Background Engaging the endocannabinoid system through inhibition of monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), degrading endocannabinoids (endoCBs) 2... Show moreBackground Engaging the endocannabinoid system through inhibition of monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), degrading endocannabinoids (endoCBs) 2-arachidonoylglycerol (2-AG) and anandamide (AEA), was proposed as a promising approach to ameliorate migraine pain. However, the activity of MAGL and FAAH and action of endoCB on spiking activity of meningeal afferents, from which migraine pain originates, has not been explored thus far. Therefore, we here explored the analgesic effects of endoCB enhancement in rat and human meningeal tissues.Methods Both MAGL and FAAH activity and local 2-AG and AEA levels were measured by activity-based protein profiling (ABPP) and LC-MS/MS, respectively, in rat meninges obtained from hemiskulls of P38-P40 Wistar rats and human meninges from elderly patients undergoing non-migraine related neurosurgery. The action on endoCBs upon administration of novel dual MAGL/FAAH inhibitor AKU-005 on meningeal afferents excitability was tested by investigating paired KCl-induced spiking and validation with local (co-)application of either AEA or 2-AG. Finally, the specific TRPV1 agonist capsaicin and blocker capsazepine were tested.Results The basal level of 2-AG exceeded that of AEA in rat and human meninges. KCl-induced depolarization doubled the level of AEA. AKU-005 slightly increased spontaneous spiking activity whereas the dual MAGL/FAAH inhibitor significantly decreased excitation of nerve fibres induced by KCl. Similar inhibitory effects on meningeal afferents were observed with local applications of 2-AG or AEA. The action of AKU-005 was reversed by CB1 antagonist AM-251, implying CB1 receptor involvement in the anti-nociceptive effect. The inhibitory action of AEA was also reversed by AM-251, but not with the TRPV1 antagonist capsazepine. Data cluster analysis revealed that both AKU-005 and AEA largely increased long-term depression-like meningeal spiking activity upon paired KCl-induced spiking.Conclusions In the meninges, high anti-nociceptive 2-AG levels can tonically counteract meningeal signalling, whereas AEA can be engaged on demand by local depolarization. AEA-mediated anti-nociceptive effects through CB1 receptors have therapeutic potential. Together with previously detected MAGL activity in trigeminal ganglia, dual MAGL/FAAH inhibitor AKU-005 appears promising as migraine treatment. Show less
Background Migraine is a highly prevalent disorder with significant economical and personal burden. Despite the development of effective therapeutics, the causes which precipitate migraine attacks... Show moreBackground Migraine is a highly prevalent disorder with significant economical and personal burden. Despite the development of effective therapeutics, the causes which precipitate migraine attacks remain elusive. Clinical studies have highlighted altered metabolic flux and mitochondrial function in patients. In vivo animal experiments can allude to the metabolic mechanisms which may underlie migraine susceptibility. Understanding the translational relevance of these studies are important to identifying triggers, biomarkers and therapeutic targets in migraine. Main body Functional imaging studies have suggested that migraineurs feature metabolic syndrome, exhibiting hallmark features including upregulated oxidative phosphorylation yet depleted available free energy. Glucose hypometabolism is also evident in migraine patients and can lead to altered neuronal hyperexcitability such as the incidence of cortical spreading depression (CSD). The association between obesity and increased risk, frequency and worse prognosis of migraine also highlights lipid dysregulation in migraine pathology. Calcitonin gene related peptide (CGRP) has demonstrated an important role in sensitisation and nociception in headache, however its role in metabolic regulation in connection with migraine has not been thoroughly explored. Whether impaired metabolic function leads to increased release of peptides such as CGRP or excessive nociception leads to altered flux is yet unknown. Conclusion Migraine susceptibility may be underpinned by impaired metabolism resulting in depleted energy stores and altered neuronal function. This review discusses both clinical and in vivo studies which provide evidence of altered metabolic flux which contribute toward pathophysiology. It also reviews the translational relevance of animal studies in identifying targets of biomarker or therapeutic development. Show less
The aim of this thesis was to identify functional biomarkers for migraine attack prediction based on neurophysiological readout parameters. The main focus of this work was on the development of... Show moreThe aim of this thesis was to identify functional biomarkers for migraine attack prediction based on neurophysiological readout parameters. The main focus of this work was on the development of methodologies to measure brain excitability over the migraine cycle, with special emphasis on identifying changes in excitability of the visual system and the occipital cortex. Applying such measures over the course of a migraine cycle could help elucidate factors that initiate the migraine attack, and might lead to better (or better timing of) preventive measures. The research described in this thesis is divided into two parts. The first part reports on the development and application of several methodologies to measure excitability of the visual system including the cortex in migraine patients and a migraine mouse model. The second part consists of two studies employing transcranial magnetic stimulation (TMS) in combination with concurrent electroencephalography (EEG) recordings to provide direct measures of cortical excitability in migraine and epilepsy. Show less
Clinic-based headache registries collect data for a wide variety of purposes including delineating disease characteristics, longitudinal natural disease courses, headache management approaches,... Show moreClinic-based headache registries collect data for a wide variety of purposes including delineating disease characteristics, longitudinal natural disease courses, headache management approaches, quality of care, treatment safety and effectiveness, factors that predict treatment response, health care resource utilization, clinician adherence to guidelines, and cost-effectiveness. Registry data are valuable for numerous stakeholders, including individuals with headache disorders and their caregivers, healthcare providers, scientists, healthcare systems, regulatory authorities, pharmaceutical companies, employers, and policymakers. This International Headache Society document may serve as guidance for developing clinic-based headache registries. Use of registry data requires a formal research protocol that includes: 1) research aims; 2) methods for data collection, harmonization, analysis, privacy, and protection; 3) methods for human subject protection; and 4) publication and dissemination plans. Depending upon their objectives, headache registries should include validated headache-specific questionnaires, patient reported outcome measures, data elements that are used consistently across studies (i.e., "common data elements"), and medical record data. Amongst other data types, registries may be linked to healthcare and pharmacy claims data, biospecimens, and neuroimaging data. Headache diagnoses should be made according to the International Classification of Headache Disorders diagnostic criteria. The data from well-designed headache registries can provide wide-ranging and novel insights into the characteristics, burden, and treatment of headache disorders and ultimately lead to improvements in the management of patients with headache. Show less
The research in this thesis is divided into two parts. Part I consists of biochemical studies in migraine, a paroxysmal brain disorder where visual disturbances may form a part of the migraine... Show moreThe research in this thesis is divided into two parts. Part I consists of biochemical studies in migraine, a paroxysmal brain disorder where visual disturbances may form a part of the migraine attack. The main objective was quantification of amine neurotransmitters and other amine molecules in cerebrospinal fluid and plasma of migraine patients, and compare these concentrations with those from healthy controls. Part II describes the clinical relation between migraine and visual snow, a brain disorder with continuous visual disturbances and that is possibly associated with migraine. Since not much is known about this relationship this thesis presents observational studies on the incidence of comorbid migraine in visual snow. Show less
This thesis provides an insight in the clinical aspects and therapy with neurostimulation in cluster headache patients. An unique cohort of Dutch cluster headache patients (LUCA - Leiden University... Show moreThis thesis provides an insight in the clinical aspects and therapy with neurostimulation in cluster headache patients. An unique cohort of Dutch cluster headache patients (LUCA - Leiden University Cluster headache neuro-Analysis programme) has been used to analyse different clinical aspects like drug-use, chronobiology and aura symptoms in cluster headache patients. Regarding neuromodulation: a case-report about occipital nerve stimulation and pregnancy is described here and a meta-analysis of non-invasive vagal nerve stimulation as acute treatment in both episodic and chronic cluster headache. Show less
The premonitory phase and early phase of both spontaneous and nitroglycerin-triggered migraine attacks were explored in this thesis, in association with clinical modulators and trigger factors.... Show moreThe premonitory phase and early phase of both spontaneous and nitroglycerin-triggered migraine attacks were explored in this thesis, in association with clinical modulators and trigger factors. Clinical research strategies, experimental designs, neuroimaging techniques and biochemical methods have revealed clinical risk factors, biochemical modulators and pharmacological triggers. Furthermore, newly discovered hypothalamus-specific alterations in metabolism and perfusion in the early phases of the migraine attack were described. Taken together, these results suggest that each migraine attack starts well before the initiation of the headache phase. The hypothalamus is postulated to have a pivotal role in the early phases of the migraine attack, and possibly affects attack susceptibility interictally as well. Show less
