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There is currently no accepted classification of autosomal recessive cerebellar ataxias, a group of disorders characterized by important genetic heterogeneity and complex phenotypes. The objective of this task force was to build a consensus on the classification of autosomal recessive ataxias in order to develop a general approach to a patient presenting with ataxia, organize disorders according to clinical presentation, and define this field of research by identifying common pathogenic molecular mechanisms in these disorders. The work of this task force was based on a previously published systematic scoping review of the literature that identified autosomal recessive disorders characterized primarily by cerebellar motor dysfunction and cerebellar degeneration. The task force regrouped 12 international ataxia experts who decided on general orientation and specific issues. We identified 59 disorders that are classified as primary autosomal recessive cerebellar ataxias. For each of these disorders, we present geographical and ethnical specificities along with distinctive clinical and imagery features. These primary recessive ataxias were organized in a clinical and a pathophysiological classification, and we present a general clinical approach to the patient presenting with ataxia. We also identified a list of 48 complex multisystem disorders that are associated with ataxia and should be included in the differential diagnosis of autosomal recessive ataxias. This classification is the result of a consensus among a panel of international experts, and it promotes a unified understanding of autosomal recessive cerebellar disorders for clinicians and researchers.

OBJECTIVES: To assess balance and ability to function in patients with spinocerebellar ataxia. METHODS: A total of 44 patients with different spinocerebellar ataxia types 1, 2, 3, and 6 were evaluated using the Tinetti balance and gait assessment and the functional independence measure. The scale for the assessment and rating of ataxia and the international cooperative ataxia rating scale were used to evaluate disease severity. RESULTS: Most patients showed significant risk of falls. The balance scores were significantly different in spinocerebellar ataxia types. A significant positive correlation between balance and disease severity was found. CONCLUSION: Patients with spinocerebellar ataxia have important balance impairment and risk of falls that influence the ability to function such as self-care, transfers, and locomotion. Furthermore, the more severe ataxia is, the more compromised are postural balance, risk of falls, and ability to function. OBJETIVOS: Avaliar o equilíbrio e a capacidade funcional em pacientes com ataxia espinocerebelar. MÉTODOS: Quarenta e quatro pacientes com diferentes tipos de ataxia espinocerebelar foram avaliados usando os testes de equilíbrio e de marcha de Tinetti, e da Medida de Independência Funcional. A Escala para Avaliação e Graduação de Ataxia e a Escala Cooperativa Internacional para Graduação de Ataxia foram utilizadas para avaliar a gravidade da doença. RESULTADOS: A maioria dos pacientes apresentou risco significativo de quedas. As pontuações de equilíbrio foram diferentes entre os tipos de ataxia espinocerebelar. Foi encontrada correlação positiva entre o déficit de equilíbrio e a gravidade da doença. CONCLUSÃO: Os pacientes com ataxia espinocerebelar possuem comprometimento importante do equilíbrio e risco de quedas, que influenciam a capacidade funcional, como por exemplo: auto-cuidado, transferências e locomoção. Além disso, quanto mais grave a ataxia, maior o comprometimento do equilíbrio postural, do risco de quedas, e da capacidade funcional.

Autosomal recessive cerebellar ataxias are a heterogeneous group of neurological disorders. In 1981, a neurological entity comprised by early onset progressive cerebellar ataxia, dysarthria, pyramidal weakness of the limbs and retained or increased upper limb reflexes and knee jerks was described. This disorder is known as early onset cerebellar ataxia with retained tendon reflexes. In this article, we aimed to call attention for the diagnosis of early onset cerebellar ataxia with retained tendon reflexes as the second most common cause of autosomal recessive cerebellar ataxias, after Friedreich ataxia, and also to perform a clinical spectrum study of this syndrome. In this data, 12 patients from different families met all clinical features for early onset cerebellar ataxia with retained tendon reflexes. Dysarthria and cerebellar atrophy were the most common features in our sample. It is uncertain, however, whether early onset cerebellar ataxia with retained tendon reflexes is a homogeneous disease or a group of phenotypically similar syndromes represented by different genetic entities. Further molecular studies are required to provide definitive answers to the questions that remain regarding early onset cerebellar ataxia with retained tendon reflexes. As ataxias cerebelares autossômicas recessivas são um grupo heterogêneo de doenças neurológicas. Em 1981, foi descrita uma entidade neurológica incluindo ataxia cerebelar progressiva de início precoce, disartria, liberação piramidal e manutenção ou aumento dos reflexos tendíneos nos membros superiores e inferiores. Essa síndrome é conhecida como ataxia cerebelar de início precoce com reflexos mantidos. Neste artigo, o objetivo foi chamar a atenção para o diagnóstico de ataxia cerebelar de início precoce com reflexos mantidos como a segunda causa mais comum de ataxia cerebelar autossômica recessiva, após a ataxia de Friedreich, e também realizar um estudo do espectro clínico da síndrome. Doze pacientes de diferentes famílias preencheram os critérios clínicos para ataxia cerebelar de início precoce com reflexos mantidos. Disartria e atrofia cerebelar foram as características mais frequentes. No entanto, não há consenso se a ataxia cerebelar de início precoce com reflexos mantidos é uma doença homogênea ou um grupo de síndromes com fenótipos semelhantes representadas por diferentes entidades genéticas. Estudos moleculares futuros são necessários para fornecer respostas definitivas para as questões pendentes em relação à ataxia cerebelar de início precoce com reflexos mantidos.