Correlation between presence of allodynia and sleep quality in migraineurs

The association of self-reported symptoms of central sensitization and sleep disturbances in neuropathic pain

Introduction

Patients with neuropathic pain (NP) report a higher impairment of quality of life and sleep than patients with chronic pain without neuropathic characteristics. These include somatosensory peculiarities like allodynia, a surrogate marker for central sensitization.

Objectives

This study aimed to investigate the relation between symptoms of central sensitization and sleep disturbances in patients with NP.

Methods

Within this cross-sectional study, data sets of 3339 patients with chronic NP syndromes (painful diabetic polyneuropathy, n = 543; postherpetic neuralgia, n = 1480) or complex regional pain syndromes (CRPS, n = 1316) were analyzed. Neuropathic pain symptoms were assessed with the painDETECT questionnaire (PD-Q), depression with the Patient Health Questionnaire-9, and sleep impairment with items of the Medical Outcomes Study Sleep Scale in 4 subscales. The association of demographic/clinical data, somatosensory phenotype, depression, and pain intensity with sleep impairment was assessed by unadjusted Spearman correlation analyses and multivariable regression analyses.

Results

Sleep impairment was observed in all pain aetiologies although with some significant differences in the single sleep items. The intensity of the individual PD-Q items differed to some extent between the 3 pain entities, whereas the PD-Q sum score was similar. Thermal hyperalgesia and burning assessed by the PD-Q were significantly associated with sleep disturbance, adequacy, and quantity but not with sleep somnolence. Only depression and self-reported allodynia had a significant relation to all 4 sleep elements.

Conclusion

Beside depression, allodynia as a surrogate marker hints to a possible impact of central sensitization on the sleep disruption of patients with NP.

Increased iron deposition in nucleus accumbens associated with disease progression and chronicity in migraine

BACKGROUND

Migraine is one of the world's most prevalent and disabling diseases. Despite huge advances in neuroimaging research, more valuable neuroimaging markers are still urgently needed to provide important insights into the brain mechanisms that underlie migraine symptoms. We therefore aim to investigate the regional iron deposition in subcortical nuclei of migraineurs as compared to controls and its association with migraine-related pathophysiological assessments.

METHODS

A total of 200 migraineurs (56 chronic migraine [CM], 144 episodic migraine [EM]) and 41 matched controls were recruited. All subjects underwent MRI and clinical variables including frequency/duration of migraine, intensity of migraine, 6-item Headache Impact Test (HIT-6), Migraine Disability Assessment (MIDAS), and Pittsburgh Sleep Quality Index (PSQI) were recorded. Quantitative susceptibility mapping was employed to quantify the regional iron content in subcortical regions. Associations between clinical variables and regional iron deposition were studied as well.

RESULTS

Increased iron deposition in the putamen, caudate, and nucleus accumbens (NAC) was observed in migraineurs more than controls. Meanwhile, patients with CM had a significantly higher volume of iron deposits compared to EM in multiple subcortical nuclei, especially in NAC. Volume of iron in NAC can be used to distinguish patients with CM from EM with a sensitivity of 85.45% and specificity of 71.53%. As the most valuable neuroimaging markers in all of the subcortical nuclei, higher iron deposition in NAC was significantly associated with disease progression, and higher HIT-6, MIDAS, and PSQI.

CONCLUSIONS

These findings provide evidence that iron deposition in NAC may be a biomarker for migraine chronicity and migraine-related dysfunctions, thus may help to understand the underlying vascular and neural mechanisms of migraine.

TRIAL REGISTRATION

ClinicalTrials.gov, number NCT04939922.

Interrelationships of Sleep Quality, Obesity Severity, and Clinical Headache Features among Women with Comorbid Migraine and Obesity

Obesity and migraine are often comorbid. Poor sleep quality is also common among individuals with migraine and may be influenced by comorbidities such as obesity. However, understanding of migraine's relationship with sleep and the potential exacerbating effect of obesity remains limited. This study evaluated the associations of migraine characteristics and clinical features with sleep quality among women with comorbid migraine and overweight/obesity and assessed the interplay between obesity severity and migraine characteristics/clinical features in relation to sleep quality. Women seeking treatment for migraine and obesity (n = 127; NCT01197196) completed a validated questionnaire assessing sleep quality (Pittsburgh Sleep Quality Index-PSQI). Migraine headache characteristics and clinical features were assessed using smartphone-based daily diaries. Weight was measured in-clinic, and several potential confounders were assessed using rigorous methods. Nearly 70% of participants endorsed poor sleep quality. Greater monthly migraine days and the presence of phonophobia related to poorer sleep quality, and specifically poorer sleep efficiency, controlling for confounders. Obesity severity was neither independently associated nor interacted with migraine characteristics/features to predict sleep quality. Poor sleep quality is common among women with comorbid migraine and overweight/obesity, although obesity severity does not appear to uniquely relate to or exacerbate the association between migraine and sleep in this population. Results can guide research on mechanisms of the migraine-sleep link and inform clinical care.

Pain Fluctuations of Women with Subacute Herpetic Neuralgia During Local Methylcobalamin in Combination with Lidocaine Treatment: A Single-Blinded Randomized Controlled Trial

Purpose

To evaluate the efficacy and pain fluctuations of methylcobalamin in combination with lidocaine local injection treatment for subacute herpetic neuralgia (SHN).

Methods

Seventy-nine women (60.4 ± 2.7 years) with thoracic SHN were enrolled and randomized to receive a combination of methylcobalamin and lidocaine local injection (MI, N=40), or a combination of lidocaine patch 5% and oral methylcobalamin (PO, N=39) for four weeks. Repeated-measures analyses of variance were used to evaluate the effect on pain levels. Generalized estimation equations were used to analyze the cause-effect relationship between pain fluctuations and influencing factors.

Results

At the treatment endpoint, the group, treatment time, and group interacted with treatment time effects of the pain scores and area were statistically significant (P<0.001), The pain scores were 2.9 ±0.9 (MI) and 4.3 ± 1.5 (PO). 80.00% (MI) or 28.21% (PO) of patients had pain scores ≤ 3, the odds ratio was 2.84 (95% CI: 1.68 to 4.79). The incidence of postherpetic neuralgia was 5.0% (2/40) at 3 months. Pain fluctuated repeatedly during treatment. The pain fluctuation increased from 8.75 log folds in the afternoon, to 79.85 log folds at night. With the ADLs level increasing from 1 to 3, the pain fluctuated from 4.28 to 17.70 log folds. Allodynia, itching, sleep quality, and ADLs were the significant influencing factors (P<0.05).

Conclusion

This study validated the efficacy of methylcobalamin combined with lidocaine for SHN, and confirmed that pain levels in patients with SHN had an obvious circadian rhythm. ADLs were an important cause of pain fluctuations.

Cutaneous allodynia in pediatric and adolescent patients and their mothers: A comparative study

BACKGROUND

Allodynia in adults with migraine is related to disease duration. In pediatric patients with migraine, the same proportion reported allodynia in the first six months of migraine presentation as in prolonged disease. This study examined a possible association between migraine pediatric allodynia and maternal allodynia.

METHODS

We interviewed children with migraine first, and then their mothers, regarding allodynia and headache symptoms. We reviewed hospital charts on pediatric medical background and headache symptoms. Mothers and children older than 11 years filled the Strengths and Difficulties Questionnaire.

RESULTS

Ninety-eight children with migraine, mean age 13.49 ± 3.1 years, and their mothers, mean age 43.5 ± 6.2 years were recruited to the study. Pediatric allodynia was associated with maternal allodynia; the latter was reported in 82.8% of children with allodynia versus 35.3% of children without allodynia (p < 0.001). Maternal migraine was reported in 44 (68.7%) of children with allodynia versus 16.3% without allodynia, p < 0.001. No difference was found in Strengths and Difficulties Questionnaire scores, between children with and without allodynia.

CONCLUSIONS

Pediatric allodynia is associated with maternal migraine. Genetic and environmental factors such as maternal behavior may contribute to reduced pain threshold.

Clinical features of definite vestibular migraine through the lens of central sensitization: a cross-sectional study

BACKGROUND

Vestibular migraine (VM) commonly causes episodic vertigo/dizziness; however, its clinical features are unknown. Based on the evidence that central sensitization is related to VM pathogenesis, we hypothesized that cutaneous allodynia is frequently associated with patients with VM compared with patients without VM. This study aims to (1) elucidate the clinical features of patients with VM and (2) evaluate whether patients with VM were more frequently associated with cutaneous allodynia than patients without VM.

METHODS

This cross-sectional study enrolled consecutive patients with migraine aged 18-65 years. The comprehensive interview form included diagnostic questions regarding migraine and VM, demographic characteristics, migraine-specific variables, migraine-associated symptoms, and cutaneous allodynia.

RESULTS

A total of 245 consecutive patients with migraine (mean age = 39.5 years, 81.2% women) were enrolled; 65 (26.5%) patients with VM were assigned to the VM group, 74 (30.2%) with migraine with vestibular symptoms not meeting the VM criteria (MwVS) were assigned to the MwVS group, and 106 (43.3%) patients with episodic migraine without vestibular symptoms (EM) were assigned to the EM group, respectively. Pairwise comparisons demonstrated no significant differences between the VM and MwVS groups, except for severe disability in the VM group. Compared with EM group, VM group had significant aura, severe disability, depression, tinnitus, sleep disorders, and widespread multimodal cutaneous allodynia.

CONCLUSIONS

VM and MwVS may be on the same spectrum of disorders. The VM group had significantly associated widespread multimodal cutaneous allodynia compared with the EM group, indicating that thalamic sensitization plays a key role in VM pathogenesis. Widespread allodynia may be a useful diagnostic aid for VM.

Migraine and sleep disorders: a systematic review

Migraine and sleep disorders are common and often burdensome chronic conditions with a high prevalence in the general population, and with considerable socio-economic impact and costs.The existence of a relationship between migraine and sleep disorders has been recognized from centuries by clinicians and epidemiological studies. Nevertheless, the exact nature of this association, the underlying mechanisms and interactions are complex and not completely understood. Recent biochemical and functional imaging studies identified central nervous system structures and neurotransmitters involved in the pathophysiology of migraine and also important for the regulation of normal sleep architecture, suggesting a possible causative role, in the pathogenesis of both disorders, of a dysregulation in these common nervous system pathways.This systematic review summarizes the existing data on migraine and sleep disorders with the aim to evaluate the existence of a causal relationship and to assess the presence of influencing factors. The identification of specific sleep disorders associated with migraine should induce clinicians to systematically assess their presence in migraine patients and to adopt combined treatment strategies.

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.

Cephalic cutaneous allodynia in children and adolescents with migraine of short duration: A retrospective cohort study

BACKGROUND

Allodynia is prevalent in adults with migraine and has been associated with long disease duration and severe course. Studies of the pediatric population are sparse. The aim of this study was to evaluate the rate of cephalic cutaneous allodynia in children and adolescents within the first 6 months of migraine onset and to identify associated clinical and migraine-related parameters.

METHODS

The electronic database of a tertiary pediatric headache clinic from 2014 to 2017 was retrospectively searched for all children and adolescents diagnosed with migraine headache within 6 months or less of symptom onset. Cephalic cutaneous allodynia was identified by validated questionnaire. Demographics, symptoms, and headache-related parameters were compared between patients with and without allodynia.

RESULTS

The cohort included 119 patients, 69 girls (58.0%) and 50 (42.0%) boys, of mean age 11.6 ± 3.6 years. Mean time since onset of migraine disease was 3.6 ± 1.8 months. Cephalic cutaneous allodynia was reported by 31.1% of patients. It was significantly associated with female gender ( p = 0.03), older age at admission ( p = 0.037), older age at onset ( p = 0.042) migraine with aura ( p = 0.002), and higher rate of awakening pain ( p = 0.017).

CONCLUSIONS

Cephalic cutaneous allodynia may occur in children and adolescents already in the first 6 months of migraine onset. Contrary to adult studies, we found no association of allodynia with migraine frequency or long disease duration. Allodynia was significantly associated with migraine with aura, female gender, and awakening pain. A genetic tendency may contribute to the appearance of allodynia in the pediatric age group.

Sleep disturbances in tension-type headache and migraine

Current research into the pathogenesis of tension-type headache (TTH) and migraine is focused on altered nociceptive pain processing. Among the potential factors that influence sensitization mechanisms, emotional stress, depression, or sleep disorders all have an essential role: they increase the excitability of nociceptive firing and trigger hyperalgesic responses. Sleep disturbances and headache disorders share common brain structures and pathogenic mechanisms and TTH, migraine, and sleep disturbances often occur together; for example, 50% of individuals who have either TTH or migraine have insomnia. Moreover, insomnia and poor sleep quality have been associated with a higher frequency and intensity of headache attacks, supporting the notion that severity and prevalence of sleep problems correlate with headache burden. It should be noted that the association between headaches and sleep problems is bidirectional: headache can promote sleep disturbances, and sleep disturbances can also precede or trigger a headache attack. Therefore, a better understanding of the factors that affect sleep quality in TTH and migraine can assist clinicians in determining better and adequate therapeutic programs. In this review, the role of sleep disturbances in headaches, and the association with depression, emotional stress, and pain sensitivity in individuals with TTH or migraine are discussed.

Sleep changes during prophylactic treatment of migraine

AIMS

To assess sleep quality in patients with primary headaches before and after prophylactic treatment using a validated sleep-screening instrument.

MATERIALS AND METHODS

A total of 147 patients, including 63 tension type headache (TTH) and 84 migraine patients were included. Patients were examined in terms of frequency and severity of headaches and sleep quality before and 12 weeks after prophylactic treatment with either propranolol or amitriptyline.

RESULTS

Baseline Visual Analogue Score (VAS) in migraine patients was 7.99 ± 1.39 compared with 6.86 ± 1.50 in TTH group (P < 0.001). VAS score after the first month of treatment was 6.08 ± 1.88 in migraine patients and 5.40 ± 1.61 in TTH (P = 0.023). VAS scores decreased after the third month of treatment to 4.32 ± 2.29 in migraine patients and 4.11 ± 1.66 in TTH patients (P = 0.344). The decrease was significant for patients treated with amitriptyline but not for those with propranolol. Baseline Pittsburgh Sleep Quality (PSQI) scores were 5.93 ± 2.43 in migraine patients and 6.71 ± 2.39 in TTH patients. Poor quality of sleep (PSQI ≥ 6) prior to prophylactic treatment was observed in 61.4% of migraine patients and in 77.7% of TTH patients. Comparison of PSQI scores before and 3 months following treatment showed significantly improved quality of sleep in all treatment groups; the greatest significance was detected in migraine patients with initial PSQI scores of ≥6 and treated with amitriptyline (P < 0.001).

CONCLUSIONS

Increased understanding of routine objective sleep measures in migraine patients is needed to clarify the nature of sleep disturbances associated with primary headaches. This may in turn lead to improvements in headache treatments.

Headaches and sleep disorders

Headaches and sleep disorders are associated in a complex manner. Both the disorders are common in the general population, but the relationship between the two is more than coincidental. Sleep disorders can exacerbate headache sand the converse is also true. Treatment of sleep disorders can have a positive impact on the treatment of headaches. Screening for sleep disorders should be considered in all patients with headaches. This can be accomplished with brief screening tools. Those who screen positively can be further evaluated or referred to asleep specialist.

The common link between functional somatic syndromes may be central sensitisation

OBJECTIVES

Functional somatic syndromes are common and disabling conditions that all include chronic pain, and which may be related to central nervous system sensitisation. Here, we address the concept of central sensitisation as a physiological basis for the functional somatic syndromes.

METHODS

A narrative review of the current literature on central sensitisation and physiological studies in the functional somatic syndromes.

RESULTS

Central sensitisation may be a common neurophysiological process that is able to explain non-painful as well as painful symptoms in these disorders. Furthermore, central sensitisation may represent an endophenotypic vulnerability to the development of these syndromes that potentially explains why they cluster together.

CONCLUSIONS

Further research is needed to verify these findings, including prospective studies and the standardisation of combined methods of investigation in the study of central sensitisation in functional somatic syndromes. In turn, this may lead to new explanatory mechanisms and treatments being evaluated. Our conclusions add to the debate over the nomenclature of these syndromes but importantly also provide an explanation for our patients.

Negative emotions in migraineurs dreams: the increased prevalence of oneiric fear and anguish, unrelated to mood disorders

Background. Migraineurs brain has shown some functional peculiarities that reflect not only in phonophobia, and photophobia, but also in mood and sleep. Dreaming is a universal mental state characterized by hallucinatory features in which imagery, emotion, motor skills, and memory are created de novo. We evaluated dream contents and associated emotions in migraineurs. Materials and Methods. 412 subjects: 219 controls; and 148 migraineurs (66 with aura, MA; 82 without aura, MO), and 45 tension type headache patients (TTH). A semistructured retrospective self-reported questionnaire was used to evaluate dreams. The Generalized Anxiety Disorder Questionnaire (GAD-7), and the Patient Health Questionnaire (PHQ-9) were administered to evaluate anxiety and depression. Results. Migraineurs showed increased levels of anxiety (P = 0.0002 for MA versus controls, P = 0.004 for MO versus controls). Fear and anguish during dreaming were more frequently reported by migraine patients compared to controls, independently by anxiety and depression scores. Discussion. The brain of migraineurs seems to dream with some peculiar features, all with a negative connotation, as fear and anguish. It may be due to the recorded negative sensations induced by recurrent migraine pain, but it may just reflect a peculiar attitude of the mesolimbic structures of migraineurs brain, activated in both dreaming and migraine attacks.

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.

Headache and insomnia: their relation reviewed

OBJECTIVE

Headache and insomnia are both very common and burdensome complaints worldwide. Numerous articles have been written on the relation between them, but the number of scientific articles is limited. The purpose of this review is to summarize the current scientific literature and analyze it in light of the nature of the headache-insomnia relation.

METHODS

An extensive literature search was conducted using the terms, headache, migraine, insomnia, sleep, sleep deprivation, and sleep loss, on the search engines PubMed, ScienceDirect, Medline, and Google Scholar. A total of twelve research articles were found, discussing the relation of insomnia to headache in general, tension-type headache, migraine, and chronic headache. The majority of the studies are cross-sectional but two are longitudinal.

RESULTS

The studies suggest an association between headache and insomnia but an asymmetrical one, with headache being more associated with insomnia than the other way around. Therefore, in the association of headache and insomnia, other factors associated with headache or migraine probably play a role, as well.

CONCLUSION

As insomnia appears to be a risk factor for headache or migraine onset, insomnia patients should probably be routinely evaluated for headache. As it also seems a risk factor for increased headache frequency, in particular in tension headache and migraine, patients with these conditions should probably be routinely treated for insomnia, if present, as part of their overall management.

Psychiatric comorbidities in allodynic migraineurs

OBJECTIVES

To evaluate the prevalence and the association of psychological disturbance in migraine patients with allodynia.

METHODS

We recruited 434 migraine patients from an outpatient clinic. The participants completed three self-administered questionnaires, including a headache questionnaire, an allodynia symptoms checklist, and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

Among the migraineurs, 48.4% participants reported allodynia. The HADS total score (15.5 ± 7.8 vs. 13.7 ± 8.5, P  = 0.022) and anxiety subscore (9.1 ± 4.5 vs. 7.6 ± 4.7, P  = 0.001) were higher in migraineurs with allodynia than in those without allodynia. The anxiety subscore in patients with moderate to severe allodynia, mild allodynia, and no allodynia were 10.0 ± 4.5, 8.4 ± 4.3, and 7.6 ± 4.7 ( P  < 0.001, by one-way analysis of variance). Among patients with moderate to severe allodynia, there was a trend of higher depression subscore (7.1 ± 4.0, P  = 0.059) than those with no (6.1 ± 4.4) or mild allodynia (5.8 ± 4.0). In a regression model, the presence of allodynia is an independent risk factor for clinically significant anxiety. Moderate to severe allodynia is an independent risk factor for clinically significant depression.

CONCLUSIONS

In migraineurs, the severity of cutaneous allodynia was associated with their mood status, especially anxiety.

Answer to comment on "sleep quality, arousal and pain thresholds in migraineurs: a blinded controlled polysomnographic study"

We discuss the comments on our article “Sleep quality, arousal and pain thresholds in migraineurs. A blinded controlled polysomnographic study” published in JHP 2013 Feb 14;14(1):12. We hypothesize that migraineurs need more sleep than healthy controls and more sleep than they manage to achieve. Some migraineurs probably have a decreased ability to process incoming stimuli. Increased spontaneous pain may follow either sleep restriction or sleep disturbance. A comparison of migraineurs with attack onset related to sleep, migraineurs with attack onset not related to sleep and controls will be reported in another paper.

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

BACKGROUND

Our aim was to compare subjective and objective sleep quality and arousal in migraine and to evaluate the relationship between sleep quality and pain thresholds (PT) in controls, interictal, preictal and postictal migraine.

METHODS

Polysomnography and PT (to pressure, heat and cold) measurements were done in 34 healthy controls and 50 migraineurs. Subjective sleep quality was assessed by sleep diaries, Epworth sleepiness scale, Karolinska sleep questionnaire and Pittsburgh sleep quality index. Migraineurs who had their sleep registration more than 48 h from an attack were classified as interictal while those who were less than 48 h from an attack were classified as either preictal or postictal.

RESULTS

Migraineurs reported more insomnia and other sleep-related symptoms than controls, but the objective sleep differences were smaller and we found no differences in daytime sleepiness. Interictal migraineurs had more awakenings (p=0.048), a strong tendency for more slow-wave sleep (p=0.050), lower thermal pain thresholds (TPT) (heat pain thresholds p=0.043 and cold pain thresholds p=0.031) than controls. Migraineurs in the preictal phase had shorter latency to sleep onset than controls (p=0.003). Slow-wave sleep correlated negatively with pressure PT and slow bursts correlated negatively with TPT.

CONCLUSION

Lower PT in interictal migraineurs seems related to increased sleep pressure. We hypothesize that migraineurs on the average suffer from a relative sleep deprivation and need more sleep than healthy controls. Lack of adequate rest might be an attack-precipitating- and hyperalgesia-inducing factor.

Cutaneous allodynia in patients with episodic migraine

Cutaneous allodynia may be observed in patients with migraine and this reflects the central sensitization of the trigeminal neurons. We aimed to investigate the frequency of cutaneous allodynia in patients with episodic migraine and to compare clinical characteristics of migraine patients with and without allodynia. One hundred and eighty-six consecutive patients with episodic migraine attacks were prospectively included in the study. The cutaneous allodynia symptoms that occurred during headache attacks were documented using a questionnaire for assessing cephalic and extracephalic cutaneous allodynia. One hundred and fourteen patients (61.3 %) were observed to develop allodynia during migraine attacks and the ratio of the female gender was found higher among the patients with allodynia (p < 0.001). Migraine disease duration was longer (p = 0.004) and accompanying nausea and phonophobia were more common (p = 0.003 and p = 0.005, respectively) in the patients with allodynia. Menstrually related migraine was found to be associated with both allodynia (p = 0.049) and its severity (p = 0.003). The results of present study revealed that cutaneous allodynia was rather frequent in episodic migraine, particularly in patients having longer disease duration. Higher frequency of allodynia in women and its association with menstrually related migraine may be related to the effects of hormonal factors on cutaneous pain thresholds and central sensitization. Association of nausea and phonophobia with allodynia may be interpreted as the common pathways are shared in the development of these symptoms.

Sinus venous stenosis-associated idiopathic intracranial hypertension without papilledema as a powerful risk factor for progression and refractoriness of headache

Data from two recent studies strongly support the hypothesis that idiopathic intracranial hypertension without papilledema (IIHWOP) could represent a powerful risk factor for the progression of pain in primary headache individuals. The first study highlights that an asymptomatic IIHWOP is much more prevalent than believed in the general population and occurs only in central venous stenosis carriers. In the second study, about one half of a large consecutive series of unresponsive primary chronic headache patients shows significant sinus venous stenosis. A continuous or intermittent IIHWOP was detectable in 91% of this subgroup and in no patient with normal venography. Moreover, after the lumbar puncture, a 2- to 4-week improvement in headache frequency was observed in most of the intracranial hypertensive patients. These findings strongly suggest that patients prone to primary headache who carry central venous outflow abnormalities are at high risk of developing a comorbid IIHWOP, which in turn is responsible for the progression and the unresponsiveness of the pain. Based on the available literature data, we propose that central sinus stenosis-related IIHWOP, although highly prevalent among otherwise healthy people, represents an important modifiable risk factor for the progression and refractoriness of pain in patients predisposed to primary headache. The mechanism could refer to up to one half of the primary chronic headache patients with minimal response to treatments referring to specialized headache clinics. Due to the clinical and taxonomic relevance of this hypothesis further studies are urgently needed.

Prevalence, clinical features and potential therapies for fibromyalgia in primary headaches

Fibromyalgia (FM) syndrome is predominantly related to generation and persistence of central sensitization, which is an aggravating factor for chronic headaches. This review aims to examine the last 11 years of studies on FM and primary headache comorbidity, focusing on prevalence, clinical features and treatments. Chronic forms of migraine and tension-type headache show a high frequency of FM comorbidity. The symptoms characterizing headache patients presenting with FM comorbidity are high headache frequency, poor sleep quality, pericranial tenderness, anxiety and reduction of physical performances. The effects of headache-preventive drugs on factors favoring FM comorbidity were poorly evaluated. Nonpharmacological approaches such as transcranial magnetic stimulation may be an option for treatment of chronic migraine associated with FM.

Clinical features of headache patients with fibromyalgia comorbidity

Our previous study assessed the prevalence of fibromyalgia (FM) syndrome in migraine and tension-type headache. We aimed to update our previous results, considering a larger cohort of primary headache patients who came for the first time at our tertiary headache ambulatory. A consecutive sample of 1,123 patients was screened. Frequency of FM in the main groups and types of primary headaches; discriminating factor for FM comorbidity derived from headache frequency and duration, age, anxiety, depression, headache disability, allodynia, pericranial tenderness, fatigue, quality of life and sleep, and probability of FM membership in groups; and types of primary headaches were assessed. FM was present in 174 among a total of 889 included patients. It prevailed in the tension-type headache main group (35%, p < 0.0001) and chronic tension-type headache subtype (44.3%, p < 0.0001). Headache frequency, anxiety, pericranial tenderness, poor sleep quality, and physical disability were the best discriminating variables for FM comorbidity, with 81.2% sensitivity. Patients presenting with chronic migraine and chronic tension-type headache had a higher probability of sharing the FM profile (Bonferroni test, p < 0.01). A phenotypic profile where headache frequency concurs with anxiety, sleep disturbance, and pericranial tenderness should be individuated to detect the development of diffuse pain in headache patients.

Possible relationships between headache-allodynia and nocturnal sleep breathing

Sleep and headache are linked in a bidirectional way. Breathing quality during sleep may be a possible link between them. The objective of this study were to evaluate the prevalence of headache--and of allodynia--in a population of subjects who underwent cardiopulmonary monitoring during sleep for presumed respiratory problems; to evaluate the possible relationships between the presence of headaches--and of allodynia--and respiratory parameters. We studied 181 subjects, 112 without headache (mean age 59.4 ± 13.1 years, 97 men and 15 women); 69 with history of headache (42 men and 27 women; 41 migraineurs and 28 with tension type headache). Headache diagnosis was made according to ICHD-II criteria. A semi-structured ad hoc questionnaire was used to evaluate the presence of allodynia. Full cardiopulmonary monitoring was performed by SOMNO check(®) effort (WEINMANN) with SaO(2), T90 and AHI determination. Headache and headache-associated allodynia were particularly frequent in this population, suggesting a positive correlation between breathing problems during sleep and head pain, and allodynia. The observation that better respiratory parameters were found among headache sufferers with respect to those without headache, even in allodynic subjects, seems to reverse this point of view: headache and allodynia may possibly have an allostatic function preventing deep sleep and, in turn, avoiding prolonged apneas.