameters in snorers and their bed partners

BACKGROUND

The objective of this study was to assess the influence of nocturnal headaches (NH) on subjective sleep parameters prospectively in habitual snorers and their bed partners.

METHODS

We recruited habitual snorers and their bed partners via newspaper articles. The participants completed a semistructured interview, filled in questionnaires about quality of sleep (PSQI), daytime sleepiness (ESS), depression (SDS) and anxiety (SAS) and they kept a 90-day headache and sleep diary.

RESULTS

Seventy-six snorers (25 female) and 41 bed partners (31 female) completed the study recording a total of 6690 and 3497 diary days, respectively. NH were recorded on 222 (3.3%) and 79 (2.2%) days in 32 (42%) snorers and 17 (41%) bed partners, respectively. Snorers with NH showed significantly higher PSQI (5 ± 3 vs. 4 ± 2, p = 0.004), SAS (38 ± 11 vs. 31 ± 10, p = 0.011) and SDS scores (39 ± 12 vs. 34 ± 10, p = 0.048) than snorers without NH. For bed partners with NH we found a significant female predominance (sex ratio f:m = 16:1 vs. 12:12, p = 0.005) and significantly higher SAS scores (38 ± 6 vs. 33 ± 8, p = 0.030) compared with bed partners without NH. The subjective quality of sleep in habitual snorers (p < 0.001) as well as their bed partners (p = 0.017) was negatively influenced by NH, but not total sleep time.

DISCUSSION

NH occurred in around 40% of snorers and their bed partners at least once during the 90-day observation period. Our results confirmed a negative impact on the subjective quality of sleep in both groups.

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

Background

The mechanisms associating sleep and migraine are unknown. No previous polysomnographic (PSG) or pain-threshold (PT) study has compared patients with sleep-related migraine attacks (SM), non-sleep related migraine attacks (NSM) and healthy controls.

Methods

We have performed a blinded, prospective exploratory study with case–control design. Thirty-four healthy controls, 15 patients with SM and 18 patients with NSM had interictal PSG heat-, cold- and pressure PT (HPT, CPT, PPT) recordings and completed diary- and questionnaire on sleep and headache related aspects.

Results

NSM patients had more slow-wave sleep (SWS) and more K-bursts than SM patients (K-bursts: p = 0.023 and SWS: p = 0.030) and controls (K-bursts: p = 0.009 and SWS: 0.041). NSM patients also had lower HPT and CPT than controls (p = 0.026 and p = 0.021). In addition, SM patients had more awakenings and less D-bursts than controls (p = 0.025 and p = 0.041).

Conclusion

SM- and NSM patients differed in objective-, but not subjective sleep quality. NSM patients had PSG findings indicating foregoing sleep deprivation. As foregoing sleep times were normal, a relative sleep deficit might explain reduced PT among NSM patients. The SM patients had signs of slightly disturbed sleep.