RÉSUMÉ
Cerebellar ataxia is a neurological syndrome characterized by the imbalance (e.g., truncal ataxia, gait ataxia) and incoordination of limbs while executing a task (dysmetria), caused by the dysfunction of the cerebellum or its connections. It is frequently associated with other signs of cerebellar dysfunction, including abnormal eye movements, dysmetria, kinetic tremor, dysarthria, and/or dysphagia. Among the so-termed mitochondrial ataxias, variants in genes encoding steps of the coenzyme Q10 biosynthetic pathway represent a common cause of autosomal recessive primary coenzyme Q10 deficiencies (PCoQD)s. PCoQD is a potentially treatable condition; therefore, a correct and timely diagnosis is essential. After a brief presentation of the illustrative case of an Italian woman with this condition (due to a novel homozygous nonsense mutation in COQ8A), this article will review ataxias due to PCoQD.
RÉSUMÉ
BACKGROUND: Fabry disease (FD) is a treatable X-linked lysosomal storage disorder caused by GLA gene variants leading to alpha-galactosidase A deficiency. FD is a rare cause of stroke, and it is still controversial whether in stroke patients FD should be searched from the beginning or at the end of the diagnostic workup (in cryptogenic strokes). METHODS: Fabry-Stroke Italian Registry is a prospective, multicentric screening involving 33 stroke units. FD was sought by measuring α-galactosidase A activity (males) and by genetic tests (males with reduced enzyme activity and females) in patients aged 18-60 years hospitalized for TIA, ischemic stroke, or intracerebral hemorrhage. We diagnosed FD in patients with 1) already known pathogenic GLA variants; 2) novel GLA variants if additional clinical, laboratory, or family-derived criteria were present. RESULTS: Out of 1906 patients, we found a GLA variant in 15 (0.79%; 95%CI 0.44-1.29) with a certain FD diagnosis in 3 (0.16%; 95%CI 0.03-0.46) patients, none of whom had hemorrhage. We identified 1 novel pathogenic GLA variant. Ischemic stroke etiologies in carriers of GLA variants were: cardioaortic embolism (33%), small artery occlusion (27%), other causes (20%), and undetermined (20%). Mild severity, recurrence, previous TIA, acroparesthesias, hearing loss, and small artery occlusion were predictors of GLA variant. CONCLUSION: In this large multicenter cohort the frequency of FD and GLA variants was consistent with previous reports. Limiting the screening for GLA variants to patients with cryptogenic stroke may miss up to 80% of diagnoses. Some easily recognizable clinical features could help select patients for FD screening.
Sujet(s)
Maladie de Fabry , Accident ischémique transitoire , Accident vasculaire cérébral ischémique , alpha-Galactosidase , Femelle , Humains , Mâle , alpha-Galactosidase/génétique , Maladie de Fabry/diagnostic , Maladie de Fabry/épidémiologie , Maladie de Fabry/génétique , Accident ischémique transitoire/diagnostic , Accident ischémique transitoire/épidémiologie , Accident vasculaire cérébral ischémique/diagnostic , Accident vasculaire cérébral ischémique/épidémiologie , Accident vasculaire cérébral ischémique/génétique , Italie/épidémiologie , Mutation , Prévalence , Études prospectives , Adolescent , Jeune adulte , Adulte , Adulte d'âge moyenRÉSUMÉ
Although larger trinucleotide expansions give rise to a neurodevelopmental disorder called fragile X syndrome, fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder caused by a "premutation" (55-200 CGG repeats) in the FMR1 gene. FXTAS is one of the more common single-gene forms of late-onset ataxia and tremor that may have a more complex development in women, with atypical presentations. After a brief presentation of the atypical case of an Italian woman with FXTAS, who had several paroxysmal episodes suggestive of acute cerebellar and/or brainstem dysfunction, this article will revise the phenotype of FXTAS in women. Especially in females, FXTAS has a broad spectrum of symptoms, ranging from relatively severe diseases in mid-adulthood to mild cases beginning in later life. Female FXTAS and male FXTAS have a different symptomatic spectrum, and studies on the fragile X premutation should be conducted separately on women or men. Hopefully, a better understanding of the molecular processes involved in the polymorphic features of FXTAS will lead to more specific and effective therapies for this complex disorder.
RÉSUMÉ
Letter to the Editor in response to Finsterer J, Scorza FA, Scorza CA. Presentation and pathophysiology of neuro-COVID. Drugs Context. 2021;10:2021-6-5. https://doi.org/10.7573/dic.2021-6-5.
RÉSUMÉ
Severe acute respiratory syndrome-correlated new coronavirus (SARS-Cov-2) infection may result in neurological signs and symptoms through different mechanisms. Although direct infection of the central nervous system is uncertain or very rare and the para-infectious complications (e.g. inflammatory neuropathies) are rare, delirium and septic encephalopathy are common in severely ill patients. Smell dysfunction and headache are very common in mild cases, especially in younger people and females. Muscle pain is common in both mild and severe cases, and in the most compromised patients, it is accompanied by increased creatine kinase levels and by a likely true myopathic damage. Ischemic stroke has been reported as a possible complication of the hypercoagulability associated with severe SARS-Cov-2 infection, but further studies are needed. Most of the neurological manifestations may occur early in the illness. Therefore, during the pandemic period, neurologists need to be involved, alert, and prepared. Neurological practice will not be the same until a vaccine is available.
RÉSUMÉ
Episodic ataxias (EAs) are characterized by recurrent, discrete episodes of vertigo and ataxia. EA1 and EA2 are the two most common forms. In the interictal interval, myokymia is typically present in EA1, whereas EA2 patients present with interictal nystagmus. Specific pharmacological therapies are available for EA1 and especially EA2. We briefly discuss the case of an Italian young man with EA2, with a novel de novo CACNA1A mutation, who in our opinion is particularly illustrative for introducing the therapeutic approach. Acetazolamide could fully suppress EA episodes in our patient. We also provide a perspective review of the topic. 4-Aminopyridine is another valid treatment option. For EA1 (and for rarer EAs), the therapeutic possibilities are more limited. Carbamazepine is probably the treatment of choice for EA1, but the optimal treatment plan is unknown. A better understanding of the molecular processes involved in the mediation of EAs will lead to more specific and efficacious therapies for this still elusive group of disorders.