Stefano Caproni

Critical role of calcitonin gene-related peptide receptors in cortical spreading depression

Cortical spreading depression (CSD) is a key pathogenetic step in migraine with aura. Dysfunctions of voltage-dependent and receptor-operated channels have been implicated in the generation of CSD and in the pathophysiology of migraine. Although a known correlation exists between migraine and release of the calcitonin gene-related peptide (CGRP), the possibility that CGRP is involved in CSD has not been examined in detail. We analyzed the pharmacological mechanisms underlying CSD and investigated the possibility that endogenous CGRP contributes to this phenomenon. CSD was analyzed in rat neocortical slices by imaging of the intrinsic optical signal. CSD was measured as the percentage of the maximal surface of a cortical slice covered by the propagation of intrinsic optical signal changes during an induction episode. Reproducible CSD episodes were induced through repetitive elevations of extracellular potassium concentration. AMPA glutamate receptor antagonism did not inhibit CSD, whereas NMDA receptor antagonism did inhibit CSD. Blockade of voltage-dependent sodium channels by TTX also reduced CSD. CSD was also decreased by the antiepileptic drug topiramate, but not by carbamazepine. Interestingly, endogenous CGRP was released in the cortical tissue in a calcium-dependent manner during CSD, and three different CGRP receptor antagonists had a dose-dependent inhibitory effect on CSD, suggesting a critical role of CGRP in this phenomenon. Our findings show that both glutamate NMDA receptors and voltage-dependent sodium channels play roles in CSD. They also demonstrate that CGRP antagonism reduces CSD, supporting the possible use of drugs targeting central CGRP receptors as antimigraine agents.

Palinopsia in patients with migraine: A case-control study

Objectives: This study was aimed at investigating the frequency of the visual phenomenon of palinopsia (visual perseveration) in patients with migraine. Methods: We interviewed 63 patients with migraine with aura (MwA), 137 patients with migraine without aura (MwoA) and 226 sex-age-matched healthy control subjects using an ad hoc structured interview/questionnaire. The interview was divided into four classes of variables for statistical testing. Results: Palinopsia occurred in 19/200 patients (9.5%); of them 10/63 had MwA and 9/137 MwoA (14.2% vs 6.6%, chi = 9.7, degrees of freedom = 1, p = 0.002). Patients with palinopsia had a significantly lower migraine attack frequency than those without this visual phenomenon (4.3 ± 0.3 vs 14.4 ± 0.2, z = 7.1, p < 0.0001). No healthy control subjects complained of palinopsia according to the structured interview/questionnaire. Discussion: Palinopsia is probably under-diagnosed in patients with migraine. Further investigations are needed to assess whether migraineurs are particularly susceptible to the development of recurrent episodes of visual perseveration.

Sodium valproate in migraine without aura and medication overuse headache: a randomized controlled trial.

OBJECTIVE To assess the efficacy, safety and tolerability of sodium valproate (800mg/die) compared with placebo in medication-overuse headache patients with a history of migraine without aura. METHODS This is a multicenter, randomized, double-blind, placebo-controlled study enrolled medication-overuse headache patients for a 3-month treatment period with sodium valproate (800mg/day) or placebo after a 6 day outpatient detoxification regimen, followed by a 3-month follow-up. Primary outcome was defined by the proportion of patients achieving ≥50% reduction in the number of days with headache per month (responders) from the baseline to the last 4 weeks of the 3-month treatment. Multivariate logistic regression models were used on the primary endpoint, adjusting for age, sex, disease duration, comorbidity and surgery. The last-observation-carried-forward method was used to adjust for missing values. RESULTS Nine sites enrolled 130 patients and, after a 6-day detoxification phase, randomized 88 eligible patients. The 3-month responder rate was higher in the sodium valproate (45.0%) than in the placebo arm (23.8%) with an absolute difference of about 20% (p=0.0431). Sodium valproate had safety and tolerability profiles comparable to placebo. CONCLUSIONS The present study supports the efficacy and safety of sodium valproate in the treatment of medication overuse headache with history of migraine after detoxification.

Psychopathological comorbidities in medication-overuse headache: a multicentre clinical study.

In medication‐overuse headache (MOH) patients, the presence of psychopathological disturbances may be a predictor of relapse and poor response to treatment. This multicentre study aimed to assess the occurrence of psychopathological disorders in MOH patients by comparing the incidence of psychopathological disturbances with episodic migraine (EM) patients and healthy controls (HC).

A novel ATP1A2 gene mutation in familial hemiplegic migraine and epilepsy.

Background Familial hemiplegic migraine (FHM) is a rare autosomal dominant migraine subtype, characterized by fully reversible motor weakness as a specific symptom of aura. Mutations in the ion transportation coding genes CACNA1A, ATP1A2 and SCN1A are responsible for the FHM phenotype. Moreover, some mutations in ATP1A2 or SCN1A also may lead to epilepsy. Case Here we report on a three-generation family with five patients having a novel ATP1A2 mutation on exon 19, causing guanine-to-adenine substitution (c.2620G>A, p.Gly874Ser) that co-segregated in the five living relatives with migraine, four of whom had hemiplegic migraine. Moreover, three patients presented with epilepsy, one of whom had generalized epilepsy with febrile seizures plus (GEFS+). Conclusions The present study provides further evidence on the involvement of ATP1A2 mutations in both migraine and epilepsy, underlying the relevance of genetic analysis in families with a comorbidity of both disorders.

Complexity of Motor Sequences and Cortical Reorganization in Parkinson's Disease: A Functional MRI Study

Motor impairment is the most relevant clinical feature in Parkinsons disease (PD). Functional imaging studies on motor impairment in PD have revealed changes in the cortical motor circuits, with particular involvement of the fronto-striatal network. The aim of this study was to assess brain activations during the performance of three different motor exercises, characterized by progressive complexity, using a functional fMRI multiple block paradigm, in PD patients and matched control subjects. Unlike from single-task comparisons, multi-task comparisons between similar exercises allowed to analyse brain areas involved in motor complexity planning and execution. Our results showed that in the single-task comparisons the involvement of primary and secondary motor areas was observed, consistent with previous findings based on similar paradigms. Most notably, in the multi-task comparisons a greater activation of supplementary motor area and posterior parietal cortex in PD patients, compared with controls, was observed. Furthermore, PD patients, compared with controls, had a lower activation of the basal ganglia and limbic structures, presumably leading to the impairment in the higher levels of motor control, including complexity planning and execution. The findings suggest that in PD patients occur both compensatory mechanisms and loss of efficiency and provide further insight into the pathophysiological role of distinct cortical and subcortical areas in motor dysfunction.

Migraine preventive drug-induced weight gain may be mediated by effects on hypothalamic peptides: The results of a pilot study

Aims: This study was aimed to verify changes in the levels of hypothalamic neuropeptides in migraineurs under preventive treatment with amitryptiline and flunarizine. Thirty-nine migraine patients with a body mass index <25 kg/m2 and without endocrinological or metabolic diseases were assigned to two treatment groups, one receiving amitryptiline, the other flunarizine, for 3 months. Orexin-A, orexin-B and neuropeptide-Y plasma levels were measured at the basal time, at the 1st, 2nd and 3rd months of preventive treatment. Results: A statistically significant reduction in plasma orexin-A and orexin-B levels emerged in both groups. Conversely, plasma neuropeptide-Y levels were markedly increased, with the highest levels at the 2nd and 3rd months, in both patient groups. Orexin-A levels were also negatively correlated to weight gain in both groups during the treatment period. Conclusions: These results suggest that changes in the levels of hypothalamic orexinergic peptides may contribute to body weight increase occurring in migraineurs during amitryptiline or flunarizine prophylactic treatment.

Epilepsy in hemiplegic migraine: Genetic mutations and clinical implications:

Objective We performed a systematic review on the comorbidities of familial/sporadic hemiplegic migraine (F/SHM) with seizure/epilepsy in patients with CACNA1A, ATP1A2 or SCN1A mutations, to identify the genotypes associated and investigate for the presence of mutational hot spots. Methods We performed a search in MEDLINE and in the Human Gene Mutation and Leiden Open Variation Databases for mutations in the CACNA1A, ATP1A2 and SCN1A genes. After having examined the clinical characteristics of the patients, we selected those having HM and seizures, febrile seizures or epilepsy. For each gene, we determined both the frequency and the positions at protein levels of these mutations, as well as the penetrance of epilepsy within families. Results Concerning F/SHM-Epilepsy1 (F/SHME1) and F/SHME2 endophenotypes, we observed a prevalent involvement of the transmembrane domains, and a strong correlation in F/SHME1 when the positively charged amino acids were involved. The penetrance of epilepsy within the families was highest for patients carrying mutation in the CACNA1A gene (60%), and lower in those having SCN1A (33.3%) and ATP1A2 (30.9%) mutations. Conclusion Among the HM cases with seizure/epilepsy, we observed mutational hot spots in the transmembrane domains of CACNA1A and ATP1A2 proteins. These findings could lead to a better understanding of the pathological mechanisms underlying migraine and epilepsy, therein guaranteeing the most appropriate therapeutic approach.

Stopping onabotulinum treatment after the first two cycles might not be justified: Results of a real-life monocentric prospective study in chronic migraine

Introduction Onabotulinum toxin A (OnabotA) cyclic treatment is approved for the prophylactic treatment of chronic migraine (CM), a highly disabling disorder. Although treatment response varies among patients, current guidelines suggest to stop treatment after cycle 2 if no response is achieved. This prospective study aimed to define, in real-life setting, the evolution of the response to OnabotA over five cycles of treatment among patients non-responding to cycle 1. The results of this study might help in decision-making, in particular whether prosecuting OnabotA further or not, when facing a patient not responding to cycle 1. Methods Patients failing to respond at cycle 1 were recruited to complete five cycles. Key outcomes were: (i) a ≥50% reduction in headache days, (ii) a ≥50% reduction in total cumulative hours of headache on headache days and (iii) a ≥5-point improvement in Headache Impact Test-6 (HIT-6) scores. Results Overall, 56 patients were included. Mean age was 45.7 years (female 83.9%). Severe (≥60) HIT-6 score was reported at baseline by 95.8% of patients. Responders (headache days reduction of more than 50%) progressively increased cycle after cycle, doubling from cycle 2 to cycle 5 (from 27 to 48%). In addition, patients regressed from CM to episodic migraine moving on with each cycle, with 78% of them reaching less than nine migraine days/month after cycle 5. The headache days per month decreased significantly from cycle 1 to cycle 5 (overall from 23.3 ± 5.7 to 9.2 ± 3.6; p < 0.001). During 12 months (5 cycles), migraine days per month progressively abated (from 18.5 to 8.7; p < 0.001), days with symptomatic medications intake/month consistently decreased (from 17.4 to 8.1; p < 0.001), and mean HIT-6 score lowered (from 72.4 ± 5.7 to 50.2 ± 4.3; p < 0.001). Conclusion The positive effect of OnabotA treatment spreads over the course of the treatment and might also manifest late in treatment course among patients with no benefit after the first two cycles. Thus, the results of this real-life study suggest to extend OnabotA treatment further, beyond cycle 2, to avoid premature withdrawal in patients who would have become responders at cycle 3, 4, or 5.

HDAC3 role in medication consumption in medication overuse headache patients: a pilot study

BackgroundMedication overuse headache (MOH) is a common and debilitating disorder characterized by generation, perpetuation, and persistence of intense chronic migraine, caused by overuse of analgesics, triptans, or other acute headache compounds. It has been suggested that MOH could share some pathogenetic mechanisms with other kinds of drug addiction. In this regard, histone deacetylases 3 (HDAC3) seems to have a role in the memory processes involved in extinction of drug-seeking behavior in animal models. HDAC3 is inhibited by sodium valproate, a drug with proven efficacy in MOH. Recent evidence suggests an involvement of genetic factors in predisposition to medication overuse.ResultsIn this association study, we sequenced all exons, intron/exon junctions, and 3′-5′UTR regions of HDAC3 in 23 MOH patients to investigate its role in medication overuse. Associations between genotypes with continuous and dichotomous clinical characteristics were tested by multivariate analysis and Fisher’s exact test, respectively.Sequencing of HDAC3 revealed six single-nucleotide polymorphisms. The G allele of rs2530223 was significantly associated with the number of acute medications/month used and with the number of days/month in which medications were used (p = 0.006 and p = 0.007, respectively), but neither with headache frequency or intensity. None of the single-nucleotide polymorphisms (SNPs) was associated with clinical characteristics or response to sodium valproate.ConclusionsHDAC3 could be implicated in excessive medication consumption in MOH patients. Our preliminary findings provide support for the need of further investigation on larger independent samples to confirm and extend the role of HDAC3 in medication overuse headache.