A study of differential microRNA expression profile in migraine: the microMIG exploratory study.

BACKGROUND: Several studies have described potential microRNA (miRNA) biomarkers associated with migraine, but studies are scarcely reproducible primarily due to the heterogeneous variability of participants. Increasing evidence shows that disease-related intrinsic factors together with lifestyle (environmental factors), influence epigenetic mechanisms and in turn, diseases. Hence, the main objective of this exploratory study was to find differentially expressed miRNAs (DE miRNA) in peripheral blood mononuclear cells (PBMC) of patients with migraine compared to healthy controls in a well-controlled homogeneous cohort of non-menopausal women. METHODS: Patients diagnosed with migraine according to the International Classification of Headache Disorders (ICHD-3) and healthy controls without familial history of headache disorders were recruited. All participants completed a very thorough questionnaire and structured-interview in order to control for environmental factors. RNA was extracted from PBMC and a microarray system (GeneChip miRNA 4.1 Array chip, Affymetrix) was used to determine the miRNA profiles between study groups. Principal components analysis and hierarchical clustering analysis were performed to study samples distribution and random forest (RF) algorithms were computed for the classification task. To evaluate the stability of the results and the prediction error rate, a bootstrap (.632 + rule) was run through all the procedure. Finally, a functional enrichment analysis of selected targets was computed through protein-protein interaction networks. RESULTS: After RF classification, three DE miRNA distinguished study groups in a very homogeneous female cohort, controlled by factors such as demographics (age and BMI), life-habits (physical activity, caffeine and alcohol consumptions), comorbidities and clinical features associated to the disease: miR-342-3p, miR-532-3p and miR-758-5p. Sixty-eight target genes were predicted which were linked mainly to enriched ion channels and signaling pathways, neurotransmitter and hormone homeostasis, infectious diseases and circadian entrainment. CONCLUSIONS: A 3-miRNA (miR-342-3p, miR-532-3p and miR-758-5p) novel signature has been found differentially expressed between controls and patients with migraine. Enrichment analysis showed that these pathways are closely associated with known migraine pathophysiology, which could lead to the first reliable epigenetic biomarker set. Further studies should be performed to validate these findings in a larger and more heterogeneous sample.

Evaluation of the concomitant use of oral preventive treatments and onabotulinumtoxinA in chronic migraine: the PREVENBOX study.

BACKGROUND AND PURPOSE: OnabotulinumtoxinA is an effective preventive treatment for chronic migraine (CM). In CM, in addition to a reduction in headache frequency, a decreased reliance on oral prophylactics is also indicative of treatment effectiveness. This study aimed to quantify the change in the use of oral prophylactics after treatment with onabotulinumtoxinA in patients with CM. METHODS: This was a retrospective, multicentric, cross-sectional study. Patients with CM (International Classification of Headache Disorders-3beta) that had been treated with onabotulinumtoxinA were enrolled consecutively. We collected parameters related to each patient's pre-treatment situation, as well as their current situation, focusing on frequency and intensity of migraine, number of oral prophylactics and the respective cycle of onabotulinumtoxinA. Univariate and logistic regression analyses were performed. RESULTS: We included 542 patients, 90.0% of whom were taking oral preventive treatments. During treatment with onabotulinumtoxinA, 47.8% withdrew at least one prophylactic and 41.6% stopped using oral prophylactics altogether. Factors associated with a reduction or cessation of oral prophylactics were >50% improvement in frequency and intensity, remission to episodic migraine, use of topiramate as an initial treatment, increased number of infiltrations and shorter chronification period (P < 0.05). The multivariate analysis showed that a chronification period <20 months, more than five cycles of onabotulinumtoxinA, >50% improvement in pain intensity and topiramate as an initial treatment were predictors of a reduction in oral prophylactics (area under the curve, 70.3%; P < 0.001). CONCLUSIONS: Our study demonstrated the efficacy and safety of onabotulinumtoxinA. This treatment reduced the use of oral prophylactics. Withdrawal of oral prophylactics was most likely to occur after five cycles of treatment.

From transformation to chronification of migraine: pathophysiological and clinical aspects.

Chronic migraine is a neurological disorder characterized by 15 or more headache days per month of which at least 8 days show typical migraine features. The process that describes the development from episodic migraine into chronic migraine is commonly referred to as migraine transformation or chronification. Ample studies have attempted to identify factors associated with migraine transformation from different perspectives. Understanding CM as a pathological brain state with trigeminovascular participation where biological changes occur, we have completed a comprehensive review on the clinical, epidemiological, genetic, molecular, structural, functional, physiological and preclinical evidence available.

Early efficacy and late gain in chronic and high-frequency episodic migraine with onabotulinumtoxinA.

BACKGROUND AND PURPOSE: The aim was to analyse the clinical characteristics of a long-term follow-up of patients with chronic and high-frequency episodic migraine in treatment with onabotulinumtoxinA. METHODS: Patients diagnosed with high-frequency episodic migraine (HFEM) or chronic migraine (CM) according to the International Classification of Headache Disorders 3 beta were included. A comparative analysis was carried out at each study time point identifying outcome measures according to initial diagnosis and treatment duration. RESULTS: In all, 578 patients were recruited and after 24 months outcome data were collected from 100 patients: 84.0% CM and 16.0% HFEM. After 24 months, headache frequency was significantly reduced by 10.5 days from baseline, 64.0% reported a ≥50% reduction in pain intensity and 70.0% of patients had ≥50% reduction in analgesic use. Comparing baseline diagnoses, at month 6 CM patients presented higher mean reduction in frequency (CM 44.3% ± 32.6% vs. HFEM 34.6% ± 24.8%) and analgesic use (CM 53.6% ± 35.4% vs. HFEM 39.3% ± 33.2%). At month 12, the mean reduction in frequency was similar in CM and HFEM patients (CM 44.7% ± 33.4% vs. HFEM 41.2% ± 28.2%). Improvement in pain intensity, analgesic use and Migraine Disability Assessment were proportional in both diagnoses. CONCLUSIONS: OnabotulinumtoxinA efficacy is significant at 6 months in frequency and analgesic intake and remains stable during follow-up, whilst the intensity of pain decreases in a stepwise manner at each time point of the analysis. The improvement in CM and HFEM patients is proportional and significant after 1 year of treatment.

OnabotulinumtoxinA in elderly patients with chronic migraine: insights from a real-life European multicenter study.

INTRODUCTION: Although migraine prevalence decreases with aging, some older patients still suffer from chronic migraine (CM). This study aimed to investigate the outcome of OnabotulinumtoxinA (OBT-A) as preventative therapy in elderly CM patients. METHODS: This is a post hoc analysis of real-life prospectively collected data at 16 European headache centers on CM patients treated with OBT-A over the first three treatment cycles (i.e., Cy1-3). We defined: OLD patients aged ≥ 65 years and nonOLD those < 65-year-old. The primary endpoint was the changes in monthly headache days (MHDs) from baseline to Cy 1-3 in OLD compared with nonOLD participants. The secondary endpoints were the responder rate (RR) ≥ 50%, conversion to episodic migraine (EM) and the changes in days with acute medication use (DAMs). RESULTS: In a cohort of 2831 CM patients, 235 were OLD (8.3%, 73.2% females, 69.6 years SD 4.7). MHDs decreased from baseline (24.8 SD 6.2) to Cy-1 (17.5 SD 9.1, p < 0.000001), from Cy-1 to Cy-2 (14.8 SD 9.2, p < 0.0001), and from Cy-2 to Cy-3 (11.9 SD 7.9, p = 0.001). DAMs progressively reduced from baseline (19.2 SD 9.8) to Cy-1 (11.9 SD 8.8, p < 0.00001), to Cy-2 (10.9 SD 8.6, p = 0.012), to Cy-3 (9.6 SD 7.4, p = 0.049). The 50%RR increased from 30.7% (Cy-1) to 34.5% (Cy-2), to 38.7% (Cy-3). The above outcome measures did not differ in OLD compared with nonOLD patients. CONCLUSION: In a population of elderly CM patients with a long history of migraine OBT-A provided a significant benefit, over the first three treatment cycles, as good as in non-old patients.

Safety of anti-CGRP monoclonal antibodies in patients with migraine during the COVID-19 pandemic: Present and future implications.

BACKGROUND AND OBJECTIVE: CGRP, a neuropeptide involved in migraine pathophysiology, is also known to play a role in the respiratory system and in immunological conditions such as sepsis. We analyzed the impact of the use of CGRP antagonists in patients with migraine during the COVID-19 pandemic, caused by the SARS-CoV-2 coronavirus. METHODS: This is a multicentre cross-sectional study. From May to November 2020, through a national survey distributed by the Spanish Society of Neurology, we collected data about the presence of COVID-19 symptoms including headache and their characteristics and severity in patients with migraine treated with anti-CGRP monoclonal antibodies (mAb), and compared them with patients with migraine not receiving this treatment. We also conducted a subanalysis of patients with COVID-19 symptoms. RESULTS: We recruited 300 patients with migraine: 51.7% (155/300) were taking anti-CGRP mAbs; 87.3% were women (262/300). Mean age (standard deviation) was 47.1 years (11.6). Forty-one patients (13.7%) met diagnostic criteria for COVID-19, with no statistically significant difference between patients with and without anti-CGRP mAb treatment (16.1% vs 11.0%, respectively; P=.320). Of the patients with COVID-19, 48.8% (20/41) visited the emergency department and 12.2% (5/41) were hospitalised. Likewise, no clinical differences were found between the groups of patients with and without anti-CGRP mAb treatment. CONCLUSION: Anti-CGRP mAbs may be safe in clinical practice, presenting no association with increased risk of COVID-19.

Safety of anti-CGRP monoclonal antibodies in patients with migraine during the COVID-19 pandemic: Present and future implications.

BACKGROUND AND OBJECTIVE: CGRP, a neuropeptide involved in migraine pathophysiology, is also known to play a role in the respiratory system and in immunological conditions such as sepsis. We analyzed the impact of the use of CGRP antagonists in patients with migraine during the COVID-19 pandemic, caused by the SARS-CoV-2 coronavirus. METHODS: This is a multicentre cross-sectional study. From May to November 2020, through a national survey distributed by the Spanish Society of Neurology, we collected data about the presence of COVID-19 symptoms including headache and their characteristics and severity in patients with migraine treated with anti-CGRP monoclonal antibodies (mAb), and compared them with patients with migraine not receiving this treatment. We also conducted a subanalysis of patients with COVID-19 symptoms. RESULTS: We recruited 300 patients with migraine: 51.7% (155/300) were taking anti-CGRP mAbs; 87.3% were women (262/300). Mean age (standard deviation) was 47.1 years (11.6). Forty-one patients (13.7%) met diagnostic criteria for COVID-19, with no statistically significant difference between patients with and without anti-CGRP mAb treatment (16.1% vs 11.0%, respectively; P=.320). Of the patients with COVID-19, 48.8% (20/41) visited the emergency department and 12.2% (5/41) were hospitalised. Likewise, no clinical differences were found between the groups of patients with and without anti-CGRP mAb treatment. CONCLUSION: Anti-CGRP mAbs may be safe in clinical practice, presenting no association with increased risk of COVID-19.