From Migraine To Chronic Daily Headache: The Biological Basis of Headache Transformation

Glia Signaling and Brain Microenvironment in Migraine

Migraine is a complicated neurological disorder affecting 6% of men and 18% of women worldwide. Various mechanisms, including neuroinflammation, oxidative stress, altered mitochondrial function, neurotransmitter disturbances, cortical hyperexcitability, genetic factors, and endocrine system problems, are responsible for migraine. However, these mechanisms have not completely delineated the pathophysiology behind migraine, and they should be further studied. The brain microenvironment comprises neurons, glial cells, and vascular structures with complex interactions. Disruption of the brain microenvironment is the main culprit behind various neurological disorders. Neuron-glia crosstalk contributes to hyperalgesia in migraine. In the brain, microenvironment and related peripheral regulatory circuits, microglia, astrocytes, and satellite cells are necessary for proper function. These are the most important cells that could induce migraine headaches by disturbing the balance of the neurotransmitters in the nervous system. Neuroinflammation and oxidative stress are the prominent reactions glial cells drive during migraine. Understanding the role of cellular and molecular components of the brain microenvironment on the major neurotransmitters engaged in migraine pathophysiology facilitates the development of new therapeutic approaches with higher effectiveness for migraine headaches. Investigating the role of the brain microenvironment and neuroinflammation in migraine may help decipher its pathophysiology and provide an opportunity to develop novel therapeutic approaches for its management. This review aims to discuss the neuron-glia interactions in the brain microenvironment during migraine and their potential role as a therapeutic target for the treatment of migraine.

Psychological Disorders, Adverse Childhood Experiences and Parental Psychiatric Disorders in Children Affected by Headache: A Systematic Review

BACKGROUND

Pediatric headaches have been linked to adverse life events or psychological factors in children and their families, with a complex and bidirectional association. Moreover, it is well-known that psychological stress can trigger headaches.

METHODS

We searched three databases for studies focusing on headaches and adverse events or psychological factors in children up to 12 years old or in their caregivers.

RESULTS

We included 28 studies. Child psychological factors, including internal and external symptoms, were commonly associated with all types of headaches. Sleep disturbances showed a positive association with headaches in 3 out of 5 studies. Family conflict and unhappiness were frequently found in children suffering with headaches, while single-parent families and divorce were not associated. Stressful environments and adverse life events, particularly bullying, were also found to be linked with headaches.

CONCLUSIONS

Childhood headaches represent an alarm bell for clinicians to investigate and treat psychological or psychiatric disorders in children and their family. Further studies are needed to elucidate the role of early-life adverse events in children and their families.

New Insights on Metabolic and Genetic Basis of Migraine: Novel Impact on Management and Therapeutical Approach

Migraine is a hereditary disease, usually one-sided, sometimes bilateral. It is characterized by moderate to severe pain, which worsens with physical activity and may be associated with nausea and vomiting, may be accompanied by photophobia and phonophobia. The disorder can occur at any time of the day and can last from 4 to 72 h, with and without aura. The pathogenic mechanism is unclear, but extensive preclinical and clinical studies are ongoing. According to electrophysiology and imaging studies, many brain areas are involved, such as cerebral cortex, thalamus, hypothalamus, and brainstem. The activation of the trigeminovascular system has a key role in the headache phase. There also appears to be a genetic basis behind the development of migraine. Numerous alterations have been identified, and in addition to the genetic cause, there is also a close association with the surrounding environment, as if on the one hand, the genetic alterations may be responsible for the onset of migraine, on the other, the environmental factors seem to be more strongly associated with exacerbations. This review is an analysis of neurophysiological mechanisms, neuropeptide activity, and genetic alterations that play a fundamental role in choosing the best therapeutic strategy. To date, the goal is to create a therapy that is as personalized as possible, and for this reason, steps forward have been made in the pharmacological field in order to identify new therapeutic strategies for both acute treatment and prophylaxis.

Glia and Orofacial Pain: Progress and Future Directions

Orofacial pain is a universal predicament, afflicting millions of individuals worldwide. Research on the molecular mechanisms of orofacial pain has predominately focused on the role of neurons underlying nociception. However, aside from neural mechanisms, non-neuronal cells, such as Schwann cells and satellite ganglion cells in the peripheral nervous system, and microglia and astrocytes in the central nervous system, are important players in both peripheral and central processing of pain in the orofacial region. This review highlights recent molecular and cellular findings of the glia involvement and glia–neuron interactions in four common orofacial pain conditions such as headache, dental pulp injury, temporomandibular joint dysfunction/inflammation, and head and neck cancer. We will discuss the remaining questions and future directions on glial involvement in these four orofacial pain conditions.

When a Head Is about to Burst: Attachment Mediates the Relationship Between Childhood Trauma and Migraine

Background: People exposed to childhood trauma show insecure attachment patterns and are more prone to chronic and pain-related conditions, including migraine. The aim of this study was to explore the mediating role of attachment in the association between childhood trauma and adulthood chronic health conditions, with a focus on migraine. Methods: Respondents from a representative sample of citizens of the Czech Republic (n = 1800, mean age: 46.6 years, 48.7% male) were asked to report various chronic and pain-related conditions, childhood trauma (The Childhood Trauma Questionnaire, CTQ), and attachment anxiety and avoidance (The Experience in Close Relationships Revised, ECR-R) in a cross-sectional, questionnaire-based survey conducted in 2016. Structural equation models (SEM) adjusted for sociodemographic variables were used to assess the relationship between childhood trauma, adulthood attachment, and adulthood chronic health conditions (migraine, other pain-related conditions, chronic health conditions other than pain, no chronic health complaints). Results: After adjusting for sociodemographic variables, SEM confirmed a significant mediation of the relationship between childhood trauma and migraine through adulthood attachment. There was no mediation effect of adulthood attachment found in other health complaints. Conclusion: This study highlights the mediation effect of attachment in the link between childhood trauma and migraine. Attachment-based therapeutic interventions can be useful in the treatment of patients with migraine.

Psychological Stress-Induced Immune Response and Risk of Alzheimer's Disease in Veterans from Operation Enduring Freedom and Operation Iraqi Freedom

PURPOSE

Psychological stress is a significant health problem in veterans and their family members. Traumatic brain injury (TBI) and stress lead to the onset, progression, and worsening of several inflammatory and neurodegenerative diseases in veterans and civilians. Alzheimer's disease (AD) is a progressive, irreversible neuroinflammatory disease that causes problems with memory, thinking, and behavior. TBIs and chronic psychological stress cause and accelerate the pathology of neuroinflammatory diseases such as AD. However, the precise molecular and cellular mechanisms governing neuroinflammation and neurodegeneration are currently unknown, especially in veterans. The purpose of this review article was to advance the hypothesis that stress and TBI-mediated immune response substantially contribute and accelerate the pathogenesis of AD in veterans and their close family members and civilians.

METHODS

The information in this article was collected and interpreted from published articles in PubMed between 1985 and 2020 using the key words stress, psychological stress, Afghanistan war, Operation Enduring Freedom (OEF), Iraq War, Operation Iraqi Freedom (OIF), Operation New Dawn (OND), traumatic brain injury, mast cell and stress, stress and neuroimmune response, stress and Alzheimer's disease, traumatic brain injury, and Alzheimer's disease.

FINDINGS

Chronic psychological stress and brain injury induce the generation and accumulation of beta-amyloid peptide, amyloid plaques, neurofibrillary tangles, and phosphorylation of tau in the brain, thereby contributing to AD pathogenesis. Active military personnel and veterans are under enormous psychological stress due to various war-related activities, including TBIs, disabilities, fear, new environmental conditions, lack of normal life activities, insufficient communications, explosions, military-related noise, and health hazards. Brain injury, stress, mast cell, and other immune cell activation can induce headache, migraine, dementia, and upregulate neuroinflammation and neurodegeneration in veterans of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn. TBIs, posttraumatic stress disorder, psychological stress, pain, glial activation, and dementia in active military personnel, veterans, or their family members can cause AD several years later in their lives. We suggest that there are increasing numbers of veterans with TBIs and stress and that these veterans may develop AD late in life if no appropriate therapeutic intervention is available.

IMPLICATIONS

Per these published reports, the fact that TBIs and psychological stress can accelerate the pathogenesis of AD should be recognized. Active military personnel, veterans, and their close family members should be evaluated regularly for stress symptoms to prevent the pathogenesis of neurodegenerative diseases, including AD.

A hypothetical proposal for association between migraine and Meniere's disease

Meniere's disease (MD) is a chronic condition affecting the inner ear whose precise etiology is currently unknown. We propose the hypothesis that MD is a migraine-related phenomenon which may have implications for future treatment options for both diseases. The association between MD and migraine is both an epidemiological and a mechanistic one, with up to 51% of individuals with MD experiencing migraine compared to 12% in the general population. The presence of endolymphatic hydrops in those with MD may be the factor that unites the two conditions, as hydropic inner ears have an impaired ability to maintain homeostasis. Migraine headaches are theorized to cause aura and symptoms via spreading cortical depression that ultimately results in substance P release, alterations in blood flow, and neurogenic inflammation. Chronically hydropic inner ears are less able to auto-regulate against the changes induced by active migraine attacks and may ultimately manifest as MD. This same vulnerability to derangements in homeostasis may also explain the common triggering factors of both MD attacks and migraine headaches, including stress, weather, and diet. Similarly, it may explain the efficacy of common treatments for both diseases: current migraine treatments such as anti-hypertensives and anti-convulsants have shown promise in managing MD. Though the etiology of both MD and migraine is likely multifactorial, further exploration of the association between the two conditions may illuminate how to best manage them in the future. MD is likely a manifestation of cochleovestibular migraine, which occurs as a result of migraine related changes in both the cochlea and vestibule.

Identifying and managing refractory migraine: barriers and opportunities?

The term refractory migraine has been used to describe persistent headache that is difficult to treat or fails to respond to standard and/or aggressive treatments. This subgroup of migraine patients are generally highly disabled and experience impaired quality of life, despite optimal treatments. Several definitions and criteria for refractory migraine have been published, but as yet, an accepted or established definition is not available. This article reviews the published criteria and proposes a new set of criteria. The epidemiology, pathophysiology and management options are also reviewed.

Systemic Morphine Produces Dose-dependent Nociceptor-mediated Biphasic Changes in Nociceptive Threshold and Neuroplasticity

We investigated the dose dependence of the role of nociceptors in opioid-induced side-effects, hyperalgesia and pain chronification, in the rat. Systemic morphine produced a dose-dependent biphasic change in mechanical nociceptive threshold. At lower doses (0.003-0.03 mg/kg, s.c.) morphine induced mechanical hyperalgesia, while higher doses (1-10 mg/kg, s.c.) induced analgesia. Intrathecal (i.t.) oligodeoxynucleotide (ODN) antisense to mu-opioid receptor (MOR) mRNA, attenuated both hyperalgesia and analgesia. 5 days after systemic morphine (0.03-10 mg/kg s.c.), mechanical hyperalgesia produced by intradermal (i.d.) prostaglandin E₂ (PGE₂) was prolonged, indicating hyperalgesic priming at the peripheral terminal of the nociceptor. The hyperalgesia induced by i.t. PGE₂ (400 ng/10 µl), in groups that received 0.03 (that induced hyperalgesia) or 3 mg/kg (that induced analgesia) morphine, was also prolonged, indicating priming at the central terminal of the nociceptor. The prolongation of the hyperalgesia induced by i.d. or i.t. PGE₂, in rats previously treated with either a hyperalgesic (0.03 mg/kg, s.c.) or analgesic (3 mg/kg, s.c.) dose, was reversed by i.d. or i.t. injection of the protein translation inhibitor cordycepin (1 µg), indicative of Type I priming at both terminals. Although pretreatment with MOR antisense had no effect on priming induced by 0.03 mg/kg morphine, it completely prevented priming by 3 mg/kg morphine, in both terminals. Thus, the induction of hyperalgesia, but not priming, by low-dose morphine, is MOR-dependent. In contrast, induction of both hyperalgesia and priming by high-dose morphine is MOR-dependent. The receptor at which low-dose morphine acts to produce priming remains to be established.

A sixteen-week three-armed, randomized, controlled trial investigating clinical and biochemical effects of targeted alterations in dietary linoleic acid and n-3 EPA+DHA in adults with episodic migraine: Study protocol

Migraine is a prevalent neurological disorder, affecting over 16% of adult women and 7% of adult men in the U.S., causing significant pain, disability, and medical expense, with incomplete benefits from conventional medical management. Migraine, as a chronic pain syndrome, provides a practical model for investigating the impact of dietary modifications in omega-3 (n-3) and omega-6 (n-6) fatty acids. This paper reports the protocol of a trial to assess whether targeted dietary modifications designed to increase n-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with or without concurrent reduction in n-6 linoleic acid (LA), will alter nociceptive lipid mediators and mediate decreases in frequency and severity of migraine. This prospective, randomized, controlled trial in 153 male and female adult subjects, ages 18-99, with diagnosed and actively managed episodic migraine tests the efficacy, safety, and biochemical effects of targeted, controlled alterations in dietary omega-3 and omega-6 fatty acids. Participants are masked to diet hypotheses and all assessors are masked to treatment assignment. Following a four-week baseline period, participants with migraine headache frequency of 5-20 per month are randomized to one of three intensive dietary regimens for 16 additional weeks followed by a less intensive observation period. Dietary intervention arms include: 1) increased n-3 EPA+DHA with low n-6 linoleic acid (H3 L6); 2) increased n-3 EPA+DHA with usual US dietary intake of n-6 linoleic acid (H3 H6); and 3) usual US dietary content of n-3 and n-6 fatty acids (L3 H6). During the actual intervention, subjects receive content-specific study oils and foods sufficient for two meals and two snacks per day, as well as dietary counseling. Biochemical and clinical outcome measures are performed at intervals throughout this period. This randomized controlled trial is designed to determine whether targeted alterations in dietary n-3 and n-6 fatty acids can alter nociceptive lipid mediators in a manner that decreases headache pain and enhances quality of life and function in adults with frequent migraines.

TRIAL REGISTRATION

NCT02012790.

Neurovascular contributions to migraine: Moving beyond vasodilation

Migraine is the third most common disease worldwide, the most common neurological disorder, and one of the most common pain conditions. Despite its prevalence, the basic physiology and underlying mechanisms contributing to the development of migraine are still poorly understood and development of new therapeutic targets is long overdue. Until recently, the major contributing pathophysiological event thought to initiate migraine was cerebral and meningeal arterial vasodilation. However, the role of vasodilation in migraine is unclear and recent findings challenge its necessity. While vasodilation itself may not contribute to migraine, it remains possible that vessels play a role in migraine pathophysiology in the absence of vasodilation. Blood vessels consist of a variety of cell types that both release and respond to numerous mediators including growth factors, cytokines, adenosine triphosphate (ATP), and nitric oxide (NO). Many of these mediators have actions on neurons that can contribute to migraine. Conversely, neurons release factors such as norepinephrine and calcitonin gene-related peptide (CGRP) that act on cells native to blood vessels. Both normal and pathological events occurring within and between vascular cells could thus mediate bi-directional communication between vessels and the nervous system, without the need for changes in vascular tone. This review will discuss the potential contribution of the vasculature, specifically endothelial cells, to current neuronal mechanisms hypothesized to play a role in migraine. Hypothalamic activity, cortical spreading depression (CSD), and dural afferent input from the cranial meninges will be reviewed with a focus on how these mechanisms can influence or be impacted by blood vessels. Together, the data discussed will provide a framework by which vessels can be viewed as important potential contributors to migraine pathophysiology, even in light of the current uncertainty over the role of vasodilation in this disorder.

Chronic Daily Headache: Mechanisms and Principles of Management

Primary headache is a common malady that is often under-recognized and frequently inadequately managed in spite of the fact that it affects up to 95 % of the population in a lifetime. Many forms of headache, including episodic tension and migraine headaches, if properly diagnosed, are reasonably amenable to treatment, but a smaller, though not insignificant, percent of the population suffer daily from a chronic, intractable form of headache that destroys one's productivity and quality of life. These patients are frequently seen in neurological practices at a point when treatment options are limited and largely ineffective. In the following review, we will discuss mechanisms drawn from recent studies that address the transition from acute to chronic pain that may apply to the transformation from episodic to chronic daily headaches which may offer opportunities for preempting headache transformation.

Chronic Daily Headache in Children and Adolescents: A Multi-Faceted Syndrome

Chronic daily headache (CDH) is a multi-faceted, often complex pain syndrome in children and adolescents. Chronic daily headache may be primary or secondary. Chronic migraine and chronic tension-type are the most frequent subtypes. Chronic daily headache is co-morbid with adverse life events, anxiety and depressive disorders, possibly with other psychiatric disorders, other pain syndromes and sleep disorders; these conditions contribute to initiating and maintaining CDH. Hence, early management of episodic headache and treatment of associated conditions are crucial to prevention. There is evidence for the benefit of psychological therapies, principally relaxation and cognitive behavioral, and promising information on acupuncture for CDH. Data on drug treatment are based primarily on open label studies. The controversies surrounding CDH are discussed and proposals for improvement presented. The multifaceted nature of CDH makes it a good candidate for a multi-axial classification system. Such an approach should facilitate biopsychosocial management and enhance consistency in clinical research.

The effect of stellate ganglion block on the atypical facial pain

Atypical facial pain (AFP) is a type of facial pain which does not fulfill any other diagnosis. It has several features such as no objective signs, no obvious explanation of the cause and poor response to treatments. We report a case of a female patient with AFP on the left maxillary area. The pain was increased by cold innocuous stimulation and thermography showed that the temperature on the painful area was significantly decreased. The pain was successfully alleviated by stellate ganglion block (SGB). Therefore, SGB can be effectively used to treat AFP.

The relationship between opioids and immune signalling in the spinal cord

Opioids are considered the gold standard for the treatment of moderate to severe pain. However, heterogeneity in analgesic efficacy, poor potency and side effects are associated with opioid use, resulting in dose limitations and suboptimal pain management. Traditionally thought to exhibit their analgesic actions via the activation of the neuronal G-protein-coupled opioid receptors, it is now widely accepted that neuronal activity of opioids cannot fully explain the initiation and maintenance of opioid tolerance, hyperalgesia and allodynia. In this review we will highlight the evidence supporting the role of non-neuronal mechanisms in opioid signalling, paying particular attention to the relationship of opioids and immune signalling.

Targeted alteration of dietary n-3 and n-6 fatty acids for the treatment of chronic headaches: a randomized trial

Omega-3 and n-6 fatty acids are biosynthetic precursors to lipid mediators with antinociceptive and pronociceptive properties. We conducted a randomized, single-blinded, parallel-group clinical trial to assess clinical and biochemical effects of targeted alteration in dietary n-3 and n-6 fatty acids for treatment of chronic headaches. After a 4-week preintervention phase, ambulatory patients with chronic daily headache undergoing usual care were randomized to 1 of 2 intensive, food-based 12-week dietary interventions: a high n-3 plus low n-6 (H3-L6) intervention, or a low n-6 (L6) intervention. Clinical outcomes included the Headache Impact Test (HIT-6, primary clinical outcome), Headache Days per month, and Headache Hours per day. Biochemical outcomes included the erythrocyte n-6 in highly unsaturated fatty acids (HUFA) score (primary biochemical outcome) and bioactive n-3 and n-6 derivatives. Fifty-six of 67 patients completed the intervention. Both groups achieved targeted intakes of n-3 and n-6 fatty acids. In intention-to-treat analysis, the H3-L6 intervention produced significantly greater improvement in the HIT-6 score (-7.5 vs -2.1; P<0.001) and the number of Headache Days per month (-8.8 vs -4.0; P=0.02), compared to the L6 group. The H3-L6 intervention also produced significantly greater reductions in Headache Hours per day (-4.6 vs -1.2; P=0.01) and the n-6 in HUFA score (-21.0 vs -4.0%; P<0.001), and greater increases in antinociceptive n-3 pathway markers 18-hydroxy-eicosapentaenoic acid (+118.4 vs +61.1%; P<0.001) and 17-hydroxy-docosahexaenoic acid (+170.2 vs +27.2; P<0.001). A dietary intervention increasing n-3 and reducing n-6 fatty acids reduced headache pain, altered antinociceptive lipid mediators, and improved quality-of-life in this population.

Medication-overuse headache and opioid-induced hyperalgesia: A review of mechanisms, a neuroimmune hypothesis and a novel approach to treatment

Introduction

Patients with chronic headache who consume large amounts of analgesics are often encountered in clinical practice. Excessive intake of analgesics is now considered to be a cause, rather than simply a consequence, of frequent headaches, and as such the diagnosis “medication-overuse headache” (MOH) has been formulated. Despite the prevalence and clinical impact of MOH, the pathophysiology behind this disorder remains unclear and specific mechanism-based treatment options are lacking.

Discussion

Although most acute headache treatments have been alleged to cause MOH, here we conclude from the literature that opioids are a particularly problematic drug class consistently associated with worsening headache. MOH may not be a single entity, as each class of drug implicated may cause MOH via a different mechanism. Recent evidence indicates that chronic opioid administration may exacerbate pain in the long term by activating toll-like receptor-4 on glial cells, resulting in a pro-inflammatory state that manifests clinically as increased pain. Thus, from the available evidence it seems opioid-overuse headache is a phenomenon similar to opioid-induced hyperalgesia, which derives from a cumulative interaction between central sensitisation, due to repeated activation of nociceptive pathways by recurrent headaches, and pain facilitation due to glial activation.

Conclusion

Treatment strategies directed at inhibiting glial activation may be of benefit alongside medication withdrawal in the management of MOH.

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.

Efficacy and tolerability of pregabalin versus topiramate in the prophylaxis of chronic daily headache with analgesic overuse: an open-label prospective study

OBJECTIVES

Medication-overuse headache is one of the most disabling headaches. Antiepileptic drugs have been considered a promising strategy as prophylactic treatment in these patients, even if their use often has been limited by low tolerability or safety. The objective of this study was to evaluate the efficacy and safety of pregabalin compared with topiramate for the prophylaxis of chronic daily headache with medication overuse using an open-label prospective study.

METHODS

After a 2-month baseline period (T0), 100 consecutive patients with medication overuse headache were assigned to receive 150 mg/d pregabalin or 100 mg/d topiramate. After a titration period of 4 weeks, a follow-up visit was scheduled every 2 months (T1 and T2) to evaluate headache frequency, the amount of rescue medication intake, and disability.

RESULTS

Of the 46 pregabalin-treated patients, the mean monthly headache frequency significantly decreased from 21.8 ± 4.8 (T0) to 5.1 ± 3.8 (T2), and the monthly number of days with medication intake decreased from 15.1 ± 4.8 (T0) to 2.9 ± 1.9 (T2). Similarly, of the 42 topiramate-treated patients, the mean monthly headache frequency decreased from 21.8 ± 4.9 (T0) to 5.3 ± 3.5 (T2), and the mean monthly number of days with medication intake decreased from 15.1 ± 3.7 (T0) to 2.6 ± 1.5 (T2). A significant improvement of disability score was reported in both groups.

CONCLUSIONS

Similar to topiramate, pregabalin seems to be an effective and well-tolerated preventive therapy in chronic headache and a new option in the management of withdrawal from abused drugs in patients with analgesic overuse, a difficult-to-treat population.

Basal cutaneous pain threshold in headache patients

The aim of this study was to analyze cutaneous pain threshold (CPT) during the interictal phase in headache patients, and the relationships between headache frequency and analgesic use. A consecutive series of 98 headache patients and 26 sex- and age-balanced controls were evaluated. Acute allodynia (AA) was assessed by Jakubowski questionnaire, and interictal allodynia (IA) by a skin test with calibrated monofilaments. AA is widely known as a symptom more present in migraine than in TTH spectrum: in our study this was confirmed only in cases of episodic attacks. When headache index rises towards chronicization, the prevalence of AA increases in both headache spectrums (χ (2) 13.55; p < 0.01). AA was associated with IA only in cases of chronic headache. When headache becomes chronic, mostly in presence of medication overuse, interictal CPT decreases and IA prevalence increases (χ (2) 20.44; p < 0.01), with closer association than AA. In MOH patients there were no significant differences depending on the diagnosis of starting headache (migraine or tension type headache) and, in both groups, we found the overuse of analgesics plays an important role: intake of more than one daily drug dramatically reduces the CPT (p < 0.05). Thus, when acute allodynia increases frequency, worsens or appears for the first time in patients with a long-standing history of chronic headache, it could reasonably suggest that the reduction of CPT had started, without using a specific practical skin test but simply by questioning clinical headache history. In conclusion, these results indicate that the role of medication overuse is more important than chronicization in lowering CPT, and suggest that prolonged periods of medication overuse can interfere with pain perception by a reduction of the pain threshold that facilitates the onset of every new attack leading to chronicization.

Low omega-6 vs. low omega-6 plus high omega-3 dietary intervention for chronic daily headache: protocol for a randomized clinical trial

BACKGROUND

Targeted analgesic dietary interventions are a promising strategy for alleviating pain and improving quality of life in patients with persistent pain syndromes, such as chronic daily headache (CDH). High intakes of the omega-6 (n-6) polyunsaturated fatty acids (PUFAs), linoleic acid (LA) and arachidonic acid (AA) may promote physical pain by increasing the abundance, and subsequent metabolism, of LA and AA in immune and nervous system tissues. Here we describe methodology for an ongoing randomized clinical trial comparing the metabolic and clinical effects of a low n-6, average n-3 PUFA diet, to the effects of a low n-6 plus high n-3 PUFA diet, in patients with CDH. Our primary aim is to determine if: A) both diets reduce n-6 PUFAs in plasma and erythrocyte lipid pools, compared to baseline; and B) the low n-6 plus high n-3 diet produces a greater decline in n-6 PUFAs, compared to the low n-6 diet alone. Secondary clinical outcomes include headache-specific quality-of-life, and headache frequency and intensity.

METHODS

Adults meeting the International Classification of Headache Disorders criteria for CDH are included. After a 6-week baseline phase, participants are randomized to a low n-6 diet, or a low n-6 plus high n-3 diet, for 12 weeks. Foods meeting nutrient intake targets are provided for 2 meals and 2 snacks per day. A research dietitian provides intensive dietary counseling at 2-week intervals. Web-based intervention materials complement dietitian advice. Blood and clinical outcome data are collected every 4 weeks.

RESULTS

Subject recruitment and retention has been excellent; 35 of 40 randomized participants completed the 12-week intervention. Preliminary blinded analysis of composite data from the first 20 participants found significant reductions in erythrocyte n-6 LA, AA and %n-6 in HUFA, and increases in n-3 EPA, DHA and the omega-3 index, indicating adherence.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01157208).

The stress and migraine interaction

There are several ways in which stress may interact with migraine in those predisposed to migraine attacks. These interactions may result from biochemical changes related to the physiological stress response, as, for example, the release of corticotrophin releasing hormone, or from changes induced by the psychological response to stressors. Stress is the factor listed most often by migraine sufferers as a trigger for their attacks, but in addition there is evidence that stress can help initiate migraine in those predisposed to the disorder, and may also contribute to migraine chronification. Migraine attacks themselves can act as a stressor, thereby potentially leading to a vicious circle of increasing migraine frequency. Since the important factor in the stress-migraine interaction is likely the individual's responses to stressors, rather than the stressors themselves, the acquisition of effective stress management skills has the potential to reduce the impact of stressors on those with migraine.

Facial pain: a possible therapy with stellate ganglion block

OBJECTIVE

The goal of the present study is to verify the efficacy of stellate ganglion block (SGB) in the treatment of facial pain that can be found in different pathological syndromes, and also to examine whether the efficacy is dependent upon when this therapy is administered.

PATIENTS

Fifty patients (divided into two randomized groups) with facial pain caused by traumas, iatrogenic issues, herpes zoster, or neurological pathologies participated in this study.

DESIGN AND INTERVENTIONS

The first group (N = 25) was treated with SGB produced by 10 administrations of 10 mg of levobupivacaine given every other day, followed by one administration per month for 6 months thereafter. The second group was treated with the drugs tramadol 100 mg/day and gabapentin 1800 mg/day orally for 6 months; during the 7th month they were given SGB therapy using the same methodology as that described for the first group.

RESULTS

Before treatment, the mean visual analog scale (VAS) pain score for the first group was 8.89; after the 10th block treatment it was just 0.2, and it remained at that reduced level for the 6th and 12th months. Before treatment, the mean VAS pain score for the second group was 8.83; after the 20th day on medication it was reduced to 4.1, after 6 months it was 5.7 and after 12 months it was 4.9.

CONCLUSIONS

Our results indicate that patients must be treated with SGB therapy precociously to receive its full benefits.

Effective prophylactic treatments of migraine lower plasma glutamate levels

The role of glutamate in migraine treatment has not been much studied, even if this amino acid seems to be crucial in the pathogenesis of migraine. Our aim was to determine if there were differences in the plasma levels of glutamate between migraine patients and control subjects and if plasma levels of glutamate in migraine patients modified after 8 weeks of prophylactic treatment. We studied 24 patients with diagnosis of migraine without aura according to International Classification of Headache Disorders, 2nd edn criteria, and 24 age- and sex-matched healthy subjects, as controls. In migraineurs the level of glutamate was measured before and after 8 weeks of prophylactic treatment (topiramate 50 mg/day, five patients; amitriptyline 20 mg/day, seven patients; flunarizine 5 mg/day, seven patients; propranolol 80 mg/day, five patients). Venous blood samples were taken in the morning, after overnight fasting, and at least 3 days after the last migraine day. Glutamate levels were measured by means of a fluorimetric detector high-pressure liquid chromatographic method. Plasma levels of glutamate were significantly higher in migraine patients-either before (61.79 +/- 18.75 micromol/l) or after prophylactic treatment (17.64 +/- 5.08 micromol/l)-than in controls (9.36 +/- 2.1 micromol/l) (P < 0.05, anova followed by Newman-Keuls' test). After prophylactic treatment, with headache frequency reduced, plasma glutamate levels were significantly lower in the same patient with respect to the prior baseline level (P < 0.0001, Student's t-test for paired data), without any differences depending on the kind of prophylactic drug. Effective prophylactic treatments reducing high glutamate plasma levels found in migraine patients could act on the underlying mechanism that contributes to cause migraine. Plasma glutamate level monitoring in migraine patients might serve as a biomarker of response to treatments and as an objective measure of disease status.