Biomedical subjects

Michel D Ferrari

Publications and source records attributed to Michel D Ferrari.

At least 19 recordsLinked to original sources

PubMed2016

Gene co-expression analysis identifies brain regions and cell types involved in migraine pathophysiology: a GWAS-based study using the Allen Human Brain Atlas.

Migraine is a common disabling neurovascular brain disorder typically characterised by attacks of severe headache and associated with autonomic and neurological symptoms. Migraine is caused by an interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified over a dozen genetic loci associated with migraine. Here, we integrated migraine GWAS data with high-resolution spatial gene expression data of normal adult brains from the Allen Human Brain Atlas to identify specific brain regions and molecular pathways that are possibly involved in migraine pathophysiology. To this end, we used two complementary methods. In GWAS data from 23,285 migraine cases and 95,425 controls, we first studied modules of co-expressed genes that were calculated based on human brain expression data for enrichment of genes that showed association with migraine. Enrichment of a migraine GWAS signal was found for five modules that suggest involvement in migraine pathophysiology of: (i) neurotransmission, protein catabolism and mitochondria in the cortex; (ii) transcription regulation in the cortex and cerebellum; and (iii) oligodendrocytes and mitochondria in subcortical areas. Second, we used the high-confidence genes from the migraine GWAS as a basis to construct local migraine-related co-expression gene networks. Signatures of all brain regions and pathways that were prominent in the first method also surfaced in the second method, thus providing support that these brain regions and pathways are indeed involved in migraine pathophysiology.

Atlases as Topic↗

PubMed2007

Trigeminal autonomic cephalgias due to structural lesions: a review of 31 cases.

Trigeminal autonomic cephalgias (TACs) include cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing. Associated structural lesions may be found, but a causal relationship is often difficult to establish. We sought to identify clinical predictors of underlying structural abnormalities by reviewing previously described and new TAC and TAC-like cases associated with a structural lesion. We found that even typical TACs can be caused by an underlying lesion. Clinical warning signs and symptoms are relatively rare. We recommend neuroimaging in all patients with a TAC or TAC-like syndrome.

Adult↗

PubMed2006

Brain stem and cerebellar hyperintense lesions in migraine.

BACKGROUND AND PURPOSE: Migraineurs are at increased risk of cerebellar infarcts and supratentorial white matter lesions. The prevalence, frequency, and distribution of infratentorial hyperintense lesions in migraine are unknown. METHODS: Migraineurs with aura (n=161), without aura (n=134), and controls (n=140) from a population-based sample of adults (30 to 60 years of age) were evaluated with MRI. RESULTS: Infratentorial hyperintensities were identified in 13 of 295 (4.4%) migraineurs and in 1 of 140 (0.7%) controls (P=0.04). Twelve cases had hyperintensities, mostly bilaterally, in the dorsal basis pontis. Those with infratentorial hyperintensities also had supratentorial white matter lesions more often. CONCLUSIONS: We found an increased prevalence of infratentorial (mostly pontine) hyperintensities in migraineurs from the general population. This extends the knowledge about vulnerable brain regions and type of lesions in migraine brains. A hemodynamic ischemic pathogenesis is likely, but further research is needed.

Adult↗

PubMed2006

Migraine and MTHFR C677T genotype in a population-based sample.

OBJECTIVE: Migraine with aura is associated with increased risk of stroke. The MTHFR C677T genotype has been associated with increased risk of migraine in selected clinical samples and with elevated homocysteine, a risk factor for stroke. We assessed the association of the MTHFR C677T variant with migraine and the mediating effect of cardiovascular risk factors and metabolic markers of genotype status. METHODS: We compared adult migraineurs with aura (MA; n = 187), without aura (MO; n = 226), and nonmigraineurs (n = 1,212) from the population-based Genetic Epidemiology of Migraine study. RESULTS: Compared with the wild-type genotype, the T/T genotype was associated with increased odds of MA (odds ratio [OR], 2.05; 95% confidence interval, 1.2-3.4; p < 0.006), with a trend of increasing numbers of T alleles (OR, 1.40; 95% confidence interval, 1.1-1.8; p < 0.007). ORs were slightly attenuated after adjusting for homocysteine. INTERPRETATION: Risk of MA is associated with MTHFR C674T homozygosity, independent of other cardiovascular risk factors.

Adult↗

PubMed2006

Conditional inactivation of the Cacna1a gene in transgenic mice.

Ca(v)2.1 (P/Q-type) voltage-gated calcium channels play an important role in neurotransmitter release at many brain synapses and at the neuromuscular junction. Mutations in the CACNA1A gene, encoding the pore forming alpha(1) subunit of Ca(v)2.1 channels, are associated with a wide spectrum of neurological disorders. Here we generated mice with a conditional, floxed, Cacna1a allele without any overt phenotype. Deletion of the floxed Cacna1a allele resulted in ataxia, dystonia, and lethality during the fourth week, a severe phenotype similar to conventional Ca(v)2.1 knockout mice. Although neurotransmitter release at the neuromuscular junction was not affected in the conditional mice, homozygous deletion of the floxed allele caused an ablation of Ca(v)2.1 channel-mediated neurotransmission that was accompanied by a compensatory upregulation of Ca(v)2.3 (R-type) channels at this synapse. Pharmacological inhibition of Ca(v)2.1 channels is possible, but the contributing cell-types and time windows relevant to the different Ca(v)2.1-related neurological disorders can only be reliably determined using Cacna1a conditional mice.

Animals↗

PubMed2006

Two de novo mutations in the Na,K-ATPase gene ATP1A2 associated with pure familial hemiplegic migraine.

Familial hemiplegic migraine (FHM) is a rare autosomal dominantly inherited subtype of migraine, in which hemiparesis occurs during the aura. The majority of the families carry mutations in the CACNA1A gene on chromosome 19p13 (FHM1). About 20% of FHM families is linked to chromosome 1q23 (FHM2), and has mutations in the ATP1A2 gene, encoding the alpha2-subunit of the Na,K-ATPase. Mutation analysis in a Dutch and a Turkish family with pure FHM revealed two novel de novo missense mutations, R593W and V628M, respectively. Cellular survival assays support the hypothesis that both mutations are disease-causative. The identification of the first de novo mutations underscores beyond any doubt the involvement of the ATP1A2 gene in FHM2.

Amino Acid Sequence↗

PubMed2005

Compensatory contribution of Cav2.3 channels to acetylcholine release at the neuromuscular junction of tottering mice.

Tottering (Tg) mice carry the mutation P601L in their Cacna1a encoded Cav2.1 channels. Transmitter release at the wild-type neuromuscular junction (NMJ) is almost exclusively mediated by Cav2.1 channels, and we used this model synapse to study synaptic consequences of the Tg mutation. With electrophysiology, and using subtype-specific Cav2 channel-blocking toxins, we assessed a possible compensatory contribution of non-Cav2.1 channels to evoked acetylcholine (ACh) release at Tg NMJs. Release was reduced by approximately 75% by the Cav2.1 channel blocker omega-agatoxin-IVA, which was less than the approximately 95% reduction observed in wild-type. Release at Tg NMJs, but not at wild-type synapses, was reduced by approximately 15% by SNX-482, a Cav2.3 channel blocker. No Cav2.2 channel involvement was found. Probably, there is a small reduction in functional presynaptic Cav2.1 channels at Tg NMJs, which is compensated for by Cav2.3 channels. The remaining Cav2.1 channels are likely to convey enlarged Ca2+ flux, because evoked ACh release at Tg NMJs, at low extracellular Ca2+ concentration, was approximately sixfold higher than at wild-type NMJs. This is the first report of compensatory expression of non-Cav2.1 channels at NMJs of mice with a single amino acid change in Cav2.1.

Acetylcholine↗

PubMed2005

Infarcts in the posterior circulation territory in migraine. The population-based MRI CAMERA study.

In a previous study, migraine cases from the general population were found to be at significantly increased risk of silent infarct-like lesions in the posterior circulation (PC) territory of the brain, notably in the cerebellum. In this study we describe the clinical and neuroimaging characteristics of migraine cases with and without aura and controls with PC lesions. In total, 39 PC infarct-like lesions represented the majority (65%) of all 60 identified brain infarct-like lesions in the study sample (n = 435 subjects with and without migraine). Most lesions (n = 33) were located in the cerebellum, often multiple, and were round or oval-shaped, with a mean size of 7 mm. The majority (88%) of infratentorial infarct-like lesions had a vascular border zone location in the cerebellum. Prevalence of these border zone lesions differed between controls (0.7%), cases with migraine without aura (2.2%) and cases with migraine with aura (7.5%). Besides higher age, cardiovascular risk factors were not more prevalent in cases with migraine with PC lesions. Presence of these lesions was not associated with supratentorial brain changes, such as white matter lesions. The combination of vascular distribution, deep border zone location, shape, size and imaging characteristics on MRI makes it likely that the lesions have an infarct origin. Previous investigators attributed cases of similar 'very small' cerebellar infarcts in non-migraine patients to a number of different infarct mechanisms. The relevance and likelihood of the aetiological options are placed in the context of known migraine pathophysiology. In addition, the specific involvement of the cerebellum in migraine is discussed. The results suggest that a combination of (possibly migraine attack-related) hypoperfusion and embolism is the likeliest mechanism for PC infarction in migraine, and not atherosclerosis or small-vessel disease.

Adult↗

PubMed2005

Should we advise patients to treat migraine attacks early: methodologic issues.

In clinical trials of triptans in acute migraine, patients have traditionally been required to take their medication only when their pain reached moderate or severe intensity. This methodology better ensured that migraine attacks rather than nonmigraine headaches were treated, minimized the placebo response and simplified comparison of improvement as all patients start from the same baseline pain level. In clinical practice, patients do not take medication in this way, and there is some theoretical evidence that early treatment might be beneficial. There are increasing numbers of reports claiming advantages of 'early' treatment, when the pain is mild, over 'late' treatment, when pain is moderate or severe, but these studies raise significant methodologic issues. Treating 'early' may equate with treating 'mild' in slowly progressing attacks only but this may not always be the case in rapidly progressing attacks; these two types of migraine attacks should be distinguished carefully and investigated separately. Trials should be placebo-controlled, blinded, assess the therapeutic gain versus placebo rather than the absolute rates, and use the sustained pain-free endpoint. Early treatment may also increase the risk of medication overuse headaches. At present, there is no scientific support to advise patient to treat early. Patients should be advised to take their medication as soon as they are sure they are developing a migraine headache, but not during the aura phase.

Humans↗

PubMed2005

Chronic cluster headache: a review.

Cluster headache (CH) is a rare but severe headache disorder characterised by repeated unilateral head pain attacks accompanied by ipsilateral autonomic features. In episodic CH, there are periods of headache attacks with pain-free intervals of weeks, months or years in between. A minority of patients have the chronic form, without pain-free intervals between the headache attacks. Chronic CH can occur as primary or secondary chronic CH; the rarest form is episodic CH arising from chronic CH. In this article, we give a review of the chronic forms of CH and focus on demographics, clinical manifestations, social habits, predictive factors, head injury, genetics, neuroimaging and therapy. It is remarkable that little is known about risk factors that make CH chronic.

Autonomic Nervous System Diseases↗

PubMed2005

Chronic daily headache in children and adolescents.

OBJECTIVE: To describe the clinical features of children with chronic daily headache (CDH) and examine the usefulness of the International Classification of Headache Disorders-II. BACKGROUND: Few data are available on chronic daily headache and analgesic overuse in children and adolescents and there are no specific criteria for headache in children. METHODS: We retrospectively reviewed all charts of 79 children and adolescents (<16 years) with headache on > or =15 days/month presenting to the outpatient clinic of the Department of Neurology of the Leiden University Medical Center between 1994 and 2001. We classified their headaches according to the International Classification of Headache Disorders-II. RESULTS: Fifty-seven (72%) children had chronic daily headache for more than 6 months, with a duration of more than 4 hours a day in 60% of them. Quality, severity, and location of pain varied. Sixty patients (76%) used analgesics, 10 patients more than one type. Thirteen patients (16%) used analgesics daily. In one-third of patients, headache led to frequent school absenteeism and sleeping problems. Twenty-eight (35%) patients could be classified, 17 patients (22%) as chronic tension-type headache, 5 patients (6%) as chronic migraine, and 6 patients (8%) as probable medication overuse headache. Fifteen patients (19%) did not fit into any category and 36 (46%) could not be classified due to insufficient data. CONCLUSIONS: Chronic daily headache in children is a serious disorder. A relatively large number of patients overuse medication and it leads to frequent school absenteeism and sleeping problems. It remains difficult to classify their headaches with the new criteria for headache disorders.

Adolescent↗

PubMed2005

Migraine: new treatment options from molecular biology.

Migraine is a common, disabling, multifactorial, episodic neurovascular disorder of largely unknown etiology. The disease is typically characterized by recurrent attacks of headaches and associated autonomic and neurologic symptoms. Current acute and prophylactic treatment options are far from optimal and in many cases, empirically chosen. Clearly, improved treatment is desperately needed. New drug targets may emerge from molecular research as the unravelling of the molecular basis of migraine should improve our understanding of the disease, notably why patients experience attacks so frequently. The first two migraine genes discovered in families with hemiplegic migraine encode ion transporters, emphasising that dysfunction of ion transport may be an important factor in migraine. Therefore, ion transporters can be considered as novel targets for the development of future antimigraine drugs. Molecular biologic research will increasingly become important in understanding the pathophysiology of migraine and in identifying potential molecular targets for novel treatments.

Animals↗

PubMed2004

A Cacna1a knockin migraine mouse model with increased susceptibility to cortical spreading depression.

Migraine is a common, disabling, multifactorial, episodic neurovascular disorder of unknown etiology. Familial hemiplegic migraine type 1 (FHM-1) is a Mendelian subtype of migraine with aura that is caused by missense mutations in the CACNA1A gene that encodes the alpha(1) subunit of neuronal Ca(v)2.1 Ca(2+) channels. We generated a knockin mouse model carrying the human pure FHM-1 R192Q mutation and found multiple gain-of-function effects. These include increased Ca(v)2.1 current density in cerebellar neurons, enhanced neurotransmission at the neuromuscular junction, and, in the intact animal, a reduced threshold and increased velocity of cortical spreading depression (CSD; the likely mechanism for the migraine aura). Our data show that the increased susceptibility for CSD and aura in migraine may be due to cortical hyperexcitability. The R192Q FHM-1 mouse is a promising animal model to study migraine mechanisms and treatments.

Animals↗

PubMed2004

Migraine as a risk factor for subclinical brain lesions.

CONTEXT: Clinical series have suggested an increased prevalence of cerebral infarction and white matter lesions (WMLs) in migraine patients. It is not known whether these lesions are prevalent in the general migraine population. OBJECTIVES: To compare the prevalence of brain infarcts and WMLs in migraine cases and controls from the general population and to identify migraine characteristics associated with these lesions. DESIGN: Cross-sectional, prevalence study of population-based sample of Dutch adults aged 30 to 60 years. PARTICIPANTS: Randomly selected patients with migraine with aura (n = 161), patients with migraine without aura (n = 134), and controls (n = 140), who were frequency matched to cases for age, sex, and place of residence. Nearly 50% of the cases had not been previously diagnosed by a physician. MAIN OUTCOME MEASURES: Brain magnetic resonance images were evaluated for infarcts, by location and vascular supply territory, and for periventricular WMLs (PVWMLs) and deep WMLs (DWMLs). The odds ratios (ORs) and 95% confidence intervals (CIs) of these brain lesions compared with controls were examined by migraine subtype (with or without aura) and monthly attack frequency (<1 attack, > or =1 attack), controlling for cardiovascular risk factors and use of vasoconstrictor migraine agents. All participants underwent a standard neurological examination. RESULTS: No participants reported a history of stroke or transient ischemic attack or had relevant abnormalities at standard neurological examination. We found no significant difference between patients with migraine and controls in overall infarct prevalence (8.1% vs 5.0%). However, in the cerebellar region of the posterior circulation territory, patients with migraine had a higher prevalence of infarct than controls (5.4% vs 0.7%; P =.02; adjusted OR, 7.1; 95% CI, 0.9-55). The adjusted OR for posterior infarct varied by migraine subtype and attack frequency. The adjusted OR was 13.7 (95% CI, 1.7-112) for patients with migraine with aura compared with controls. In patients with migraine with a frequency of attacks of 1 or more per month, the adjusted OR was 9.3 (95% CI, 1.1-76). The highest risk was in patients with migraine with aura with 1 attack or more per month (OR, 15.8; 95% CI, 1.8-140). Among women, the risk for high DWML load (top 20th percentile of the distribution of DWML load vs lower 80th percentile) was increased in patients with migraine compared with controls (OR, 2.1; 95% CI, 1.0-4.1); this risk increased with attack frequency (highest in those with > or =1 attack per month: OR, 2.6; 95% CI, 1.2-5.7) but was similar in patients with migraine with or without aura. In men, controls and patients with migraine did not differ in the prevalence of DWMLs. There was no association between severity of PVWMLs and migraine, irrespective of sex or migraine frequency or subtype. CONCLUSIONS: These population-based findings suggest that some patients with migraine with and without aura are at increased risk for subclinical lesions in certain brain areas.

Brain↗

PubMed2004

Toward a molecular genetic classification of familial hemiplegic migraine.

The genetics of migraine is a fascinating and rapidly moving research area. Familial hemiplegic migraine, a rare subtype of migraine with a Mendelian pattern of inheritance, is caused by mutations in the chromosome 19 CACNA1A gene or in the chromosome 1 ATP1A2 gene. Familial migraine variants are classified on the basis of clinical, descriptive criteria, but this is insufficient. In the future, a diagnostic classification based on mutation-analysis is needed.

Humans↗

PubMed2004

Prioritizing treatment attributes and their impact on selecting an oral triptan: results from the TRIPSTAR Project.

Seven oral triptans, which differ on a range of attributes important for treatment selection, are now available for treating migraine. US neurologists were surveyed to assess the relative importance of treatment attributes, prespecified by clinical relevance and availability of controlled study data, for selecting among oral triptans. Using a multiattribute decision model, we combined these data on the importance of treatment attributes with information on the relative performance of the oral triptans derived from a recent meta-analysis of controlled clinical trials.

Animals↗

PubMed2004

Priorities for triptan treatment attributes and the implications for selecting an oral triptan for acute migraine: a study of US primary care physicians (the TRIPSTAR Project).

BACKGROUND: Physicians treating patients with migraine can now choose from among 7 triptans, which differ on a range of attributes that may be important for treatment selection. OBJECTIVE: The aims of this study were to determine the relative importance of treatment attributes of the available triptans and assess their impact on deciding the most appropriate treatment for a particular patient with migraine. METHODS: As part of the TRIPSTAR project, US primary care physicians were surveyed to elicit their views on the relative importance of a prespecified set of treatment attributes for making treatment choices in clinical practice. The treatment attributes assessed were those for which data from controlled clinical trials were available for subsequent comparison. The resulting attribute-importance weights were then combined with data on the performance of individual triptans across these attributes in a multiattribute decision model to assist selection of an oral triptan. RESULTS: Efficacy attributes were considered more important than tolerability or consistency of effect in selecting an oral triptan. For triptan-naive but not triptan-experienced patients, tolerability was considered significantly more important than consistency (30% [95% CI, 27%-34%] vs 21% [19%-24%]). Sustained pain-free status and freedom from cardiovascular (chest) adverse events were the most important efficacy and tolerability attributes for both patient categories. When the relative importance of the treatment attributes was combined in a multiattribute decision model with meta-analysis data from controlled trials, almotriptan, eletriptan, and rizatriptan were significantly closer to the hypothetical ideal triptan than the reference product, sumatriptan 100 mg. CONCLUSION: Multiattribute decision-making models (such as that used in the TRIPSTAR project) that determine and apply the relative importance of treatment attributes to drug selection have considerable potential value as a decision support tool in the treatment of acute migraine.

Acute Disease↗

PubMed2004

Recent findings in headache genetics.

PURPOSE OF REVIEW: The progress in headache genetics, especially migraine genetics, recently jumped ahead with some major discoveries. RECENT FINDINGS: Family and epidemiological studies further strengthen the genetic contribution to migraine and two recent observations gave new molecular insights in the disease. Studies on the genetics of familial hemiplegic migraine revealed, in addition to the previously identified familial hemiplegic migraine type 1 gene CACNA1A on chromosome 19, the familial hemiplegic migraine type 2 gene ATP1A2, encoding the alpha2-subunit of sodium/potassium pumps. Recent genome screens in families with migraine identified susceptibility loci on chromosomes 4, 6, 11 and 14. SUMMARY: The findings in familial hemiplegic migraine confirm that dysfunction in ion transport is a key factor in migraine pathophysiology and might help us in the elucidation of migraine molecular pathways. The identification of several migraine susceptibility loci underline its genetically complex nature.

Calcium Channels↗