Calcitonin gene-related peptide in migraine: from pathophysiology to treatment

Migraine treatment consensus document of the Spanish Society of Neurology (SEN), Spanish Society of Family and Community Medicine (SEMFYC), Society of Primary Care Medicine (SEMERGEN) and Spanish Association of Migraine and Headache (AEMICE) on migraine treatment

Migraine is a disease with a high prevalence and incidence, in addition to being highly disabling, causing a great impact on the patient's quality of life at a personal, family and work level, but also social, given its high expense due to its direct (care) and indirect (presenteeism and work absenteeism) costs. The multiple and recent developments in its pathophysiological knowledge and in its therapy require updating and, therefore, in this article the Spanish scientific societies most involved in its study and treatment (SEN, SEMFYC and SEMERGEN), together with the Association Spanish Association for Patients with Migraine and other Headaches (AEMICE), we have developed these updated care recommendations. We reviewed the treatment of migraine attacks, which consisted mainly of the use of NSAIDs and triptans, to which ditans and gepants have been added. We also discuss preventive treatment consisting of oral preventive drugs, botulinum toxin, and treatments that block the action of calcitonin-related peptide (CGRP). Finally, we emphasize that pharmacological treatments must be complementary to carrying out general measures consisting of identifying and managing/deletion the precipitating factors of the attacks and the chronicizing factors, controlling the comorbidities of migraine and eliminating analgesic overuse.

RE-START: Exploring the effectiveness of anti-calcitonin gene-related peptide resumption after discontinuation in migraine

BACKGROUND AND PURPOSE

According to the latest European guidelines, discontinuation of monoclonal antibodies against calcitonin gene-related peptide (anti-CGRP MAb) may be considered after 12-18 months of treatment. However, some patients may worsen after discontinuation. In this study, we assessed the response following treatment resumption.

METHODS

This was a prospective study conducted in 14 Headache Units in Spain. We included patients with response to anti-CGRP MAb with clinical worsening after withdrawal and resumption of treatment. Numbers of monthly migraine days (MMD) and monthly headache days (MHD) were obtained at four time points: before starting anti-CGRP MAb (T-baseline); last month of first treatment period (T-suspension); month of restart due to worsening (T-worsening); and 3 months after resumption (T-reintroduction). The response rate to resumption was calculated. Possible differences among periods were analysed according to MMD and MHD.

RESULTS

A total of 360 patients, 82% women, with a median (interquartile range [IQR]) age at migraine onset of 18 (12) years. The median (IQR) MHD at T-baseline was 20 (13) and MMD was 5 (6); at T-suspension, the median (IQR) MHD was 5 (6) and MMD was 4 (5); at T-worsening, the median (IQR) MHD was 16 (13) and MMD was 12 (6); and at T-reintroduction, the median (IQR) MHD was 8 (8) and MHD was 5 (5). In the second period of treatment, a 50% response rate was achieved by 57.4% of patients in MHD and 65.8% in MMD. Multivariate models showed significant differences in MHD between the third month after reintroduction and last month before suspension of first treatment period (p < 0.001).

CONCLUSION

The results suggest that anti-CGRP MAb therapy is effective after reintroduction. However, 3 months after resumption, one third of the sample reached the same improvement as after the first treatment period.

Calcitonin gene-related peptide inhibits neuronal apoptosis in heatstroke rats via PKA/p-CREB pathway

PURPOSE

The incidence of heatstroke (HS) is not particularly high; however, once it occurs, the consequences are serious. It is reported that calcitonin gene-related peptide (CGRP) is protective against brain injury in HS rats, but detailed molecular mechanisms need to be further investigated. In this study, we further explored whether CGRP inhibited neuronal apoptosis in HS rats via protein kinase A (PKA)/p-cAMP response element-binding protein (p-CREB) pathway.

METHODS

We established a HS rat model in a pre-warmed artificial climate chamber with a temperature of (35.5 ± 0.5) °C and a relative humidity of 60% ± 5%. Heatstress was stopped once core body temperature reaches above 41 °C. A total of 25 rats were randomly divided into 5 groups with 5 animals each: control group, HS group, HS+CGRP group, HS+CGRP antagonist (CGRP8-37) group, and HS+CGRP+PKA/p-CREB pathway blocker (H89) group. A bolus injection of CGRP was administered to each rat in HS+CGRP group, CGRP8-37 (antagonist of CGRP) in HS+CGRP8-37 group, and CGRP with H89 in HS+CGRP+H89 group. Electroencephalograms were recorded and the serum concentration of S100B, neuron-specific enolase (NSE), neuron apoptosis, activated caspase-3 and CGRP expression, as well as pathological morphology of brain tissue were detected at 2 h, 6 h, and 24 h after HS in vivo. The expression of PKA, p-CREB, and Bcl-2 in rat neurons were also detected at 2 h after HS in vitro. Exogenous CGRP, CGRP8-37, or H89 were used to determine whether CGRP plays a protective role in brain injury via PKA/p-CREB pathway. The unpaired t-test was used between the 2 samples, and the mean ± SD was used for multiple samples. Double-tailed p < 0.05 was considered statistically significant.

RESULTS

Electroencephalogram showed significant alteration of θ (54.50 ± 11.51 vs. 31.30 ± 8.71, F = 6.790, p = 0.005) and α wave (16.60 ± 3.21 vs. 35.40 ± 11.28, F = 4.549, p = 0.020) in HS group compared to the control group 2 h after HS. The results of triphosphate gap terminal labeling (TUNEL) showed that the neuronal apoptosis of HS rats was increased in the cortex (9.67 ± 3.16 vs. 1.80 ± 1.10, F = 11.002, p = 0.001) and hippocampus (15.73 ± 8.92 vs. 2.00 ± 1.00, F = 4.089, p = 0.028), the expression of activated caspase-3 was increased in the cortex (61.76 ± 25.13 vs. 19.57 ± 17.88, F = 5.695, p = 0.009) and hippocampus (58.60 ± 23.30 vs. 17.80 ± 17.62, F = 4.628, p = 0.019); meanwhile the expression of serum NSE (5.77 ± 1.78 vs. 2.35 ± 0.56, F = 5.174, p = 0.013) and S100B (2.86 ± 0.69 vs. 1.35 ± 0.34, F = 10.982, p = 0.001) were increased significantly under HS. Exogenous CGRP decreased the concentrations of NSE and S100B, and activated the expression of caspase-3 (0.41 ± 0.09 vs. 0.23 ± 0.04, F = 32.387, p < 0.001) under HS; while CGRP8-37 increased NSE (3.99 ± 0.47 vs. 2.40 ± 0.50, F = 11.991, p = 0.000) and S100B (2.19 ± 0.43 vs. 1.42 ± 0.30, F = 4.078, p = 0.025), and activated the expression caspase-3 (0.79 ± 0.10 vs. 0.23 ± 0.04, F = 32.387, p < 0.001). For the cell experiment, CGRP increased Bcl-2 (2.01 ± 0.73 vs. 2.15 ± 0.74, F = 8.993, p < 0.001), PKA (0.88 ± 0.08 vs. 0.37 ± 0.14, F = 20.370, p < 0.001), and p-CREB (0.87 ± 0.13 vs. 0.29 ± 0.10, F = 16.759, p < 0.001) levels; while H89, a blocker of the PKA/p-CREB pathway reversed the expression.

CONCLUSIONS

CGRP can protect against HS-induced neuron apoptosis via PKA/p-CREB pathway and reduce activation of caspase-3 by regulating Bcl-2. Thus CGRP may be a new target for the treatment of brain injury in HS.

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.

[Translated article] Consensus recommendations on the preventive treatment of migraine

OBJECTIVE

The objectives are to know the opinion of neurologists and hospital pharmacists on those aspects still under debate regarding the role of anti-Calcitonin Gene-related Peptide monoclonal antibodies in the preventive treatment of migraine. To identify those controversies that still exist. To propose agreed recommendations for improvement of care. And to promote access of clinicians and patients to these new treatments in the prevention of migraine with biological drugs, in order to improve patient care and follow-up.

METHODOLOGY

Recommendations for the use of biological drugs in the prevention of migraine were identified and evaluated through the Delphi consensus methodology, proposing 88 statements grouped into 3 themes: a clinical module that deals with the management of biological treatments in migraine; a patient module that discusses patient education and adherence improvement strategies; and a coordination module that includes statements related to strategies to improve joint work between the two groups. The 9-point Likert ordinal scale was used to score these recommendations and, subsequently, the data was statistically analysed through different metrics.

RESULTS

After both rounds of voting, consensus was reached in agreement on 71 of the 88 statements (80.7%), leaving 1 statement (1.1%) with consensus in disagreement and 16 remaining as indeterminate (18.2%).

CONCLUSIONS

The high degree of consensus indicates that the opinion of neurologists and hospital pharmacists on the role of anti-Calcitonin Gene-related Peptide monoclonal antibodies in the preventive treatment of migraine is very similar and allows identifying those controversies that still exist, to improve the care and follow-up of patients with migraine.

Is an "Epigenetic Diet" for Migraines Justified? The Case of Folate and DNA Methylation

Migraines are a common disease with limited treatment options and some dietary factors are recognized to trigger headaches. Although migraine pathogenesis is not completely known, aberrant DNA methylation has been reported to be associated with its occurrence. Folate, an essential micronutrient involved in one-carbon metabolism and DNA methylation, was shown to have beneficial effects on migraines. Moreover, the variability of the methylenetetrahydrofolate reductase gene, important in both folate metabolism and migraine pathogenesis, modulates the beneficial effects of folate for migraines. Therefore, migraine could be targeted by a folate-rich, DNA methylation-directed diet, but there are no data showing that beneficial effects of folate consumption result from its epigenetic action. Furthermore, contrary to epigenetic drugs, epigenetic diets contain many compounds, some yet unidentified, with poorly known or completely unknown potential to interfere with the epigenetic action of the main dietary components. The application of epigenetic diets for migraines and other diseases requires its personalization to the epigenetic profile of a patient, which is largely unknown. Results obtained so far do not warrant the recommendation of any epigenetic diet as effective in migraine prevention and therapy. Further studies including a folate-rich diet fortified with valproic acid, another modifier of epigenetic profile effective in migraine prophylaxis, may help to clarify this issue.