Episodic ataxia (EA) designates a group of autosomal dominant channelopathies that manifest as paroxysmal attacks of imbalance and incoordination. EA conditions are clinically and genetically ...heterogeneous. Seven types of EA have been reported so far but the majority of clinical cases result from two recognized entities.
Episodic ataxia type 1 (EA1) is characterized by brief episodes of ataxia and dysarthria, and interictal myokymia. Onset occurs during the first two decades of life. Associated epilepsy has been reported in some EA1 patients. EA1 is caused by mutations of the KCNA1 gene coding for the voltage-gated potassium channel Kv1.1. Mutation is mostly missense mutations. Acetazolamide, a carbonic-anhydrase inhibitor, may reduce the frequency and severity of the attacks in some but not all affected individuals. Episodic ataxia type 2 (EA2) is characterized by episodes lasting longer than in EA1, that manifest by ataxia, dysarthria, vertigo, and also, in most of the cases, an interictal nystagmus. Other clinical features as developmental delay or epilepsy can be present in some patients. Brain MRI shows frequently a vermian atrophy. Onset occurs typically in childhood or early adolescence, but can sometimes be in adulthood. EA2 is caused by mutations in CACNA1A, a gene coding for the neuronal voltage-gated calcium channel Cav1.1. For two-thirds of the cases, mutations lead to a stop codon. This type is most often responsive to acetazolamide that reduces the frequency and severity of attacks, but does not appear to prevent the progression of interictal symptoms.
This article summarizes current knowledge on episodic ataxia type 1 and 2 and describes briefly the other types of EA.
Molecular analysis of KCNA1 or CACNA1A provides a confirmation of the diagnosis of EA1 and EA2. Other types remain rare phenotypic variants. Among them, only two genes have been identified: CACNB4 in EA5 and SLC1A3 in EA6 and mutations have been found in a very few cases. No mutation can be detected in some familial cases of episodic ataxia, suggesting further heterogeneity.
A survey was carried out on a large family presenting the symptoms of familial arteriopathy (CADASIL) recently mapped to chromosome 19. This is characterised clinically by recurrent subcortical ...infarcts developing into pseudobulbar palsy and subcortical dementia, and radiologically by early MRI abnormalities. To characterise this familial condition, 43 members older than 20 years and spreading over four generations were studied clinically (31 living, 12 deceased), genetically, and radiologically by MRI (n = 31). Twenty out of 43 were found to be clinically symptomatic and of these 13 out of 31 had MRI abnormalities. Genetic studies mapped this condition to the locus of CADASIL (lod score > 3). The natural history suggests a chronological clinicoradiological staging of this phenotype of CADASIL: stage I between 20 and 40 years with frequent migraine-like episodes and well delineated lesions of the white matter; stage II between 40 and 60 years with stroke-like episodes, bipolar or monopolar-like psychotic disorders, coalescent lesions of the white matter, and well delineated lesions of the basal ganglia; and stage III over 60 years with subcortical dementia, pseudobulbar palsy, diffuse leukoencephalopathy, and multiple well delineated lesions of the basal ganglia. This phenotype differs from the other two previously described by high frequency of migraine, frequency of psychotic disorders, and early neurological manifestations. The new acronym "cerebral autosomal dominant arteriopathy with subcortical infarcts, leukoencephalopathy, and migraine" (CADASILM) is proposed to better describe this particular subvariety of CADASIL.
Hemiplegic migraine (HM) is a rare subtype of migraine with aura that occurs as a familial or sporadic condition. The 3 culprit genes identified so far do not account for all familial forms of HM. ...PRRT2 mutations have recently been shown to cause various childhood-onset episodic syndromes including paroxysmal kinesigenic dyskinesia, infantile convulsions with choreoathetosis syndrome, and benign familial infantile epilepsy. Our objective was to test the possible implication of PRRT2 in HM, another episodic disorder with early onset in most cases.
The whole genomic coding region of PRRT2 was sequenced in 101 index cases with HM that started before age 20 years and for whom no mutation was found in the 3 known HM genes. Affected relatives of mutated patients were analyzed when available.
PRRT2 mutations were identified in 4 patients: the previously reported c.649dupC mutation was found in 2 cases, and a novel mutation, c.649delC, was found in the other 2. One patient with mutation subsequently developed paroxysmal dyskinesia, as well as generalized epileptic seizures.
PRRT2 mutations can occasionally cause HM. This underscores the complexity of the phenotypic consequences of PRRT2 mutations.
Late onset hereditary episodic ataxia Damak, M; Riant, F; Boukobza, M ...
Journal of neurology, neurosurgery and psychiatry,
05/2009, Letnik:
80, Številka:
5
Journal Article
Recenzirano
Objective: Episodic ataxias (EA) are hereditary paroxysmal neurological diseases with considerable clinical and genetic heterogeneity. So far seven loci have been reported and four different genes ...have been identified. Analysis of additional sporadic or familial cases is needed to better delineate the clinical and genetic spectrum of EA. Methods: A two generation French family with late onset episodic ataxia was examined. All consenting family members had a brain MRI with volumetric analysis of the cerebellum. Haplotype analysis was performed for the EA2 locus (19p13), the EA5 locus (2q22), the EA6 locus (5p13) and the EA7 locus (19q13). Mutation screening was performed for all exons of CACNA1A (EA2), EAAT1 (EA6) and the coding sequence of KCNA1 (EA1). Results: Four family members had episodic ataxia with onset between 48 and 56 years of age but with heterogeneity in the severity and duration of symptoms. The two most severely affected had daily attacks of EA with a slowly progressive and disabling permanent cerebellar ataxia and a poor response to acetazolamide. Brain MRI showed in three affected members a decrease in the ratio of cerebellar volume:total intracranial volume, indicating cerebellar atrophy. No deleterious mutation was found in CACNA1A, SCA6, EAAT1 or KCNA1. In addition, the EA5 locus was excluded. Conclusions: A new phenotype of episodic ataxia has been described, characterised clinically by a late onset and progressive permanent cerebellar signs, and genetically by exclusion of the genes so far identified in EA.
This study shows that mice with mutant type IV collagen α1 protein are susceptible to trauma-induced hemorrhage and stroke. Building on this finding is the discovery that a variant of the human ...orthologue is associated with small-vessel disease and hemorrhagic stroke.
This study shows that mice with mutant type IV collagen α1 protein are susceptible to trauma-induced hemorrhage and stroke.
Stroke is a leading cause of death and serious long-term disability in developed nations.
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Survivors often have a severely diminished quality of life, require long-term care, and are at high risk for recurrence.
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Intracerebral hemorrhage accounts for 10 to 15 percent of strokes and is a particularly severe form of stroke, with disproportionately high rates of death and long-term disability.
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Hypertension and amyloid angiopathy are important risk factors associated with intracerebral hemorrhage; other risk factors include vascular malformations, coagulation abnormalities, and the use of sympathomimetic drugs.
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However, intracerebral hemorrhage often occurs in the absence of a history of known risk . . .
The main hereditary vascular conditions involving both retinal and cerebral vessels include cerebroretinal vasculopathy, HERNS (hereditary endotheliopathy with retinopathy, nephropathy, and stroke), ...and hereditary vascular retinopathy; all are linked to the same locus on chromosome 3p21. Hereditary retinal arteriolar tortuosity is a distinct, autosomal dominant condition characterized by retinal arteriolar tortuosity and recurrent retinal hemorrhages. This condition is known to affect only retinal vessels.
Clinical and brain MRI investigations of eight members of a three-generation family and extensive biological and systemic vascular investigations within one affected family member were conducted.
Six of eight family members were clinically symptomatic; disorders included infantile hemiparesis (2), migraine with aura (3), and retinal hemorrhage (1). Five individuals had retinal arteriolar tortuosities. A diffuse leukoencephalopathy in association with dilated perivascular spaces was observed in six individuals. Two family members had silent, deep cerebral infarcts as demonstrated on MRI. Genetic linkage analysis strongly suggests that this disorder is not linked to the 3p21 hereditary vascular retinopathy/cerebroretinal vasculopathy/HERNS locus.
The authors describe a novel hereditary autosomal dominant condition affecting both retinal and cerebral vessels and characterized by infantile hemiparesis, migraine with aura, retinal hemorrhage, retinal arterial tortuosity, and leukoencephalopathy with dilatation of perivascular spaces and microbleeds on brain MRI. Investigation of additional families should help to map the gene and to better categorize the spectrum of hereditary cerebroretinal small vessel diseases.
Formation of a fully functional artery proceeds through a multistep process. Here we show that Notch3 is required to generate functional arteries in mice by regulating arterial differentiation and ...maturation of vascular smooth muscle cells (vSMC). In adult Notch3-/- mice distal arteries exhibit structural defects and arterial myogenic responses are defective. The postnatal maturation stage of vSMC is deficient in Notch3-/- mice. We further show that Notch3 is required for arterial specification of vSMC but not of endothelial cells. Our data reveal Notch3 to be the first cell-autonomous regulator of arterial differentiation and maturation of vSMC.
Lake Eibsee, Garmisch-Partenkirchen, 16 to 18 November, 2017: The European Stroke Organisation convened >120 stroke experts from 21 countries to discuss latest results and hot topics in clinical, ...translational and basic stroke research. Since its inception in 2011, the European Stroke Science Workshop has become a cornerstone of European Stroke Organisation’s academic activities and a major highlight for researchers in the field. Participants include stroke researchers at all career stages and with different backgrounds, who convene for plenary lectures and discussions. The workshop was organised in seven scientific sessions focusing on the following topics: (1) acute stroke treatment and endovascular therapy; (2) small vessel disease; (3) opportunities for stroke research in the omics era; (4) vascular cognitive impairment; (5) intracerebral and subarachnoid haemorrhage; (6) alternative treatment concepts and (7) neural circuits, recovery and rehabilitation. All sessions started with a keynote lecture providing an overview on current developments, followed by focused talks on a timely topic with the most recent findings, including unpublished data. In the following, we summarise the key contents of the meeting. The program is provided in the online only Data Supplement.
The workshop started with a key note lecture on how to improve the efficiency of clinical trial endpoints in stroke, which was delivered by Craig Anderson (Sydney, Australia) and set the scene for the following discussions.
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