The research in this thesis was aimed at identifying and understanding mechanisms underlying modulating factors for and consequences of cortical spreading depression (CSD), the pathophysiological... Show moreThe research in this thesis was aimed at identifying and understanding mechanisms underlying modulating factors for and consequences of cortical spreading depression (CSD), the pathophysiological substrate for migraine aura that occurs in one-third of migraine patients. In this thesis, experimental studies on CSD were performed in wild-type (WT) and transgenic migraine mice, which express CaV2.1 Ca2+ channels with a mutated _1 subunit that contains the R192Q missense mutation. The R192Q mutation was previously identified in patients with familial hemiplegic migraine type 1 (FHM1) and causes gain-of-function effects in terms of neuronal Ca2+ influx, neurotransmission, and susceptibility to experimentally induced CSD. Using various experimental strategies, in this thesis, the FHM1 R192Q mouse model was used to study pathophysiological mechanisms of the initiation and modulation of CSD as well as of neurobiological and molecular changes that accompany CSD events. Show less
Migraine and cluster headache are disabling brain disorders. Current treatment is ineffective in many patients. The research performed in this thesis aimed at elucidating some of the molecular... Show moreMigraine and cluster headache are disabling brain disorders. Current treatment is ineffective in many patients. The research performed in this thesis aimed at elucidating some of the molecular genetic mechanisms in these two headache disorders by means of clinical and genetic studies in complex and/or monogenic forms of these diseases and related disorders. Knowledge from studies like these could be used to the benefit of patients by improving clinical diagnoses and/or by providing useful drug targets for future drug development strategies. Show less
This thesis is about migraine. Three elements are discussed. First element is preventive treatment, second element is attack treatment and the third part focuses on medication overuse headache. The... Show moreThis thesis is about migraine. Three elements are discussed. First element is preventive treatment, second element is attack treatment and the third part focuses on medication overuse headache. The preventive treatment of migraine is a valuable intervention in primary care. If preventive treatment is applied, usually only one attempt with one type of medication is performed. A number of considerations hinder GPs to address preventive treatment of migraine. Also several patient-related aspects cause that the GP differ from national guidelines. The decision to start preventive treatment is based on a complex of considerations from the patient. For example, experienced suffering from migraine and interaction with family, colleagues and general practitioner. Interest in preventive therapy increases with increased concerns about migraine symptoms. In attack treatment of migraine, most patients had a clear preference for one of both treatments. Preference correlated only moderately with the commonly used "two-hour pain-free score." Multi-attack, crossover, 'patient preference' studies are well able to detect clinically relevant differences between existing treatments. Overuse of triptans, resulting in chronic headaches is common and causes unnecessary costs. The common thread through this thesis is what patients want in migraine and which interventions they prefer: patients' preference in migraine. Show less
In this dissertation clinical genetic investigations on migraine, related syndromes and comorbid conditions are described. The first migraine syndrome studied is Familial Hemiplegic Migraine (FHM),... Show moreIn this dissertation clinical genetic investigations on migraine, related syndromes and comorbid conditions are described. The first migraine syndrome studied is Familial Hemiplegic Migraine (FHM), a monogenic migraine variant. The clinical spectrum of FHM1-3 and the relation with closely related diseases such as Alternating hemiplegia of Chilhood, Early Seizures and Cerebral Edema after Trivial Head Trauma, epilepsy and episodic ataxia were investigated. The second monogenic migraine syndrome studied is Retinal Vasculopathy with Cerebral Leukodystrophy (later renamed CHARIOT), where common migraine is part of the clinical spectrum. The identification of TREX1 as the causal gene for RVCL is described. Investigation of the clinical spectrum showed retinal, cerebral and internal organ involvement, without an apparent genotype-phenotype correlation. Endothelial dysfunction of large arteries was shown in RVCL patients and is proposed as a possible disease mechanism. Lastly, migraine patients were identified in a Dutch genetic isolate and the relation with depression and atherosclerosis was assessed. For depression it was shown that shared genetic factors, at least partly, underlie the comorbidity with migraine, in particular migraine with aura. These studies improve our insight in genetic factors and pathofysiological mechanisms involved in migraine, which may ultimately contribute to better treatment options for migraine patients Show less
Room for improvement is present in the treatment of migraine in primary care. However, inviting all patients who receive prescriptions for __2 triptans each month to have an evaluation consultation... Show moreRoom for improvement is present in the treatment of migraine in primary care. However, inviting all patients who receive prescriptions for __2 triptans each month to have an evaluation consultation with their general practitioner (GP), produces insufficient effect on headache outcomes and costs. However, it remains important to stay alert on patients who are candidate for preventive treatment. When discussing the possibility of preventive treatment, GPs should keep in mind possible barriers in patients. Also, GPs have to ask themselves if they do not deny patients a possibly effective treatment because of their own negative ideas towards preventive medication. Also, we learned that when designing pragmatic studies in primary care, there are methodological issues that make it harder to prove the effectiveness of an intervention. First, the outcomes of pragmatic studies in primary care can negatively affected by changes in the behaviour of GPs and patients in the control group. Second, the quality of life outcome measures that are often used in this type of research are harder to validate and to interpret than the more robust outcome measures that are used in clinical trials Show less
CADASIL is a hereditary cerebral small vessel disease, caused by a mutation in the NOTCH3 gene, leading to migraine with aura, cerebrovascular accidents and cognitive decline at young to middle... Show moreCADASIL is a hereditary cerebral small vessel disease, caused by a mutation in the NOTCH3 gene, leading to migraine with aura, cerebrovascular accidents and cognitive decline at young to middle adult age. MRI scans of the brain may show lacunar infarcts, white matter lesions and microbleeds. In this thesis MRI scans of the brains are used to investigate the disease course in CADASIL. It is shown that lacunar infarcts, white matter lesions and microbleeds are progressive in CADASIL patients. Vascular risk factors are not associated with rate of progression of these MRI abnormalities. However, the rate of disease progression can be predicted by measuring the amount of MRI abnormalities at baseline. Lacunar infarcts, microbleeds and increased white ventricular volume are strongly associated with cognitive decline in CADASIL. Progression of white matter hyperintensities can be predicted by measurements of cerebrovascular reactivity. Using high-field MRI we demonstrated that luminal diameters of lenticulostriate arteries are normal in CADASIL, and that lacunar infarcts in CADASIL are not the result of luminal narrowing of these vessels. High-field MRI also showed that CADASIL patients have an increased diffuse iron deposition in the putamen and caudate nucleus of the brain. Show less
The research in this thesis was aimed at identifying and characterizing novel migraine gene mutations and pathways. Several FHM and non-FHM genes were investigated in patients with monogenic... Show moreThe research in this thesis was aimed at identifying and characterizing novel migraine gene mutations and pathways. Several FHM and non-FHM genes were investigated in patients with monogenic familial hemiplegic migraine or other monogenic disorders in which migraine can be prevalent. Functional consequences of these mutations and the clinical phenotypes associated with them were investigated. Common migraine with a complex genetic background was studied using a genome-wide association analysis in an isolated population and with a meta-analysis study. Furthermore, FHM1 mice were used to study expression profiles in brain tissues that are relevant for the induction of cortical spreading depression ___ underlying the migraine aura - (i.e., the occipital cortex) and cerebellar ataxia (i.e., the cerebellum). These studies will further our insight in the molecular pathophysiology of migraine. Show less
The objective of this thesis was to elucidate whether migraine is a true and independent risk factor for brain lesions. We summarized migraine symptoms, diagnostic criteria, epidemiologic data, and... Show moreThe objective of this thesis was to elucidate whether migraine is a true and independent risk factor for brain lesions. We summarized migraine symptoms, diagnostic criteria, epidemiologic data, and assumed pathophysiology. We described the existing literature on the relationship between migraine and ischemic stroke and cerebral white matter lesions (WML). The findings of the population-based CAMERA MRI-study are reported. Posterior circulation (cerebellar) infarcts occurred in 8% of migraineurs with aura (adjusted-OR 13.7). Female migraineurs were at increased risk of high-deep-WML-load (OR 2.0). Risks increased with attack frequency, suggestive of a causal relationship. We detailed on the infarcts and other infratentorial lesions. Findings of higher iron-concentration in deep brain nuclei in younger migraineurs suggest that repeated migraine attacks are associated with changes in regions known to be involved in central pain processing and migraine pathophysiology. In addition, we showed that migraineurs had more syncope-related autonomic-nervous-system symptoms, and we identified frequent syncope and orthostatic insufficiency as independent risk factors for high-DWML-load. With these data, there is now strong evidence that migraine is indeed an independent risk factor for silent brain lesions. The real extent of brain injury in migraine patients in the general population is likely underestimated. Show less
Migraine is a severe headache syndrome, affecting approximately 33% of females and 13% of males. Patients suffer from recurring headache episodes in combination with nausea, vomiting, phono and... Show moreMigraine is a severe headache syndrome, affecting approximately 33% of females and 13% of males. Patients suffer from recurring headache episodes in combination with nausea, vomiting, phono and photophobia. It is a paroxysmal disorder for which several several trigger factors have been identified by patients. This thesis has focused on the relation between i) psychosocial stress, ii) nitroglycerin and iii) hypoxia and the occurrence of a migraine attack, as well as the mechanism of action. The first conclusion is that, in contrast to previous studies, we could not detect a correlation between psychosocial stress and migraine. The second conclusion is that normobaric hypoxia might be a trigger factor for migraine possibly through the development of mild cerebral edema. The third conclusion is that migraine can be triggered by nitroglycerin through a vascular effect without any indication of vasodilation in cerebral or meningeal arteries during the delayed provoked attack. Show less
Migraine has a strong genetic component, but the identification of these factors has proven difficult mainly because of the complex interaction of multiple loci and environmental factors.... Show moreMigraine has a strong genetic component, but the identification of these factors has proven difficult mainly because of the complex interaction of multiple loci and environmental factors. Unraveling its molecular basis and deciphering pathways leading to migraine attacks will help identifying novel treatment targets. For this thesis different genetic approaches were applied. Families with hemiplegic migraine (FHM), a rare monogenic subtype of migraine, were studied. Three genes were identified, all involved in modulation of ion influxes across neuronal and glial cell membranes. We identified many mutations in these genes and performed assays in cellular models to understand their functional consequences. In addition, we investigated the role of these genes in sporadic hemiplegic migraine (SHM). Importantly, we expanded the clinical spectrum associated with FHM genes, and established the link between migraine and epilepsy. We also performed genetic studies in common migraine families using two different approaches; the first was an outbred linkage approach with MO families, the second a family-based association approach with severe MA patients from a genetic isolate. Our results supported that, most likely, the intrinsic genetic heterogeneity in migraine families seriously hampers the identification of migraine loci and ultimately migraine genes. Show less
The objective of the investigations described in this thesis was the development of novel PK-PD modelling for the characterisation and prediction of the effects of anti-migraine drugs in clinical... Show moreThe objective of the investigations described in this thesis was the development of novel PK-PD modelling for the characterisation and prediction of the effects of anti-migraine drugs in clinical investigations. The Markov approach has first been applied to migraine data by Hassani and Ebutt. They used a two-state approach that distinguished between headache and no headache. This approach is appropriate for describing the pain free response, but not the pain relief response, as this endpoint would require that an additional state be included. Moreover, this model does not consider a relationship between drug concentration and transition rate. Rather, dose was used as a predictor of pain resolution. Markov models and other state-space models have always enjoyed much appeal in the analysis of disease progression. However, they have seen little application in PK-PD modelling. The current series of studies attempts to evaluate the usefulness of Markov models in determining the PK-PD relationships of 5-HT1B/1D receptor agonists. Show less
