The good, the bad and the ugly of pain in haemophilia: Recent evidence on the epidemiology, molecular mechanisms and knowledge gaps preventing optimal treatment.

INTRODUCTION: Haemophilia is an inherited, X-linked blood clotting disorder caused by the deficiency of coagulation factors VIII (FVIII, haemophilia A) or IX (FIX, haemophilia B). Spontaneous bleeds are common in severe forms of haemophilia and can also occur in moderate and mild haemophilia. Severe or repeated bleeding at a joint can evolve into chronic haemophilic arthropathy, with functional damage of the joint, disability, and intense chronic articular pain. Nonetheless, acute and chronic pain may emerge due to secondary conditions related to bleedings. AIM: This narrative review aims to critically discuss the most recent evidence about pain in haemophilia to give healthcare professionals a clear picture of current knowledge hence favouring the optimisation of clinical management of pain. METHODS: Extensive literature search with the terms 'hemophilia' AND 'pain', focusing on the time window 2021-2023. RESULTS: Acute and chronic pain is a critical aspect of haemophilia at all ages. It should be considered a multifaceted phenomenon, with a positive role as an early emergency signal of a clinical event (haemarthrosis), and numerous detrimental aspects linked to its burden that heavily affects the health-related quality of life, with psychological and social consequences. CONCLUSION: Despite its prevalence and frequency in people with haemophilia, pain is often underestimated by healthcare professionals, leading to insufficient and inadequate treatment, also due to uncertainty linked to the presence of the coagulation disorder or arthritic flares.

Endometriosis and the diagnosis of different forms of migraine: an association with dysmenorrhoea.

RESEARCH QUESTION: Women with endometriosis are frequently affected by headache. How many of these have a clear diagnosis of migraine? Are the different forms of migraine related to the phenotypes and/or characteristics of endometriosis? DESIGN: This was a prospective nested case-control study. A consecutive series of 131 women with endometriosis who attended the endometriosis clinic were enrolled and examined for the presence of headache. A headache questionnaire was used to determine the characteristics of the headaches, and the diagnosis of migraine was confirmed by a specialist. The case group included women with endometriosis and a diagnosis of migraine, while the control group included women with only endometriosis. History, symptoms and other comorbidities were collected. A pelvic pain score and associated symptoms were assessed using a visual analogue scale. RESULTS: A diagnosis of migraine was made in 53.4% (70/131) of participants. Pure menstrual migraine was reported by 18.6% (13/70), menstrually related migraine by 45.7% (32/70) and non-menstrual migraine by 35.7% (25/70). Dysmenorrhoea and dysuria were significantly more frequent in patients with endometriosis and migraine than in those without migraine (P = 0.03 and P = 0.01). No difference was found for other variables, including age at diagnosis and duration of endometriosis, endometriosis phenotype, the presence of other autoimmune comorbidities or heavy menstrual bleeding. In most patients with migraine (85.7%) the headache symptoms had started years before the diagnosis of endometriosis. CONCLUSION: The occurrence of headache in many patients with endometriosis is associated with the presence of different forms of migraine, is related to pain symptoms and often precedes the diagnosis of endometriosis.

Utilization patterns, cardiovascular risk, and concomitant serotoninergic medications among triptan users between 2008 and 2018: A gender analysis in one Italian region, Tuscany.

OBJECTIVE: To describe the pattern of triptan use by gender in Tuscany, Italy, focusing on special user populations in which evidence on triptan safety is still not conclusive. BACKGROUND: Growing evidence supports the role of gender differences in migraine pathophysiology and treatment. However, gender impact on triptan real-word utilization has been poorly investigated. METHODS: A retrospective, descriptive, cohort study was performed using the population-based Administrative Healthcare Database of Tuscany region (Italy). Subjects registered in the database on the January 1 of each year between 2008 and 2018 were identified. New users (NU) of triptans (ATC:N02CC*) were patients with one or more triptan dispensation during the year of interest and none in the past. Age, cardiovascular comorbidities representing an absolute or a possible contraindication to triptan utilization, concomitant serotonergic medications, and pattern of triptan use during 1-year follow-up were described by gender. RESULTS: A total of 86,109 patients who received one or more triptan dispensing were identified. Of 64,672 NU (men = 17,039; women = 47,633), 10.2% (6823/64,672) were aged >65 years, who were mostly women (n = 4613). Among NU, men and women with absolute cardiovascular contraindications were 4.3% (740/17,039) and 2.1% (1022/47,633), respectively, while those concomitantly taking serotonergic medications were 17.2% (267/1549) and 21.9% (949/4330), respectively (949/4330). Regular users (two or more dispensing with ≥3 months between first and last observed dispensing) accounted for 26.4% of women (12,597/47,633) and 19.11% of men (3250/17,039); frequent users (≥15 dosage units/month during ≥3 consecutive months) were overall 0.1% (94/64,672) and 62.0% (58/94) of them concomitantly received serotonergic medications. CONCLUSION: Considering gender differences in triptan use highlighted here, large scale observational studies are warranted to better define what populations are safe to use triptans and whether it is appropriate to tighten or relax certain recommendations on triptan use. In the meantime, any suspected adverse drug reaction observed in the special user populations highlighted in this study should be promptly reported.

Effectiveness of anti-CGRP monoclonal antibodies on central symptoms of migraine.

BACKGROUND: Clinical trials and observational studies with anti-calcitonin gene-related peptide antibodies poorly investigated their impact on migraine prodromal and accompanying symptoms. This information might help deciphering the biologics' pharmacodynamic and provide hints on migraine pathogenesis. Herein, we report the effects of erenumab, fremanezumab and galcanezumab on attack prodromal and accompanying symptoms and on neurological and psychiatric traits. . METHODS: An explorative, prospective, questionnaire-based study was completed by a cohort (n = 80) of patients with chronic migraine patients presenting a sustained reduction of ≥50% of Migraine Disability Assessment Score and ≥30% of monthly migraine days three months after anti-calcitonin gene-related peptide antibodies treatment. RESULTS: The majority of patients experienced a complete prevention of migraine symptoms without evidence of initial onset followed by attack abortion. Few patients reported the recurrence of prodromal (from 10% to 12.5%) or accompanying (from 1.3% to 8.8%) symptoms without headache. All patients with migraine with aura reported a decrease of aura incidence. Sleep changes (51.2%), increase in appetite (20.0%) and weight (18.8%) as well as a reduction in stress (45.0%), anxiety (26.3%), and panic attacks (15%) were also reported. CONCLUSION: Anti-calcitonin gene-related peptide antibodies seems to significantly impact brain functions of migraineurs, preventing not only migraine headache but also its anticipatory and accompanying symptoms.

Self-administered subcutaneous diclofenac sodium in acute migraine attack: A randomized, double-blind, placebo-controlled dose-finding pilot study.

BACKGROUND: A novel formulation of diclofenac, complexed with hydroxypropyl-ß-cyclodextrin (HPßCD) as a solubility enhancer, in a prefilled syringe for self-administered subcutaneous injection may overcome the limitations of acute migraine treatments administered by oral, rectal, intramuscular, or intravenous routes. METHODS: This multicentre, phase 2, double-blind, randomized, placebo-controlled, dose-finding pilot study evaluated the efficacy, safety and tolerability of three different doses (25/50/75 mg/1 mL) of subcutaneous diclofenac sodium in the treatment of an acute migraine attack in 122 subjects. The primary efficacy endpoint was the percentage of patients pain-free at 2 hours after the study drug injection. RESULTS: A significantly higher percentage of patients in the 50 mg diclofenac group 14 (46.7%) were pain-free at 2 hours when compared with placebo: 9 (29.0%) (p = 0.01). The 50 mg dose proved superior to placebo also in the majority of the secondary endpoints. The overall global impression favoured diclofenac vs placebo. There were no adverse events leading to study withdrawal. The majority of treatment-emergent adverse events were mild. CONCLUSIONS: The 50 mg dose of this novel formulation of diclofenac represents a valuable self-administered option for the acute treatment of migraine attacks.Trial registration: EudraCT Registration No. 2017-004828-29.

Predictors of sustained response and effects of the discontinuation of anti-calcitonin gene related peptide antibodies and reinitiation in resistant chronic migraine.

BACKGROUND AND PURPOSE: Guidelines for migraine prophylaxis suggest stopping medication after 6-12 months to reevaluate treatment appropriateness. The Italian Medicines Agency set a mandatory regulation to stop anti-calcitonin gene related protein (CGRP) pathway monoclonal antibody (anti-CGRP mAb) treatments for 3 months after 12 months of treatment. Herein, the effects of discontinuation and retreatment of anti-CGRP mAbs in resistant chronic migraine patients are assessed, evaluating predictive factors of sustained response. METHODS: This was a monocentric prospective cohort study, enrolling 44 severe (resistant to ≥3 preventive treatments) chronic migraine patients (all with medication-overuse), treated with erenumab (54.5%) or galcanezumab (45.5%) for 12 months, who discontinued treatment for 3 months and then restarted for 1 month. RESULTS: Overall, patients reported an increasing deteriorating trend during the 3 months of discontinuation. Monthly migraine days, number of analgesics, days with at least one analgesic used, a ≥50% response rate (reduction in monthly migraine days), and Migraine Disability Assessment Score and Headache Impact Test 6 total score, remained lower than baseline values, but increased compared to month 12 of treatment. All outcome measures decreased again during the month of retreatment. Patients who did not meet criteria for restarting treatment had a lower Migraine Disability Assessment Score (p = 0.03) and Headache Impact Test 6 (p = 0.01) score at baseline and better outcome measures during discontinuation compared to patients who restarted treatment. CONCLUSIONS: In most patients, the 3-month discontinuation of anti-CGRP mAbs resulted in progressive migraine deterioration that was rapidly reverted by retreatment. However, one-quarter of patients who reported better quality of life indices before treatment showed a sustained benefit during discontinuation and did not need retreatment.

Mental pain as a global person-centered outcome measure.

BACKGROUND: Mental pain has been proposed as a global person-centered outcome measure. The aim of this cross-sectional study was to test an essential requisite of such a measure, namely that mental pain incorporates independent contributions from a range of discrete but disparate outcome measures. METHODS: Two hundred migraine patients were assessed concerning migraine disability, psychosomatic syndromes, mental pain, depression, anxiety, and psychosocial dimensions. General linear models were tested to verify which measures would individually make unique contributions to overall mental pain. RESULTS: The final model, accounting for 44% of variance, identified that higher mental pain was associated with more severe depressive symptoms, higher migraine disability, lower well-being, and poorer quality of life. CONCLUSION: In this sample, mental pain was shown to behave as expected of a global outcome measure, since multiple measures of symptomatology and quality of life showed modest but significant bivariate correlations with mental pain and some of these measures individually made unique contributions to overall mental pain.

Time lost due to an attack - a novel patient-reported outcome measure for acute migraine treatments.

OBJECTIVE: We propose a new outcome measure to assess the efficacy of migraine treatments translating the approach of the Global Burden of Disease studies from a societal to an individual level: Instead of calculating "years lived with disability", we suggest estimating "time lost due to an attack". METHODS: Time lost due to an attack is calculated by multiplying the duration and the degree of impaired functioning during an attack. RESULTS: Time lost due to an attack, different from other outcome measures, does not just focus on the short-term analgesic effects of treatments, but rather on the improvement of all migraine symptoms and restoration of functioning, also considering therapy-related impairment. Importantly, time lost due to an attack measures the entire time patients are not functioning normally, from onset to complete resolution. CONCLUSIONS: Time lost due to an attack represents a new paradigm to assess migraine burden in single patients for a patient-centered evaluation of both acute and prophylactic treatments.

Mental pain and pain-proneness in patients with migraine: results from the PAINMIG cohort-study.

BACKGROUND: Pain has been qualified under four categories: nociception, perception of pain, suffering, and pain behaviors. Most of the literature on migraine has devoted attention to the first two. The aim of the present cohort study was to investigate patients with migraine enrolled at a tertiary care unit to study suffering and mental pain and identify potential risk factors for migraine. METHODS: An observational cross-sectional study was carried out on patients with chronic migraine (CM) and episodic migraine (EM), and healthy subjects (HS). The three groups were matched for age and sex. A comprehensive assessment of migraine disability, pain, psychiatric disorders, psychosomatic syndromes, depressive and anxious symptoms, euthymia, psychosocial variables, mental pain, and pain-proneness (PP) was performed. RESULTS: Three hundred subjects were enrolled (100 CM, 100 EM, and 100 HS). Based on the multiple regression analyses, those presenting PP (social impairment: odds ratio [OR] = 3.59, 95% confidence interval [CI] = 1.14-11.29; depressive symptoms: OR = 3.82, 95% CI = 1.74-8.41) were more likely to be CM than HS. Those with higher levels of PP (social impairment: OR = 4.04, 95% CI = 1.60-10.22; depressive symptoms: OR = 2.02, 95% CI = 1.26-3.24) were more likely to be EM than HS. Those presenting higher levels of mental pain were more likely to be CM than EM (OR = 1.45, 95% CI = 1.02-2.07). CONCLUSION: Migraine is an unpleasant sensory and emotional experience associated with psychosocial manifestations that might contribute to the level of suffering of the individuals. Mental pain resulted to be the variable that most differentiated patients with CM from EM.

Medicines for headache before and during pregnancy: a retrospective cohort study (ATENA study).

OBJECTIVE: To investigate headache treatment before and during pregnancy. BACKGROUND: Most headaches in pregnancy are primary disorders. Headaches are likely to ameliorate during pregnancy, although they may also begin or worsen. Most headache medications should be avoided during pregnancy because of potential fetal risks. However, only scarce evidence on headache drug consumption during pregnancy is available. DESIGN: ATENA was a retrospective, self-administered questionnaire-based, cohort study on women in either pregnancy or who have just delivered and reporting headache before and/or during pregnancy. RESULTS: Out of 271 women in either pregnancy or who have just delivered, 100 (37%) reported headache before and/or during pregnancy and constituted our study sample. Before pregnancy, the attitude toward the use of symptomatic drugs was characterized by both a strong focus on their safety and the willingness to avoid possible dependence from them. Compared to the year before, pregnancy led to changes in behavior and therapeutic habits as shown by a higher proportion of patients looking for information about drugs (44/100 [44%] vs. 36/100 [36%]) and a lower proportion of those treating headache attacks (88/100 [88%] vs. 52/100 [52%]) and by a lower use of nonsteroidal anti-inflammatory drugs (68/100 [68%] vs. 5/100 [5%]) and a much higher use of paracetamol (33/100 [33%] vs. 95/100 [95%]). CONCLUSIONS: Pregnancy changes how women self-treat their headache, and leads to search for information regarding drug safety, mostly due to the perception of fetal risk of drugs. Healthcare providers have to be ready to face particular needs of pregnant women with headache.

Low-dose methadone for refractory chronic migraine accompanied by medication-overuse headache: a prospective cohort study.

OBJECTIVES: A refractory chronic migraine (RCM) accompanied by medication-overuse headache (MOH) is an extremely disabling disease. Evidence suggests that in selected patients, chronic opioids may be a valuable therapeutic option for RCM. The aim of the present study was to evaluate the effectiveness and safety of prophylaxis with low-dose methadone (LDM) in patients affected by RCM with continuous headache and MOH. METHODS: A prospective cohort study was performed between May 2012 and November 2015 at the Headache Center and Toxicology Unit of the Careggi University Hospital. Eligible patients were treated with prophylactic LDM and followed up for 12 months. Headache exacerbations, pain intensity, use of rescue medications, and occurrence of adverse drug reactions (ADRs) were recorded. RESULTS: Thirty patients (24 females, median age 48 years) were enrolled. Nineteen (63%) patients dropped out, mainly because of early ADRs (n = 10), including nausea, vomiting, and constipation. At last available follow-up, LDM was associated with a significant decrease in the number of headache attacks/month (from a median of 45 (interquartile range 30-150) to 16 (5-30), p < 0.001), in pain intensity (from 8.5 (8-9) to 5 (3-6), p < 0.001), and in the number of rescue medications consumed per month (from 95 (34-240) to 15 (3-28), p < 0.001). No misuse or diversion cases were observed. CONCLUSION: LDM could represent a valuable and effective option in selected patients affected by RCM with continuous headache and MOH, although the frequency of early ADRs poses major safety concerns. Randomized controlled trials are needed to confirm the efficacy and safety of LDM prophylaxis.

Criterion-related validity in a sample of migraine outpatients: the diagnostic criteria for psychosomatic research.

OBJECTIVE: The Diagnostic Criteria for Psychosomatic Research (DCPR) are those of psychosomatic syndromes that did not find room in the classical taxonomy. More recently, the DCPR were updated, called DCPR-revised (DCPR-R). The present study was conducted to test the criterion-related validity of the DCPR-R. METHODS: Two hundred consecutive subjects were enrolled at the Headache Center of Careggi University Hospital (Italy): 100 subjects had a diagnosis of chronic migraine (CM) and 100 had a diagnosis of episodic migraine (EM). Participants received a clinical assessment, which included the DCPR-revised Semi-Structured Interview (DCPR-R SSI), the Structured Clinical Interview for DSM-5 (SCID-5), and the psychosocial index (PSI). RESULTS: Forty-seven subjects (23.5%) had at least one DSM-5 diagnosis: major depressive disorder (8.5%; n = 17) and agoraphobia (7.5%; n = 15) were the most frequent. One hundred and ten subjects (55%) reported a DCPR-R diagnosis: allostatic overload (29%; n = 58) and type A behavior (10.5%; n = 21) were the most frequent. When the incremental validity of the DCPR system over the DSM system was tested using PSI subscales as the criterion variable, the DCPR-R increased up to 0.11-0.24 the amount of explained variance. Subjects with at least one DCPR-R diagnosis showed lower PSI well-being scores (p = .001), higher PSI stress scores (p < .001), and higher PSI psychological distress scores (p = .008) than subjects without a DCPR-R diagnosis. CONCLUSION: The DCPR-R showed a good criterion-related validity in migraine outpatients. Thus, they might be implemented, together with the DSM-5, in the assessment of migraine subjects.

Nummular headache: a gender-oriented perspective on a case series from the RegistRare Network.

BACKGROUND: Nummular headache (NH) is a rare headache disorder characterized by a small, circumscribed painful area of the scalp. The description of many cases in the last years has supported its re-classification as a primary headache from the International Headache Society, moving it from its previous placement in the Appendix of the International Criteria of Headache Disorders. METHODS: Data were collected from a retro-prospective observational study about rare headaches promoted by the RegistRare Network, a collaborative group of seven Italian Headache Centres. According to the gender-biased profile of certain primary headaches, we have looked further NH patients from a gender perspective. RESULTS: Nineteen NH patients (11 men, 8 women) have been enrolled in the study. Headache onset was at 39 years and preceded approximately 8 years the diagnosis. No clinically evident differences between men and women have been found, including treatment prescriptions and headache resolution. Of note, the mean time from the onset of NH to the first visit in a Headache Centre was longer in men, compared with women (13.5 vs. 0.9 years). NH attacks were efficaciously treated with nonsteroidal anti-inflammatory drugs in 60% of patients receiving treatment. Headache prophylaxis with pregabalin and amitriptyline has been reported as effective in 40% and 67% of the treated patients, respectively. CONCLUSIONS: NH is a primary headache clinically heterogeneous in terms of temporal patterns and pain characteristics. Further research is needed to investigate the existence of male and female phenotypes, by clarifying whether it may be relevant for therapeutic purposes.

Persistent post-traumatic headache: a migrainous loop or not? The preclinical evidence.

BACKGROUND: According to the International Classification of Headache Disorders 3, post-traumatic headache (PTH) attributed to traumatic brain injury (TBI) is a secondary headache reported to have developed within 7 days from head injury, regaining consciousness following the head injury, or discontinuation of medication(s) impairing the ability to sense or report headache following the head injury. It is one of the most common secondary headache disorders, and it is defined as persistent when it lasts more than 3 months. MAIN BODY: Currently, due to the high prevalence of this disorder, several preclinical studies have been conducted using different animal models of mild TBI to reproduce conditions that engender PTH. Despite representing a simplification of a complex disorder and displaying different limitations concerning the human condition, animal models are still a mainstay to study in vivo the mechanisms of PTH and have provided valuable insight into the pathophysiology and possible treatment strategies. Different models reproduce different types of trauma and have been ideated in order to ensure maximal proximity to the human condition and optimal experimental reproducibility. CONCLUSION: At present, despite its high prevalence, PTH is not entirely understood, and the differential contribution of pathophysiological mechanisms, also observed in other conditions like migraine, has to be clarified. Although facing limitations, animal models are needed to improve understanding of PTH. The knowledge of currently available models is necessary to all researchers who want to investigate PTH and contribute to unravel its mechanisms.

Persistent post-traumatic headache: a migrainous loop or not? The clinical evidence.

BACKGROUND: Headache is a common complication of traumatic brain injury. The International Headache Society defines post-traumatic headache as a secondary headache attributed to trauma or injury to the head that develops within seven days following trauma. Acute post-traumatic headache resolves after 3 months, but persistent post-traumatic headache usually lasts much longer and accounts for 4% of all secondary headache disorders. MAIN BODY: The clinical features of post-traumatic headache after traumatic brain injury resemble various types of primary headaches and the most frequent are migraine-like or tension-type-like phenotypes. The neuroimaging studies that have compared persistent post-traumatic headache and migraine found different structural and functional brain changes, although migraine and post-traumatic headache may be clinically similar. Therapy of various clinical phenotypes of post-traumatic headache almost entirely mirrors the therapy of the corresponding primary headache and are currently based on expert opinion rather than scientific evidence. Pharmacologic therapies include both abortive and prophylactic agents with prophylaxis targeting comorbidities, especially impaired sleep and post-traumatic disorder. There are also effective options for non-pharmacologic therapy of post-traumatic headache, including cognitive-behavioral approaches, onabotulinum toxin injections, life-style considerations, etc. CONCLUSION: Notwithstanding some phenotypic similarities, persistent post-traumatic headache after traumatic brain injury, is considered a separate phenomenon from migraine but available data is inconclusive. High-quality studies are further required to investigate the pathophysiological mechanisms of this secondary headache, in order to identify new targets for treatment and to prevent disability.

TRPA1/NOX in the soma of trigeminal ganglion neurons mediates migraine-related pain of glyceryl trinitrate in mice.

Glyceryl trinitrate is administered as a provocative test for migraine pain. Glyceryl trinitrate causes prolonged mechanical allodynia in rodents, which temporally correlates with delayed glyceryl trinitrate-evoked migraine attacks in patients. However, the underlying mechanism of the allodynia evoked by glyceryl trinitrate is unknown. The proalgesic transient receptor potential ankyrin 1 (TRPA1) channel, expressed by trigeminal nociceptors, is sensitive to oxidative stress and is targeted by nitric oxide or its by-products. Herein, we explored the role of TRPA1 in glyceryl trinitrate-evoked allodynia. Systemic administration of glyceryl trinitrate elicited in the mouse periorbital area an early and transient vasodilatation and a delayed and prolonged mechanical allodynia. The systemic, intrathecal or local administration of selective enzyme inhibitors revealed that nitric oxide, liberated from the parent drug by aldehyde dehydrogenase 2 (ALDH2), initiates but does not maintain allodynia. The central and the final phases of allodynia were respectively associated with generation of reactive oxygen and carbonyl species within the trigeminal ganglion. Allodynia was absent in TRPA1-deficient mice and was reversed by TRPA1 antagonists. Knockdown of neuronal TRPA1 by intrathecally administered antisense oligonucleotide and selective deletion of TRPA1 from sensory neurons in Advillin-Cre; Trpa1fl/fl mice revealed that nitric oxide-dependent oxidative and carbonylic stress generation is due to TRPA1 stimulation, and resultant NADPH oxidase 1 (NOX1) and NOX2 activation in the soma of trigeminal ganglion neurons. Early periorbital vasodilatation evoked by glyceryl trinitrate was attenuated by ALDH2 inhibition but was unaffected by TRPA1 blockade. Antagonists of the calcitonin gene-related peptide receptor did not affect the vasodilatation but partially inhibited allodynia. Thus, although both periorbital allodynia and vasodilatation evoked by glyceryl trinitrate are initiated by nitric oxide, they are temporally and mechanistically distinct. While vasodilatation is due to a direct nitric oxide action in the vascular smooth muscle, allodynia is a neuronal phenomenon mediated by TRPA1 activation and ensuing oxidative stress. The autocrine pathway, sustained by TRPA1 and NOX1/2 within neuronal cell bodies of trigeminal ganglia, may sensitize meningeal nociceptors and second order trigeminal neurons to elicit periorbital allodynia, and could be of relevance for migraine-like headaches evoked by glyceryl trinitrate in humans.

Development and validation of the ID-EC - the ITALIAN version of the identify chronic migraine.

BACKGROUND: Case-finding tools, such as the Identify Chronic Migraine (ID-CM) questionnaire, can improve detection of CM and alleviate its significant societal burden. We aimed to develop and validate the Italian version of the ID-CM (ID-EC) in paper and as a smart app version in a headache clinic-based setting. METHODS: The study investigators translated and adapted to the Italian language the original ID-CM questionnaire (ID-EC) and further implemented it as a smart app. The ID-EC was tested in its paper and electronic version in consecutive patients referring to 9 Italian tertiary headache centers for their first in-person visit. The scoring algorithm of the ID-EC paper version was applied by the study investigators (case-finding) and by patients (self-diagnosis), while the smart app provided to patients automatically the diagnosis. Diagnostic accuracy of the ID-EC was assessed by matching the questionnaire results with the interview-based diagnoses performed by the headache specialists during the visit according to the criteria of International Classification of Headache Disorders, III edition, beta version. RESULTS: We enrolled 531 patients in the test of the paper version of ID-EC and 427 in the validation study of the smart app. According to the clinical diagnosis 209 patients had CM in the paper version study and 202 had CM in the smart app study. 79.5% of patients returned valid paper questionnaires, while 100% of patients returned valid and complete smart app questionnaires. The paper questionnaire had a 81.5% sensitivity and a 81.1% specificity for case-finding and a 30.7% sensitivity and 90.7% specificity for self-diagnosis, while the smart app had a 64.9% sensitivity and 90.2% specificity. CONCLUSIONS: Our data suggest that the ID-EC, developed and validated in tertiary headache centers, is a valid case-finding tool for CM, with sensitivity and specificity values above 80% in paper form, while the ID-EC smart app is more useful to exclude CM diagnosis in case of a negative result. Further studies are warranted to assess the diagnostic accuracy of the ID-EC in general practice and population-based settings.

Rare primary headaches in Italian tertiary Headache Centres: Three year nationwide retrospective data from the RegistRare Network.

Background Rare primary headaches are mainly included in Chapters 3, Trigeminal autonomic cephalalgias, and 4, Other primary headache disorders, Part One of the International Classification of Headache Disorders 3rd edition. Epidemiological data are scarce, mostly emerging from case series or small studies, with the exception of cluster headache. In order to overcome the knowledge gap about rare primary headaches, the RegistRare Network was launched in 2017 to promote research in the field. Methods A retrospective cohort study including patients who, from April 30, 2014 to May 1, 2017, visited seven Italian tertiary Headache Centres, was undertaken to estimate in that clinical setting prevalence and incidence of headaches included in Chapters 3 and 4, Part One of the International Classification of Headache Disorders 3rd edition. Prevalent headache is defined as a headache recorded within the study timeframe, regardless of when the diagnosis was made. Incident headache is defined as a headache diagnosed for the first time in the patient during the study period. Results Twenty thousand and eighty-three patients visited the participating centres, and 822 (4.1%) prevalent cases, of which 461 (2.3%) were incident cases, were registered. Headaches listed in Chapter 3 affected 668 patients, representing 81.3% of the total number of prevalent cases. Headaches listed in Chapter 4 affected 154 patients and represent 18.7% of the total number of prevalent cases. Cluster headaches represent the most frequently diagnosed rare headaches (70.4%). For 13 entities out of 20, no cases were registered in more than 50% (n ≥ 4) of the centres, and for 14 entities more than 50% of diagnoses were incident. Conclusions This large, multicentre study gives the first wide-ranging snapshot of the burden in clinical practice of rare headaches and confirms that cooperative networks are necessary to study rare headaches, as their prevalence is often very low. The launch of a disease registry by the RegistRare Network will favour research in this neglected population of headache patients. Trial registration NCT03416114.

Migraine and cluster headache - the common link.

Although clinically distinguishable, migraine and cluster headache share prominent features such as unilateral pain, common pharmacological triggers such glyceryl trinitrate, histamine, calcitonin gene-related peptide (CGRP) and response to triptans and neuromodulation. Recent data also suggest efficacy of anti CGRP monoclonal antibodies in both migraine and cluster headache. While exact mechanisms behind both disorders remain to be fully understood, the trigeminovascular system represents one possible common pathophysiological pathway and network of both disorders. Here, we review past and current literature shedding light on similarities and differences in phenotype, heritability, pathophysiology, imaging findings and treatment options of migraine and cluster headache. A continued focus on their shared pathophysiological pathways may be important in paving future treatment avenues that could benefit both migraine and cluster headache patients.

Vasodilator activity of hydrogen sulfide (H2S) in human mesenteric arteries.

The role of endogenous H2S has been highlighted as a gaseous transmitter. The vascular smooth muscle inhibitory effects of H2S have been characterized in isolated aorta and mesenteric arteries in rats and mice. Our study was aimed at investigating the vascular effects of H2S on human isolated mesenteric arteries and examining the underlying mechanisms involved. All experiments were performed on rings (4-8mm long) of human mesenteric arteries obtained from patients undergoing abdominal surgery. Ethical approval was obtained from the Ethics Committee of the University Hospital of the University of Florence (app. N. 2015/0024947). The effect of NaHS, an H2S donor, was determined using noradrenaline pre-contracted human isolated mesenteric rings. NaHS evoked a concentration-dependent relaxation (EC50 57µM). In contrast, homocysteine, an endogenous precursor of H2S, failed to affect human isolated mesenteric rings. Vasorelaxant response to NaHS was reduced by endothelium removal, application of the nitric oxide synthase inhibitor L-NAME and ODQ inhibitor of cyclic GMP. SQ 22536, an adenylate-cyclase inhibitor, failed to block NaHS-induced vasorelaxation. Inhibition of endogenous prostanoid production by indomethacin significantly reduced NaHS induced vasorelaxation. The role of potassium channels was also examined: blockers of the Ca2+-dependent potassium channel, charybdotoxin and apamin, failed to have any influence on the relaxant response to NaHS on this vascular tissue. In summary, H2S induced relaxation of isolated rings of human mesenteric arteries. Endothelium-dependent related mechanisms with the stimulation of ATP-sensitive potassium channels represents important cellular mechanisms for H2S effect on human mesenteric arteries.