Andrea Negro

Spreading depression and the clinical correlates of migraine

Abstract Migraine is the most common neurologic condition. One-third of migraineurs experience transient neurologic symptoms, the so-called aura. There is strong evidence that spreading depression (SD) is the electrophysiologic substrate of migraine aura. SD is an intense pan-depolarization wave that slowly propagates in gray matter by way of contiguity and transiently disrupts neuronal function. When induced subcortically, striatal SD causes hemiparesis, hippocampal SD can trigger seizures and impact cognition, and bilateral thalamic SD can diminish consciousness. Recent data show that transgenic mice expressing familial hemiplegic migraine (FHM) type 1 mutations in voltage-gated Ca2+ channels (Cav2.1) develop mutation-specific aura-like signs after a cortical SD similar to patients with the respective mutation. These signs are associated with facilitated subcortical SD propagation. As in FHM, mice with the R192Q mutation develop pure hemiplegia associated with cortical SDs propagating into caudoputamen. S218L mice display additional signs such as seizures and coma when SD propagates into hippocampus and thalamus. In hyperexcitable FHM brains, SD may propagate between cortex and subcortical structures via permissive gray matter bridges, or originate de novo in subcortical structures, to explain unusual and severe aura signs and symptoms. Reciprocal spread and reverberating waves can explain protracted attacks.

Sumatriptan succinate: pharmacokinetics of different formulations in clinical practice

Introduction: Migraine is a common neurovascular disorder characterized by recurrent episodes of disabling headache, autonomic nervous system dysfunction, and in some patients, neurological aura symptoms. Triptans are frequently prescribed drugs for the treatment of the acute migraine attack, considering their capability to provide wide efficacy and tolerability. Areas covered: This review discusses pharmacodynamics and pharmacokinetics of sumatriptan succinate, considering the clinical impact of new drug formulations in the treatment of acute migraine and cluster headache. The data were obtained by searching the following keywords in MEDLINE: sumatriptan succinate, pharmacokinetics, pharmacodynamics, triptans, migraine, new delivery systems, relative to the period 1989 – 2012. Expert opinion: Subcutaneous sumatriptan has been considered as the most efficacious treatment in the acute phase of migraine both on pain alone as well as on associated autonomic symptoms. Pharmacologically, pharmacokinetic parameters, in particular bioavailability, Tmax and Cmax are responsible for the wide efficacy of the compound and the limited adverse effect (AE) profile. The new drug formulations that are the most similar to the pharmacokinetics parameters of the subcutaneous one are promising because they both improve pharmacokinetic bioavailability bypassing the first-pass metabolism and increase patient compliance.

Abnormal synaptic Ca2+ homeostasis and morphology in cortical neurons of familial hemiplegic migraine type 1 mutant mice

Migraine is among the most common and debilitating neurological conditions. Familial hemiplegic migraine type 1 (FHM1), a monogenic migraine subtype, is caused by gain‐of‐function of voltage‐gated CaV2.1 calcium channels. FHM1 mice carry human pathogenic mutations in the α1A subunit of CaV2.1 channels and are highly susceptible to cortical spreading depression (CSD), the electrophysiologic event underlying migraine aura. To date, however, the mechanism underlying increased CSD/migraine susceptibility remains unclear.

Sensitivity to acute cerebral ischemic injury in migraineurs: A retrospective case-control study.

Objective: Migraine, particularly with aura, is a risk factor for ischemic stroke. Recent data in migraine mutant mice suggest that cerebral hyperexcitability associated with migraine accelerates recruitment of ischemic penumbra into the core, resulting in faster infarct growth compared with wild type. We hypothesized that individuals with a history of migraine are more likely to exhibit increased recruitment of ischemic tissue into the infarct in acute stroke. Methods: In this retrospective case-control study, we identified participants with reliably documented migraine history, measured lesion volumes on diffusion-weighted and perfusion-weighted MRI obtained within 72 hours of symptom onset, calculated the proportion of ischemic tissue on perfusion-weighted imaging (PWI) hyperintense on diffusion-weighted imaging (DWI), and compared the proportion of patients with no-mismatch pattern defined as DWI lesion >83% of PWI lesion. Results: Migraineurs (n = 45) were younger, more often female, less likely to have vascular risk factors, and more often had cervical artery dissection, but otherwise did not differ from controls (n = 27). A significantly larger proportion of migraineurs had no-mismatch pattern, indicating that the entire perfusion defect was recruited into the infarct by the time of MRI (22% vs 4% of migraineurs and controls, respectively; p = 0.044). The difference was even more prominent in migraineurs with aura (36% vs 4%, p = 0.019). The association between migraine and no-mismatch pattern persisted after adjustment for time to MRI (p = 0.041). Conclusions: This case-control study supports the hypothesis that a history of migraine, particularly with aura, is associated with a no-mismatch pattern during acute ischemic stroke, consistent with data obtained in migraine mutant mice.

Deciphering the task of N-acetyl aspartate in migraine

Evaluation of: de Tommaso M, Ceci E, Pica C et al. Serum levels of N-acetyl-aspartate in migraine and tension-type headache. J. Headache Pain 13(5), 389–394 (2012). Migraine is a common neurological disorder producing significant personal and societal burden. In the evaluated study, serum concentrations of N-acetyl aspartate (NAA), a biomarker of neuronal integrity, was found to be decreased in patients suffering from migraine with aura. These interesting results suggest a dual clinical readout. Since migraine-with-aura patients show an increased risk for stroke; the evaluation of serum levels of NAA is crucial in the control of the conventional risk factors. In addition, the therapeutic metabolite monitoring of NAA may be helpful in the assessment of the chronicization process.