Calcitonin gene-related peptide causes migraine aura.

BACKGROUND: Although the involvement of calcitonin gene-related peptide (CGRP) in migraines is well-established, its specific role in investigating the aura phase, which often precedes the headache, remains largely unexplored. This study aims to instigate CGRP's potential in triggering aura, thus establishing its role in the early stages of migraine. METHODS: In this open-label, non-randomized, single-arm trial, 34 participants with migraine with aura received continuous intravenous infusion of CGRP (1.5 µg/min) over 20 min on a single experimental day. Participants were required to be free of headache and report no use of acute medications 24 h before infusion start. The primary endpoint was the incidence of migraine aura during the 12-hour observational period after the start of infusion. RESULTS: Thirteen (38%) of 34 participants developed migraine aura after CGRP infusion. In addition, 24 (71%) of 34 participants developed migraine headache following CGRP infusion. CONCLUSIONS: Our findings suggest that CGRP could play an important role in the early phases of a migraine attack, including during the aura phase. These insights offer a new perspective on the pathogenesis of migraines with aura. They underscore the need for additional research to further explore the role of CGRP in these initial stages of a migraine attack, and potentially inform future development of therapeutic interventions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04592952.

Use of combined hormonal contraception and stroke: A case-control study of the impact of migraine type and estrogen dose on ischemic stroke risk.

OBJECTIVE: To clarify how factors such as estrogen dose and migraine history (including migraine subtype) impact ischemic stroke risks associated with combined hormonal contraceptive (CHC) use. BACKGROUND: CHC use in those with migraine with aura has been restricted due to concerns about stroke risk. METHODS: We conducted a case-control analysis of stroke risk associated with estrogen dose and migraine history among CHC users in a large tertiary care center. All women aged 18-55 who used a CHC between January 1, 2010, and December 31, 2019, were identified. Those with a stroke diagnosis were identified using ICD codes and confirmed via chart and imaging review. Details of personal and family medical history, stroke evaluation, ethinyl estradiol dosing (EE; ≥30 vs. <30 µg), and demographics were collected. From a random sample of 20,000 CHC users without stroke, a control cohort (n = 635) was identified and matched based on patient characteristics, medical and family histories, as well as stroke risk factors, to assess association between migraine diagnosis, migraine subtype, estrogen dose, and stroke. RESULTS: Of the 203,853 CHC users in our cohort, 127 had confirmed stroke (0.06%; CI 0.05%, 0.07%). In unadjusted analyses, a higher number of patients in the case cohort had a diagnosis of migraine (34/127, 26.8%) compared to controls (109/635, 17.2%; p = 0.011). Stroke risk was higher with ≥30-µg EE doses compared to those using a <30-µg dose (OR, 1.52; CI 1.02, 2.26; p = 0.040). Compared to no migraine, personal history of migraine increased the odds of stroke (OR, 2.00; CI 1.27, 3.17; p = 0.003). Compared to no migraine, stroke risk was not significantly increased in those with migraine with aura, but migraine without aura increased the risk (OR, 2.35; CI 1.32, 4.2; p = 0.004). CONCLUSIONS: Overall stroke risk in our cohort of CHC users was low. When CHCs are used in those with migraine, formulations containing ≤30 µg EE are preferred. Shared decision-making should include discussions about ischemic stroke risks in patients with migraine, even those without aura.

Benign fasciculation syndrome and migraine aura without headache as possible adverse events after BNT162b2 mRNA vaccination: a web-based survey.

AIM: To determine the characteristics of patients who experienced muscle fasciculations and migraine auras without headache after BNT162b2 immunization. METHODS: In January 2022, we published a case report that described a 48-year-old female patient who experienced muscle twitching and migraine auras without headache following BNT162b2 immunization. A self-administered online survey was sent to people who had written to us and complained of similar symptoms described in the case report (N=20). RESULTS: The survey was completed by 11 participants, of whom 10 reported muscle twitching following BNT162b2 immunization lasting a median of 14 (4-36.5) days. Five of these participants (50%) reported migraine auras without headache. Participants further reported on self-identified triggers that altered the intensity of their symptoms, such as anxiety or caffeine. Fifty percent of participants who got an acute SARS-CoV-2 infection (3/6) experienced increased muscle symptom intensity during the acute phase of the disease. CONCLUSION: To the best of our knowledge, our survey is the first to summarize patients' experiences of these phenomena occurring after BNT162b2 immunization. It is important to note that no causal relationship between vaccination and these phenomena can be inferred.

Efficacy of Lasmiditan Across Patient and Migraine Characteristics in Japanese Patients with Migraine: A Secondary Analysis of the MONONOFU Trial.

INTRODUCTION: This MONONOFU trial subgroup analysis evaluates the efficacy of lasmiditan across patient and migraine characteristics in Japanese patients with migraine. METHODS: MONONOFU trial was a multicenter, randomized, double-blind, placebo-controlled study. The patients were randomly assigned in a 3:7:6:7 ratio to receive lasmiditan 50 mg, 100 mg, 200 mg, or placebo for a single migraine attack within 4 h of pain onset. Efficacy of lasmiditan vs placebo was evaluated at 2 h post dose for proportion of patients with headache pain freedom. Efficacy was assessed across patient characteristics (age, sex, body weight, cardiovascular risk factors (CVRF), and comorbidity of tension-type headache), migraine disease characteristics (history of migraine with aura, migraine prevention therapy, triptan response, and triptan use or nonuse), and migraine attack characteristics (headache severity, aggressive headache, attack during perimenstrual period, time to dosing, time of dosing, experienced treatment-emergent adverse event (TEAE) of dizziness, and experienced TEAE of somnolence). Logistic regression was used; all subgroup analyses were not analyzed with multiplicity-adjusted statistical tests. RESULTS: Treatment-by-subgroup interactions (by each arm) were not significant (p ≥ 0.05) for pain freedom at 2 h post dose across all patient subgroups and lasmiditan doses, except for CVRF (100 mg and 200 mg), migraine with aura (50 mg), triptan response (50 mg), and time to dosing (200 mg). Treatment-by-subgroup interactions (by overall) were not significant (p ≥ 0.05) for pain freedom at 2 h post dose across all patient subgroups, except for CVRFs. Higher proportions of patients were pain free at 2 h post dose when treated with lasmiditan (50 mg, 100 mg, and 200 mg) versus placebo, irrespective of most patient characteristics, migraine disease characteristics, and migraine attack characteristics. CONCLUSION: Although few interactions were observed, lasmiditan could be a promising acute treatment option in a wide range of Japanese patients with migraine, as efficacy is not generally influenced by patient and migraine characteristics.

Opening of ATP sensitive potassium channels causes migraine attacks with aura.

Migraine afflicts more than one billion individuals worldwide and is a leading cause of years lived with disability. In about a third of individuals with migraine aura occur in relation to migraine headache. The common pathophysiological mechanisms underlying migraine headache and migraine aura are yet to be identified. Based on recent data, we hypothesized that levcromakalim, an ATP-sensitive potassium channel opener, would trigger migraine attacks with aura in patients. In a randomized, double-blind, placebo-controlled, crossover study, 17 patients aged 21-59 years and diagnosed with migraine with aura exclusively were randomly allocated to receive an infusion of 0.05 mg/min levcromakalim or placebo (isotonic saline) on two different days (ClinicalTrials.gov, ID: NCT04012047). The primary end points were the difference in incidence of migraine attacks with or without aura, headache and the difference in the area under the curve for headache intensity scores (0-12 h). Seventeen patients completed the study. Fourteen of 17 (82%) patients developed migraine attacks with and without aura after levcromakalim compared with 1 of 17 (6%) after placebo (P < 0.001). Ten patients (59%) developed migraine with aura after levcromakalim compared with none after placebo (P = 0.002). One additional patient reported 'possible' aura, only partially fulfilling the criteria. Levcromakalim is likely a novel migraine aura-inducing substance in humans. These findings highlight the ATP-sensitive potassium channel as a shared target in migraine aura and migraine headache. Likely, ATP-sensitive potassium channel opening leads to triggering of aura and headache, respectively, via distinct mechanisms.

Intravenous Endothelin-1 Infusion Does Not Induce Aura or Headache in Migraine Patients With Aura.

OBJECTIVE: To investigate whether intravenously infused provokes migraine aura and migraine headache in migraine patients with aura. BACKGROUND: Migraine with aura has been associated with endothelial dysfunction and increased stroke risk. The initiating mechanism of migraine aura symptoms is not known. Experimental provocation of migraine headache using vasoactive peptides has provided tremendous advances in the understanding of migraine pathophysiology but substances that can induce migraine aura have not been identified. Endothelin-1 (ET-1), an endogenous, potent vasoconstrictor peptide released from the vascular endothelium, has been proposed to trigger migraine aura. This hypothesis is based on reports of increased plasma ET-1 levels early during the migraine attacks and the observation that ET-1 applied to the cortical surface potently induces the cortical spreading depolarization, the underlying electrophysiological phenomenon of migraine aura, in animals. Further, endothelial damage due to, for example, carotid puncture and vascular pathology is known to trigger aura episodes. METHODS: We investigated whether intravascular ET-1 would provoke migraine aura in patients. Using a two-way crossover, randomized, placebo-controlled, double-blind design, we infused high-dose (8 ng/kg/minutes for 20 minutes) intravenous ET-1 in patients with migraine with typical aura. The primary end-point was the difference in incidence of migraine aura between ET-1 and placebo. Experiments were carried out at a public tertiary headache center (Danish Headache Center, Rigshospitalet Glostrup, Denmark). RESULTS: Fourteen patients received intravenous ET-1. No patients reported migraine aura symptoms or migraine headache during or up to 24 hours following the ET-1 infusion. Four patients reported mild to moderate headache only on the ET-1 day, 3 patients reported moderate headache on the placebo day, and 1 patient reported mild headache on both days. No serious adverse events occurred during or after infusion. CONCLUSIONS: Provocation of migraine aura by procedures or conditions involving vascular irritation is unlikely to be mediated by ET-1.

CSD-Induced Arterial Dilatation and Plasma Protein Extravasation Are Unaffected by Fremanezumab: Implications for CGRP's Role in Migraine with Aura.

Cortical spreading depression (CSD) is a wave of neuronal depolarization thought to underlie migraine aura. Calcitonin gene-related peptide (CGRP) is a potent vasodilator involved in migraine pathophysiology. Evidence for functional connectivity between CSD and CGRP has triggered scientific interest in the possibility that CGRP antagonism may disrupt vascular responses to CSD and the ensuing plasma protein extravasation (PPE). Using imaging tools that allow us to generate continuous, live, high-resolution views of spatial and temporal changes that affect arteries and veins in the dura and pia, we determined the extent to which CGRP contributes to the induction of arterial dilatation or PPE by CSD in female rats, and how these events are affected by the anti-CGRP monoclonal antibody (anti-CGRP-mAb) fremanezumab. We found that the CSD-induced brief dilatation and prolonged constriction of pial arteries, prolonged dilatation of dural arteries and PPE are all unaffected by fremanezumab, whereas the brief constriction and prolonged dilatation of pial veins are affected. In comparison, although CGRP infusion gave rise to the expected dilatation of dural arteries, which was effectively blocked by fremanezumab, it did not induce dilatation in pial arteries, pial veins, or dural veins. It also failed to induce PPE. Regardless of whether the nociceptors become active before or after the induction of arterial dilatation or PPE by CSD, the inability of fremanezumab to prevent them suggests that these events are not mediated by CGRP, a conclusion with important implications for our understanding of the mechanism of action of anti-CGRP-mAbs in migraine prevention.SIGNIFICANCE STATEMENT The current study identifies fundamental differences between two commonly used models of migraine, CSD induction and systemic CGRP infusion. It raises the possibility that conclusions drawn from one model may not be true or relevant to the other. It sharpens the need to accept the view that there is more than one truth to migraine pathophysiology and that it is unlikely that one theory will explain all types of migraine headache or the mechanisms of action of drugs that prevent it. Regarding the latter, it is concluded that not all vascular responses in the meninges are born alike and, consequently, that drugs that prevent vascular dilatation through different molecular pathways may have different therapeutic outcomes in different types of migraine.

Induction of migraine-like headache, but not aura, by cilostazol in patients with migraine with aura.

Whether migraine headache and migraine aura share common pathophysiological mechanisms remains to be understood. Cilostazol causes cAMP accumulation and provokes migraine-like headache in migraine patients without aura. We investigated if cilostazol induces aura and migraine-like headache in patients with migraine with aura and alters peripheral endothelial function and levels of endothelial markers. In a randomized, double-blinded, placebo-controlled crossover study, 16 patients with migraine with aura (of whom 12 patients exclusively had attacks of migraine with aura) received 200 mg cilostazol (Pletal®) or placebo on two separate days. The development, duration, and characteristics of aura and headache were recorded using a questionnaire. Peripheral endothelial function was assessed by digital pulse amplitude tonometry using EndoPAT2000, and endothelial markers (VCAM1, E-selectin, and VEGFA) were measured. After administration of cilostazol, 14 patients (88%) experienced headache compared with six patients (38%) after placebo (P = 0.009). The headache in 12 patients (75%) after cilostazol and one patient (6%) after placebo fulfilled the criteria for migraine-like attacks (P = 0.0002). Patients reported that the attack mimicked the headache phase during their usual migraine attacks. However, aura symptoms were elicited in one patient after cilostazol and one patient after placebo. Further, endothelial function, as assessed by peripheral arterial tonometry, and endothelial markers were not significantly altered by cilostazol. Accumulation of cAMP by cilostazol induces migraine-like headache, but not aura, in patients with migraine with aura, even in those who exclusively reported attacks of migraine with aura in their spontaneous attacks. These findings further support dissociation between the aura and the headache phase with a yet unknown trigger for the aura and link between aura and headache. In addition, cilostazol administration did not significantly alter endothelial function, as assessed by peripheral arterial tonometry, or the endothelial markers, VCAM1, E-selectin, and VEGFA. However, post hoc analyses showed that our study was statistically underpowered for these outcomes.

Part I: Pituitary adenylate cyclase-activating polypeptide-38 induced migraine-like attacks in patients with and without familial aggregation of migraine.

Background Intravenous infusion of adenylate cyclase-activating polypeptide-38 (PACAP38) provokes migraine-like attacks in 65-70% of migraine sufferers. Whether aggregation of migraine in first-degree relatives contributes to this discrepancy in PACAP38-induced response is unknown. We hypothesized that genetic enrichment plays a role in triggering of migraine and that migraine without aura patients with a high family load ( ≥ 2 first-degree relatives with migraine) would report more migraine-like attacks after intravenous infusion of human PACAP38. Methods In this study, we allocated 32 previously genotyped migraine without aura patients to receive intravenous infusion of 10 pmol/kg/min PACAP38 and recorded migraine-like attacks including headache characteristics and associated symptoms. Information of familial aggregation was obtained by telephone interview of first-degree relatives using a validated semi-structured questionnaire. Results PACAP38 infusion induced a migraine-like attack in 75% (nine out of 12) of patients with high family load compared to 70% (14 out of 20) with low family load ( P = 0.761). In an explorative investigation, we found that the migraine response after PACAP38 was not associated with the risk allele of rs2274316 ( MEF2D), which confers increased risk of migraine without aura and may regulate PACAP38 expression. Conclusion Migraine response to PACAP38 infusion in migraine without aura patients is not associated with high family load or the risk allele of rs2274316 ( MEF2D).

Calcitonin gene-related peptide induced migraine attacks in patients with and without familial aggregation of migraine.

Background Calcitonin gene-related peptide provokes migraine attacks in 65% of patients with migraine without aura. Whether aggregation of migraine in first-degree relatives (family load) or a high number of risk-conferring single nucleotide polymorphisms contributes to migraine susceptibility to calcitonin gene-related peptide infusion in migraine patients is unknown. We hypothesized that genetic enrichment plays a role in triggering of migraine and, therefore, migraine without aura patients with high family load would report more migraine attacks after calcitonin gene-related peptide infusion than patients with low family load. Methods We allocated 40 previously genotyped migraine without aura patients to receive intravenous infusion of 1.5 µg/min calcitonin gene-related peptide and recorded migraine attacks including headache characteristics and associated symptoms. Information of familial aggregation was obtained by telephone interview of first-degree relatives using a validated semi-structured questionnaire. Results Calcitonin gene-related peptide infusion induced a migraine-like attack in 75% (12 out of 16) of patients with high family load compared to 52% (12 out of 23) with low family load ( P = 0.150). In addition, we found that the migraine response after calcitonin gene-related peptide was not associated with specific or a high number of risk-conferring single nucleotide polymorphisms of migraine without aura. Conclusion We found no statistical association between familial aggregation of migraine and hypersensitivity to calcitonin gene-related peptide infusion in migraine without aura patients. We also demonstrated that the currently known single nucleotide polymorphisms conferring risk of migraine without aura have no additive effect on calcitonin gene-related peptide induced migraine-like attacks.

Very unusual symptoms consistent with a possible migraine immediately following the injection of recombinant follitropin beta.

PURPOSE: To present a new side effect of follitropin beta not shared with highly purified urinary follicle stimulating honnone (FSH). MATERIALS AND METHODS: Follitropin beta was administered for preparation of in vitro fertilization-embryo transfer (IVF-ET). RESULTS: Within a few minutes of injection of subcutaneously of follitropin beta, a 27-year-old woman developed a feeling of fever, headache, nausea, vomiting dizziness, and a visual aura consistent with migraine syndrome. These side effects did not occur when switched to highly purified urinary FSH. CONCLUSIONS: Since this reaction did not occur when injected with FSH not made with recombinant DNA technology, it is concluded that recombinant FSH (at least with follitropin beta) can produce an immediate migraine-like syndrome.

Should foam made with physiologic gases be the standard in sclerotherapy?

OBJECTIVES: The aim of this paper is to look at the pros and cons of using physiologic gas to produce foam for use in sclerotherapy. With the expanding use of foam sclerotherapy, there have been increased reports of transient neurologic adverse events such as visual disturbance. Although rare, increased numbers of serious adverse events such as transient ischemic attacks (TIAs) and stroke have been described. These events are seen more often in patients who have migraine with aura and those with a right-to-left shunt. METHODS: A literature search of the databases Ovid and Google Scholar was performed for studies looking specifically at neurologic side effects associated with sclerotherapy and use of physiologic foams. Included studies were randomized controlled trials, meta-analyses, review articles, observational studies and case studies. RESULTS: Although physiologic gases have been shown in several studies to reduce the incidence of visual disturbance, increasing evidence from recent studies suggest endothelin, rather than gas bubbles to be the cause of these side effects. The cause of stroke and TIA has not been proven and occlusion of cerebral arterioles from gas emboli should still be considered. Many authors state that only good quality foam be injected and volumes should be kept low in an attempt to prevent these rare, but potentially serious events. Foam made with physiologic gases are more biocompatible compared to air-based foam and have been found to be at least as effective in sclerotherapy as foam made with room air. CONCLUSION: The use of physiologic gases should be considered for those at increased risk of neurologic side effects such as migraineurs with aura and those with a known PFO. Additionally, as there are few disadvantages to the use of physiologic foam, the use of CO2 or CO2/O2 foam should be considered in all patients receiving foam sclerotherapy.

New onset migraine with aura after treatment initiation with ivabradine.

BACKGROUND: Migraine with aura is a complex neurological disorder modeled in animals by cortical spreading depression. It is less usual to find complete animal models for the disease so any opportunity to test a human effect back at the bench is welcome. FINDINGS: We report the case of a 24 year old woman who developed new onset episodic migraine with visual aura shortly after treatment initiation with the If ion channel blocker ivabradine for frequency control in hypertrophic cardiomyopathy. We studied whether ivabradine could alter cortical spreading depression in a suitable animal model. Sixteen rats received either ivabradine or saline, and the number of depolarization shifts and blood flow changes induced by cortical spreading depression were measured in both groups. No significant differences between the ivabradine and saline group were detected. CONCLUSIONS: Ivabradine is an interesting substance since it is known to produce migraine-like phosphenes frequently and the patient we report developed de novo migraine with aura. However, we were unable to demonstrate that the drug influences the susceptibility of the brain to cortical spreading depression with acute administration. The combined data show the relationship of migraine aura to cortical spreading depression may have some nuances yet to be identified.

Prostaglandin E(2) induces immediate migraine-like attack in migraine patients without aura.

BACKGROUND: Prostaglandin E(2) (PGE(2)) has been suggested to play an important role in the pathogenesis of migraine. In the present experiment we investigated if an intravenous infusion of PGE(2) would induce migraine-like attacks in patients with migraine. METHODS: Twelve patients with migraine without aura were randomly allocated to receive 0.4 µg/kg/min PGE(2) (Prostin(®)E2, dinoprostone) or placebo over 25 minutes in a two-way, crossover study. Headache intensity was recorded on a verbal rating scale, middle cerebral artery blood flow velocity (V(MCA)) was measured by transcranial Doppler (TCD) and diameter of the superficial temporal artery (STA) was obtained by c-series scan (Dermascan C). RESULTS: In total, nine migraine patients (75%) experienced migraine-like attacks after PGE(2) compared to none after placebo (p = 0.004). Seven out of 9 (58%) patients reported the migraine-like attacks during the immediate phase (0-90 min) (p = 0.016). Only two patients experienced the delayed migraine-like attacks several hours after the PGE(2) infusion stop (p = 0.500). The V(MCA) decreased during the PGE(2) infusion (p = 0.005) but there was no significant dilatation of the STA (p = 0.850). CONCLUSION: The migraine-like attacks during, and immediately after, the PGE(2) infusion contrast with those found in previous provocation studies, in which the other pharmacological compounds triggered the delayed migraine-like attacks several hours after the infusion. We suggest that PGE(2) may be one of the important final products involved in the generation of migraine attacks.

Chronic daily cortical spreading depressions suppress spreading depression susceptibility.

BACKGROUND: Migraine is a disabling chronic episodic disorder. Attack frequency progressively increases in some patients. Incremental cortical excitability has been implicated as a mechanism underlying progression. Cortical spreading depression (CSD) is the electrophysiological event underlying migraine aura, and a headache trigger. We hypothesized that CSD events during frequent migraine attacks condition the cortex to increase the susceptibility to further attacks. METHODS: A single daily CSD was induced for 1 or 2 weeks in mouse frontal cortex; contralateral hemisphere served as sham control. At the end of CSD conditioning, occipital CSD susceptibility was determined by measuring the frequency of CSDs evoked by topical KCl application. RESULTS: Sham hemispheres developed 8.4 ± 0.3 CSDs/hour, and did not significantly differ from naïve controls without prior cranial surgery (9.3 ± 0.4 CSDs/hour). After 2 but not 1 week of daily CSD conditioning, CSD frequency (4.9 ± 0.3 CSDs/hour) as well as the duration and propagation speed were reduced significantly in the conditioned hemispheres. Histopathological examination revealed marked reactive astrocytosis without neuronal injury throughout the conditioned cortex after 2 weeks, temporally associated with CSD susceptibility. CONCLUSIONS: These data do not support the hypothesis that frequent migraine attacks predispose the brain to further attacks by enhancing tissue susceptibility to CSD.

Calcitonin gene-related peptide does not cause migraine attacks in patients with familial hemiplegic migraine.

BACKGROUND: Calcitonin gene-related peptide (CGRP) is a key molecule in migraine pathogenesis. Intravenous CGRP triggers migraine-like attacks in patients with migraine with aura and without aura. In contrast, patients with familial hemiplegic migraine (FHM) with known mutations did not report more migraine-like attacks compared to controls. Whether CGRP triggers migraine-like attacks in FHM patients without known mutations is unknown. OBJECTIVE: In the present study we therefore examined the migraine-inducing effect of CGRP in FHM patients without known mutations and healthy controls. METHODS AND DESIGN: Eleven patients suffering from FHM without known mutations and 11 controls received an intravenous infusion of 1.5 µg/minute CGRP over 20 minutes. The study design was a balanced and controlled provocation study. Headache and other migraine symptoms were scored for 1 hour and self-recorded hourly thereafter until 13-hour postinfusion. RESULTS: We found no difference in the incidence of migraine-like attacks between the 2 groups, with 9% (1 of 11) of patients and 0% (0 of 10) of controls reporting migraine-like headache (P = 1.00). CGRP infusion did not induce aura symptoms in any of the participants. There was no difference in the incidence of CGRP-induced delayed headaches between the groups (P = .18). CONCLUSION: In contrast to patients suffering from migraine with aura and without aura, CGRP infusion did not induce more migraine-like attacks in FHM patients without known mutations compared to controls. It seems that the majority of FHM patients with and without known mutation display no sensitivity to CGRP signaling compared to common types of migraine.

Calcitonin gene-related peptide triggers migraine-like attacks in patients with migraine with aura.

INTRODUCTION: Calcitonin gene-related peptide (CGRP) is a key molecule in migraine pathogenesis. Intravenous CGRP infusion triggers delayed migraine-like attacks in patients with migraine without aura (MO). In contrast to patients with MO, in prior studies patients with familial hemiplegic migraine (FHM) did not report more migraine-like attacks compared to controls. Whether CGRP triggers migraine in patients with typical (non-hemiplegic) migraine with aura is (MA) unknown. In the present study we examined the migraine inducing effect of CGRP infusion in patients suffering from MA and healthy controls. METHODS: Fourteen patients suffering exclusively from migraine with typical aura (MA) and 11 healthy volunteers received a continuous intravenous infusion of 1.5 µg/min CGRP over 20 minutes. Headache and other migraine symptoms were scored every 10 minutes for one hour and self recorded hourly thereafter and until 13 hours post-infusion. RESULTS: CGRP infusion induced significantly more delayed headaches in MA patients (12 out of 14) than in controls (2 out of 11) (p = 0.001). Furthermore, significantly more MA patients (57%; 8 out of 14) fulfilled criteria for an experimentally induced migraine attack after CGRP than controls (0%; 0 out of 11) (P = 0.003). Four patients (28%) reported aura symptoms after CGRP infusion. CONCLUSION: CGRP triggered migraine-like attacks without aura in patients suffering exclusively from MA. It also triggered a typical aura in 28% of the patients. These data indicate similar neurobiological pathways responsible for triggering migraine headache in MA and MO patients, and suggest differences between MA/MO and FHM.

Coexisting typical migraine in familial hemiplegic migraine.

OBJECTIVE: In contrast to patients with migraine with aura (MA) and migraine without aura (MO), most patients with familial hemiplegic migraine (FHM) do not report migraine-like attacks after pharmacologic provocation with glyceryl trinitrate (GTN), a donor of nitric oxide. In the present study, we examined patients with FHM without known gene mutations and hypothesized that 1) GTN would cause more migraine-like attacks in patients with FHM compared to controls, and 2) GTN would cause more migraine attacks in patients with FHM with coexisting MA or MO compared to the pure FHM phenotype. METHODS: The study design was a balanced provocation study. Twenty-three patients with FHM and 11 healthy controls received a continuous IV infusion of 0.5 mug/kg/min GTN over 20 minutes. RESULTS: We found no difference in the incidence of migraine-like attacks comparing all patients with FHM (30%) to controls (9%) (p = 0.15). Patients with FHM with coexisting MA or MO reported more migraine attacks after GTN (55%) than patients with the pure FHM phenotype (8.3%) (p = 0.02). Compared to healthy controls, more patients with FHM with coexisting MA or MO reported migraine-like attacks than controls (p = 0.03), whereas the FHM group with the pure FHM phenotype did not (p > 0.05). CONCLUSIONS: Compared to patients with migraine with aura (MA) and migraine without aura (MO), patients with familial hemiplegic migraine (FHM) without known gene mutations display a reduced sensitivity to nitric oxide. A subset of patients with FHM with coexisting nonhemiplegic migraine is more sensitive than controls. These data extend our previous findings that pathophysiologic pathways in FHM may differ from those of MO and MA.