Migraine pathophysiology: anatomy of the trigeminovascular pathway and associated neurological symptoms, CSD, sensitization and modulation of pain

Bi-sinusoidal light stimulation reveals an enhanced response power and reduced phase coherence at the visual cortex in migraine

Introduction

Migraine is associated with enhanced visual sensitivity during and outside attacks. Processing of visual information is a highly non-linear process involving complex interactions across (sub)cortical networks. In this exploratory study, we combined electroencephalography with bi-sinusoidal light stimulation to assess non-linear features of visual processing in participants with migraine.

Methods

Twenty participants with migraine (10 with aura, 10 without aura) and ten non-headache controls were measured (outside attacks). Participants received bi-sinusoidal 13 + 23 Hz red light visual stimulation. Electroencephalography spectral power and multi-spectral phase coherence were compared between groups at the driving stimulation frequencies together with multiples and combinations of these frequencies (harmonic and intermodulation frequencies) caused by non-linearities.

Results

Only at the driving frequency of 13 Hz higher spectral power was found in migraine with aura participants compared with those with migraine without aura and controls. Differences in phase coherence were present for 2nd, 4th, and 5th-order non-linearities in those with migraine (migraine with and without aura) compared with controls. Bi-sinusoidal light stimulation revealed evident non-linearities in the brain's electroencephalography response up to the 5th order with reduced phase coherence for higher order interactions in interictal participants with migraine.

Discussion

Insight into interictal non-linear visual processing may help understand brain dynamics underlying migraine attack susceptibility. Future research is needed to determine the clinical value of the results.

Role of TNF-α in the Pathogenesis of Migraine

Background

Neurogenic neuroinflammation has a wide role in migraine pathogenesis including the transition from episodic migraine to chronic one. The seed molecule of neurogenic neuroinflammation, i.e., the TNF-α proinflammatory molecule, has gathered a lot of attention. This pleiotropic cytokine is a classical component of inflammatory soup, secreted by the microglial cell, and promotes a wide range of inflammatory reactions.

Aim

In this review, we aimed to provide a culminating and comprehending glimpse into the TNF-α in association with the migraine.

Method

A systematic literature survey method with a mixture of keywords was utilized to grasp the different elements that represent the association between TNF-α and migraine. Discussion. Highlighted the probable involvement of the TNF-α with migraine, the complexity of the matter such as activation of NF-KB signaling cascade, autoactivation, sensitization, and increased likelihood of transition cannot be neglected. Being TNF-α as a core node, it becomes the factor for linking diseases such as chronic inflammatory disorders, including COVID-19, and also interaction with other genes to develop severe conditions.

Conclusion

To this end, TNF-α plays a critical role in chronification, and inhibiting its signaling would likely be a crucial strategy for migraine therapy.

Trigeminal nerve stimulation: a current state-of-the-art review

Nearly 5 decades ago, the effect of trigeminal nerve stimulation (TNS) on cerebral blood flow was observed for the first time. This implication directly led to further investigations and TNS' success as a therapeutic intervention. Possessing unique connections with key brain and brainstem regions, TNS has been observed to modulate cerebral vasodilation, brain metabolism, cerebral autoregulation, cerebral and systemic inflammation, and the autonomic nervous system. The unique range of effects make it a prime therapeutic modality and have led to its clinical usage in chronic conditions such as migraine, prolonged disorders of consciousness, and depression. This review aims to present a comprehensive overview of TNS research and its broader therapeutic potentialities. For the purpose of this review, PubMed and Google Scholar were searched from inception to August 28, 2023 to identify a total of 89 relevant studies, both clinical and pre-clinical. TNS harnesses the release of vasoactive neuropeptides, modulation of neurotransmission, and direct action upon the autonomic nervous system to generate a suite of powerful multitarget therapeutic effects. While TNS has been applied clinically to chronic pathological conditions, these powerful effects have recently shown great potential in a number of acute/traumatic pathologies. However, there are still key mechanistic and methodologic knowledge gaps to be solved to make TNS a viable therapeutic option in wider clinical settings. These include bimodal or paradoxical effects and mechanisms, questions regarding its safety in acute/traumatic conditions, the development of more selective stimulation methods to avoid potential maladaptive effects, and its connection to the diving reflex, a trigeminally-mediated protective endogenous reflex. The address of these questions could overcome the current limitations and allow TNS to be applied therapeutically to an innumerable number of pathologies, such that it now stands at the precipice of becoming a ground-breaking therapeutic modality.

GV16 acupoint stimulation with bee venom reduces peripheral hypersensitivity via activation of α2 adrenoceptors in a nitroglycerin-induced migraine mouse model

Background

Peripheral hypersensitivities develop in the face and hindpaws of mice with nitroglycerin (NTG)-induced migraine. We evaluated whether diluted bee venom (DBV) injections at acupoints prevented these peripheral hypersensitivities and c-Fos expression in the trigeminal nucleus caudalis (TNC).

Methods

NTG (10 mg/kg, intraperitoneal, i.p.) was administered every other day for nine days. DBV (0.1 mg/kg) was subcutaneously injected into the ST36 (Zusanli), LI4 (Hegu), or GV16 (Fengfu) acupoints 75 min after each NTG injection. Mice were pretreated with naloxone (5 mg/kg, i.p.) or yohimbine (5 mg/kg, i.p.) 30 min before the DBV injections.

Results

NTG injection caused facial cold allodynia, hindpaw mechanical allodynia, and increased c-Fos-immunoreactive (ir) cells in the TNC. Repetitive DBV injections at GV16, but not the ST36, or LI4 acupoints, suppressed NTG-induced hindpaw mechanical allodynia and facial cold allodynia. The number of c-Fos-ir cells also decreased in response to DBV injections at the GV16 acupoint. Remarkably, pretreatment with yohimbine reversed the anti-allodynic effects of DBV injections and attenuated the decreased c-Fos expression in response to GV16 DBV treatment. Naloxone did not block the effects of GV16 DBV stimulation.

Conclusion

These findings demonstrate that repetitive DBV treatment at the GV16 acupoint relieves NTG-induced facial and hindpaw hypersensitivities and decreases in c-Fos expression in the TNC via activation of the alpha-2 adrenoceptors, but not the opioid receptors.

The Burden of Migraine on Quality of Life in Chronic Rhinosinusitis

OBJECTIVE

To determine the impact of comorbid migraine on quality of life (QOL) in chronic rhinosinusitis (CRS).

METHODS

A total of 213 adult patients with CRS were recruited. All participants completed the 22-item Sinonasal Outcome Test (SNOT-22), from which total and validated nasal, ear/facial pain, sleep, and emotional subdomain scores were calculated, and the 5-dimension EuroQol general health questionnaire (EQ-5D), from which the visual analogue scale (VAS) and health utility value (HUV) were calculated. The presence of comorbid migraine was determined by a score of ≥4 on the 5-item Migraine Screen Questionnaire (MS-Q).

RESULTS

Of the participants, 36.2% were screened positive for having comorbid migraine. The mean SNOT-22 score was 64.9 (SD: 18.7) in participants with migraine and 41.5 (SD: 21.1) in participants without migraine (p < 0.001). The mean EQ-5D VAS and HUV were 60.2 (SD: 21.9) and 0.69 (SD: 0.18), respectively, in participants with migraine and 71.4 (SD: 19.4) and 0.84 (SD: 0.13), respectively, in participants without migraine (p < 0.001 for both). Higher ear/facial pain (OR = 1.22, 95% CI: 1.10-1.36, p < 0.001) and sleep (OR = 1.11, 95% CI: 1.04-1.18, p = 0.002) SNOT-22 subdomain scores were positively associated with migraine. The SNOT-22 item scores related to dizziness, reduced concentration, and facial pain, in descending order, were most associated with migraine. The presence of nasal polyps (OR = 0.24, 95% CI: 0.07 - 0.80, p = 0.020) was negatively associated with migraine.

CONCLUSION

Comorbid migraine may be relatively common amongst CRS patients, and its presence is associated with significantly worse QOL. Dizziness as a symptom in CRS patients may be particularly indicative of migraine.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3279-3284, 2023.

Targeting CGRP pathways and aura: A peripheral site with a central effect

Targeting CGRP-pathways has substantially expanded our options for treating individuals with migraine. Although the efficacy of these drugs on migraine aura is yet to be fully revealed, it seems from existing studies that CGRP antagonism reduces the number of migraine auras. The present perspective summarizes the evidence linking CGRP to the migraine aura and proposes a model by which targeting the CGRP-pathways and, thus, inhibition the interaction between C- and Aδ-trigeminal fibers might reverse a possible high cortical glutamate level leading to a reduced number of migraine auras.

Bi-directional nasal drug delivery systems: A scoping review of nasal particle deposition patterns and clinical application

Objectives

To compare the deposition patterns within the nasal cavity between the bi-directional and unilateral nasal delivery systems. And to summarize the clinical application of the bi-directional nasal drug delivery devices.

Data source

PubMed, Cochrane Library, Embase, and Web of Science databases.

Methods

A scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We included studies exploring patterns and influencing factors of particle depositions within the nasal cavity among patients, healthy controls, and nose cast models using the bi-directional and unilateral nasal delivery system. The clinical application of the bi-directional delivery devices was also summarized.

Results

A total of 24 studies were included in this review. Bi-directional nasal delivery systems utilize forced exhalation to power the delivery of drugs to deeper areas of the nasal cavity and paranasal sinuses. Unilateral nasal delivery systems included traditional liquid spray pumps, the aerosol mask system, nebulization, and conventional nasal inhalation. Compared with unilateral delivery systems, the bi-directional nasal delivery system provided a more extensive and efficient nasal deposition in the nasal cavity, especially in the olfactory cleft, without lung deposition. Several parameters, including particle size, pulsatile flow, and nasal geometry, could significantly influence nasal deposition. The bi-directional nasal delivery system enables better delivery of steroids or sumatriptan to the sinonasal cavity's high and deep target sites. This bi-directional delivery device demonstrated an effective and well-tolerated treatment that produced high drug utilization, rapid absorption, and sustained symptom improvement among patients with chronic rhinosinusitis (CRS) or migraine.

Conclusion

The bi-directional nasal drug delivery systems demonstrated significantly higher drug deposition in superior and posterior regions of the nasal cavity than unilateral nasal delivery systems. Further studies should explore its potential role in delivering drugs to the olfactory cleft among patients with olfactory disorders and central nervous system diseases.

Level of evidence

N/A.

Quantitative electroencephalography as a potential biomarker in migraine

OBJECTIVE

The aim of this study was to investigate the utility of quantitative electroencephalography (QEEG) as a diagnostic tool for migraine and as an indicator of treatment response by comparing QEEG characteristics between migraine patients and controls, and monitoring changes in these characteristics alongside clinical symptoms in response to treatment BACKGROUND: We hypothesized that patients with migraine exhibit distinctive characteristics in QEEG measurements, which could be used as potential diagnostic biomarkers and as a tool for monitoring treatment response.

METHODS

A total of 720 patients were included in the study, comprising 619 patients with migraine and 101 subjects as a control group. QEEG measurements were analyzed for absolute power across specific frequency bands: delta wave (0.5-4 Hz), theta wave (4-8 Hz), alpha wave (8-12 Hz), beta wave (12-25 Hz), and high beta wave (25-30 Hz). The absolute power was normalized against a normative dataset from NeuroGuide, with electrodes being highlighted for significance if they exceeded 1.96. Clinical symptoms were also monitored for correlation with QEEG changes.

RESULTS

Our analysis showed that patients with migraine exhibited significantly higher absolute power across all frequencies, most markedly within the high beta frequency range. When considering electrodes with z-scores exceeding the threshold of 1.96 in the high beta range, a significant association with migraine diagnosis was observed (per 1 electrode increase, OR 1.06; 95% CI 1.01-1.11; p = .012). Moreover, pre- and posttreatment changes in QEEG measurements corresponded with changes in clinical symptoms.

CONCLUSION

Patients with migraine have distinctive QEEG measurements, particularly regarding absolute power and the number of electrodes that surpassed the z-score threshold in high beta wave activity. These findings suggest the potential of QEEG as a diagnostic biomarker and as a tool for monitoring treatment response in migraine patients, warranting further large-scale studies for confirmation and expansion.

Risk factors for migraine disease progression: a narrative review for a patient-centered approach

BACKGROUND

In individuals with migraine, attacks may increase in frequency, severity, or both. Preventing migraine progression has emerged as a treatment goal in headache subspecialty practice, but there may be less awareness in general neurology or primary care settings where most people with migraine who seek treatment consult. Herein, we review the definition of and risk factors for migraine progression and consider strategies that could reduce its risk.

METHODS

A group of headache expert healthcare professionals, clinicians, and researchers reviewed published evidence documenting factors associated with increased or decreased rates of migraine progression and established expert opinions for disease management recommendations. Strength of evidence was rated as good, moderate, or based solely on expert opinion, using modified criteria for causation developed by AB Hill.

RESULTS

Migraine progression is commonly operationally defined as the transition from ≤ 15 to ≥ 15 monthly headache days among people with migraine; however, this does not necessarily constitute a fundamental change in migraine biology and other definitions should be considered. Established and theoretical key risk factors for migraine progression were categorized into five domains: migraine disease characteristics, treatment-related factors, comorbidities, lifestyle/exogenous factors, and demographic factors. Within these domains, good evidence supports the following risk factors: poorly optimized acute headache treatment, cutaneous allodynia, acute medication overuse, selected psychiatric symptoms, extra-cephalic chronic pain conditions, metabolism-related comorbidities, sleep disturbances, respiratory conditions, former/current high caffeine intake, physical inactivity, financial constraints, tobacco use, and personal triggers as risk factors. Protective actions that may mitigate migraine progression are sparsely investigated in published literature; our discussion of these factors is primarily based on expert opinion.

CONCLUSIONS

Recognizing risk factors for migraine progression will allow healthcare providers to suggest protective actions against migraine progression (Supplementary Fig. 1). Intervention studies are needed to weight the risk factors and test the clinical benefit of hypothesized mitigation strategies that emerge from epidemiological evidence.

Ion Channel Disturbances in Migraine Headache: Exploring the Potential Role of the Kynurenine System in the Context of the Trigeminovascular System

Migraine is a primary headache disorder, which is an enormous burden to the healthcare system. While some aspects of the pathomechanism of migraines remain unknown, the most accepted theory is that activation and sensitization of the trigeminovascular system are essential during migraine attacks. In recent decades, it has been suggested that ion channels may be important participants in the pathogenesis of migraine. Numerous ion channels are expressed in the peripheral and central nervous systems, including the trigeminovascular system, affecting neuron excitability, synaptic energy homeostasis, inflammatory signaling, and pain sensation. Dysfunction of ion channels could result in neuronal excitability and peripheral or central sensitization. This narrative review covers the current understanding of the biological mechanisms leading to activation and sensitization of the trigeminovascular pain pathway, with a focus on recent findings on ion channel activation and modulation. Furthermore, we focus on the kynurenine pathway since this system contains kynurenic acid, which is an endogenous glutamate receptor antagonist substance, and it has a role in migraine pathophysiology.

Unveiling the Role of Contingent Negative Variation (CNV) in Migraine: A Review of Electrophysiological Studies in Adults and Children

Migraine has been considered a chronic neuronal-based pain disorder characterized by the presence of cortical hyperexcitability. The Contingent Negative Variation (CNV) is the most explored electrophysiological index in migraine. However, the findings show inconsistencies regarding its functional significance. To address this, we conducted a review in both adults and children with migraine without aura to gain a deeper understanding of it and to derive clinical implications. The literature search was conducted in the PubMed, SCOPUS and PsycINFO databases until September 2022m and 34 articles were retrieved and considered relevant for further analysis. The main results in adults showed higher CNV amplitudes (with no habituation) in migraine patients. Electrophysiological abnormalities, particularly focused on the early CNV subcomponent (eCNV), were especially prominent a few days before the onset of a migraine attack, normalizing during and after the attack. We also explored various modulatory factors, including pharmacological treatments-CNV amplitude was lower after the intake of drugs targeting neural hyperexcitability-and other factors such as psychological, hormonal or genetic/familial influences on CNV. Although similar patterns were found in children, the evidence is particularly scarce and less consistent, likely due to the brain's maturation process during childhood. As the first review exploring the relationship between CNV and migraine, this study supports the role of the CNV as a potential neural marker for migraine pathophysiology and the prediction of pain attacks. The importance of further exploring the relationship between this neurophysiological index and childhood migraine is critical for identifying potential therapeutic targets for managing migraine symptoms during its development.

Quality by design for sumatriptan loaded nano-ethosomal mucoadhesive gel for the therapeutic management of nitroglycerin induced migraine

Migraine is a progressive neurological condition often accompanied by nausea and vomiting. Various drugs have recently been used in the treatment of migraine, including sumatriptan (SUT). However, SUT has poor pharmacological effects mainly due to its reduced permeability, blood brain barrier (BBB) effect, half-life and bioavailability. Herein, we developed SUT loaded nano-ethosomes (SUT-NEs) for intranasal (IN) delivery, after their incorporation into chitosan based mucoadhesive gel (SUT-NEsG). The observed mean particle size of SUT-NEs was 109.45 ± 4.03 nm with spherical morphology, mono dispersion (0.191 ± 0.001), negatively charged (-20.90 ± 1.98 mV) and with excellent entrapment efficiency (96.90 ± 1.85 %). Fourier-transform infrared (FTIR) spectra have depicted the compatibility of the components. Moreover, SUT-NEsG was homogeneous having suitable viscosity and mucoadhesive strength. In vitro release and ex vivo permeation analysis showed sustained release and improved permeation of the SUT-NEsG, respectively. Additionally, histopathological studies of nasal membrane affirmed the safety of SUT-NEsG after IN application. In vivo pharmacokinetic study demonstrated improved brain bioavailability of SUT-NEsG as compared to orally administered sumatriptan solution (SUT-SL). Furthermore, significantly enhanced pharmacological effect of SUT-NEsG was observed in behavioral and biochemical analysis, immunohistochemistry for NF-κB, and enzyme linked immuno assay (ELISA) for IL-1β and TNF-α in Nitroglycerin (NTG) induced migraine model. It can be concluded that migraine may be successfully managed through IN application of SUT-NEsG owing to the direct targeted delivery to the brain.

Identification of brain areas in mice with peak neural activity across the acute and persistent phases of post-traumatic headache

BACKGROUND

Post-traumatic headache is very common after a mild traumatic brain injury. Post-traumatic headache may persist for months to years after an injury in a substantial proportion of people. The pathophysiology underlying post-traumatic headache remains unknown but is likely distinct from other headache disorders. Identification of brain areas activated in acute and persistent phases of post-traumatic headache can provide insights into the underlying circuits mediating headache pain. We used an animal model of mild traumatic brain injury-induced post-traumatic headache and c-fos immunohistochemistry to identify brain regions with peak activity levels across the acute and persistent phases of post-traumatic headache.

METHODS

Male and female C57BL/6 J mice were briefly anesthetized and subjected to a sham procedure or a weight drop closed-head mild traumatic brain injury . Cutaneous allodynia was assessed in the periorbital and hindpaw regions using von Frey filaments. Immunohistochemical c-fos based neural activity mapping was then performed on sections from whole brain across the development of post-traumatic headache (i.e. peak of the acute phase at 2 days post- mild traumatic brain injury), start of the persistent phase (i.e. >14 days post-mild traumatic brain injury) or after provocation with stress (bright light). Brain areas with consistent and peak levels of c-fos expression across mild traumatic brain injury induced post-traumatic headache were identified and included for further analysis.

RESULTS

Following mild traumatic brain injury, periorbital and hindpaw allodynia was observed in both male and female mice. This allodynia was transient and subsided within the first 14 days post-mild traumatic brain injury and is representative of acute post-traumatic headache. After this acute post-traumatic headache phase, exposure of mild traumatic brain injury mice to a bright light stress reinstated periorbital and hindpaw allodynia for several hours - indicative of the development of persistent post-traumatic headache. Acute post-traumatic headache was coincident with an increase in neuronal c-fos labeling in the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and the nucleus accumbens. Neuronal activation returned to baseline levels by the persistent post-traumatic headache phase in the spinal nucleus of the trigeminal caudalis and primary somatosensory cortex but remained elevated in the nucleus accumbens. In the persistent post-traumatic headache phase, coincident with allodynia observed following bright light stress, we observed bright light stress-induced c-fos neural activation in the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and nucleus accumbens.

CONCLUSION

Examination of mild traumatic brain injury-induced changes in peak c-fos expression revealed brain regions with significantly increased neural activity across the acute and persistent phases of post-traumatic headache. Our findings suggest mild traumatic brain injury-induced post-traumatic headache produces neural activation along pain relevant pathways at time-points matching post-traumatic headache-like pain behaviors. These observations suggest that the spinal nucleus of the trigeminal caudalis, primary somatosensory cortex, and nucleus accumbens may contribute to both the induction and maintenance of post-traumatic headache.

Vessel-wall MRI in primary headaches: The role of neurogenic inflammation

OBJECTIVE

The purpose of this study was to investigate if vessel-wall magnetic resonance imaging (VW-MRI) could differentiate among primary headaches disorders, such as migraine and cluster headache (CH), and detect the presence of neurogenic inflammation.

BACKGROUND

The pathophysiology of primary headaches disorders is complex and not completely clarified. The activation of nociceptive trigeminal afferents through the release of vasoactive neuropeptides, termed "neurogenic inflammation," has been hypothesized. VW-MRI can identify vessel wall changes, reflecting the inflammatory remodeling of the vessel walls despite different etiologies.

METHODS

In this case series, we enrolled seven patients with migraine and eight patients with CH. They underwent a VW-MRI study before and after the intravenous administration of contrast medium, during and outside a migraine attack or cluster period. Two expert neuroradiologists analyzed the magnetic resonance imaging (MRI) studies to identify the presence of vessel wall enhancement or other vascular abnormalities.

RESULTS

Fourteen out of 15 patients had no enhancement. One out of 15, with migraine, showed a focal parietal enhancement in the intracranial portion of a vertebral artery, unmodified during and outside the attack, thus attributable to atherosclerosis. No contrast enhancement attributable to neurogenic inflammation was observed in VW-MRI, both during and outside the attack/cluster in all patients. Moreover, MRI angiography registered slight diffuse vasoconstriction in one of seven patients with migraine during the attack and in one of eight patients with cluster headache during the cluster period; both patients had taken triptans as symptomatic therapy for pain.

CONCLUSIONS

These preliminary results suggest that VW-MRI studies are negative in patients with primary headache disorders even during migraine attacks or cluster periods. The VW-MRI studies did not detect signs of neurogenic inflammation in the intracranial intradural vessels of patients with migraine or CH.

The association of serum vitamin D concentrations in paediatric migraine

INTRODUCTION

Migraine is a neurologic condition characterized by hypersensitivity to auditory, olfactory, visual, and cutaneous stimuli; vomiting and nausea; and severe headache. It is the most frequent headache syndrome in children and can be categorized in chronic and/or episodic. Multiple dietary supplements have been inaugurated for the management of migraine, the most prevalent of which is vitamin D.

BACKGROUND

In recent years, vitamin D deficiency has been a global public health problem, with 30-80% of the worldwide population having vitamin D deficiency. The significant role of vitamin D in neurological disorders is underlined by its key role in the brain function of the central nervous system (CNS). Current approaches in paediatric neurology include nonsteroidal anti-inflammatory drugs (NSAID) for the treatment of paediatric migraine, among others. Vitamin D is one of the dietary factors that has been linked to migraine, however, this association has mostly been examined in the adult population.

OBJECTIVE

The aim of this study is to investigate the association between serum vitamin D and paediatric migraine by conducting a review of existing literature. The main question is described with the PICO format (population, intervention, control, and outcomes), while the assessment of the present research is under the PRISMA guidelines for systematic reviews.

RESULTS/CONCLUSION

A systematic review of the literature reveals a remarkable association between vitamin D and migraine presentation in the paediatric population, affecting the frequency and duration of the episodes. That being the case, vitamin D supplementation could potentially improve the quality of life of paediatric patients suffering from migraine headaches.

Preclinical effects of cannabidiol in an experimental model of migraine

ABSTRACT

Migraine is a disabling disorder characterized by recurrent headaches, accompanied by abnormal sensory sensitivity and anxiety. Despite extensive historical use of cannabis in headache disorders, there is limited research on the nonpsychoactive cannabidiol (CBD) for migraine and there is no scientific evidence to prove that CBD is an effective treatment. The effects of CBD are examined here using a calcitonin gene-related peptide (CGRP)-induced migraine model that provides measures of cephalic allodynia, spontaneous pain, altered light sensitivity (photophobia), and anxiety-like behavior in C57BL/6J mice. A single administration of CGRP induced facial hypersensitivity in both female and male mice. Repeated CGRP treatment produced progressively decreased levels in basal thresholds of allodynia in females, but not in males. A single CBD administration protected both females and males from periorbital allodynia induced by a single CGRP injection. Repeated CBD administration prevented increased levels of basal allodynia induced by repeated CGRP treatment in female mice and did not lead to responses consistent with migraine headache as occurs with triptans. Cannabidiol, injected after CGRP, reversed CGRP-evoked allodynia. Cannabidiol also reduced spontaneous pain traits induced by CGRP administration in female mice. Finally, CBD blocked CGRP-induced anxiety in male mice, but failed in providing protection from CGRP-induced photophobia in females. These results demonstrate the efficacy of CBD in preventing episodic and chronic migraine-like states with reduced risk of causing medication overuse headache. Cannabidiol also shows potential as an abortive agent for treating migraine attacks and headache-related conditions such as spontaneous pain and anxiety.

Functional MRI and Diffusion Tensor Imaging in Migraine: A Review of Migraine Functional and White Matter Microstructural Changes

Migraine is a complex and heterogenous disorder whose disease mechanisms remain disputed. This narrative review summarizes functional MRI (fMRI) and diffusion tensor imaging (DTI) findings and interprets their association with migraine symptoms and subtype to support and expand our current understanding of migraine pathophysiology. Our PubMed search evaluated and included fMRI and DTI studies involving comparisons between migraineurs vs healthy controls, migraineurs with vs without aura, and episodic vs chronic migraineurs. Migraineurs demonstrate changes in functional connectivity (FC) and regional activation in numerous pain-related networks depending on migraine phase, presence of aura, and chronicity. Changes to diffusion indices are observed in major cortical white matter tracts extending to the brainstem and cerebellum, more prominent in chronic migraine and associated with FC changes. Reported changes in FC and regional activation likely relate to pain processing and sensory hypersensitivities. Diffuse white matter microstructural changes in dysfunctional cortical pain and sensory pathways complement these functional differences. Interpretations of reported fMRI and DTI measure trends have not achieved a clear consensus due to inconsistencies in the migraine neuroimaging literature. Future fMRI and DTI studies should establish and implement a uniform methodology that reproduces existing results and directly compares migraineurs with different subtypes. Combined fMRI and DTI imaging may provide better pathophysiological explanations for nonspecific FC and white matter microstructural differences.

Intravascular laser irradiation of blood as novel migraine treatment: an observational study

BACKGROUND

Migraine is one of four major chronic diseases that cause disability. Decreases in regional cerebral blood flow (rCBF) occur during migraine attacks. Laser therapy is extensively employed in treating other vascular diseases; nevertheless, its effectiveness in migraine management remains largely unknown. Therefore, we evaluated the effect of low-level intravascular laser irradiation of blood (ILIB) therapy in patients with migraine.

METHODS

We performed an observational case-control study in 24 patients suffering from migraine. Patients were divided into an ILIB treatment group and a traditional rehabilitation group. This study performed clinical assessments and single-photon emission computed tomography (SPECT) prior to and after the treatment and 1 month later. Changes in rCBF-SPECT between groups and between timepoints were compared to clinical outcomes.

RESULTS

Nine patients undergoing rehabilitation and fifteen patients undergoing ILIB were studied from baseline to 1 month follow-up. The ILIB group, visual analog scale for pain (P = 0.001), Montreal Cognitive Assessment (P = 0.003), and Athens Insomnia Scale (P < 0.001) symptom scores significantly improved after treatment. SPECT imaging showed a 1.27 ± 0.27 fold increase in rCBF after ILIB treatment, and no significant differences in the rehabilitation group.

CONCLUSIONS

Low-level ILIB therapy is associated with better clinical and vascular outcomes, and may be a feasible treatment option for migraine. Although our sample size was small, our data provide a starting point for migraine laser therapy research.

Multimodal Migraine Management and the Pursuit of Migraine Freedom: A Narrative Review

Migraine is a neurologic disease with a complex pathophysiology that can be controlled with current treatment options but not cured. Therefore, treatment expectations are highly variable. The concept of migraine freedom was recently introduced and can mean different things, with some, for example, expecting complete freedom from headache and associated symptoms and others accepting the occasional migraine attack if it does not impact functioning. Therefore, migraine management should be optimized so that patients can have the best opportunity to achieve their optimal treatment goals. With migraine freedom as a goal and, given the complex pathophysiology of migraine and the high incidence of comorbidities among individuals with migraine, treatment with a single modality may be insufficient, as it may not achieve migraine freedom in those with more frequent or disabling attacks. In this clinical perspective article, we have identified four key, partially overlapping principles of multimodal migraine treatment: (1) manage common comorbidities; (2) control modifiable risk factors for progression by addressing medication and caffeine overuse; (3) diagnose and treat secondary causes of headache, if present; and (4) individualize acute and preventive treatments to minimize pain, functional disability, and allodynia. There are many barriers to pursuing migraine freedom, and strategies to overcome them should be optimized. Migraine freedom should be an aspirational goal both at the individual attack level and for the disease overall. We believe that a comprehensive and multimodal approach that addresses all barriers people with migraine face could move patients closer to migraine freedom.

Central generators of migraine and autonomic cephalalgias as targets for personalized pain management: Translational links

BACKGROUND AND OBJECTIVE

Migraine oscillates between different states in association with internal homeostatic functions and biological rhythms that become more easily dysregulated in genetically susceptible individuals. Clinical and pre-clinical data on migraine pathophysiology support a primary role of the central nervous system (CNS) through 'dysexcitability' of certain brain networks, and a critical contribution of the peripheral sensory and autonomic signalling from the intracranial meningeal innervation. This review focuses on the most relevant back and forward translational studies devoted to the assessment of CNS dysfunctions involved in primary headaches and discusses the role they play in rendering the brain susceptible to headache states.

METHODS AND RESULTS

We collected a body of scientific literature from human and animal investigations that provide a compelling perspective on the anatomical and functional underpinnings of the CNS in migraine and trigeminal autonomic cephalalgias. We focus on medullary, hypothalamic and corticofugal modulation mechanisms that represent strategic neural substrates for elucidating the links between trigeminovascular maladaptive states, migraine triggering and the temporal phenotype of the disease.

CONCLUSION

It is argued that a better understanding of homeostatic dysfunctional states appears fundamental and may benefit the development of personalized therapeutic approaches for improving clinical outcomes in primary headache disorders.

SIGNIFICANCE

This review focuses on the most relevant back and forward translational studies showing the crucial role of top-down brain modulation in triggering and maintaining primary headache states and how these central dysfunctions may interact with personalized pain management strategies.

The Medical Burden of Obesity and Overweight in the US Military: Association of BMI with Clinically Diagnosed Medical Conditions in United States Military Service Members

BACKGROUND

A high BMI is associated with various medical conditions, notably type 2 diabetes, cardiovascular disease, and mental health disorders. In the US military, BMI increased linearly between 1975 and 2015.

OBJECTIVE

This cross-sectional study investigated the associations between BMI and a comprehensive range of clinically diagnosed medical conditions (CDMCs) in US military service members (SMs).

METHODS

A stratified random sample of SMs (n=26,177) completed an online questionnaire reporting their height, weight, and demographic/lifestyle characteristics. Medical conditions for 6 mo before questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 39 CDMCs covering both broad (largely systemic) and specific medical conditions. BMI was calculated as weight/height2 (kg/m2). The prevalence of CDMCs was compared among normal weight (<25.0 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2) SMs.

RESULTS

After multivariable adjustment for demographic/lifestyle characteristics, higher BMI was associated with higher odds of a diagnosed medical condition in 30 of 39 CDMCs, with all 30 displaying dose-response relationships. The 5 major CDMCs with the largest odds ratios comparing obese to normal weight were endocrine/nutritional/metabolic diseases (OR=2.67, 95%CI=2.24-3.15), nervous system diseases (odds ratio [OR]=2.59, 95%CI=2.32-2.90), circulatory system diseases (OR=2.56, 95%CI=2.15-3.06), musculoskeletal system diseases (OR=1.92, 95%CI=1.76-2.09), and mental/behavioral disorders (OR=1.69, 95%CI=1.51-1.90). Compared with normal weight SMs, overweight or obese SMs had a higher number of CDMCs (1.8±1.9 vs. 2.0±2.0 and 2.5±2.3, mean ± standard deviation, respectively, P<0.01).

CONCLUSIONS

In a young, physically active population, higher BMI was associated with a host of medical conditions, even after adjustment for demographic/lifestyle characteristics. The US Department of Defense should improve nutrition education and modify other factors that contribute to overweight and obesity. This study demonstrates that the medical burden of obesity is substantial in overweight and obese SMs.

Comparative Efficacy and Safety of Five Anti-calcitonin Gene-related Peptide Agents for Migraine Prevention: A Network Meta-analysis

OBJECTIVES

Anti-calcitonin gene-related peptide (CGRP) agents are some of the newest preventive medications for migraine. There is limited literature comparing the efficacy of the most recent CGRP antagonist, atogepant, to CGRP monoclonal antibodies for migraine prevention. In this network meta-analysis, the efficacy and safety of migraine treatments including different doses of atogepant and CGRP monoclonal antibodies were evaluated to provide a reference for future clinical trials.

MATERIALS AND METHODS

A search using PubMed, Embase, and Cochrane Library identified all randomized controlled trials published through May 2022 and including patients diagnosed with episodic or chronic migraine and treated with erenumab, fremanezumab, eptinezumab, galcanezumab, atogepant, or placebo. The primary outcomes were the reduction of monthly migraine days, 50% response rate, and the number of adverse events (AEs). The Cochrane Collaboration tool was used to assess the risk of bias.

RESULTS

In this study, 24 articles were considered for analysis. Regarding efficacy, all interventions were superior to placebo with a statistically significant difference. The most effective intervention was monthly fremanezumab 225 mg in change from baseline of migraine days (standard mean difference = -0.49, 95% CI: -0.62, -0.37) and 50% response rate (risk ratio = 2.98, 95% CI: 2.16,4.10), while the optimal choice for reducing acute medication days was monthly erenumab 140 mg (standard mean difference = -0.68, 95% CI: -0.79, -0.58). In terms of AEs, all therapies and placebo did not achieve statistical significance except for monthly galcanezumab 240 mg and quarterly fremanezumab 675 mg. There was no significant difference in discontinuation due to AEs between interventions and placebo.

DISCUSSION

All anti-CGRP agents were more effective than placebo in migraine prevention. Overall, monthly fremanezumab 225 mg, monthly erenumab 140 mg, and daily atogepant 60 mg were effective interventions with fewer side effects.

Treatment of Frequent or Chronic Primary Headaches in Children and Adolescents: Focus on Acupuncture

BACKGROUND

Acupuncture is a spreading and promising intervention, which has proven to be very useful in the treatment and prevention of chronic pain, in particular chronic headaches, in adults; the literature about the treatment of pediatric chronic headaches is scarce. In addition, few guidelines advise its use in children. The aim of this review is to collect all relevant studies with available data about the use, effect, and tolerability of acupuncture as a treatment for pediatric primary headaches.

METHODS

This is a narrative review based on eight studies selected from 135 papers including pediatric cases treated with acupuncture for headache.

RESULTS

Despite the differences in tools, procedures, and application sites, acupuncture demonstrated a positive effect on both the frequency and intensity of headaches and was well tolerated. There are no studies considering the long-term efficacy of acupuncture.

CONCLUSION

Further additional studies are needed on acupuncture in children and adolescents, with larger series and standardized procedures, in order to better assess efficacy, tolerability, and long-term prognosis and to define guidelines for the use of this promising and safe treatment. It is particularly relevant to identify safe and well-tolerated treatment options in pediatric patients affected by recurrent and debilitating headaches.

A Case Report of Migraine With Aura Worsened After Starting Apixaban and Literature Review

INTRODUCTION

Multiple medications have been related to triggering headache attacks or worsening headache frequency or severity in patients with migraine disease. However, the impact of direct oral anticoagulants on headache frequency and severity in patients with migraine disease is unclear. Current literature is scarce and controversial.

CASE REPORT

A 45-year-old male with a history of migraine with aura for the last 20 years underwent percutaneous transcatheter closure of an atrial septal defect due to right ventricular enlargement and systolic dysfunction. The intervention was complicated by postprocedural atrial fibrillation, for which he was started on apixaban. Shortly after starting the apixaban, the patient experienced an increase in the frequency and severity of his migraine with aura episodes that were persistent until he discontinued this medication 7 months later. Following the discontinuation of apixaban, the patient's frequency and severity of migraine episodes returned to baseline almost immediately.

CONCLUSION

Novel oral anticoagulants, including apixaban, may be associated with an increase in the frequency and severity of migraine attacks in patients with migraine disease. Larger observational studies are required to investigate further the impact of direct oral anticoagulants on migraine disease.

The Neuropsychiatric Safety Profile of Lasmiditan: A Comparative Disproportionality Analysis with Triptans

Migraine constitutes the world's second-leading cause of disability. Triptans, as serotonin 5-HT1B/1D receptor agonists, remain the first-line treatment, despite discouraged use in individuals at high cardiovascular risk. Lasmiditan, a selective lipophilic 5-HT1F agonist without vasoconstrictive effects, is an emerging option. We aimed to investigate the safety profile of lasmiditan in the WHO pharmacovigilance database (VigiBase®) using a comparative disproportionality analysis with triptans. VigiBase® was queried for all reports involving lasmiditan and triptans. Disproportionality analyses relied on the calculation of the information component (IC), for which 95% confidence interval (CI) lower bound positivity was required for signal detection. We obtained 826 reports involving lasmiditan. Overall, 10 adverse drug reaction classes were disproportionately reported with triptans, while only neurological (IC 1.6; 95% CI 1.5-1.7) and psychiatric (IC 1.5; 95% CI 1.3-1.7) disorders were disproportionately reported with lasmiditan. Sedation, serotonin syndrome, euphoric mood, and autoscopy had the strongest signals. When compared with triptans, 19 out of 22 neuropsychiatric signals persisted. The results of our analysis provide a more precise semiology of the neuropsychiatric effects of lasmiditan, with symptoms such as autoscopy and panic attacks. The cardiovascular adverse drug reaction risk with triptans was confirmed. In contrast, caution is warranted with lasmiditan use in patients with neurological or psychiatric comorbidities or serotonin syndrome risk. Our study was hindered by pharmacovigilance flaws, and further studies should help in validating these results. Our findings suggest that lasmiditan is a safe alternative for migraine treatment, especially when the neuropsychiatric risk is outweighed by the cardiovascular burden.

Altered resting-state effective connectivity of trigeminal vascular system in migraine without aura: A spectral dynamic causal modeling study

BACKGROUND

The trigeminal vascular system is an important part of the anatomical and physiological basis of migraine. The effective connectivity (EC) among the regions of interest (ROIs) in the trigeminal vascular system involved in migraine without aura (MWoA) remains unclear.

METHODS

In this cross-sectional study, 48 patients (mean [SD] age 38.06 [10.35] years; male, 14/48 [29%]) with MWoA during the interictal phase and 48 healthy controls of similar age and sex (mean [SD] age 38.96 [10.96] years; male, 14/48 [29%]) underwent resting-state functional magnetic resonance imaging (fMRI). Dynamic causal modeling analysis was conducted to investigate directional EC among ROIs in the trigeminal vascular system including the bilateral brainstem, the primary somatosensory cortex (S1), the thalamus, and the insula.

RESULTS

Compared with the healthy control group, MWoA represented significantly reduced EC from the left brainstem (Brainstem.L) to the left insula (MWoA: mean [SD] -0.16 [0.36]; healthy controls: mean [SD] 0.11 [0.41]; Pcorrected  = 0.021), reduced EC from the Brainstem.L to the right insula (MWoA: mean [SD] -0.15 [0.39]; healthy controls: mean [SD] 0.03 [0.35]; Pcorrected  = 0.021), and decreased EC from the left thalamus (Thalamus.L) to the Brainstem.L (MWoA: mean [SD] -0.13 [0.56]; healthy controls: mean [SD] 0.10 [0.45]; Pcorrected  = 0.021). Altered EC parameters were not significantly correlated with MWoA clinical data.

CONCLUSION

These results further provide increasing evidence that disturbed homeostasis of the trigeminovascular nociceptive pathway is involved in the pathophysiological mechanisms of migraine. Patients with MWoA exhibited a regional interaction distinct from healthy controls in the neural pathway of the Bilateral Insula-Brainstem.L-Thalamus.L, which may shed light on the future understanding of brain mechanisms for MWoA. Future brain-based interventions are suggested to consider the dysregulation in the Bilateral Insula-Brainstem.L-Thalamus.L circuits.

Impact of anti-CGRP monoclonal antibodies on migraine attack accompanying symptoms: A real-world evidence study

BACKGROUND

Clinical trials on anti-calcitonin gene-related peptide monoclonal antibodies poorly investigated their impact on migraine accompanying symptoms.

OBJECTIVE

To evaluate the impact of basal accompanying symptoms on anti-CGRP monoclonal antibodies treatment response and their evolution after six months of treatment in migraine patients.

METHODS

Patients with migraine diagnosis seen in the Headache Clinic and treated with erenumab, galcanezumab or fremanezumab were prospectively recruited. They completed a daily eDiary which provided data on headache frequency and the following accompanying symptoms of each day: photophobia, phonophobia, nausea, dizziness, and aura. Patients were classified as responders or non-responders based on 50% or greater reduction in headache days per month at month 6 (≥50% response rate). Accompanying symptoms ratios based on headache days per month were assessed per patient at baseline and after three and six months. Comparisons for basal characteristics, basal accompanying symptoms ratios and their evolution after six months between responders and non-responders were performed.

RESULTS

One hundred and fifty-eight patients were included, 44% (69/158) showed ≥50% response rate after six months. A significant reduction in headache days per month in both groups was found at month 6 (-9.4 days/month in ≥50% response rate group; p < 0.001, -2.2 days/month in <50% response rate group; p = 0.004). Additionally, significant decreases in photophobia (-19.5%, p < 0.001), phonophobia (-12.1%, p = 0.010) and aura ratios (-25.1%, p = 0.008) were found in ≥50% response rate group. No statistically significant reductions were found in nausea and dizziness in any group since their reduction was correlated with the decrease in headache days per month. Higher photophobia ratios at baseline were predictive of an increased response between months 3 and 6 (Incidence Risk Ratio = 0.928, p = 0.040).

CONCLUSIONS

The days per month with photophobia, phonophobia and aura decreased at a higher rate than headache days per month after six months in the ≥50% response group. Higher photophobia ratios were associated with higher response rates between three and six months. It could indicate an involvement of peripheral CGRP in photophobia as well as a central modulation of migraine through these treatments which mainly act on the periphery.

Aromatherapy for the brain: Lavender's healing effect on epilepsy, depression, anxiety, migraine, and Alzheimer's disease: A review article

Neurological diseases affect the nervous system, including the brain, spinal cord, cranial nerves, nerve roots, autonomic nervous system, neuromuscular junctions, and muscles. Herbal medicine has long been used to cure these diseases. One of these plants is lavender, which is composed of various compounds, including terpenes, such as linalool, limonene, triterpenes, linalyl acetate, alcohols, ketones, polyphenols, coumarins, cineole, and flavonoids. In this review, the literature was searched using scientific search engines and databases (Google Scholar, Science Direct, Scopus, and PubMed) for papers published between 1982 and 2020 via keywords, including review, lavender, and neurological disorders. This plant exerts its healing effect on many diseases, such as anxiety and depression through an inhibitory effect on GABA. The anti-inflammatory effects of this plant have also been documented. It improves depression by regulating glutamate receptors and inhibiting calcium channels and serotonergic factors, such as SERT. Its antiepileptic mechanism is due to an increase in the inhibitory effect of GABA and potassium current and a decrease in sodium current. Therefore, many vegetable oils are also used in herbal medicine. In this review, the healing effect of lavender on several neurological disorders, including epilepsy, depression, anxiety, migraine, and Alzheimer's disease was investigated. All findings strongly support the traditional uses of lavender. More clinical studies are needed to investigate the effect of the plants' pharmacological active constituents on the treatment of life-threatening diseases in humans. The limitations of this study are the low quality and the limited number of clinical studies. Different administration methods of lavender are one of the limitations of this review.

Neck pain repercussions in migraine - The role of physiotherapy

INTRODUCTION

Migraine is a neurological and disabling disease whose peripheral manifestations can be addressed with physiotherapy. These manifestations can include pain and hypersensitivity to muscular and articular palpation in the neck and face region, a higher prevalence of myofascial trigger points, limitation in global cervical motion, especially in the upper segment (C1-C2), and forward head posture with worse muscular performance. Furthermore, patients with migraine can present cervical muscle weakness and greater co-activation of antagonists in maximum and submaximal tasks. In addition to musculoskeletal repercussions, these patients can also present balance impairment and a greater risk of falls, especially when chronicity of migraine frequency is present. The physiotherapist is a relevant player in the interdisciplinary team and can help these patients to control and manage their migraine attacks.

PURPOSE

This position paper discusses the most relevant musculoskeletal repercussions of migraine in the craniocervical area under the perspective of sensitization and disease chronification, besides addressing physiotherapy as an important strategy for evaluating and treating these patients.

IMPLICATIONS

Physiotherapy as a non-pharmacological treatment option in migraine treatment may potentially reduce musculoskeletal impairments related to neck pain in this population. Disseminating knowledge about the different types of headaches and the diagnostic criteria can support physiotherapists who compose a specialized interdisciplinary team. Furthermore, it is important to acquire competencies in neck pain assessment and treatment approaches according to the current evidence.

Migraine Treatment: Towards New Pharmacological Targets

Migraine is a debilitating neurological condition affecting millions of people worldwide. Until a few years ago, preventive migraine treatments were based on molecules with pleiotropic targets, developed for other indications, and discovered by serendipity to be effective in migraine prevention, although often burdened by tolerability issues leading to low adherence. However, the progresses in unravelling the migraine pathophysiology allowed identifying novel putative targets as calcitonin gene-related peptide (CGRP). Nevertheless, despite the revolution brought by CGRP monoclonal antibodies and gepants, a significant percentage of patients still remains burdened by an unsatisfactory response, suggesting that other pathways may play a critical role, with an extent of involvement varying among different migraine patients. Specifically, neuropeptides of the CGRP family, such as adrenomedullin and amylin; molecules of the secretin family, such as pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP); receptors, such as transient receptor potential (TRP) channels; intracellular downstream determinants, such as potassium channels, but also the opioid system and the purinergic pathway, have been suggested to be involved in migraine pathophysiology. The present review provides an overview of these pathways, highlighting, based on preclinical and clinical evidence, as well as provocative studies, their potential role as future targets for migraine preventive treatment.

Blocking the CGRP Receptor: Differences across Human Vascular Beds

Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for the treatment of migraine. Here, the effect of the small-molecule CGRP receptor antagonist zavegepant (0.1 nM-1 µM) on CGRP-induced relaxation in isolated human coronary arteries (HCAs) was investigated. A Schild plot was constructed and a pA2 value was calculated to determine the potency of zavegepant. The potency and Schild plot slopes of atogepant, olcegepant, rimegepant, telcagepant, ubrogepant and zavegepant in HCAs and human middle meningeal arteries (HMMAs), obtained from our earlier studies, were compared. Zavegepant shifted the concentration-response curve to CGRP in HCAs. The corresponding Schild plot slope was not different from unity, resulting in a pA2 value of 9.92 ± 0.24. No potency difference between HCAs and HMMAs was observed. Interestingly, olcegepant, atogepant and rimegepant, with a Schild plot slope < 1 in HCAs, were all >1 log unit more potent in HMMAs than in HCAs, while telcagepant, ubrogepant and zavegepant, with a Schild plot slope not different from unity, showed similar (<1 log difference) potency across both tissues. As a Schild plot slope < 1 may point to the involvement of multiple receptors, it is important to further identify the receptors involved in the relaxation to CGRP in HCAs, which may be used to improve the cardiovascular safety of future antimigraine drugs.

Optogenetic cortical spreading depolarization induces headache-related behaviour and neuroinflammatory responses some prolonged in familial hemiplegic migraine type 1 mice

BACKGROUND

Cortical spreading depolarization (CSD), the neurophysiological correlate of the migraine aura, can activate trigeminal pain pathways, but the neurobiological mechanisms and behavioural consequences remain unclear. Here we investigated effects of optogenetically-induced CSDs on headache-related behaviour and neuroinflammatory responses in transgenic mice carrying a familial hemiplegic migraine type 1 (FHM1) mutation.

METHODS

CSD events (3 in total) were evoked in a minimally invasive manner by optogenetic stimulation through the intact skull in freely behaving wildtype (WT) and FHM1 mutant mice. Related behaviours were analysed using mouse grimace scale (MGS) scoring, head grooming, and nest building behaviour. Neuroinflammatory changes were investigated by assessing HMGB1 release with immunohistochemistry and by pre-treating mice with a selective Pannexin-1 channel inhibitor.

RESULTS

In both WT and FHM1 mutant mice, CSDs induced headache-related behaviour, as evidenced by increased MGS scores and the occurrence of oculotemporal strokes, at 30 min. Mice of both genotypes also showed decreased nest building behaviour after CSD. Whereas in WT mice MGS scores had normalized at 24 h after CSD, in FHM1 mutant mice scores were normalized only at 48 h. Of note, oculotemporal stroke behaviour already normalized 5 h after CSD, whereas nest building behaviour remained impaired at 72 h; no genotype differences were observed for either readout. Nuclear HMGB1 release in the cortex of FHM1 mutant mice, at 30 min after CSD, was increased bilaterally in both WT and FHM1 mutant mice, albeit that contralateral release was more pronounced in the mutant mice. Only in FHM1 mutant mice, contralateral release remained higher at 24 h after CSD, but at 48 h had returned to abnormal, elevated, baseline values, when compared to WT mice. Blocking Panx1 channels by TAT-Panx₃₀₈ inhibited CSD-induced headache related behaviour and HMGB1 release.

CONCLUSIONS

CSDs, induced in a minimally invasive manner by optogenetics, investigated in freely behaving mice, cause various migraine relevant behavioural and neuroinflammatory phenotypes that are more pronounced and longer-lasting in FHM1 mutant compared to WT mice. Prevention of CSD-related neuroinflammatory changes may have therapeutic potential in the treatment of migraine.

Management of Migraine-Associated Vestibulocochlear Disorders

Migraine is a chronic neurological disorder that frequently coexists with different vestibular and cochlear symptoms (sudden hearing loss, tinnitus, otalgia, aural fullness, hyperacusis, dizziness, imbalance, and vertigo) and disorders (recurrent benign positional vertigo, persistent postural perceptual dizziness, mal de debarquement, and Menière's disease). Despite evidence of an epidemiological association and similar pathophysiology between migraine and these vestibulocochlear disorders, patients suffering from migraine-related symptoms are usually underdiagnosed and undertreated. Current migraine treatment options have shown success in treating vestibulocochlear symptoms. Lifestyle and dietary modifications (reducing stress, restful sleep, avoiding migraine dietary triggers, and avoiding starvation and dehydration) and supplements (vitamin B2 and magnesium) offer effective first-line treatments. Treatment with migraine prophylactic medications such as tricyclic antidepressants (e.g., nortriptyline), anticonvulsants (e.g., topiramate), and calcium channel blockers (e.g., verapamil) is implemented when lifestyle and dietary modifications are not sufficient in improving a patient's symptoms. We have included an algorithm that outlines a suggested approach for addressing these symptoms, taking into account our clinical observations. Greater recognition and understanding of migraine and its related vestibular and cochlear symptoms are needed to ensure the appropriate diagnosis and treatment of affected patients.

The impact of the COVID-19 pandemic era on children with primary headache: a questionnaire survey study and literature review

Background

The coronavirus disease (COVID-19) pandemic has resulted in individual isolation and secondary problems, especially in children. Research on the effect of the social isolation on children with primary headache is limited. This study aimed at exploring the effects of environmental changes caused by COVID-19 on headache in children.

Methods

This cross-sectional survey study enrolled school-aged children (age, 8-16 years) with headache who were able to complete the questionnaire from a Pediatric Headache Clinic between January 2021 and December 2022. Headache diaries for all patients were in their medical records and two questionnaire responses were requested at a 3-month interval. The questionnaires included headache type, frequency, previous medical conditions, family history, Pediatric Migraine Disability Assessment scores (PedMIDAS) scores, changes in daily life after COVID-19, and factors that aggravated headaches associated with social distancing.

Results

We identified 35 patients who were diagnosed with primary headache and continued to visit our outpatient clinic for at least 3 months. Among them, 33 (15 males and 18 females) patients responded to the first survey. The average age (±SD) of patients was 12.5 ± 1.9 years. PedMIDAS scores were not affected by the COVID-19 infection history. Prolonged use of masks and increased use of digital devices were reported as the most common factors that aggravated headache during the pandemic era.

Conclusion

COVID-19 did not affect in worsening primary headache in children. However, the pandemic can introduce various changes in daily life, which in turn can affect the management of headache. By gathering feedback regarding the thoughts of the patients on the impact of the current pandemic environment, patient counseling on the precautions and management can be conducted in advance in the case of repeated lockdown in the future.

Rare GPR37L1 variants reveal potential roles in anxiety and migraine disorders

GPR37L1 is an orphan receptor that couples through heterotrimeric G-proteins to regulate physiological functions. Since its role in humans is not fully defined, we used an unbiased computational approach to assess the clinical significance of rare GPR37L1 genetic variants found among 51,289 whole exome sequences from the DiscovEHR cohort. Briefly, rare GPR37L1 coding variants were binned according to predicted pathogenicity, and analyzed by Sequence Kernel Association testing to reveal significant associations with disease diagnostic codes for epilepsy and migraine, among others. Since associations do not prove causality, rare GPR37L1 variants were then functionally analyzed in SK-N-MC cells to evaluate potential signaling differences and pathogenicity. Notably, receptor variants exhibited varying abilities to reduce cAMP levels, activate MAPK signaling, and/or upregulate receptor expression in response to the agonist prosaptide (TX14(A)), as compared to the wild-type receptor. In addition to signaling changes, knockout of GPR37L1 or expression of certain rare variants altered cellular cholesterol levels, which were also acutely regulated by administration of the agonist TX14(A) via activation of the MAPK pathway. Finally, to simulate the impact of rare nonsense variants found in the large patient cohort, a knockout (KO) mouse line lacking Gpr37L1 was generated, revealing loss of this receptor produced sex-specific changes implicated in migraine-related disorders. Collectively, these observations define the existence of rare GPR37L1 variants in the human population that are associated with neuropsychiatric conditions and identify the underlying signaling changes that are implicated in the in vivo actions of this receptor in pathological processes leading to anxiety and migraine.

SIGNIFICANCE STATEMENT

G-protein coupled receptors (GPCRs) represent a diverse group of membrane receptors that contribute to a wide range of diseases and serve as effective drug targets. However, a number of these receptors have no identified ligands or functions, i.e., orphan receptors. Over the past decade, advances have been made, but there is a need for identifying new strategies to reveal their roles in health and disease. Our results highlight the utility of rare variant analyses of orphan receptors for identifying human disease associations, coupled with functional analyses in relevant cellular and animal systems, to ultimately reveal their roles as novel drug targets for treatment of neurological disorders that lack wide-spread efficacy.

Course of Headaches and Predictive Factors Associated With Analgesia Failure Following Spontaneous Subarachnoid Hemorrhage: A Prospective Cohort Study

BACKGROUND

Headache is the most common presenting symptom of spontaneous subarachnoid hemorrhage and managing this acute pain can be challenging. The aim of this study was to describe the course of headaches and factors associated with analgesic failure in patients with spontaneous subarachnoid hemorrhage.

METHODS

We conducted a prospective observational study in patients admitted to a neurocritical care unit (between April 2016 and March 2017) within 48 hours of spontaneous subarachnoid hemorrhage. Headache intensity was assessed using a Numerical Pain Rating Scale (NPRS) ranging from 0 to 10. Analgesic failure was defined as any day average NPRS score >3 after 72 hours of hospitalization despite analgesic treatment.

RESULTS

Sixty-three patients were included in the analysis. Thirty-six (56.25%) patients experienced at least 1 episode of severe headache (NPRS ≥7), and 40 (63.5%) patients still reported moderate to severe headache on the final day of the study (day 12). Forty-six (73.0%) patients required treatment with opioids and 37 (58.7%) experienced analgesic failure. Multivariable analysis showed that analgesic failure was associated with smoking history (odds ratio [OR]=4.31, 95% confidence interval [CI]: 1.23-17.07; P =0.027), subarachnoid blood load (OR=1.11, 95% CI: 1.01-1.24; P =0.032) and secondary complications, including rebleeding, hydrocephalus, delayed cerebral ischemia, hyponatremia, or death (OR=4.06, 95% CI: 1.17-15.77; P =0.032).

CONCLUSIONS

Headaches following spontaneous subarachnoid hemorrhage are severe and persist during hospitalization despite standard pain-reducing strategies. We identified risk factors for analgesic failure in this population.

Botulinum toxin A decreases neural activity in pain-related brain regions in individuals with chronic ocular pain and photophobia

Introduction

To examine the effect of botulinum toxin A (BoNT-A) on neural mechanisms underlying pain and photophobia using functional magnetic resonance imaging (fMRI) in individuals with chronic ocular pain.

Methods

Twelve subjects with chronic ocular pain and light sensitivity were recruited from the Miami Veterans Affairs eye clinic. Inclusion criteria were: (1) chronic ocular pain; (2) presence of ocular pain over 1 week recall; and (3) presence of photophobia. All individuals underwent an ocular surface examination to capture tear parameters before and 4-6 weeks after BoNT-A injections. Using an event-related fMRI design, subjects were presented with light stimuli during two fMRI scans, once before and 4-6 weeks after BoNT-A injection. Light evoked unpleasantness ratings were reported by subjects after each scan. Whole brain blood oxygen level dependent (BOLD) responses to light stimuli were analyzed.

Results

At baseline, all subjects reported unpleasantness with light stimulation (average: 70.8 ± 32.0). Four to six weeks after BoNT-A injection, unpleasantness scores decreased (48.1 ± 33.6), but the change was not significant. On an individual level, 50% of subjects had decreased unpleasantness ratings in response to light stimulation compared to baseline ("responders," n = 6), while 50% had equivalent (n = 3) or increased (n = 3) unpleasantness ("non-responders"). At baseline, several differences were noted between responders and non-responders; responders had higher baseline unpleasantness ratings to light, higher symptoms of depression, and more frequent use of antidepressants and anxiolytics, compared to non-responders. Group analysis at baseline displayed light-evoked BOLD responses in bilateral primary somatosensory (S1), bilateral secondary somatosensory (S2), bilateral anterior insula, paracingulate gyrus, midcingulate cortex (MCC), bilateral frontal pole, bilateral cerebellar hemispheric lobule VI, vermis, bilateral cerebellar crus I and II, and visual cortices. BoNT-A injections significantly decreased light evoked BOLD responses in bilateral S1, S2 cortices, cerebellar hemispheric lobule VI, cerebellar crus I, and left cerebellar crus II. BoNT-A responders displayed activation of the spinal trigeminal nucleus at baseline where non-responders did not.

Discussion

BoNT-A injections modulate light-evoked activation of pain-related brain systems and photophobia symptoms in some individuals with chronic ocular pain. These effects are associated with decreased activation in areas responsible for processing the sensory-discriminative, affective, dimensions, and motor responses to pain.

Inhibiting neuronal AC1 for treating anxiety and headache in the animal model of migraine

Migraines are a common medical condition. From a basic science point of view, the central mechanism for migraine and headache is largely unknown. In the present study, we demonstrate that cortical excitatory transmission is significantly enhanced in the anterior cingulate cortex (ACC)-a brain region which is critical for pain perception. Biochemical studies found that the phosphorylation levels of both the NMDA receptor GluN2B and AMPA receptor GluA1 were enhanced in ACC of migraine rats. Both the presynaptic release of glutamate and postsynaptic responses of AMPA receptors and NMDA receptors were enhanced. Synaptic long-term potentiation (LTP) was occluded. Furthermore, behavioral anxiety and nociceptive responses were increased, which were reversed by application of AC1 inhibitor NB001 within ACC. Our results provide strong evidence that cortical LTPs contribute to migraine-related pain and anxiety. Drugs that inhibit cortical excitation such as NB001 may serve as potential medicines for treating migraine in the future.

Arterial spin labeling MRI applied to migraine: current insights and future perspectives

INTRODUCTION

Advanced neuroimaging techniques have extensively contributed to elucidate the complex mechanisms underpinning the pathophysiology of migraine, a neurovascular disorder characterized by episodes of headache associated with a constellation of non-pain symptoms. The present manuscript, summarizing the most recent progresses of the arterial spin labelling (ASL) MRI techniques and the most significant findings from ASL studies conducted in migraine, is aimed to clarify how ASL investigations are contributing to the evolving insight on migraine pathophysiology and their putative role in migraine clinical setting. ASL techniques, allowing to quantitatively demonstrate changes in cerebral blood flow (CBF) both during the attacks and in the course of interictal period, could represent the melting point between advanced neuroimaging investigations, conducted with pure scientific purposes, and conventional neuroimaging approaches, employed in the diagnostic decision-making processes.

MAIN BODY

Converging ASL evidences have demonstrated that abnormal CBF, exceeding the boundaries of a single vascular territory, with biphasic trend dominated by an initial hypoperfusion (during the aura phenomenon but also in the first part of the headache phase) followed by hyperperfusion, characterizes migraine with aura attack and can represent a valuable clinical tool in the differential diagnosis from acute ischemic strokes and epileptic seizures. Studies conducted during migraine without aura attacks are converging to highlight the involvement of dorsolateral pons and hypothalamus in migraine pathophysiology, albeit not able to disentangle their role as "migraine generators" from mere attack epiphenomenon. Furthermore, ASL findings tend to support the presence of perfusion abnormalities in brain regions known to be involved in aura ignition and propagation as well as in areas involved in multisensory processing, in both patients with migraine with aura and migraine without aura.

CONCLUSION

Although ASL studies have dramatically clarified quality and timing of perfusion abnormalities during migraine with aura attacks, the same cannot be said for perfusion changes during migraine attacks without aura and interictal periods. Future studies with more rigorous methodological approaches in terms of study protocol, ASL technique and sample selection and size are mandatory to exploit the possibility of better understanding migraine pathophysiology and identifying neuroimaging biomarkers of each migraine phase in different migraine phenotypes.

Burden of migraine with acute medication overuse or psychiatric comorbidities and treatment with CGRP pathway-targeted monoclonal antibodies: A review

Migraine is a complex and often debilitating neurological disease that affects more than 1 billion people worldwide. It is characterized by moderate-to-intense, throbbing headache attacks that are worsened by activity and is associated with nausea, vomiting, and sensitivity to light and sound. Migraine, ranked the second leading cause of years lived with disability by the World Health Organization, can diminish patients' quality of life and bring significant personal and economic burden. Furthermore, migraine patients with a history of acute medication overuse (AMO) or psychiatric comorbidities, such as depression or anxiety, may experience even greater impairment and burden, and their migraine may be more difficult-to-treat. Appropriate treatment of migraine is essential to reduce this burden and improve patient outcomes, especially for those with AMO or psychiatric comorbidities. There are several available preventive treatment options for migraine, though many of these are not migraine-specific and may have limited efficacy and/or poor tolerability. The calcitonin gene-related peptide pathway plays a key role in the pathophysiology of migraine, and monoclonal antibodies that target the calcitonin gene-related peptide pathway have been developed as specific preventive treatments for migraine. Four of these monoclonal antibodies have been approved for the preventive treatment of migraine after demonstrating favorable safety and efficacy profiles. These treatments offer substantial benefits for migraine patients, including those with AMO or common psychiatric comorbidities, by reducing monthly headache days and migraine days, days of acute medication use, and disability measures, as well as improving quality of life.

Nonpharmacological modulation of cortical spreading depolarization

AIMS

Cortical spreading depolarization (CSD) is a wave of pathologic neuronal dysfunction that spreads through cerebral gray matter, causing neurologic disturbance in migraine and promoting lesion development in acute brain injury. Pharmacologic interventions have been found to be effective in migraine with aura, but their efficacy in acutely injured brains may be limited. This necessitates the assessment of possible adjunctive treatments, such as nonpharmacologic methods. This review aims to summarize currently available nonpharmacological techniques for modulating CSDs, present their mechanisms of action, and provide insight and future directions for CSD treatment.

MAIN METHODS

A systematic literature review was performed, generating 22 articles across 3 decades. Relevant data is broken down according to method of treatment.

KEY FINDINGS

Both pharmacologic and nonpharmacologic interventions can mitigate the pathological impact of CSDs via shared molecular mechanisms, including modulating K⁺/Ca²⁺/Na⁺/Cl^- ion channels and NMDA, GABA_A, serotonin, and CGRP ligand-based receptors and decreasing microglial activation. Preclinical evidence suggests that nonpharmacologic interventions, including neuromodulation, physical exercise, therapeutic hypothermia, and lifestyle changes can also target unique mechanisms, such as increasing adrenergic tone and myelination and modulating membrane fluidity, which may lend broader modulatory effects. Collectively, these mechanisms increase the electrical initiation threshold, increase CSD latency, slow CSD velocity, and decrease CSD amplitude and duration.

SIGNIFICANCE

Given the harmful consequences of CSDs, limitations of current pharmacological interventions to inhibit CSDs in acutely injured brains, and translational potentials of nonpharmacologic interventions to modulate CSDs, further assessment of nonpharmacologic modalities and their mechanisms to mitigate CSD-related neurologic dysfunction is warranted.

Unusually Severe Bout in a Patient With a History of Cluster Headache Associated With COVID-19: A Case Report and Review of the Literature

Although coronavirus disease 2019 (COVID-19) mainly exhibits respiratory symptoms, neurological symptoms are also reported, with headache being the most common neurological symptom. Headache associated with COVID-19 is widely reported. However, there are few precise case reports concerning headaches in patients with a history of migraine, tension headaches, or cluster headaches associated with COVID-19. Herein, we report a case of a woman with a history of cluster headaches who showed an unusually severe bout 10 days before typical COVID-19 symptoms. Such a case has not been reported until now.

Neuropeptide Y in the medial habenula alleviates migraine-like behaviors through the Y1 receptor

BACKGROUND

Migraine is a highly disabling health burden with multiple symptoms; however, it remains undertreated because of an inadequate understanding of its neural mechanisms. Neuropeptide Y (NPY) has been demonstrated to be involved in the modulation of pain and emotion, and may play a role in migraine pathophysiology. Changes in NPY levels have been found in patients with migraine, but whether and how these changes contribute to migraine is unknown. Therefore, the purpose of this study was to investigate the role of NPY in migraine-like phenotypes.

METHODS

Here, we used intraperitoneal injection of glyceryl trinitrate (GTN, 10 mg/kg) as a migraine mouse model, which was verified by light-aversive test, von Frey test, and elevated plus maze test. We then performed whole-brain imaging with NPY-GFP mice to explore the critical regions where NPY was changed by GTN treatment. Next, we microinjected NPY into the medial habenula (MHb), and further infused Y1 or Y2 receptor agonists into the MHb, respectively, to detect the effects of NPY in GTN-induced migraine-like behaviors.

RESULTS

GTN effectively triggered allodynia, photophobia, and anxiety-like behaviors in mice. After that, we found a decreased level of GFP⁺ cells in the MHb of GTN-treated mice. Microinjection of NPY attenuated GTN-induced allodynia and anxiety without affecting photophobia. Furthermore, we found that activation of Y1-but not Y2-receptors attenuated GTN-induced allodynia and anxiety.

CONCLUSIONS

Taken together, our data support that the NPY signaling in the MHb produces analgesic and anxiolytic effects through the Y1 receptor. These findings may provide new insights into novel therapeutic targets for the treatment of migraine.

Evaluation of External Trigeminal Nerve Stimulation to Prevent Cerebral Vasospasm after Subarachnoid Hemorrhage Due to Aneurysmal Rupture: A Randomized, Double-Blind Proof-of-Concept Pilot Trial (TRIVASOSTIM Study)

Cerebral vasospasm remains the most frequent and devastating complication after subarachnoid aneurysmal hemorrhage because of secondary cerebral ischemia and its sequelae. The underlying pathophysiology involves vasodilator peptide release (such as CGRP) and nitric oxide depletion at the level of the precapillary sphincters of the cerebral (internal carotid artery network) and dural (external carotid artery network) arteries, which are both innervated by craniofacial autonomic afferents and tightly connected to the trigeminal nerve and trigemino-cervical nucleus complex. We hypothesized that trigeminal nerve modulation could influence the cerebral flow of this vascular network through a sympatholytic effect and decrease the occurrence of vasospasm and its consequences. We conducted a prospective double-blind, randomized controlled pilot trial to compare the effect of 10 days of transcutaneous electrical trigeminal nerve stimulation vs. sham stimulation on cerebral infarction occurrence at 3 months. Sixty patients treated for aneurysmal SAH (World Federation of Neurosurgical Societies scale between 1 and 4) were included. We compared the radiological incidence of delayed cerebral ischemia (DCI) on magnetic resonance imaging (MRI) at 3 months in moderate and severe vasospasm patients receiving trigeminal nerve stimulation (TNS group) vs. sham stimulation (sham group). Our primary endpoint (the infarction rate at the 3-month follow-up) did not significantly differ between the two groups (p = 0.99). Vasospasm-related infarctions were present in seven patients (23%) in the TNS group and eight patients (27%) in the sham group. Ultimately, we were not able to show that TNS can decrease the rate of cerebral infarction secondary to vasospasm occurrence. As a result, it would be premature to promote trigeminal system neurostimulation in this context. This concept should be the subject of further research.

Multiple Chemical Sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersensitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psychosocial influences. The development of MCS may be attributed to the sensitization of transient receptor potential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

Migraine and the Gender Divide

Migraine is a global neurologic disease that is highly prevalent, especially in women. Studies have observed a predisposition for the development of migraine in women, although the mechanisms involved have yet to be fully elucidated. This review aimed to summarize the recent evidence regarding the epidemiology, pathophysiology, and treatment of migraine and highlight key sex differences. We also identify gaps in care for both women and men living with migraine and discuss the presence of migraine-related stigma and how this may impact the efficacy of clinical care.

Targeting Nociceptive Neurons and Transient Receptor Potential Channels for the Treatment of Migraine

Migraine is a neurovascular disorder that affects approximately 12% of the global population. While its exact causes are still being studied, researchers believe that nociceptive neurons in the trigeminal ganglia play a key role in the pain signals of migraine. These nociceptive neurons innervate the intracranial meninges and convey pain signals from the meninges to the thalamus. Targeting nociceptive neurons is considered promising due to their accessibility and distinct molecular profile, which includes the expression of several transient receptor potential (TRP) channels. These channels have been linked to various pain conditions, including migraine. This review discusses the role and mechanisms of nociceptive neurons in migraine, the challenges of current anti-migraine drugs, and the evidence for well-studied and emerging TRP channels, particularly TRPC4, as novel targets for migraine prevention and treatment.

Emerging drugs for the preventive treatment of migraine: a review of CGRP monoclonal antibodies and gepants trials

INTRODUCTION

Migraine is a leading cause of years lived with disability and preventive strategies represent a mainstay to reduce health-related disability and improve quality of life of migraine patients. Until a few years ago, migraine prevention was based on drugs developed for other clinical indications and relocated in the migraine therapeutic armamentarium, characterized by unfavourable tolerability profiles. The advent of monoclonal antibodies against Calcitonin Gene-Related Peptide (CGRP) and gepants, CGRP receptor antagonists, has been a turning point in migraine prevention owing to advantageous efficacy, safety and tolerability profiles.Nevertheless, while in an ideal scenario a drug characterized by significant greater efficacy and tolerability compared to existing therapeutic strategies should be adopted as a first-line treatment, cost-effectiveness analyses available for monoclonal antibodies against CGRP pathway tend to limit their administration to more severe migraine phenotypes.

AREAS COVERED

The present narrative review aim to provide a critical appraisal of phase II and III CGRP-mAbs and gepants trials to analyse their use in clinical practice.

EXPERT OPINION

Despite monoclonal antibodies against CGRP pathway and gepants can be undoubtedly considered top-of-the-range treatments, there are still issues deserving to be addressed in the coming years as the risk of off-target effects as well as their economic sustainability based on the considerable migraine burden.

Enlightening the association between TNF-α -308 G > A and migraine: a meta-analysis with meta-regression and trial sequential analysis

BACKGROUND

Migraine is a complex neurological disorder that is characterized by a "lower threshold of neuronal hyperexcitability" with distinctive periodicity and complex vascular dysfunction. Genetic factors have impacted incredibly on the susceptibility of migraine and one such example is the TNF-α 308G > A.

AIM

Therefore, we aim to provide a glimpse of the association of the TNF-α 308G > A risk on the susceptibility of migraine.

METHOD

The pooled odds ratio with the associated 95% of confidence interval were calculated using different genetic models. Heterogeneity was accessed by using Cochran's Q Test and I² statistics and Begg's and Egger's tests were used for finding the publication bias, tests were two-sided, and a p-value of < 0.05 was considered statistically significant. The Trial Sequential Analysis with Meta-regression Analysis were also utilized to find out the sample size requirement for meta-analysis to avoid type I error and source of heterogeneity respectively.

RESULT

A total of 13 studies with cases: 7193 and controls: 23,091 were included and after using different genetic models, no overall association with migraine and its clinical subtype migraine with aura was observed (Allele model "OR: 1.28, 95% C.I. [0.96-1.69] and OR: 0.99,95% C.I. [0.69-1.42]) respectively. Interestingly, after sub-grouping using the "ethnicity criteria" in the migraine group, it was observed that the allelic genetic model and the dominant model were found to be significantly associated with the Asian ethnic group (OR: 1.79, 95% C.I. [1.13-2.84], and OR: 1.85, 95% C.I. [1.0927; 3.1580].

CONCLUSION

In conclusion, the present meta-analysis has provided evidence that 308G > A increases the risk of migraine only in the Asian population.