Dopaminergic symptoms in migraine

Bridging migraine and psychosis: a neuropsychiatric review of shared dopaminergic mechanisms

Migraine is increasingly recognized as a disorder with both neurological and psychiatric dimensions, with increasing evidence suggesting a potential link to psychotic symptoms through shared dopaminergic dysfunction. Both conditions exhibit dopamine receptor hypersensitivity, neurotransmitter imbalances, and altered cortical excitability, raising the question of whether migraineurs, particularly those with aura, may be more susceptible to transient psychotic-like symptoms. This review explores the neurobiological overlap between migraine and psychosis, focusing on shared pathophysiological mechanisms, neuroimaging findings, and clinical evidence. Neuroimaging studies have revealed that migraineurs exhibit altered dopamine receptor binding and reduced synaptic dopamine during attacks, whereas psychotic disorders are characterized by sustained dopaminergic hyperactivity. These observations support the hypothesis that dopaminergic dysregulation may predispose migraineurs to sensory-perceptual disturbances that occasionally resemble psychotic symptoms. Importantly, this overlap does not imply that migraine leads to psychosis but rather suggests that shared neurochemical dysfunction may transiently modulate perception. Future research should clarify this interaction to improve the early identification and management of neuropsychiatric manifestations in migraine patients.

Investigating the causal and genetic relationship between migraine and Parkinson's disease

OBJECTIVE

The relationship between migraine and Parkinson's disease (PD) remains controversial. We aimed to investigate the causal and genetic associations between migraine and PD.

METHODS

Genetic data for migraine [any migraine (AM), migraine without aura (MO), and migraine with aura (MA)] and PD were sourced from the latest genome-wide meta-analyses conducted by the International Headache Genetics Consortium and the International Parkinson's Disease Genomics Consortium, respectively. Various analyses were performed to evaluate the potential causal associations and explore genetic correlations between these conditions.

RESULTS

The analyses indicated that AM (odds ratio [OR] 1.02, 95% confidence interval [CI] 0.91-1.14; p = 0.785), MO (OR 0.94, 95% CI 0.84-1.07; p = 0.358), and MA (OR 1.01, 95% CI 0.95-1.06; p = 0.846) were not significantly associated with the risk of PD. Similarly, reverse analyses also demonstrated no significant causality between PD and the risks of migraine or its subtypes. After adjusting for coronary heart disease, AM (OR 0.99, 95% CI 0.90-1.10; p = 0.897), MO (OR 0.94, 95% CI 0.86-1.03; p = 0.207), and MA (OR 1.00, 95% CI 0.93-1.07; p = 0.902) remained unrelated to PD risk. Likewise, PD was found to be unassociated with AM (OR 0.96, 95% CI 0.92-1.02; p = 0.168), MO (OR 0.95, 95% CI 0.86-1.05; p = 0.287), and MA (OR 1.02, 95% CI 0.93-1.13; p = 0.669). These null findings persisted even when adjusting for hypertension. Apart from above causal inference results, no significant genetic correlation was found between AM (rg = -0.06, p = 0.127), MA (rg = -0.05, p = 0.516), or MO (rg = -0.06, p = 0.492) and PD, and no correlations were observed across specific genomic regions. Additionally, no shared heritability was observed between PD and migraine, or its subtypes, in tissue expression.

CONCLUSION

Our study suggests that there is no significant causal association or genetic correlation between migraine and PD from a genetic perspective.

Analysis of the relationships between the degree of migraine with right-to-left shunts and changes in white matter lesions and brain structural volume

To investigate the location of white matter lesions (WMLs) in migraineurs with right‒to‒left shunts (RLS); the relationships among the severity of WMLs, changes in brain structural volume and RLS shunts; and the relationships among the severity of WMLs, changes in brain structural volume and degree of headache in RLS migraine patients. A total of 102 migraineurs with RLS admitted to the affiliated Central Hospital of Dalian University of Technology from December 2018 to December 2022 were enrolled in this study. RLS flow and the 6-item Headache Impact Test (HIT-6) scores were recorded to reflect the degree of headache. The brain structural volumes of 102 migraineurs with RLS were calculated from T1-weighted images via artificial intelligence, and the brain structural volumes of healthy controls matched according to age and sex were also calculated. The correlations among WML location, RLS, headache degree, WML severity and brain structural volume changes in migraineurs were analyzed. (1) The WMLs of migraineurs with RLS were concentrated mainly in the white matter of the lateral ventricular margin and deep white matter. Subcortical WMLs were concentrated mainly in the parietal lobe, occipital lobe and frontal lobe. (2) There were no significant differences in the WML variables of cerebral white matter high signal volume, ratio of high-signal white matter volume to whole-brain white matter volume (%) or Fazekas score among migraineurs with different RLS flows, but there were significant differences in WML variables among migraineurs with RLS with different HIT-6 grades and MIDAS grades. RLS flow, HIT-6 score and MIDAS grade were not correlated with the WML variables measured in this study. (3) There was a significant difference in the volume of the precentral gyrus between migraineurs with RLS and normal controls (P < 0.001), and there was a significant difference between migraineurs with different RLS flows and different HIT-6 scores and peripheral cerebrospinal fluid volumes. There was also a positive correlation between frontal pole structural volume and RLS flow. The volume of the precentral gyrus was negatively correlated with RLS flow, whereas the volume of the pons gyrus was positively correlated with the HIT-6 score. The volume of the temporal pole was negatively correlated with the HIT-6 score. (1) The WMLs of migraineurs with RLS were concentrated mainly in the white matter of the lateral ventricular margin and deep white matter. Subcortical WMLs were concentrated mainly in the parietal lobe, occipital lobe and frontal lobe. (2) There was no correlation between WML severity and RLS flow in migraineurs with RLS. (3) There was no correlation between WML severity and migraine severity in migraineurs with RLS. (4) Volume changes occurred in some brain structures of migraineurs with RLS. (5) Shunt flow and the degree of headache in migraineurs with RLS were correlated with structural volume changes in specific brain regions.

Prevalence and features of headache in Parkinson's disease: the role of dopamine

INTRODUCTION

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra, but dopamine also plays a role in the pathophysiology of migraine.

OBJECTIVE

The aim of this study is to assess lifetime and previous year prevalence rates of headache in PD patients compared with controls.

PATIENTS AND METHODS

We enrolled 101 patients (57 M and 44 W) and 101 controls (62 M and 39 W), comparable for age and gender, who underwent a semi-structured questionnaire to assess the occurrence and the features of headache, and Beck Depression Inventory (BDI).

RESULTS

We did not find any significant differences in the overall prevalence of lifetime and last 12-month headache between the two groups, as well as lifetime and last year tension-type headache (TTH) and migraine. Patients, especially those suffering from migraine and treated with dopamine agonists (DA), more frequently showed headache remission after the onset of motor symptoms compared to the age-related remission observed in controls (p = 0.001). Patients affected by headache were less frequently treated with DA in comparison with those without (p = 0.051). Depression of mood was more severe among PD patients with migraine than with TTH (p = 0.021). PD patients with headache exhibiting the akinetic-rigid subtype more frequently reported motor fluctuations than those presenting with tremor-dominant disease (p = 0.040).

CONCLUSIONS

The prevalence of headache in PD follows that described in the general population, but dopaminergic pathway degeneration, loss of dopamine activation on the trigeminal-vascular system, and DA treatment might favor migraine improvement and remission in PD patients.

The impact of genetic factors on the response to migraine therapy

Migraine is a multidimensional disease affecting a large portion of the human population presenting with a variety of symptoms. In the era of personalized medicine, successful migraine treatment presents a challenge, as several studies have shown the impact of a patient's genetic profile on therapy response. However, with the emergence of contemporary treatment options, there is promise for improved outcomes. A literature search was conducted in PubMed and Scopus, in order to obtain studies investigating the impact of genetic factors on migraine therapy outcome. Overall, 23 studies were included in the current review, exhibiting diversity in the treatments used and the genetic variants investigated. Divergent genes were assessed for each category of migraine treatment. Several genetic factors were identified to contribute to the heterogeneous response to treatment. SNPs related to pharmacodynamic receptors, pharmacogenetics and migraine susceptibility loci were the most investigated variants, revealing some interesting significant results. To date, various associations have been recorded correlating the impact of genetic factors on migraine treatment responses. More extensive research needs to take place with the aim of shedding light on the labyrinthine effects of genetic variations on migraine treatment, and, consequently, these findings can promptly affect migraine treatment and improve migraine patients' life quality in the vision of precise medicine.

From garden to madness: herbal products and psychotic experiences

Psychotic symptoms, characterized by hallucinations, delusions, and cognitive disturbances, are associated with various psychiatric and neurological disorders. This manuscript explores two cases of acute psychotic episodes triggered by the regular consumption of herbal products. The cases highlight the need for increased awareness of the potential toxic side effects of herbal products. The impact of herbal ingredients like maca and matcha on neurotransmitter activity is explored, shedding light on the underlying mechanisms leading to psychosis. The manuscript highlights the need to report both the benefits and risks of herbal products, challenging the misconception that they are inherently safe.

Pathophysiology of Migraine

OBJECTIVE

This article provides an overview of the current understanding of migraine pathophysiology through insights gained from the extended symptom spectrum of migraine, neuroanatomy, migraine neurochemistry, and therapeutics.

LATEST DEVELOPMENTS

Recent advances in human migraine research, including human experimental migraine models and functional neuroimaging, have provided novel insights into migraine attack initiation, neurochemistry, neuroanatomy, and therapeutic substrates. It has become clear that migraine is a neural disorder, in which a wide range of brain areas and neurochemical systems are implicated, producing a heterogeneous clinical phenotype. Many of these neural pathways are monoaminergic and peptidergic, such as those involving calcitonin gene-related peptide and pituitary adenylate cyclase-activating polypeptide. We are currently witnessing an exciting era in which specific drugs targeting these pathways have shown promise in treating migraine, including some studies suggesting efficacy before headache has even started.

ESSENTIAL POINTS

Migraine is a brain disorder involving both headache and altered sensory, limbic, and homeostatic processing. A complex interplay between neurotransmitter systems, physiologic systems, and pain processing likely occurs. Targeting various therapeutic substrates within these networks provides an exciting avenue for future migraine therapeutics.

D2 dopamine receptor-mediated mechanisms of dopaminergic system modulation in in vivo and in vitro experimental models of migraine

The dopaminergic system is implicated in the pathophysiology of migraine. However, the underlying mechanisms remain unclear. We explored the effects and mechanisms of dopaminergic system modulation in the in vivo and in vitro rat models of migraine. Dopaminergic agonist apomorphine, D2 receptor antagonists metoclopramide and haloperidol and 5-HT3 receptor antagonist ondansetron alone and together were tested in nitroglycerin-induced migraine model, in vivo. Likewise, the combinations of drugs were also tested on basal calcitonin gene-related peptide (CGRP) release in vitro hemiskull preparations. Mechanical allodynia was tested by von Frey filaments. CGRP concentrations in trigeminovascular structures and in vitro superfusates and c-Fos levels in the brainstem were determined by enzyme-linked immunosorbent assay. Meningeal mast cells were evaluated with toluidine blue staining. Apomorphine further enhanced nitroglycerin-induced mechanical allodynia, brainstem c-fos expression, trigeminal ganglion and brainstem CGRP concentrations and meningeal mast cell degranulation, in vivo. Haloperidol completely antagonised all apomorphine-induced effects and also alleviated changes induced by nitroglycerin without apomorphine. Metoclopramide and ondansetron partially attenuated apomorphine- or nitroglycerin-induced effects. A combination of haloperidol and ondansetron decreased basal CGRP release, in vitro, whereas the other administrations were ineffective. Apomorphine-mediated dopaminergic activation exacerbated nitroglycerin-stimulated nociceptive reactions by further enhancing c-fos expression, CGRP release and mast cell degranulation in strategical structures associated with migraine pain. Metoclopramide partially attenuated the effects of apomorphine, most likely because it is also a 5-HT3 receptor antagonist. Haloperidol with pure D2 receptor antagonism feature appears to be more effective than metoclopramide in reducing migraine-related parameters in dopaminergic activation- and/or NTG-induced migraine-like conditions.

Nine-Month Continuous Fremanezumab Prophylaxis on the Response to Triptans and Also on the Incidence of Triggers, Hypersensitivity and Prodromal Symptoms of Patients with High-Frequency Episodic Migraine

Objective: To investigate whether the incidence of triggers, prodromal symptoms, hypersensitivity symptoms accompanying headache and responses to triptans were modified during a continuous 9-month fremanezumab therapy for migraine prophylaxis. Patients and methods: We studied 63 patients with high-frequency episodic migraine (HFEM). Enrolled patients received fremanezumab for nine consecutive months before defining the response rates and being stratified into treatment responders (≥50-74% reduction in monthly headache days (MHDs)), super responders (≥75%), partial non-responders (<50%) and super non-responders (<30%). Through headache diaries, patients provided data in order to document the impact of fremanezumab on the incidence of triggers, associated symptoms followed by headache and response to triptans (the use of the migraine treatment optimization questionnaire-4 (mTOQ-4)) during the 9-month treatment period. Results: Fremanezumab had early (after 3 monthly cycles) beneficial effects on the response to triptans in the majority of responders with relevant increases in mTOQ-4 scoring, but also in half of partial non-responders. A significant reduction in median days with migraine-associated symptoms was seen in responders after 6 months of therapy with fremanezumab, mostly for osmophobia, photophobia, phonophobia and nausea/vomiting, but partial non-responders also benefited. Likewise, the incidence of self-reported prodromal symptoms was significantly reduced in responders and was modestly diminished in partial non-responders. Triggers remained unaffected in both responders and non-responders. Conclusions: Fremanezumab given for at least 6-9 months may exert neuromodulatory effects in the migraine brain. These effects could result both in the inhibition of migraine chronification, but also in the diminishing of the magnitude of migraine-associated symptoms, mostly in responders and in partial non-responders.

The association between migraine and Parkinson's disease: a nationwide cohort study

OBJECTIVES

Clinical studies have suggested an association between migraine and the occurrence of Parkinson's disease (PD). However, it is unknown whether migraine affects PD risk. We aimed to investigate the incidence of PD in patients with migraine and to determine the risk factors affecting the association between migraine and PD incidence.

METHODS

Using the Korean National Health Insurance System database (2002-2019), we enrolled all Koreans aged ≥40 years who participated in the national health screening program in 2009. International Classification of Diseases (10th revision) diagnostic codes and Rare Incurable Diseases System diagnostic codes were used to define patients with migraine (within 12 months of enrollment) and newly diagnosed PD.

RESULTS

We included 214,193 patients with migraine and 5,879,711 individuals without migraine. During 9.1 years of follow-up (55,435,626 person-years), 1,973 (0.92%) and 30,664 (0.52%) individuals with and without migraine, respectively, were newly diagnosed with PD. Following covariate adjustment, patients with migraine showed a 1.35-fold higher PD risk than individuals without migraine. The incidence of PD was not significantly different between patients with migraine with aura and those without aura. In males with migraine, underlying dyslipidemia increased the risk of PD (p=0.012). In contrast, among females with migraine, younger age (<65 years) increased the risk of PD (p=0.038).

CONCLUSIONS

Patients with migraine were more likely to develop PD than individuals without migraine. Preventive management of underlying comorbidities and chronic migraine may affect the incidence of PD in these patients. Future prospective randomized clinical trials are warranted to clarify this association.

Neuroimaging in the pre-ictal or premonitory phase of migraine: a narrative review

BACKGROUND

The premonitory phase, or prodrome, of migraine, provides valuable opportunities to study attack initiation and for treating the attack before headache starts. Much that has been learned about this phase in recent times has come from the outcomes of functional imaging studies. This review will summarise these studies to date and use their results to provide some feasible insights into migraine neurobiology.

MAIN BODY

The ability to scan repeatedly a patient without radiation and with non-invasive imaging modalities, as well as the recognition that human experimental migraine provocation compounds, such as nitroglycerin (NTG) and pituitary adenylate cyclase activating polypeptide (PACAP), can trigger typical premonitory symptoms (PS) and migraine-like headache in patients with migraine, have allowed feasible and reproducible imaging of the premonitory phase using NTG. Some studies have used serial scanning of patients with migraine to image the migraine cycle, including the 'pre-ictal' phase, defined by timing to headache onset rather than symptom phenotype. Direct observation and functional neuroimaging of triggered PS have also revealed compatible neural substrates for PS in the absence of headache. Various imaging methods including resting state functional MRI (rsfMRI), arterial spin labelling (ASL), positron emission tomography (PET) and diffusion tensor imaging (DTI) have been used. The results of imaging the spontaneous and triggered premonitory phase have been largely consistent and support a theory of central migraine attack initiation involving brain areas such as the hypothalamus, midbrain and limbic system. Early dysfunctional pain, sensory, limbic and homeostatic processing via monoaminergic and peptidergic neurotransmission likely manifests in the heterogeneous PS phenotype.

CONCLUSION

Advances in human migraine research, including the use of functional imaging techniques lacking radiation or radio-isotope exposure, have led to an exciting opportunity to study the premonitory phase using repeated measures imaging designs. These studies have provided novel insights into attack initiation, migraine neurochemistry and therapeutic targets. Emerging migraine-specific therapies, such as those targeting calcitonin gene-related peptide (CGRP), are showing promise acutely when taken during premonitory phase to reduce symptoms and prevent subsequent headache. Therapeutic research in this area using PS for headache onset prediction and early treatment is likely to grow in the future.

The effect of topiramate versus flunarizine on the non-headache symptoms of migraine

OBJECTIVES

To investigate the impact of topiramate versus flunarizine on the non-headache symptoms (NHS) of migraine, and to observe the changes of dopamine (DA) and prolactin (PRL) before and after prophylactic treatment.

METHODS

Sixty-six episodic migraine patients were enrolled and randomized 1:1 to receive either flunarizine or topiramate treatment. Clinical characteristics and NHS associated with migraine were investigated before and after prophylactic treatment. The DA and PRL levels were also determined before and after prophylactic treatment.

RESULTS

The NHS of migraine in the two groups were significantly better after treatment than before treatment in premonitory phase (PP), headache phase (HP), and resolution phase (RP). The NHS in the two groups had no significant difference in PP, HP, and RP before and after treatment. In the flunarizine group, the PRL content after treatment was significantly higher than that before treatment (t = -4.097, p < 0.001), but the DA content was decreased slightly compared with that before treatment (t = 1.909, p = 0.066). There was no significant difference in PRL content (t = 1.099, p = 0.280) and DA content (t = 1.556, p = 0.130) in topiramate group before and after treatment.

CONCLUSIONS

The two classical prophylactic drugs of migraine were significantly effective in treating the NHS of migraine, but there was no significant difference between the two drugs. The DA-PRL axis may be involved in the underlying mechanism of the flunarizine treatment for the NHS of migraine.

Migraine, Tension-Type Headache and Parkinson's Disease: A Systematic Review and Meta-Analysis

Background and Objectives: The relationship between migraine and tension-type headache (TTH) with Parkinson's disease (PD) is controversial, while a common pathophysiological link remains obscure. The aim of this systematic review is to investigate the association between PD, migraine and TTH. Materials and Methods: Following PRISMA, we searched MEDLINE, WebofScience, Scopus, CINAHL, Cochrane Library and ClinicalTrials.gov up to 1 July 2022 for observational studies examining the prevalence and/or associations of PD with migraine and TTH. We pooled proportions, standardized mean differences (SMD) and odds ratios (OR) with random effects models. The risk of bias was assessed with the Newcastle-Ottawa scale (PROSPERO CRD42021273238). Results: Out of 1031 screened studies, 12 were finally included in our review (median quality score 6/9). The prevalence of any headache among PD patients was estimated at 49.1% (760 PD patients; 95% CI 24.8-73.6), migraine prevalence at 17.2% (1242 PD patients; 95% CI 9.9-25.9), while 61.5% (316 PD patients; 95% CI 52.6-70.1) of PD patients with migraine reported headache improvement after PD onset. Overall, migraine was not associated with PD (302,165 individuals; ORpooled = 1.11; 95% CI 0.72-1.72).However, cohort studies demonstrated a positive association of PD among lifetime migraineurs (143,583 individuals; ORpooled = 1.54, 95% CI 1.28-1.84), while studies on 12-month migraine prevalence yielded an inverse association (5195 individuals; ORpooled = 0.64, 95% CI 0.43-0.97). Similar findings were reported by 3 studies with data on the TTH-PD relationship (high prevalence, positive association when examined prospectively and an inverse relationship on 12-month prevalence). These data were not quantitatively synthesized due to methodological differences among the studies. Finally, PD patients suffering from any headache had a lower motor unified Parkinson's disease rating scale (UPDRS) score (503 PD patients; SMD -0.39; 95% CI -0.57 to -0.21) compared to PD patients not reporting headache. There is an unclear association of headaches in genetic PD cohorts. Conclusions: Observational data suggest that migraine and TTH could be linked to PD, but the current literature is conflicting.

Microstructural changes of basal ganglia in migraine with restless legs syndrome: findings from a neuroimaging study

In this study, it is planned to investigate the integrity of the basal ganglia structures in migraineurs with restless legs syndrome (RLS) to explore this relationship. In this study, 58 patients who were diagnosed migraine and 51 healthy controls (HCs) were included. Patients diagnosed with migraine were divided into two groups: Group I (migraine without RLS) and Group II (migraine with RLS). The integrity of basal ganglia was evaluated with region of interest diffusion tensor imaging method which allows us to assess microstructural changes of the tissue. The mean age of the patients was 35.98 ± 7.92 years, and the mean age of the HCs was 33.84 ± 11.06. 84.5% (n = 49) of the patients were female and 15.5% (n = 9) were male. 82.4% (n = 42) of the HCs were female, 17.6% (n = 9) were male. The number of  the patients without RLS was 41 (Group I), and the number of the patients with RLS was 17 (Group II). When basal ganglia structures were compared between groups of the patients with and without RLS, the fractional anisotropy (FA) value of the left putamen differed (Group I: 0.30 ± 0.06 vs. Group II: 0.25 ± 0.7, p = 0.01). The significant relationship was found attack frequency and presence of RLS with left putamen FA values according to multiple regression analysis. It was determined in this study that the changes in the microstructure of putamen, one of the basal ganglia structures, may be associated with the presence of RLS in migraineurs.

Anti-migraine activity of freeze-dried latex obtained from Calotropis gigantea Linn

Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post-harvesting stability issues of latex affect its biological potential. Freeze-drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun ray-dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze-drying microencapsulation technique and evaluation of its anti-migraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C*, and E*), moisture, water activity, solubility, and hygroscopicity. Additionally, apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity were used to evaluate the anti-migraine potential of powdered latex. FDCG showed good physicochemical properties due to its higher concentration of phenolic and flavonoid contents. Moreover, FDCG significantly reduced the apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity in a dose-dependent manner through an interaction of dopaminergic and serotonergic receptors. In conclusion, the method developed for shelf life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential; thus, it can be effectively utilized in the treatment or management of migraine. Anti-migraine effect of Calotropis gigantea freeze-dried latex by inhibition of dopamine and serotonin receptors (D1 and D2: dopamine receptors; 5-HT: serotonin receptors); yellow color represents serotonergic, and blue color indicates dopaminergic neurons.

Evaluation of clinical relationship of serum niacin and dopamine levels in patients with fibromyalgia syndrome

Objectives

The aim of this study was to investigate the role of serum niacin and dopamine (DA) levels and their clinical importance in fibromyalgia syndrome (FMS) patients.

Patients and methods

Between April 2018 and October 2018, a total of 53 female patients (mean age: 38.3±5.5 years; range, 21 to 45 years) with a clinical diagnosis of FMS and 35 healthy female controls (mean age: 36.7±5.2 years; range, 25 to 44 years) were included in this cross-sectional study. The Visual Analog Scale (VAS), Beck Depression Inventory (BDI), and Fibromyalgia Impact Questionnaire (FIQ) were applied to the patients. Serum levels of niacin and DA were measured by high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) methods, respectively.

Results

Niacin and DA levels of the patient group were significantly lower than those of control group (p=0.003 and p=0.02, respectively). A very strong positive correlation was found between niacin and DA levels (r=0.96 p<0.001). Evaluation of the diagnostic performance of niacin and DA by the receiver operating characteristic analysis yielded an area under the curve (AUC) of 0.73 (p<0.001, 95% confidence interval [CI]: 0.62-0.85) and an AUC of 0.68 (p=0.004, 95% CI: 0.56-0.80), respectively.

Conclusion

Serum niacin and DA levels decrease in FMS patients in relation to the tender point numbers. It can be suggested that the levels of these two markers can be considered additional tools in the diagnosis of FMS.

Migraine: beyond pain

Most people who see, treat or experience migraine will be aware that its clinical manifestations exceed the symptom of head pain. However, available acute treatments so far have targeted migraine symptoms only in the context of the pain phase of an attack. The associated disability clearly involves more than just these symptoms, and the phenotype can include additional painless features, including alterations in mood, cognition and homeostasis and sensory sensitivities. Recognising these symptoms, understanding their neurobiological basis and systematically recording them prospectively in clinical therapeutic trials are likely to offer valuable pathophysiological and therapeutic insights into this complex brain disorder, ultimately helping to improve the quality of lives of sufferers. We aim to explore the multifaceted disorder that is migraine, with a particular focus on the non-painful non-aura symptoms.

Migraine and Sleep-An Unexplained Association?

Migraine and sleep disorders are common chronic diseases in the general population, with significant negative social and economic impacts. The association between both of these phenomena has been observed by clinicians for years and is confirmed by many epidemiological studies. Despite this, the nature of this relationship is still not fully understood. In recent years, there has been rapid progress in understanding the common anatomical structures of and pathogenetic mechanism between sleep and migraine. Based on a literature review, the authors present the current view on this topic as well as ongoing research in this field, with reference to the key points of the biochemical and neurophysiological processes responsible for both these disorders. In the future, a better understanding of these mechanisms will significantly expand the range of treatment options.

Dopaminergic Regulation of Reward System Connectivity Underpins Pain and Emotional Suffering in Migraine

Purpose

It has been suggested that reward system dysfunction may account for emotion and pain suffering in migraine. However, there is a lack of evidence whether the altered reward system connectivity is directly associated with clinical manifestations, including negative affect and ictal pain severity and, at the molecular level, the dopamine (DA) D2/D3 receptors (D2/3Rs) signaling implicated in encoding motivational and emotional cues.

Patients and Methods

We acquired resting-state functional MRI from interictal episodic migraine (EM) patients and age-matched healthy controls, as well as positron emission tomography (PET) with [¹¹C]raclopride, a selective radiotracer for DA D2/3Rs, from a subset of these participants. The nucleus accumbens (NAc) was seeded to measure functional connectivity (FC) and DA D2/3Rs availability based on its essential involvement in pain-related aversive/reward functions. Associations of the brain measures with positive/negative affect and ictal pain severity were also assessed.

Results

Compared with controls, the EM group showed weaker right NAc connectivity with areas implicated in pain and emotional regulation, such as the amygdala, rostral anterior cingulate cortex, hippocampus, and thalamus; but showed stronger left NAc connectivity with the dorsolateral prefrontal cortex and lingual gyrus. Moreover, among the altered NAc connectivities, only right NAc-amygdala connectivity was inversely correlated with DA D2/3Rs availability in migraine patients (diagnostic group-by-D2/3Rs interaction p < 0.007). At a clinical level, such weaker NAc-amygdala connectivity was associated with lower interictal positive affect and greater ictal pain severity over the head and facial extension area (pain area and intensity number summation, PAINS).

Conclusion

Together, our findings suggest that altered reward system connectivity, specifically between the NAc and amygdala, might be affected by endogenous DA D2/3Rs signaling, and such process might be a neural mechanism that underlies emotional and pain suffering in episodic migraineurs.

Erenumab in the prevention of high-frequency episodic and chronic migraine: Erenumab in Real Life in Italy (EARLY), the first Italian multicenter, prospective real-life study

OBJECTIVE

To assess the effectiveness, safety, and tolerability of erenumab in a real-life migraine population, while trying to identify responsiveness predictors.

BACKGROUND

Erenumab is a fully human Ig-2 monoclonal antibody blocking the calcitonin gene-related peptide receptor, indicated for migraine prophylaxis. Phase II and III trials demonstrated that erenumab is effective, safe, and well tolerated in the prevention of episodic and chronic migraine (CM), showing an early onset of action.

METHODS

This is a multicenter, prospective, cohort, and real-life study. We considered for enrolment all consecutive patients aged 18-65 affected by high-frequency episodic migraine (HFEM) or CM, with or without medication overuse, visited at nine Italian Headache Centers from December 20, 2018 to September 30, 2019. Each patient was treated with erenumab 70 mg, administered subcutaneously every 4 weeks. Treatment duration was planned to last from 6 to 12 months, depending on the patient's response. The primary endpoint was the change in monthly migraine days (MMDs) at weeks 9-12 compared to baseline. Secondary endpoints included changes in monthly analgesics intake, ≥50%, ≥75%, and 100% responder rates and any variation in the Visual Analog Scale (VAS) and Headache Impact Test scores (HIT).

RESULTS

In total, 372 migraine patients were treated with at least one dose of erenumab 70 mg. At weeks 9-12, erenumab decreased MMDs by 4.5 ± 4.1 days (mean ± SD) in patients with HFEM and by 9.3 ± 9.1 (mean ± SD) days in those with CM compared to baseline. At weeks 9-12 VAS score was reduced by 1.9 ± 1.9 (mean ± SD), HIT score by 10.7 ± 8.8 (mean ± SD), and median monthly analgesics intake passed from 12.0 (interquartile range [IQR] 10.0-14.0) to 5.0 (IQR 3.0-7.0) in HFEM. In CM patients, VAS was reduced by 1.7 ± 2.0 (mean ± SD), HIT by 9.7 ± 10.4 (mean ± SD), and median monthly analgesics intake passed from 20.0 (IQR 15.0-30.0) to 8.0 (IQR 5.0-15.0). At week 12, ≥50% responders were 60/101 (59.4%) for HFEM and 146/263 (55.5%) for CM, ≥75% responders were 17/101 (16.8%) and 59/263 (22.4%) and 100% responders 1/101 (1.0%) and 3/263 (1.1%), respectively. Erenumab responsiveness in HFEM was positively associated with unilateral pain localization (OR: 3.03, 95% CI: 1.24-7.40; p = 0.015), whereas in CM responsiveness was positively associated with and baseline migraine frequency (OR: 1.06, 95% CI:1.02-1.11; p = 0.031), dopaminergic symptoms (OR: 2.01, 95% CI: 1.14-3.52; p = 0.015), and negatively associated with psychiatric comorbidities (OR: 0.43, 95% CI: 0.20-0.93; p = 0.003).

CONCLUSIONS

Erenumab 70 mg is effective, safe, and well tolerated in real life. Easily obtainable clinical features might be of help in predicting patient's responsiveness.

Dopaminergic symptoms in migraine: A cross-sectional study on 1148 consecutive headache center-based patients

BACKGROUND

Dopaminergic symptoms may be extremely pronounced in some migraine patients during the attack, representing a major source of disability.

OBJECTIVES

We aimed to carefully characterize the clinical picture of migraine patients with dopaminergic symptoms in a large patients' population as a putative migraine endophenotype, allowing more precise disease management, treatment and outcome prediction.

METHODS

We screened 1148 consecutive tertiary care episodic and chronic migraine patients with face-to-face interviews collecting thorough data on lifestyle, socio-demographic factors, and clinical migraine features.

RESULTS

We identified 374 patients with migraine with dopaminergic symptoms (32.6%). The most frequent dopaminergic symptom was yawning followed by somnolence, nausea, vomiting, fatigue, mood changes and diuresis. Migraine patients with dopaminergic symptoms had longer attack duration (OR: 1.82; 95% CI: 1.41-2.36, p < 0.0001), more frequent osmophobia (OR: 2.01; 95% CI: 1.50-2.69, p < 0.0001), allodynia (OR: 1.43; 95% CI: 1.10-1.85, p = 0.0071) and unilateral cranial autonomic symptoms (OR: 1.31; 95% CI: 1.01-1.68, p = 0.045), but used less preventative treatments (OR: 0.74; 95% CI: 0.57-0.98, p = 0.033) than patients without dopaminergic symptoms.

CONCLUSIONS

Migraine patients with dopaminergic symptoms are characterized by a full-blown, more disabling migraine. Dopaminergic system modulation should be carefully considered in individuals with migraine with dopaminergic symptoms for both acute and preventative treatments in future ad hoc designed studies.

Dopamine-beta-hydroxylase 19-bp insertion/deletion polymorphism affects medication overuse in patients with chronic migraine

Dopamine-beta-hydroxylase (DBH) enzyme activity is modulated at the genetic level by the presence of several polymorphisms. Among these, the 19-bp insertion/deletion (I/D) polymorphism (rs72393728/rs141116007) was investigated in several genetic association studies for its correlation with the susceptibility to develop episodic migraine, but conflicting results were achieved. In the present study we analyzed this genetic variant in a carefully characterized population of migraineurs encompassing both episodic and chronic migraine (with and without medication overuse) with the aim to perform a replication study and verify any possible correlation with migraine endophenotypes. Genotyping of the DBH 19-bp I/D polymorphism was performed on 400 migraine patients and 204 healthy individuals. The associations between genotypic frequencies and the clinical and sociodemographic features of migraineurs were then investigated. The DBH 19-bp I/D polymorphism did not correlate with migraine susceptibility or most clinical variables, with the exception of a statistically significant correlation within the subgroup of patients affected by chronic migraine were the individuals carrying the deleted (D) allele were significantly more prone to abuse in analgesics. As a result of this finding, the DBH 19-bp I/D polymorphism does not influence migraine susceptibility, but it might contribute to the development of medication overuse in patient with chronic migraine.

Role of Descending Dopaminergic Pathways in Pain Modulation

Pain, especially when chronic, is a common reason patients seek medical care and it affects the quality of life and well-being of the patients. Unfortunately, currently available therapies for chronic pain are often inadequate because the neurobiological basis of such pain is still not fully understood. Although dopamine has been known as a neurotransmitter to mediate reward and motivation, accumulating evidence has shown that dopamine systems in the brain are also involved in the central regulation of chronic pain. Most importantly, descending dopaminergic pathways play an important role in pain modulation. In this review, we discuss dopamine receptors, dopaminergic systems in the brain, and the role of descending dopaminergic pathways in the modulation of different types of pain.

Association of expression of DRD2 rs1800497 polymorphism with migraine risk in Han Chinese individuals

Background

Previous studies suggested that single-nucleotide polymorphisms in dopamine receptor D2 (DRD2) are the susceptibility loci for migraine. This study was aimed at evaluating the contribution of DRD2 rs1800497 and its expression to migraine risk in Han Chinese subjects.

Methods

In total, 250 patients with migraine and 250 age- and sex-matched control subjects were included in this study. TaqMan allelic discrimination assay was used for DRD2 rs1800497 genotyping. Plasma DRD2 concentration was determined using enzyme-linked immunosorbent assay.

Results

Significant associations were observed for the rs1800497 genotype (c²=6.37, p=0.041) and allele (c²=4.69, p=0.03; odds ratio [OR]=1.33, 95% CI=1.03-1.72, power=58%) frequencies between the migraine and control groups. Sex analysis indicated a positive association for rs1800497 between female patients with migraine and control individuals (genotype: c²=7.84, p=0.019; allele: c²=6.60, p=0.010; OR=1.61, 95% CI=1.12-2.30, power=73.4%). Furthermore, a significant association was observed only in female patients with migraine without aura (MO) (genotype: c²=6.88, p=0.032; allele: c²=5.65, p=0.017; OR=1.59, 95% CI=1.08-2.36, power=65.1%). The mean plasma DRD2 levels in the control group (mean±SD: 24.20±2.78) were significantly lower than those in the migraine with aura (MA) (30.86±3.69, p<0.0001) and MO groups (31.88±4.99, p<0.0001). Additionally, there was a sex-based difference in DRD2 expression in the MA (male vs female: 29.46±3.59 vs 32.27±3.27, p<0.01) and MO groups (male vs female: 29.18±3.50 vs 34.58±4.84, p<0.0001). Moreover, plasma DRD2 levels in patients were significantly different among the three genotypes (CC vs CT vs TT: 24.76±3.76 vs 30.93±3.85 vs 37.06±3.95, p<0.0001). Similar results were observed both in the MA (CC vs CT vs TT: 25.09±3.84 vs 28.57±2.84 vs 33.37±1.58, p<0.0001) and MO groups (CC vs CT vs TT: 24.65±3.79 vs 31.65±3.86 vs 38.29±3.74, p<0.0001).

Conclusion

Our case-control study suggested that the DRD2 polymorphism rs1800497 was significantly associated with the risk of migraine in Han Chinese females. Additionally, the plasma DRD2 level was high in patients with migraine. Females with migraine had considerably higher DRD2 levels than males with migraine. DRD2 expression may be regulated by DRD2 rs1800497 genotype in patients with migraine.

Migraine Treatment: Current Acute Medications and Their Potential Mechanisms of Action

Migraine is a common and disabling primary headache disorder with a significant socioeconomic burden. The management of migraine is multifaceted and is generally dichotomized into acute and preventive strategies, with several treatment modalities. The aims of acute pharmacological treatment are to rapidly restore function with minimal recurrence, with the avoidance of side effects. The choice of pharmacological treatment is individualized, and is based on the consideration of the characteristics of the migraine attack, the patient's concomitant medical problems, and treatment preferences. Notwithstanding, a good understanding of the pharmacodynamic and pharmacokinetic properties of the various drug options is essential to guide therapy. The current approach and concepts relevant to the acute pharmacological treatment of migraine will be explored in this review.

Opioid-Induced "Likeability" and "Feeling Good" Are Not Associated With Return Visits to an ED Among Migraine Patients Administered IV Hydromorphone

BACKGROUND

Parenteral opioids are used in more than 50% of emergency department (ED) visits for migraine. Use of opioids for migraine has been associated with subsequent ED visits, perhaps because of opioid-induced euphoria. In this study, we quantify the extent to which nontherapeutic effects of opioids influence migraine outcomes. We hypothesized that "feeling good" and medication likeability would in fact be associated with receipt of opioids (rather than relief of migraine pain) and that receipt of opioids (rather than relief of migraine pain) would be associated with return visits to the ED.

METHODS

During an ED-based clinical trial, migraine patients were randomized to receive hydromorphone 1 mg or prochlorperazine 10 mg + diphenhydramine 25 mg IV. Thirty minutes after medication administration, we asked, (1) How much did you like the medication you received? and (2) How good did the medication make you feel? Participants were asked to provide answers on a 0-10 scale. We also determined 0-10 pain scores at baseline and 1 hour and number of return visits for headache during the subsequent month.

RESULTS

Sixty-three patients received prochlorperazine and 64 hydromorphone. Prochlorperazine pain scores improved by 6.8 (SD: 2.6), hydromorphone by 4.7 (SD: 3.3) (95%CI for difference of 2.1: 1.0, 3.2). On the 0-10 likeability scale, prochlorperazine patients reported a mean of 7.2 (SD: 2.8), hydromorphone 6.9 (SD: 2.9) (95% CI for difference of 0.3: -0.7, 1.3). On the 0-10 feeling good scale, prochlorperazine patients reported a mean of 7.5 (SD: 2.3), hydromorphone 6.8 (SD: 2.8) (95%CI: for difference of 0.7: -0.2, 1.6). In the hydromorphone group, 8/57 (14%, 95%CI: 7, 26%) returned to the ED vs 5/63 (8%, 95%CI: 3,18%) in the prochlorperazine group. In regression modeling, feeling good was independently associated with pain relief (P < .01) but not with medication received (P = .67) or return visits (P = .12). Similarly, medication likeability was independently associated with pain relief (P < .01) but not medication received (P = .12) or return visits (P = .16).

CONCLUSION

We did not detect an association between hydromorphone and medication likeability, feeling good, or return visits to the ED. Headache relief was associated with medication likeability and feeling good.

Neurological comorbidity in children with neurofibromatosis type 1

BACKGROUND

The aim of this study was to determine the frequency of central nervous system comorbidities in children with neurofibromatosis type 1 (NF1).

METHODS

We performed a nationwide survey to investigate neurological comorbidities in 3-15-year-old children with NF1 in Japan by sending questionnaires to pediatricians and pediatric neurologists. A secondary questionnaire was sent to the parents of identified NF1 patients to assess neurological comorbidities including headache, attention deficit-hyperactivity disorder (ADHD) Rating Scale (RS), and the Social Responsiveness Scale 2.

RESULTS

The primary survey identified 760 NF1 patients, and the parents of 565 patients were sent the secondary questionnaire. The parental response rate was 25.7% (145; 63 girls, 81 boys, one unspecified). Among the patients, 42.9% (55/128; 35 girls, 20 boys) were reported to exhibit intellectual problems. On the ADHD-RS, 40.2% (47/117) of NF1 patients aged 6-15 had ADHD (RS score >93rd percentile), with a rate of 47.7% in boys and 30.8% in girls. Furthermore, 20.2% of patients had suspected autism spectrum disorder (29/143; 10 girls, 19 boys), with Social Responsiveness Scale score ≥76. Headache was reported by 49.6% (61/123) of children over 5 years old, and 25.2% (31/123; 10 girls, 21 boys) reported migraine. Other neurological comorbidities included 20 cases of epilepsy (13.8%), 11 cases of optic nerve glioma (7.6%), five cases of brain tumor (3.4%), six cases of cerebrovascular disease (4.1%), and two cases of hydrocephalus (1.4%).

CONCLUSION

Intellectual problems, ADHD, autism spectrum disorder, and migraine are major neurological comorbidities in NF1.

The premonitory phase: A crucial stage in migraine

INTRODUCTION

The premonitory phase comprises a wide range of symptoms that precede the onset of pain in a migraine episode by up to 48hours. Premonitory symptoms are often not recognised by patients but do have a significant impact on their quality of life. As these symptoms represent the first stage of a migraine attack, they are crucial in improving our understanding of the key points of the origin of migraine.

DEVELOPMENT

This paper uses a question-answer format to review the main clinical studies analysing premonitory symptoms, their predictive capacity, the relationship between these symptoms and the biology of migraine, and the role of neuroimaging in the premonitory phase. Finally, we discuss the relevance of these symptoms as potential therapeutic targets in the future.

CONCLUSIONS

This study of the premonitory phase has demonstrated that the hypothalamus plays an essential role in the origin of migraine attacks. We should consider the search for new targets in acute migraine treatment in order to act before the onset of the pain. This would imply a radical change in the lives of patients with migraine.

Age- and sex-related differences in the presentation of paediatric migraine: A retrospective cohort study

Introduction Although migraine is a common headache complaint in children and adolescents there remains a significant gap in understanding the unique aspects of the disease in these age groups and their evolution with development. The aim of this retrospective cohort study was to identify migraine features that are influenced by age and sex. Methods The headache characteristics of 359 paediatric patients with a clinical diagnosis of migraine from a tertiary paediatric headache clinic were assessed. Patients retrospectively reported headache characteristics during a structured intake interview and clinical exam. Headache characteristics, description and associated symptoms were compared between children (age ≤ 12 years) and adolescents (age > 12 years), and between male and female migraineurs. Results Several migraine features differed significantly with age and/or sex, including: (i) a marked change from a 1:1 sex ratio in children to a 2:1 predominance of girls in adolescents; (ii) a higher frequency of headache attacks per month in adolescents and female migraineurs; (iii) a higher proportion of adolescents endorsed a 'throbbing' pain quality; (iv) a higher proportion of children reporting nausea and vomiting; and (v) a higher proportion of adolescents, particularly female migraineurs, had a diagnosis of a co-morbid anxiety. Conclusion The presentation of migraine, both in terms of its headache characteristics and associated symptoms, appear to vary as a function of age and sex. Given that migraine symptoms have a neural basis, it is not surprising that during the key period of neurodevelopment from childhood to adolescence this may impact their presentation.

The effect of foetal growth restriction on the development of migraine and tension-type headache in adulthood. The HUNT Study

BACKGROUND

There is little knowledge about how factors early in life affect the development of migraine and tension-type headache. We aimed to examine whether growth restriction in utero is associated with development of migraine and frequent tension-type headache in adults.

METHODS

The population-based Nord-Trøndelag Health Study (HUNT 3) contained a validated headache questionnaire, which differentiated between migraine and tension-type headache. These data were linked to information on weight and gestational age at birth from the Norwegian Medical Birth Registry. In total 4557 females and 2789 males, aged 19-41 years, were included in this registry-based study. Participants were categorized as appropriate for gestational age (AGA, 10th-90th percentile), small for gestational age (SGA, 3rd-10th percentile) or very small for gestational age (VSGA, < 3rd percentile). Logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for migraine and tension-type headache, with exposure being growth restriction at birth.

RESULTS

The effect of growth restriction on migraine was modified by sex, with a significant association in males (p<0.001), but not in females (p = 0.20). In particular, males born VSGA were at increased risk of developing migraine (OR 2.73, 95% CI 1.63-4.58, p<0.001), with an intermediate risk among those born SGA (OR 1.50, 95% CI 0.96-2.35, p = 0.08) compared to those born AGA. There was no significant association between growth restriction and frequent TTH (p = 0.051).

CONCLUSION

Growth restriction was associated with increased risk of migraine in adulthood among males, but not among females. This suggests that migraine might, in part, be influenced by early life events, and that males seem to be particularly vulnerable.

Susceptible genes of restless legs syndrome in migraine

Objective Several genetic variants have been found to increase the risk of restless legs syndrome (RLS). The aim of the present study was to determine if these genetic variants were also associated with the comorbidity of RLS and migraine in patients. Methods Thirteen single-nucleotide polymorphisms (SNPs) at six RLS risk loci ( MEIS1, BTBD9, MAP2K5, PTPRD, TOX3, and an intergenic region on chromosome 2p14) were genotyped in 211 migraine patients with RLS and 781 migraine patients without RLS. Association analyses were performed for the overall cohort, as well as for the subgroups of patients who experienced migraines with and without aura and episodic migraines (EMs) vs. chronic migraines (CMs). In order to verify which genetic markers were potentially related to the incidence of RLS in migraine patients, multivariate regression analyses were also performed. Results Among the six tested loci, only MEIS1 was significantly associated with RLS. The most significant SNP of MEIS1, rs2300478, increased the risk of RLS by 1.42-fold in the overall cohort ( p = 0.0047). In the subgroup analyses, MEIS1 augmented the risk of RLS only in the patients who experienced EMs (odds ratio (OR) = 1.99, p = 0.0004) and not those experiencing CMs. Multivariate regression analyses further showed that rs2300478 in MEIS1 (OR = 1.39, p = 0.018), a CM diagnosis (OR = 1.52, p = 0.022), and depression (OR = 1.86, p = 0.005) were independent predictors of RLS in migraine. Conclusions MEIS1 variants were associated with an increased risk of RLS in migraine patients. It is possible that an imbalance in iron homeostasis and the dopaminergic system may represent a link between RLS incidence and migraines.

Migraine is related to an increased risk of Parkinson’s disease: A population-based, propensity score-matched, longitudinal follow-up study

Background

The association between migraine and Parkinson’s disease (PD) remains controversial. The purpose of the present population-based, propensity score-matched follow-up study was to investigate whether migraineurs are at a higher risk of developing PD.

Methods

A total of 41,019 subjects aged between 40 and 90 years with at least two ambulatory visits with a diagnosis of migraine in 2001 were enrolled in the migraine group. A logistic regression model that included age, sex, pre-existing comorbidities and socioeconomic status as covariates was used to compute the propensity score. The non-migraine group consisted of 41,019 propensity score-matched, randomly sampled subjects without migraine. The PD-free survival rate were estimated using the Kaplan–Meier method. Stratified Cox proportional hazard regression was used to estimate the effect of migraine on the risk of developing PD.

Results

During follow-up, 148 subjects in the migraine group and 101 in the non-migraine group developed PD. Compared to the non-migraine group, the hazard ratio of PD for the migraine group was 1.64 (95% confidence interval: 1.25–2.14, p = 0.0004). The PD-free survival rate for the migraine group was significantly lower than that for the non-migraine group ( p = 0.0041).

Conclusions

This study showed an increased risk of developing PD in patients with migraine.

The association between COMT Val158Met polymorphism and migraine risk: A meta-analysis

Background The COMT Val158Met polymorphism has long been regarded as a risk factor for migraine. The possible association between COMT Val158Met polymorphism and migraine has been evaluated in several studies, but the results are not consistent. Therefore, we conduct this meta-analysis to address these issues. Methods The WEB OF SCIENCE and EMBASE databases were searched for eligible studies. The odds ratio (OR) with the corresponding 95% confidence interval (CI) was calculated to estimate the strength of the association between COMT Val158Met polymorphism and migraine. Results Five studies with 979 cases and 1870 controls were ultimately included in the present meta-analysis. The overall data showed no significant association between COMT Val158Met polymorphism and migraine in the multiplicative model (OR = 0.97, 95% CI: 0.78-1.21, p = 0.805) and dominant model (OR = 1.05, 95% CI: 0.75-1.48, p = 0.773), neither in the additive model (OR = 0.97, 95% CI: 0.77-1.23, p = 0.817) nor in the recessive model (OR = 0.88, 95% CI: 0.71-1.09, p = 0.246). In subgroup analysis, both for Caucasian and Asian populations, no statistically significant associations were observed in any genetic models. Conclusions Our meta-analysis suggested that the COMT Val158Met polymorphism was not associated with migraine risk.

Genetic epidemiology of migraine and depression

Background

Migraine and major depressive disorder (commonly referred to as depression) are both common disorders with a significant impact on society. Studies in both clinical and community-based settings have demonstrated a strong relationship between migraine and depression. In addition to complicating the diagnosis, depression that is comorbid with migraine may lower treatment adherence, increase risk of medication overuse and is associated with migraine chronification, thus leading to higher direct and indirect costs and poorer health-related outcomes with increased disability.

Aim

The aim of this review is to summarise the current knowledge on the genetic epidemiology of migraine and depression and the possible biological mechanisms underlying their comorbidity.

Methods

We present a narrative review reporting on the current literature.

Results and conclusions

Epidemiological findings indicate that there is a bidirectional relationship between migraine and depression, with one disorder increasing the risk for the other and vice versa, suggesting shared biological mechanisms. Twin and family studies indicate that this bidirectional relationship can be explained, at least partly, by shared underlying genetically determined disease mechanisms. Although no genes have been robustly associated with the aetiology of both migraine and depression, genes from serotonergic, dopaminergic and GABAergic systems together with variants in the MTHFR and BDNF genes remain strong candidates.

Restless legs syndrome associated with major diseases: A systematic review and new concept

Recent publications on both the genetics and environmental factors of restless legs syndrome (RLS) defined as a clinical disorder suggest that overlapping genetic risk factors may play a role in primary (idiopathic) and secondary (symptomatic) RLS. Following a systematic literature search of RLS associated with comorbidities, we identified an increased prevalence of RLS only in iron deficiency and kidney disease. In cardiovascular disease, arterial hypertension, diabetes, migraine, and Parkinson disease, the methodology of studies was poor, but an association might be possible. There is insufficient evidence for conditions such as anemia (without iron deficiency), chronic obstructive pulmonary disease, multiple sclerosis, headache, stroke, narcolepsy, and ataxias. Based on possible gene-microenvironmental interaction, the classifications primary and secondary RLS may suggest an inappropriate causal relation. We recognize that in some conditions, treatment of the underlying disease should be achieved as far as possible to reduce or eliminate RLS symptoms. RLS might be seen as a continuous spectrum with a major genetic contribution at one end and a major environmental or comorbid disease contribution at the other.

Dopamine and T cells: dopamine receptors and potent effects on T cells, dopamine production in T cells, and abnormalities in the dopaminergic system in T cells in autoimmune, neurological and psychiatric diseases

Dopamine, a principal neurotransmitter, deserves upgrading to 'NeuroImmunotransmitter' thanks to its multiple, direct and powerful effects on most/all immune cells. Dopamine by itself is a potent activator of resting effector T cells (Teffs), via two independent ways: direct Teffs activation, and indirect Teffs activation by suppression of regulatory T cells (Tregs). The review covers the following findings: (i) T cells express functional dopamine receptors (DRs) D1R-D5R, but their level and function are dynamic and context-sensitive, (ii) DR membranal protein levels do not necessarily correlate with DR mRNA levels, (iii) different T cell types/subtypes have different DR levels and composition and different responses to dopamine, (iv) autoimmune and pro-inflammatory T cells and T cell leukaemia/lymphoma also express functional DRs, (v) dopamine (~10(-8) M) activates resting/naive Teffs (CD8(+) >>>CD4(+) ), (vi) dopamine affects Th1/Th2/Th17 differentiation, (vii) dopamine inhibits already activated Teffs (i.e. T cells that have been already activated by either antigen, mitogen, anti-CD3 antibodies cytokines or other molecules), (viii) dopamine inhibits activated Tregs in an autocrine/paracrine manner. Thus, dopamine 'suppresses the suppressors' and releases the inhibition they exert on Teffs, (ix) dopamine affects intracellular signalling molecules and cascades in T cells (e.g. ERK, Lck, Fyn, NF-κB, KLF2), (x) T cells produce dopamine (Tregs>>>Teffs), can release dopamine, mainly after activation (by antigen, mitogen, anti-CD3 antibodies, PKC activators or other), uptake extracellular dopamine, and most probably need dopamine, (xi) dopamine is important for antigen-specific interactions between T cells and dendritic cells, (xii) in few autoimmune diseases (e.g. multiple sclerosis/SLE/rheumatoid arthritis), and neurological/psychiatric diseases (e.g. Parkinson disease, Alzheimer's disease, Schizophrenia and Tourette), patient's T cells seem to have abnormal DRs expression and/or responses to dopamine or production of dopamine, (xiii) drugs that affect the dopaminergic system have potent effects on T cells (e.g. dopamine=Intropin, L-dopa, bromocriptine, haloperidol, quinpirole, reserpine, pergolide, ecopipam, pimozide, amantadine, tetrabenazine, nomifensine, butaclamol). Dopamine-induced activation of resting Teffs and suppression of Tregs seem beneficial for health and may also be used for immunotherapy of cancer and infectious diseases. Independently, suppression of DRs in autoimmune and pro-inflammatory T cells, and also in cancerous T cells, may be advantageous. The review is relevant to Immunologists, Neurologists, Neuroimmunologists, Hematologists, Psychiatrists, Psychologists and Pharmacologists.

Migraine Triggers and Oxidative Stress: A Narrative Review and Synthesis

BACKGROUND

Blau theorized that migraine triggers are exposures that in higher amounts would damage the brain. The recent discovery that the TRPA1 ion channel transduces oxidative stress and triggers neurogenic inflammation suggests that oxidative stress may be the common denominator underlying migraine triggers.

OBJECTIVE

The aim of this review is to present and discuss the available literature on the capacity of common migraine triggers to generate oxidative stress in the brain.

METHODS

A Medline search was conducted crossing the terms "oxidative stress" and "brain" with "alcohol," "dehydration," "water deprivation," "monosodium glutamate," "aspartame," "tyramine," "phenylethylamine," "dietary nitrates," "nitrosamines," "noise," "weather," "air pollutants," "hypoglycemia," "hypoxia," "infection," "estrogen," "circadian," "sleep deprivation," "information processing," "psychosocial stress," or "nitroglycerin and tolerance." "Flavonoids" was crossed with "prooxidant." The reference lists of the resulting articles were examined for further relevant studies. The focus was on empirical studies, in vitro and of animals, of individual triggers, indicating whether and/or by what mechanism they can generate oxidative stress.

RESULTS

In all cases except pericranial pain, common migraine triggers are capable of generating oxidative stress. Depending on the trigger, mechanisms include a high rate of energy production by the mitochondria, toxicity or altered membrane properties of the mitochondria, calcium overload and excitotoxicity, neuroinflammation and activation of microglia, and activation of neuronal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. For some triggers, oxidants also arise as a byproduct of monoamine oxidase or cytochrome P450 processing, or from uncoupling of nitric oxide synthase.

CONCLUSIONS

Oxidative stress is a plausible unifying principle behind the types of migraine triggers encountered in clinical practice. The possible implications for prevention and for understanding the nature of the migraine attack are discussed.

Look beyond Catechol-O-Methyltransferase genotype for cathecolamines derangement in migraine: the BioBIM rs4818 and rs4680 polymorphisms study

BACKGROUND

The study of COMT gene polymorphisms in migraine could be of particular interest since impaired catecholaminergic neurotransmission, namely chronic dopaminergic and noradrenergic hypofunction, is a peculiar migraine trait. In this study, for the first time, we focused on the role of COMT rs4818 genetic variant, the polymorphism most strongly affecting COMT activity, in migraine. This study was conducted in a cohort of carefully clinical characterized Caucasian migraineurs recruited in a specifically dedicated migraine biobank, providing also a replication study on rs4680 polymorphism.

FINDINGS

Genotyping of rs4680 and rs4818 Catechol-O-Methyltransferase gene polymorphisms was performed on 380 unrelated migraine patients, and 132 healthy subjects matched for age, gender and race-ethnicity, with no clinical evidence or family history of migraine or other neurological diseases. The rs4680 and rs4818 genotypic frequencies did not deviate from those expected for a population in Hardy-Weinberg equilibrium and did not correlate with demographics or clinical migraine features, even when considering migraine subtypes such as dopaminergic migraine, menstrual migraine, and menstrually related migraine .

CONCLUSIONS

COMT genotype does not influence migraine susceptibility or phenotype, even considering rs4818 polymorphism and peculiar clinical subtypes. This finding prompts to go over COMT to explain catecholamine derangement in migraine, exploring enzymes involved in catecholamines synthesis and catabolism, such as monoamine-oxidase, dopamine beta-hydroxylase, tyrosine-hydroxylase or tyrosine-decarboxylase, among others.

Neuroplasticity underlying the comorbidity of pain and depression

Acute pain induces depressed mood, and chronic pain is known to cause depression. Depression, meanwhile, can also adversely affect pain behaviors ranging from symptomology to treatment response. Pain and depression independently induce long-term plasticity in the central nervous system (CNS). Comorbid conditions, however, have distinct patterns of neural activation. We performed a review of the changes in neural circuitry and molecular signaling pathways that may underlie this complex relationship between pain and depression. We also discussed some of the current and future therapies that are based on this understanding of the CNS plasticity that occurs with pain and depression.

Migraine and reward system-or is it aversive?

Migraine is a debilitating neurological disorder with grave consequences for both the individual and society. This review will focus on recent literature investigating how brain structures implicated in reward and aversion contribute to the genesis of migraine pain. There exist many overlapping and interacting brain regions within pain and reward circuitry that contribute to negative affect and subjective experience of pain. The emotional component of pain has been argued to be a greater metric of quality of life than its sensory component, and thus understanding the processes that influence this pain characteristic is essential to developing novel treatment strategies for mitigating migraine pain. We emphasize and provide evidence that abnormalities within the mesolimbic cortical reward pathways contribute to migraine pain and that there are structural and functional neuroplasticity within the overlapping brain regions common to both pain and reward.

Midlife migraine and late-life parkinsonism: AGES-Reykjavik study

OBJECTIVE

In the present study, we tested the hypothesis that having migraine in middle age is related to late-life parkinsonism and a related disorder, restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED).

METHODS

The AGES-Reykjavik cohort (born 1907-1935) has been followed since 1967. Headaches were classified based on symptoms assessed in middle age. From 2002 to 2006, 5,764 participants were reexamined to assess symptoms of parkinsonism, diagnosis of Parkinson disease (PD), family history of PD, and RLS/WED.

RESULTS

Subjects with midlife migraine, particularly migraine with aura (MA), were in later life more likely than others to report parkinsonian symptoms (odds ratio [OR]MA = 3.6 [95% CI 2.7-4.8]) and diagnosed PD (ORMA = 2.5 [95% CI 1.2-5.2]). Women with MA were more likely than others to have a parent (ORMA = 2.26 [95% CI 1.3-4.0]) or sibling (ORMA = 1.78 [95% CI 1.1-2.9]) with PD. Late-life RLS/WED was increased for headache generally. Associations were independent of cardiovascular disease and MRI-evident presumed ischemic lesions.

CONCLUSIONS

These findings suggest there may be a common vulnerability to, or consequences of, migraine and multiple indicators of parkinsonism. Additional genetic and longitudinal observational studies are needed to identify candidate pathways that may account for the comorbid constellation of symptoms.

A multivariate approach linking reported side effects of clinical antidepressant and antipsychotic trials to in vitro binding affinities

The vast majority of approved antidepressants and antipsychotics exhibit a complex pharmacology. The mechanistic understanding of how these psychotropic medications are related to adverse drug reactions (ADRs) is crucial for the development of novel drug candidates and patient adherence. This study aims to associate in vitro assessed binding affinity profiles (39 compounds, 24 molecular drug targets) and ADRs (n=22) reported in clinical trials of antidepressants and antipsychotics (n>59.000 patients) by the use of robust multivariate statistics. Orthogonal projection to latent structures (O-PLS) regression models with reasonable predictability were found for several frequent ADRs such as nausea, diarrhea, hypotension, dizziness, headache, insomnia, sedation, sleepiness, increased sweating, and weight gain. Results of the present study support many well-known pharmacological principles such as the association of hypotension and dizziness with α1-receptor or sedation with H1-receptor antagonism. Moreover, the analyses revealed novel or hardly investigated mechanisms for common ADRs including the potential involvement of 5-HT6-antagonism in weight gain, muscarinic receptor antagonism in dizziness, or 5-HT7-antagonism in sedation. To summarize, the presented study underlines the feasibility and value of a multivariate data mining approach in psychopharmacological development of antidepressants and antipsychotics.