Pathophysiology and Therapy of Associated Features of Migraine

Neural Interconnections of Extracranial Nerves in Headache Surgery: Anatomical Landmarks and Clinical Implications: A Review of the Literature

SUMMARY

Headache disorders (HDs) remain a nationwide challenge for the US health care system, affecting nearly 60% of the US population. Surgical deactivation of the peripheral trigger site, also referred to as headache surgery, represents an effective treatment for patients with refractory HD pain or nonresponse to pharmacologic regimens. Research stemming from other surgical specialties has underlined the clinical relevance of neural interconnections in refining diagnostic algorithms, adapting surgical techniques, and improving overall patient outcomes. Different HD trigger points have been identified, but there is a paucity of studies discussing the mostly sensory neural interconnections between these trigger points in a comprehensive fashion. The authors provide an overview of the specific nerves involved in HD and synthesize the literature on HD nerve interconnections to deduce clinical implications. Overall, this line of research may help refine the perioperative workflow and enhance HD patient care.

A post hoc analysis of migraine-associated symptoms from the phase 3 randomized, double-blind, sham-controlled Trial of External trigeminal nerve stimulation for the Acute treatment of Migraine (TEAM) study

BACKGROUND

The Trial of External trigeminal nerve stimulation (eTNS) for the Acute treatment of Migraine (TEAM) study demonstrated that eTNS use during active migraine resulted in significantly higher rates of resolution of migraine-associated most bothersome symptom (MBS) compared to sham. However, no previous studies have examined the association between pretreatment MBS subtype and efficacy of eTNS treatment for active migraine.

OBJECTIVE

We conducted a post hoc analysis examining efficacy of eTNS for different pretreatment MBS subtypes using TEAM study data.

METHODS

Pretreatment MBS subtypes included photophobia (n = 345), nausea (n = 109), phonophobia (n = 73), and vomiting (n = 11). We examined MBS sub-group × treatment group (verum n = 259; sham n = 279) interaction for each post-treatment outcome to explore differential effects conditional on the total sample. We further explored direct, between treatment group comparisons for each MBS subtype, as well as compared treatment outcomes among all MBS subtypes within the sham, verum, and total sample. Finally, clinical heterogeneity of treatment effect (HTE) was assessed using a 1% absolute treatment effect difference as the clinically important threshold.

RESULTS

Significant sub-group × treatment interactions were found for resolution of MBS at 2 h (p = 0.008), pain relief at 2 h (p = 0.001), rescue medication between 2 and 24 h (p = 0.012), sustained pain freedom at 24 h (p = 0.033), and sustained pain relief at 24 h (p = 0.003). Significant sub-group × treatment interactions were not found for pain freedom at 2 h (p = 0.054) or absence of all symptoms at 2 h (p = 0.265). Between treatment group comparisons indicated that pain freedom after 2 h of eTNS was not significantly different between the verum and sham groups for any pretreatment MBS. The verum group had a significantly greater proportion of participants who had resolution of nausea MBS after 2 h of treatment compared to sham (37/55 [67.3%] vs. 25/54 [46.3%], respectively; p = 0.028) and resolution of photophobia MBS compared to sham (85/162 [52.5] vs. 71/183 [38.8%], respectively; p = 0.011). There were no significant differences between treatment groups for phonophobia or vomiting. Pain freedom after 2 h of eTNS was not significantly different among pretreatment MBS groups. Within the sham group and total sample, a greater proportion of participants who had vomiting MBS had resolution of their MBS compared to any other pretreatment MBS (p < 0.05 after Bonferroni adjustment). A greater proportion of participants with nausea MBS used rescue medications between 2 and 24 h after eTNS compared to participants with photophobia or phonophobia MBS within the verum and total sample (p < 0.05 after Bonferroni adjustment). No statistical differences were found among MBS groups for any other treatment outcomes. Clinically important HTE was present in vomiting MBS for resolution of MBS and present in nausea MBS for pain freedom and pain relief after 2 h, need for rescue medication, and sustained pain freedom at 24 h post-treatment. There was no clinically relevant HTE in the nausea MBS group for resolution of MBS at 2 h, absence of all migraine-associated symptoms and sustained pain relief at 24 h, or for any endpoint for other MBS subtypes.

CONCLUSION

Our results suggest the presence of both statistically significant HTE as well as clinically meaningful HTE. Statistical differences were primarily found for photophobia MBS, while clinically meaningful HTE was primarily found for nausea MBS. These findings may be clinically relevant for patients and clinicians when developing a treatment plan for acute treatment of migraine. Further studies are needed to elucidate the underlying pathophysiological differences between MBS subtypes and treatment optimization, particularly for patients with nausea MBS subtypes.

Different effects of migraine associated features on headache impact, pain intensity, and psychiatric conditions in patients with migraine

Migraine is a multifactorial brain disorder characterized by recurrent disabling headaches and their associated features. Several studies have suggested that these features are related to headache impact, pain intensity, and psychiatric conditions. However, differences in the relationship between each associated feature and headache impact, pain intensity, or psychiatric conditions remain unclear. This study aimed to assess the impact of migraine-associated features on headache impact, pain intensity, and psychiatric conditions in patients with migraine. In this two-centered study, patients with migraine without aura (MwoA) were enrolled to exclude those without headaches and avoid the influence of medication overuse, which is commonly associated with chronic migraine. We used multiple logistic regression to analyze the headache impact, pain intensity, and psychiatric conditions measured using the Headache Impact Test (HIT-6), Visual Analog Scale (VAS), Generalized Anxiety Disorder 7-item scale (GAD-7), and Patient Health Questionnaire-9 (PHQ-9). Patients' likelihood of experiencing symptoms such as nausea, vomiting, photophobia, phonophobia, osmophobia, and allodynia were also recorded. A total of 1103 patients with MwoA were enrolled in this study, and 164 patients were excluded from the study because of missing data. Finally, 939 patients with MwoAs were included. On multiple logistic regression analyses, nausea (odd ratios [OR] 1.87, confidence interval [CI]: 1.37-2.54), vomiting (OR 1.57, CI: 1.11-2.23), photophobia (OR 1.67, CI: 1.18-2.35), and allodynia (OR 1.56, CI: 1.06-2.28) were independent positive predictors of higher HIT-6 scores, and nausea (OR 1.72, CI: 1.22-2.43), vomiting (OR 1.84, CI: 1.29-2.63), phonophobia (OR 1.58, CI: 1.10-2.25), photophobia (OR 1.49, CI: 1.07-2.08), and allodynia (OR 1.81, CI: 1.24-2.66) were independent positive predictors of higher VAS score. Nausea (OR 1.49, CI: 1.09-2.02), phonophobia (OR 2.00, CI: 1.42-2.82), and allodynia (OR 1.81, CI: 1.24-2.63) were independent positive predictors of GAD-7 score. Nausea (OR 1.66, CI: 1.21-2.28), phonophobia (OR 1.49, CI: 1.05-2.11), and allodynia (OR 1.68, CI: 1.16-2.45) were independent positive predictors and vomiting (OR 0.54, CI: 0.37-0.78) was an independent negative predictor of PHQ-9 score. Our results suggest that nausea, vomiting, photophobia, phonophobia, and osmophobia have distinct effects on headache impact, pain intensity, and psychiatric conditions. Understanding these differences can aid in the personalized management of patients with MwoA.

Antimigraine activity of Asarinin by OPRM1 pathway with multifaceted impacts through network analysis

Migraine is a debilitating neurological disorder impacting millions worldwide. Calcitonin Gene-Related Peptide (CGRP) has emerged as a key player in migraine pathophysiology, leading to the development of targeted therapies. This study reviews novel CGRP-targeted treatments, including monoclonal antibodies small molecule inhibitors/nutraceuticals and introduces Asarinin as a potential modulator of the pathway. Asarinin, a natural compound found in various plants, is examined for its pharmacological potential in migraine management. Pharmacokinetic assessments, toxicological modelling, molecular property analysis, and network pharmacology were conducted. Molecular docking and dynamics studies with CGRP reveal potential interactions, providing a foundation for understanding Asarinin's therapeutic effects. Asarinin's favourable pharmacokinetics, safety profile, and bioactivity, supporting its candidacy as a therapeutic agent. In-depth molecular docking studies with the CGRP receptor (PDB: 6ZHO) demonstrate strong binding affinity (- 10.3kcal/mol), while molecular dynamics simulations unveil the dynamic behavior of the Asarinin-CGRP complex, (- 10.53 kcal/mol) for Atogepant-CGRP complex. Network analysis highlights key proteins in migraine pathology, indicating Asarinin's potential efficacy. The groundwork for future investigations, suggests Asarinin as a promising candidate for migraine management by targeting OPRM1 pathway. The integration of diverse assessments provides a comprehensive understanding of Asarinin's potential and paves the way for further preclinical and clinical research.

Children and adolescents with primary headaches exhibit altered sensory profiles - a multi-modal investigation

BACKGROUND

Pediatric headache is an increasing medical problem that has adverse effects on children's quality of life, academic performance, and social functioning. Children with primary headaches exhibit enhanced sensory sensitivity compared to their healthy peers. However, comprehensive investigations including multimodal sensory sensitivity assessment are lacking. This study aimed to compare sensory sensitivity of children with primary headaches with their healthy peers across multiple sensory domains.

METHODS

The study included 172 participants aged 6 to 17 years (M = 13.09, SD = 3.02 years; 120 girls). Of these 80 participants were patients with migraine, 23 were patients with tension-type headache, and 69 were healthy controls. The following sensory measures were obtained: Mechanical Detection Threshold (MDT), Mechanical Pain Threshold (MPT), Mechanical Pain Sensitivity (MPS), detection and pain threshold for Transcutaneous Electrical Nerve Stimulation (TENS), olfactory and intranasal trigeminal detection threshold, and odor identification ability. Sensory sensitivity was compared between groups with a series of Kruskal-Wallis tests. Binomial regression models were used to compare the relative utility of sensory sensitivity measures in classifying participants into patients and healthy controls, as well as into patients with migraine and tension-type headache.

RESULTS

Patients with migraine had lower MPT measured at the forearm than patients with tension-type headaches and healthy controls. MPS was higher in patients with migraine than in healthy controls. All patients with headaches had lower detection threshold of TENS and higher olfactory sensitivity. Healthy controls showed increased intranasal trigeminal sensitivity. Scores in MPS, TENS, and olfactory and trigeminal thresholds were significantly predicting presence of primary headaches. Additionally, scores in MPT, olfactory and trigeminal threshold were positive predictors of type of headache.

CONCLUSIONS

Children with primary headaches exhibit different sensory profiles than healthy controls. The obtained results suggest presence of increased overall, multimodal sensitivity in children with primary headaches, what may negatively impact daily functioning and contribute to further pain chronification.

TRIAL REGISTRATION

The study was registered in the German Registry of Clinical Trials (DRKS) DRKS00021062.

Navigating the Neurobiology of Migraine: From Pathways to Potential Therapies

Migraine is a debilitating neurological disorder characterized by recurring episodes of throbbing headaches that are frequently accompanied by sensory disturbances, nausea, and sensitivity to light and sound [...].

Latent class analysis of migraine associated vestibular-auditory symptoms

OBJECTIVE

This study aimed to identify the potential subgroups of migraines based on the patterns of migraine associated symptoms, vestibular and auditory symptoms using latent class analysis and to explore their characteristics.

METHOD

A total of 555 patients with migraine participated in the study. Symptoms such as nausea, vomiting, photophobia, phonophobia, osmophobia, visual symptoms, vestibular symptoms (dizziness, vertigo), and auditory symptoms (tinnitus, hearing loss, aural fullness) were assessed. Latent class analysis was performed to identify subgroups of migraines. Covariates such as gender, age of migraine onset, frequency of migraine attacks per month, and family history were also considered.

RESULTS

The analysis revealed four latent classes: the Prominent Vestibular; Prominent Nausea; Presenting Symptoms but not prominent or dominant; and Sensory Hypersensitivity groups. Various covariates, such as gender, age of migraine onset, and frequency of migraine attacks, demonstrated significant differences among the four groups. The Sensory Hypersensitivity group showed the presence of multiple sensory symptoms, earlier age of migraine onset, and higher proportion of females. The Prominent Vestibular group had the highest probability of dizziness or vertigo but lacked the presence of auditory symptoms. The Prominent Nausea group exhibited prominent nausea. The Presenting Symptoms but not prominent or dominant group comprised individuals with the highest migraine attacks per month and proportion of chronic migraine.

CONCLUSION

This study identifies four subgroups of migraines based on the patterns of symptoms. The findings suggest potential different but overlapped mechanisms behind the vestibular and auditory symptoms of migraine. Considering the different patterns of migraine-related symptoms may provide deeper insights for patients' prognosis and clinical decision-making.

Vestibular migraine: an update

PURPOSE OF REVIEW

We performed a narrative review of the recent findings in epidemiology, clinical presentation, mechanisms and treatment of vestibular migraine.

RECENT FINDINGS

Vestibular migraine is an underdiagnosed condition that has a high prevalence among general, headache and neuro-otology clinics. Vestibular migraine has a bimodal presentation probably associated with a hormonal component in women. These patients could have a complex clinical phenotype including concomitant autonomic, inflammatory or connective tissue conditions that have a higher prevalence of psychological symptoms, which may mistakenly lead to a diagnosis of a functional neurological disorder. A high proportion of patients with postural perceptual persistent dizziness have a migraine phenotype. Independently of the clinical presentation and past medical history, patients with the vestibular migraine phenotype can respond to regular migraine preventive treatments, including those targeting the calcitonin gene-related peptide pathways.

SUMMARY

Vestibular migraine is an underdiagnosed migraine phenotype that shares the pathophysiological mechanisms of migraine, with growing interest in recent years. A thorough anamnesis is essential to increase sensitivity in patients with unknown cause of dizziness and migraine treatment should be considered (see supplemental video-abstract).

Global trends and hotspots in pain associated with bipolar disorder in the last 20 years: a bibliometric analysis

Purpose

The prevalence of comorbid pain and Bipolar Disorder in clinical practice continues to be high, with an increasing number of related publications. However, no study has used bibliometric methods to analyze the research progress and knowledge structure in this field. Our research is dedicated to systematically exploring the global trends and focal points in scientific research on pain comorbidity with bipolar disorder from 2003 to 2023, with the goal of contributing to the field.

Methods

Relevant publications in this field were retrieved from the Web of Science core collection database (WOSSCC). And we used VOSviewer, CiteSpace, and the R package "Bibliometrix" for bibliometric analysis.

Results

A total of 485 publications (including 360 articles and 125 reviews) from 66 countries, 1019 institutions, were included in this study. Univ Toront and Kings Coll London are the leading research institutions in this field. J Affect Disorders contributed the largest number of articles, and is the most co-cited journal. Of the 2,537 scholars who participated in the study, Stubbs B, Vancampfort D, and Abdin E had the largest number of articles. Stubbs B is the most co-cited author. "chronic pain," "neuropathic pain," "psychological pain" are the keywords in the research.

Conclusion

This is the first bibliometric analysis of pain-related bipolar disorder. There is growing interest in the area of pain and comorbid bipolar disorder. Focusing on different types of pain in bipolar disorder and emphasizing pain management in bipolar disorder are research hotspots and future trends. The study of pain related bipolar disorder still has significant potential for development, and we look forward to more high-quality research in the future.

Beyond Pain: The Effects of OnabotulinumtoxinA Therapy on Sensitization and Interictal Symptoms in Chronic Migraine

Chronic migraine is a disease with a high burden on patients from both a working and quality of life point of view. The pathophysiology of this subtype of migraine is due to several factors, such as medication overuse. Nevertheless, the detrimental recurring of headache attacks with central and peripheral sensitization plays a central role and explains some additional symptoms complained about by these patients even in the interictal phase. OnabotulinumtoxinA is a therapy indicated for chronic migraine since it has proven to reduce peripheral sensitization, showing even efficacy on central symptoms. The aim of this narrative review is to present the current evidence regarding the effect of OnabotulinumtoxinA on sensitization and interictal symptoms.

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.

Managing and Preventing Migraine in the Emergency Department: A Review

Migraine is a leading cause of disability worldwide, and acute migraine attacks are a common reason for patients to seek care in the emergency department (ED). There have been recent advancements in the care of patients with migraine, specifically emerging evidence for nerve blocks and new pharmacological classes of medications like gepants and ditans. This article serves as a comprehensive review of migraine in the ED, including diagnosis and management of acute complications of migraine (eg, status migrainosus, migrainous infarct, persistent aura without infarction, and aura-triggered seizure) and use of evidence-based migraine-specific treatments in the ED. It highlights the role of migraine preventive medications and provides a framework for emergency physicians to prescribe them to eligible patients. Finally, it evaluates the evidence for nerve blocks in the treatment of migraine and introduces the possible role of gepants and ditans in the care of patients with migraine in the ED.

From CGRP to PACAP, VIP, and Beyond: Unraveling the Next Chapters in Migraine Treatment

Migraine is a neurovascular disorder that can be debilitating for individuals and society. Current research focuses on finding effective analgesics and management strategies for migraines by targeting specific receptors and neuropeptides. Nonetheless, newly approved calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) have a 50% responder rate ranging from 27 to 71.0%, whereas CGRP receptor inhibitors have a 50% responder rate ranging from 56 to 71%. To address the need for novel therapeutic targets, researchers are exploring the potential of another secretin family peptide, pituitary adenylate cyclase-activating polypeptide (PACAP), as a ground-breaking treatment avenue for migraine. Preclinical models have revealed how PACAP affects the trigeminal system, which is implicated in headache disorders. Clinical studies have demonstrated the significance of PACAP in migraine pathophysiology; however, a few clinical trials remain inconclusive: the pituitary adenylate cyclase-activating peptide 1 receptor mAb, AMG 301 showed no benefit for migraine prevention, while the PACAP ligand mAb, Lu AG09222 significantly reduced the number of monthly migraine days over placebo in a phase 2 clinical trial. Meanwhile, another secretin family peptide vasoactive intestinal peptide (VIP) is gaining interest as a potential new target. In light of recent advances in PACAP research, we emphasize the potential of PACAP as a promising target for migraine treatment, highlighting the significance of exploring PACAP as a member of the antimigraine armamentarium, especially for patients who do not respond to or contraindicated to anti-CGRP therapies. By updating our knowledge of PACAP and its unique contribution to migraine pathophysiology, we can pave the way for reinforcing PACAP and other secretin peptides, including VIP, as a novel treatment option for migraines.

Sinonasal symptoms in migraine without aura: results from the cross-sectional 'Migraine in Poland' study

Background

Migraine without aura (MwoA) is often mistaken for rhinosinusitis. The purpose of this study was to assess the prevalence of sinonasal symptoms, sinusitis-targeting medication use and burden of migraine in a large group of people with MwoA attacks accompanied by rhinologic symptoms.

Methods

Data was collected in a cross-sectional online survey based on an adapted population-based study questionnaire. The analysis included the prevalence of rhinorrhea, mucopurulent nasal discharge, nasal congestion, facial pressure and tenderness to palpation, hyposmia/anosmia and osmophobia.

Results

1,679 (52.73%) MwoA people were identified among 3,225 respondents (women n = 2,809, 87.10%) aged 13-80 years (median age 39; standard deviation 10.4). 1004/1679 (59.8%) migraine patients reported one or more rhinologic symptoms and 341/1679 (20.3%) MwoA respondents had symptoms that met rhinosinusitis clinical diagnostic criteria during their headache attacks. In migraine patients, osmophobia was associated with hyposmia [n = 141 (12.7%) vs. n = 41 (7.2%); p = 0.001] and a sensation of unpleasant smells [n = 216 (19.4%) vs. n = 45 (8.5%); p = 0.001], while facial tenderness to palpation was associated with facial allodynia [n = 532 (50.4%) vs. n = 211 (33.9%); p < 0.001]. People with migraine accompanied by rhinosinusitis-like symptoms experienced more disease burden and used 'sinus medications' more often.

Conclusion

MwoA patients with rhinosinusitis-like symptoms during migraine attacks require cautious assessment, especially that some symptoms seem to have little value in distinguishing between these disorders (i.e., facial tenderness, hyposmia), while many of these patients have a greater disease burden and therefore often choose medications targeting rhinologic instead of neurologic mechanisms.

Neurovascular Compression-Induced Intracranial Allodynia May Be the True Nature of Migraine Headache: an Interpretative Review

PURPOSE OF REVIEW

Surgical deactivation of migraine trigger sites by extracranial neurovascular decompression has produced encouraging results and challenged previous understanding of primary headaches. However, there is a lack of in-depth discussions on the pathophysiological basis of migraine surgery. This narrative review provides interpretation of relevant literature from the perspective of compressive neuropathic etiology, pathogenesis, and pathophysiology of migraine.

RECENT FINDINGS

Vasodilation, which can be asymptomatic in healthy subjects, may produce compression of cranial nerves in migraineurs at both extracranial and intracranial entrapment-prone sites. This may be predetermined by inherited and acquired anatomical factors and may include double crush-type lesions. Neurovascular compression can lead to sensitization of the trigeminal pathways and resultant cephalic hypersensitivity. While descending (central) trigeminal activation is possible, symptomatic intracranial sensitization can probably only occur in subjects who develop neurovascular entrapment of cranial nerves, which can explain why migraine does not invariably afflict everyone. Nerve compression-induced focal neuroinflammation and sensitization of any cranial nerve may neurogenically spread to other cranial nerves, which can explain the clinical complexity of migraine. Trigger dose-dependent alternating intensity of sensitization and its synchrony with cyclic central neural activities, including asymmetric nasal vasomotor oscillations, may explain the laterality and phasic nature of migraine pain. Intracranial allodynia, i.e., pain sensation upon non-painful stimulation, may better explain migraine pain than merely nociceptive mechanisms, because migraine cannot be associated with considerable intracranial structural changes and consequent painful stimuli. Understanding migraine as an intracranial allodynia could stimulate research aimed at elucidating the possible neuropathic compressive etiology of migraine and other primary headaches.

InfluenCEF study: Clinical phenotype and duration of headache attributed to influenza infection

INTRODUCTION

Headache is a frequent symptom of infections. We aimed to characterize the clinical phenotype and duration of headache attributed to influenza infection.

METHODS

Prospective cohort study done in 53 primary care centers between January and April 2023. Patients were included if they had a confirmed influenza diagnosis, were older than 15 years and had a new-onset headache. Patients' demographics, prior medical history, headache phenotype and duration, associated symptoms and patients' outcomes were assessed. The International Classification of Headache Disorders criteria for headache attributed to a systemic viral infection, migraine and tension-type headache were assessed.

RESULTS

Of the 478 patients 75 fulfilled eligibility criteria. The mean age was 43, 56% were men, and 27% had a prior headache history. The headache phenotype was a bilateral headache (52%), with frontal topography (48%), pressing quality (61%), moderate intensity, rhinorrhea (79%), nasal congestion (76%), and photophobia (59%). All patients fulfilled headache attributed to acute systemic viral infection criteria, 43% fulfilled migraine criteria and 31% tension-type headache criteria. The median duration of the headache was four (Inter-quartile range: two-six) days.

CONCLUSION

The clinical phenotype of headache attributed to influenza infection was similar to other infections, with more pronounced cranial autonomic symptoms. The headache was an early symptom and was self-limited within a few days.Trial Registration: The study protocol is registered in ClinicalTrial.gov (NCT05704335).

Exploring Novel Therapeutic Targets in the Common Pathogenic Factors in Migraine and Neuropathic Pain

Migraine and neuropathic pain (NP) are both painful, disabling, chronic conditions which exhibit some symptom similarities and are thus considered to share a common etiology. The calcitonin gene-related peptide (CGRP) has gained credit as a target for migraine management; nevertheless, the efficacy and the applicability of CGRP modifiers warrant the search for more effective therapeutic targets for pain management. This scoping review focuses on human studies of common pathogenic factors in migraine and NP, with reference to available preclinical evidence to explore potential novel therapeutic targets. CGRP inhibitors and monoclonal antibodies alleviate inflammation in the meninges; targeting transient receptor potential (TRP) ion channels may help prevent the release of nociceptive substances, and modifying the endocannabinoid system may open a path toward discovery of novel analgesics. There may exist a potential target in the tryptophan-kynurenine (KYN) metabolic system, which is closely linked to glutamate-induced hyperexcitability; alleviating neuroinflammation may complement a pain-relieving armamentarium, and modifying microglial excitation, which is observed in both conditions, may be a possible approach. Those are several potential analgesic targets which deserve to be explored in search of novel analgesics; however, much evidence remains missing. This review highlights the need for more studies on CGRP modifiers for subtypes, the discovery of TRP and endocannabinoid modulators, knowledge of the status of KYN metabolites, the consensus on cytokines and sampling, and biomarkers for microglial function, in search of innovative pain management methods for migraine and NP.

Human Brain Organoids in Migraine Research: Pathogenesis and Drug Development

Human organoids are small, self-organized, three-dimensional (3D) tissue cultures that have started to revolutionize medical science in terms of understanding disease, testing pharmacologically active compounds, and offering novel ways to treat disease. Organoids of the liver, kidney, intestine, lung, and brain have been developed in recent years. Human brain organoids are used for understanding pathogenesis and investigating therapeutic options for neurodevelopmental, neuropsychiatric, neurodegenerative, and neurological disorders. Theoretically, several brain disorders can be modeled with the aid of human brain organoids, and hence the potential exists for understanding migraine pathogenesis and its treatment with the aid of brain organoids. Migraine is considered a brain disorder with neurological and non-neurological abnormalities and symptoms. Both genetic and environmental factors play essential roles in migraine pathogenesis and its clinical manifestations. Several types of migraines are classified, for example, migraines with and without aura, and human brain organoids can be developed from patients with these types of migraines to study genetic factors (e.g., channelopathy in calcium channels) and environmental stressors (e.g., chemical and mechanical). In these models, drug candidates for therapeutic purposes can also be tested. Here, the potential and limitations of human brain organoids for studying migraine pathogenesis and its treatment are communicated to generate motivation and stimulate curiosity for further research. This must, however, be considered alongside the complexity of the concept of brain organoids and the neuroethical aspects of the topic. Interested researchers are invited to join the network for protocol development and testing the hypothesis presented here.

TRP Channels: Recent Development in Translational Research and Potential Therapeutic Targets in Migraine

Migraine is a chronic neurological disorder that affects approximately 12% of the population. The cause of migraine headaches is not yet known, however, when the trigeminal system is activated, neuropeptides such as calcitonin gene-related peptide (CGRP) and substance P (SP) are released, which cause neurogenic inflammation and sensitization. Advances in the understanding of migraine pathophysiology have identified new potential pharmacological targets. In recent years, transient receptor potential (TRP) channels have been the focus of attention in the pathophysiology of various pain disorders, including primary headaches. Genetic and pharmacological data suggest the role of TRP channels in pain sensation and the activation and sensitization of dural afferents. In addition, TRP channels are widely expressed in the trigeminal system and brain regions which are associated with the pathophysiology of migraine and furthermore, co-localize several neuropeptides that are implicated in the development of migraine attacks. Moreover, there are several migraine trigger agents known to activate TRP channels. Based on these, TRP channels have an essential role in migraine pain and associated symptoms, such as hyperalgesia and allodynia. In this review, we discuss the role of the certain TRP channels in migraine pathophysiology and their therapeutic applicability.