History and national survey on reflex hammers: which is the chosen one of Brazilian neurologists? / História e questionário nacional sobre martelos de reflexo: qual é o escolhido dos neurologistas brasileiros?

Abstract Background Percussion is an important part of the neurological examination and reflex hammers are necessary to obtain it properly. Objective We aimed to review the historical aspects of the main reflex hammers and to define the favorite one of Brazilian neurologists. Methods We searched original and review articles about historical aspects of the reflex hammers in Scielo and Pubmed and conducted an online survey to investigate the favorite reflex hammer of Brazilian neurologists. Results In the first part, we describe the major milestones in the creation of the reflex hammers. Following, we exhibit the results of the online survey: Babinski-Rabiner was the most voted. Conclusions The origins of the reflex hammers goes back long before their creation, from a basic clinical examination method: percussion. Since the description of deep tendon reflexes and the creation of percussion hammers, much has been improved in this technique. Among all the hammers surveyed, the Babinski-Rabiner was the chosen one by a significant portion of Brazilian neurologists.

Resumo Antecedentes A percussão é uma parte importante do exame neurológico e os martelos de reflexo são necessários para obtê-la adequadamente. Objetivo Nós visamos revisar os aspectos históricos dos principais martelos de reflexo neurológico e definir qual é o preferido dos neurologistas brasileiros. Métodos Procuramos artigos originais e artigos de revisão sobre os aspectos históricos dos martelos de reflexo na Scielo e no Pubmed, e conduzimos um questionário online para investigar qual é o preferido dos neurologistas brasileiros. Resultados Na primeira parte, descrevemos os principais marcos na criação dos martelos de reflexo. Na sequência, expomos os resultados do questionário online: Babinski-Rabiner foi o martelo mais votado. Conclusões A origem dos martelos de reflexos vem muito antes de sua criação, a partir de um método de exame clínico básico: a percussão. Desde a descrição dos reflexos tendinosos profundos e da criação de martelos de percussão, muito se aperfeiçoou sobre essa técnica. Dentre todos os martelos pesquisados, o de Babinski-Rabiner foi o escolhido por uma parcela significativa dos neurologistas brasileiros.

Professor Ângelo Machado: career, scientific contributions, and the iconic neuroanatomy book / Professor Ângelo Machado: carreira, contribuições científicas e o icônico livro de neuroanatomia

ABSTRACT Professor Ângelo Barbosa Monteiro Machado (May 22, 1934 to April 6, 2020) was one of the most outstanding and respected professors in the Brazilian history. He worked broadly as a professor, neuroscientist, writer, dramaturgist, neurobiologist, and entomologist. The publication of the neuroanatomy book is pioneer, revolutionary, and iconic in the history of academic medical education in Brazil. In the literature field, he also wrote many books in which he adapted scientific knowledge to children. In this article, the authors approach the academic life of Professor Ângelo Machado and the steps that culminated in the most renowned Brazilian textbook of neuroanatomy: Neuroanatomia Funcional.

RESUMO O professor Ângelo Barbosa Monteiro Machado (22/05/1934-06/04/2020) foi um dos mais destacados e respeitados professores da história do Brasil. Ele trabalhou amplamente como professor, neurocientista, escritor, dramaturgo e entomologista. A publicação do livro de neuroanatomia é pioneira, revolucionária e icônica na história da educação médica acadêmica no Brasil. No campo da literatura, também escreveu diversos livros nos quais adaptou o conhecimento científico para as crianças. Neste artigo, os autores abordam a vida acadêmica do professor Ângelo Machado e as etapas que culminaram no mais conceituado livro brasileiro de neuroanatomia: Neuroanatomia Funcional.

Immunosuppressors and immunomodulators in Neurology - Part I: a guide for management of patients underimmunotherapy.

For patients with autoimmune diseases, the risks and benefits of immunosuppressive or immunomodulatory treatment are a matter of continual concern. Knowledge of the follow-up routine for each drug is crucial, in order to attain better outcomes and avoid new disease activity or occurrence of adverse effects. To achieve control of autoimmune diseases, immunosuppressive and immunomodulatory drugs act on different pathways of the immune response. Knowledge of the mechanisms of action of these drugs and their recommended doses, adverse reactions and risks of infection and malignancy is essential for safe treatment. Each drug has a specific safety profile, and management should be adapted for different circumstances during the treatment. Primary prophylaxis for opportunistic infections and vaccination are indispensable steps during the treatment plan, given that these prevent potential severe infectious complications. General neurologists frequently prescribe immunosuppressive and immunomodulatory drugs, and awareness of the characteristics of each drug is crucial for treatment success. Implementation of a routine before, during and after use of these drugs avoids treatment-related complications and enables superior disease control.

Immunosuppressors and immunomodulators in Neurology - Part I: a guide for management of patients underimmunotherapy / Imunossupressores e imunomoduladores em Neurologia - Parte I: um guia para o manejo de pacientes em imunoterapia

ABSTRACT For patients with autoimmune diseases, the risks and benefits of immunosuppressive or immunomodulatory treatment are a matter of continual concern. Knowledge of the follow-up routine for each drug is crucial, in order to attain better outcomes and avoid new disease activity or occurrence of adverse effects. To achieve control of autoimmune diseases, immunosuppressive and immunomodulatory drugs act on different pathways of the immune response. Knowledge of the mechanisms of action of these drugs and their recommended doses, adverse reactions and risks of infection and malignancy is essential for safe treatment. Each drug has a specific safety profile, and management should be adapted for different circumstances during the treatment. Primary prophylaxis for opportunistic infections and vaccination are indispensable steps during the treatment plan, given that these prevent potential severe infectious complications. General neurologists frequently prescribe immunosuppressive and immunomodulatory drugs, and awareness of the characteristics of each drug is crucial for treatment success. Implementation of a routine before, during and after use of these drugs avoids treatment-related complications and enables superior disease control.

RESUMO Pacientes com doenças autoimunes exigem uma constante preocupação com os riscos e benefícios do tratamento imunossupressor ou imunomodulador. O conhecimento das rotinas no uso de cada uma dessas drogas é fundamental para o bom desfecho clínico, evitando a piora da doença ou efeitos colaterais. As drogas imunossupressoras e imunomoduladoras agem em diferentes pontos da resposta imunológica a fim de controlar a doença para qual são indicadas. O conhecimento do mecanismo de ação, principais posologias, efeitos adversos e os riscos de infecções e neoplasias relacionadas ao uso dessas medicações são fundamentais para um tratamento seguro. Cada uma delas apresenta um perfil específico de complicações e o manejo deve ser individualizado em diferentes cenários ao longo do seguimento do paciente. O uso de medicações para profilaxia primária de infecções e a vacinação são pontos essenciais no planejamento do tratamento, prevenindo potenciais complicações infecciosas ao longo do acompanhamento. O uso de imunossupressores e imunomoduladores é uma frequente realidade no dia-a-dia do neurologista, e o conhecimento das características de cada droga é crucial para o sucesso do tratamento. A realização de uma rotina antes, durante e depois do uso dessas medicações evita complicações relacionadas com o tratamento e alcança um melhor controle da doença.

A journey through the history of Neurogenetics / Uma jornada pela história da Neurogenética

ABSTRACT Since the late 19th century, when several inherited neurological disorders were described, the close relationship between Neurology and heredity were well documented by several authors in a pre-genetic era. The term Neurogenetics came to integrate two large sciences and clinical practices: Neurology and Genetics. Neurogenetics is the emerging field that studies the correlation between genetic code and the development and function of the nervous system, including behavioral traits, personality and neurological diseases. In this historical note, a timeline shows the main events and contributors since the first reports of neurogenetic diseases until the current days. In the recent years, neurologists are experiencing much broader use of new genetic diagnosis techniques in clinical practice. Thus, new challenges are arising in diagnostic approach, ethical considerations, and therapeutic options. This article aims to summarize the main historical hallmarks of Neurogenetics, from the pre-DNA era to the present, and the future directions of the field.

RESUMO Desde o final do século XIX, quando diversas doenças neurológicas hereditárias foram descritas, a associação entre neurologia e hereditariedade foi bem documentada por vários autores na era pré-genética. O termo Neurogenética integra dois campos da ciência e da prática clínica: Neurologia e Genética. A Neurogenética é o campo que estuda a correlação entre o código genético e o desenvolvimento e a função do sistema nervoso, incluindo comportamento, personalidade e doenças neurológicas. Nesta nota histórica, a linha do tempo mostra os principais eventos e pesquisadores desde os primeiros relatos de doenças neurogenéticas até os dias atuais. Recentemente, neurologistas estão se deparando com maior uso de técnicas diagnósticas genéticas na prática clínica; portanto, novos desafios surgem na abordagem diagnóstica, nas considerações éticas e na terapêutica. Este artigo almeja resumir os principais marcos históricos da Neurogenética, desde a era pré-DNA até o presente, e os caminhos futuros desse campo de conhecimento.

Nystagmus may be the first neurological sign in early stages of spinocerebellar ataxia type 3 / Nistagmo pode ser o primeiro sinal neurológico nos estágios precoces da ataxia espinocerebelar tipo 3

Abstract Background: Spinocerebellar ataxia type 3 (SCA3) is the most common autosomal dominant spinocerebellar ataxia worldwide. Almost all patients with SCA3 exhibit nystagmus and/or saccades impairment. Objective: To investigate the presence of nystagmus as an early neurological manifestation, before ataxia, in some patients with SCA3 in the first six months of the disease. Methods: We evaluated a series of 155 patients with clinically and molecularly proven SCA3 between 2013 and 2020. Data regarding sex, age, age at onset, disease duration, CAG repeat expansion length, first symptom, presence of ataxia, scores on SARA and ICARS scales, and presence and characteristics of nystagmus were collected. Results: We identified seven patients with symptomatic SCA3 who presented with isolated nystagmus. In these seven individuals the age at onset ranged from 24 to 57 years, and disease duration from four to six months. Conclusions: Our study showed that nystagmus may be the first neurological sign in SCA3. This clinical observation reinforces the idea that the neurodegenerative process in SCA3 patients may start in vestibular system connections or in flocculonodular lobe. This study adds relevant information about pre-symptomatic features in SCA3 that may work as basis for a better understanding of brain degeneration and for future therapeutic clinical trials.

RESUMO Antecedentes: A ataxia espinocerebelar tipo 3 (SCA3) é a ataxia espinocerebelar de herança autossômica dominante mais comum em todo o mundo. Quase todos os pacientes com SCA3 têm nistagmo e/ou comprometimento das sácades. Objetivo: Investigar a presença de nistagmo como manifestação neurológica precoce, antes do surgimento da ataxia, em alguns pacientes com SCA3 nos primeiros seis meses de doença. Métodos: Foram avaliados 155 pacientes com diagnóstico clínico e molecular de SCA3, entre 2013 e 2020, em relação a sexo, idade, idade de início, duração da doença, expansão da repetição CAG, primeiro sintoma, presença de ataxia, pontuações nas escalas SARA e ICARS, e presença e caracterização de nistagmo. Resultados: Identificamos sete pacientes com SCA3 que apresentavam nistagmo isolado. A idade de início da doença nesses pacientes variou de 24 a 57 anos e a duração da doença variou de quatro a seis meses. Conclusões: O nosso estudo mostrou que o nistagmo pode ser o primeiro sinal neurológico na SCA3. Essa observação clínica reforça a ideia de que o processo neurodegenerativo nos pacientes com SCA3 pode se iniciar nas conexões do sistema vestibular ou no lobo floculonodular. Este estudo adiciona informações relevantes sobre características pré-sintomáticas na SCA3 e que podem servir de base para melhor entendimento da degeneração cerebral e para futuras terapias.

A clinical approach to hypertrophic pachymeningitis.

IMPORTANCE: Hypertrophic pachymeningitis (HP) is a non-usual manifestation of rheumatologic, infectious, and neoplastic diseases. Etiological diagnosis is a challenge, but when made promptly it creates a window of opportunity for treatment, with the possibility of a total reversal of symptoms. OBSERVATIONS: HP is an inflammatory process of the dura mater that can occur as a manifestation of sarcoidosis, granulomatosis with polyangiitis, and IgG4-related disease. The HP case evaluation is extensive and includes central nervous system imaging, cerebrospinal fluid analysis, serology, rheumatologic tests, and systemic survey for other manifestations sites. After systemic investigation, meningeal biopsy might be necessary. Etiology guides HP treatment, and autoimmune disorders are treated with corticosteroids alone or associated with an immunosuppressor. CONCLUSION: HP is a manifestation of several diseases, and a precise etiological diagnosis is crucial because of the difference among treatments. An extensive investigation of patients with HP helps early diagnosis and correct treatment.

A clinical approach to hypertrophic pachymeningitis / Abordagem diagnóstica para paquimeningite hipertrófica

ABSTRACT Importance: Hypertrophic pachymeningitis (HP) is a non-usual manifestation of rheumatologic, infectious, and neoplastic diseases. Etiological diagnosis is a challenge, but when made promptly it creates a window of opportunity for treatment, with the possibility of a total reversal of symptoms. Observations: HP is an inflammatory process of the dura mater that can occur as a manifestation of sarcoidosis, granulomatosis with polyangiitis, and IgG4-related disease. The HP case evaluation is extensive and includes central nervous system imaging, cerebrospinal fluid analysis, serology, rheumatologic tests, and systemic survey for other manifestations sites. After systemic investigation, meningeal biopsy might be necessary. Etiology guides HP treatment, and autoimmune disorders are treated with corticosteroids alone or associated with an immunosuppressor. Conclusion: HP is a manifestation of several diseases, and a precise etiological diagnosis is crucial because of the difference among treatments. An extensive investigation of patients with HP helps early diagnosis and correct treatment.

RESUMO Importância: Paquimeningite hipertrófica (PH) é uma manifestação não usual de doenças reumatológicas, infecciosas e neoplásicas. O diagnóstico etiológico por vezes é um desafio, entretanto quando realizado em tempo cria uma janela de tratamento com a possibilidade de reversão total dos sintomas. Observações: A PH é um processo inflamatório da dura-máter que pode ocorrer como manifestação da sarcoidose, granulomatose com poliangeíte e doença relacionada à IgG4. A avaliação dos casos de PH é extensa e inclui imagem do sistema nervoso central, análise de líquor, sorologias, provas reumatológicas e rastreio sistêmico para doença em outros sítios. Por vezes, após toda a investigação sistêmica, a biópsia de meninge é necessária. A etiologia orienta o tratamento da HP, sendo que em doenças autoimunes adota-se o uso de corticosteroides isolados ou associados a um imunossupressor. Conclusão e Relevância: A PH é uma manifestação de várias doenças, e seu diagnóstico etiológico preciso é fundamental, visto a diferença entre os possíveis tratamentos. Uma investigação ampla nos casos de PH ajuda no diagnóstico precoce e tratamento adequado.

Should we investigate mitochondrial disorders in progressive adult-onset undetermined ataxias?

BACKGROUND: Despite the broad development of next-generation sequencing approaches recently, such as whole-exome sequencing, diagnostic workup of adult-onset progressive cerebellar ataxias without remarkable family history and with negative genetic panel testing for SCAs remains a complex and expensive clinical challenge. CASE PRESENTATION: In this article, we report a Brazilian man with adult-onset slowly progressive pure cerebellar ataxia, which developed neuropathy and hearing loss after fifteen years of ataxia onset, in which a primary mitochondrial DNA defect (MERRF syndrome - myoclonus epilepsy with ragged-red fibers) was confirmed through muscle biopsy evaluation and whole-exome sequencing. CONCLUSIONS: Mitochondrial disorders are a clinically and genetically complex and heterogenous group of metabolic diseases, resulting from pathogenic variants in the mitochondrial DNA or nuclear DNA. In our case, a correlation with histopathological changes identified on muscle biopsy helped to clarify the definitive diagnosis. Moreover, in neurodegenerative and neurogenetic disorders, some symptoms may be evinced later during disease course. We suggest that late-onset and adult pure undetermined ataxias should be considered and investigated for mitochondrial disorders, particularly MERRF syndrome and other primary mitochondrial DNA defects, together with other more commonly known nuclear genes.

Paroxysmal Autonomic Instability with Dystonia after Severe Traumatic Brain Injury.

Background: Paroxysmal autonomic instability with dystonia (PAID) syndrome, a subset of dysautonomia, is characterized by paroxysms of marked agitation, diaphoresis, hyperthermia, hypertension, tachycardia and tachypnea accompanied by hypertonia and extensor posturing. Case Report: We report a 52-year-old man who was severely brain injured and developed spastic tetraparesis with cognitive impairment. During his Intensive care unit stay and rehabilitation period, he presented with paroxysmal episodes of dystonic posturing accompanied by dysautonomia. Discussion: Our case raises awareness of PAID, a life-threatening condition which can mimic many others and poses significant challenges in the acute management and rehabilitation of patients. Highlights: PAID is characterized by paroxysms of marked agitation, diaphoresis, hyperthermia, hypertension, tachycardia and tachypnea accompanied by hypertonia and extensor posturing.It usually presents in patients with severe brain injury primarily due to trauma or hypoxia resulting in diffuse axonal or brainstem injury.PAID is also associated with tuberculous meningitis, interpeduncular tuberculoma, pneumococcal meningoencephalitis, intracerebral hemorrhage and paraneoplastic limbic encephalopathy.Differential diagnosis of PAID include neuroleptic malignant syndrome, malignant hyperthermia, sepsis, thyroid storm, pheochromocytoma, autonomic epileptic seizures, sepsis and impending cerebral herniation.

Neurological complications in patients with SARS-CoV-2 infection: a systematic review / Complicações neurológicas em pacientes infectados pelo SARS-CoV-2: uma revisão sistemática

ABSTRACT Background: As the COVID-19 pandemic unfolds worldwide, different forms of reports have described its neurologic manifestations. Objective: To review the literature on neurological complications of SARS-CoV-2 infection. Methods: Literature search performed following systematic reviews guidelines, using specific keywords based on the COVID-19 neurological complications described up to May 10th, 2020. Results: A total of 43 articles were selected, including data ranging from common, non-specific symptoms, such as hyposmia and myalgia, to more complex and life-threatening conditions, such as cerebrovascular diseases, encephalopathies, and Guillain-Barré syndrome. Conclusion: Recognition of neurological manifestations of SARS-CoV-2 should be emphasized despite the obvious challenges faced by clinicians caring for critical patients who are often sedated and presenting other concurrent systemic complications.

RESUMO Introdução: À medida que a pandemia da COVID-19 se desenvolve em todo o mundo, diferentes tipos de publicações descreveram suas manifestações neurológicas. Objetivo: Revisar a literatura sobre complicações neurológicas da infecção por SARS-CoV-2. Métodos: A pesquisa bibliográfica foi realizada seguindo diretrizes de revisões sistemáticas, usando palavras-chave específicas baseadas nas complicações neurológicas da COVID-19 descritas até 10 de maio de 2020. Resultados: Foram selecionados 43 artigos, incluindo descrições que variam de sintomas comuns e inespecíficos, como hiposmia e mialgia, a condições mais complexas e com risco de vida, como doenças cerebrovasculares, encefalopatias e síndrome de Guillain-Barré. Conclusão: O reconhecimento das manifestações neurológicas da SARS-CoV-2 deve ser enfatizado apesar dos óbvios desafios enfrentados pelos clínicos que cuidam de pacientes críticos, muitas vezes sedados e apresentando outras complicações sistêmicas concomitantes.

Clinical, ophthalmological, imaging and genetic features in Brazilian patients with ARSACS.

BACKGROUND: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an important form of inherited ataxia with a varied clinical spectrum. Detailed studies of phenotype and genotype are necessary to improve diagnosis and elucidate this disorder pathogenesis. OBJECTIVE AND METHODS: To investigate the clinical phenotype, retinal architecture, neuroimaging features and genetic profile of Brazilian patients with ARSACS, we performed neurological and ophthalmological evaluation in thirteen Brazilian patients with molecularly confirmed ARSACS, and examined their mutation profiles. Optical coherence tomography protocol (OCT) consisted in peripapillary retinal nerve fiber layer (RNFL) measurement and qualitative analysis of perifoveal scans. Neuroimaging protocol accessed the frequency of atrophy in cerebellum, corpus callosum and parietal lobe, brainstem signal abnormalities, and posterior fossa arachnoid cysts. We reviewed the literature to delineate the ARSACS phenotype in the largest series worldwide. RESULTS: All patients had ataxia and spasticity, and 11/13 had peripheral neuropathy. Macular microcysts were present in two patients. Peripapillary striations, dentate appearance of inner retina and papillomacular fold were found in eleven cases. All individuals exhibited thickening of RNFL in OCT. The most frequent radiological signs were cerebellar atrophy (13/13), biparietal atrophy (12/13), and linear pontine hypointensities (13/13). Genetic analysis revealed 14 different SACS variants, of which two are novel. CONCLUSION: Macular microcysts, inner retina dentate appearance and papillomacular fold are novel retinal imaging signs of ARSACS. Ophthalmological and neuroimaging changes are common findings in Brazilian patients. The core clinical features of ARSACS are ataxia, spasticity and peripheral neuropathy with onset predominantly in the first decade of life.

Cross-cultural adaptation and validation of the International Cooperative Ataxia Rating Scale (ICARS) to Brazilian Portuguese / Tradução para o português e validação da Escala Cooperativa Internacional para Avaliação das Ataxias (ICARS)

ABSTRACT Introduction: The clinical assessment of patients with ataxias requires reliable scales. We aimed to translate, adapt and validate the International Cooperative Ataxia Rating Scale (ICARS) into Brazilian Portuguese. Methods: The steps of this study were forward translation, translation synthesis, backward translation, expert committee meeting, preliminary pilot testing and final assessment. Thirty patients were enrolled in the preliminary pilot testing and 61 patients were evaluated for construct validity, internal consistency, intra- and inter-rater reliability and external consistency. Results: This study showed good validity of the construct and high internal consistency for the full scale, except for the oculomotor domain (Cronbach's alpha = 0.316, intraclass correlation coefficients intra- = 82.4% and inter- = 79.2%). A high correlation with the Scale for the Assessment and Rating of Ataxia was observed. We found good intra-rater agreement and relative inter-rater disagreement, except in the posture and gait domain. Conclusion: The present ICARS version is adapted for the Brazilian culture and can be used to assess our ataxic patients.

RESUMO Introdução: A avaliação clínica de pacientes atáxicos requer instrumentos confiáveis. Nosso objetivo foi traduzir, adaptar culturalmente e validar a International Cooperative Ataxia Rating Scale (ICARS) para a língua portuguesa do Brasil. Métodos: As etapas foram tradução, síntese das traduções, retrotradução, comitê de especialistas, pré-teste e avaliação final. O pré-teste foi realizado com 30 pacientes. Outros 61 pacientes foram avaliados para validade do constructo, consistência interna, confiabilidade intra e interexaminadores e consistência externa. Resultados: Este estudo mostrou boa validade do constructo e alta consistência interna para o total da escala, exceto para o domínio Oculomotor (alfa de Cronbach = 0.316, CCIintra = 82.4% e CCIinter = 79.2%). Alta correlação com a Scale for the Assessment and Rating of Ataxia foi observada. Nós encontramos boa concordância intraexaminador e relativa discordância interexaminadores, com exceção dos domínios postura e marcha. Conclusão: Esta versão da ICARS está adaptada para a cultura brasileira e pode ser usada em pacientes com ataxia.

Twenty-five years since the identification of the first SCA gene: history, clinical features and perspectives for SCA1 / Vinte e cinco anos desde a identificação do primeiro gene das SCAs: história, aspectos clínicos e perspectivas para a SCA1

ABSTRACT Spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of monogenic diseases that share ataxia and autosomal dominant inheritance as the core features. An important proportion of SCAs are caused by CAG trinucleotide repeat expansions in the coding region of different genes. In addition to genetic heterogeneity, clinical features transcend motor symptoms, including cognitive, electrophysiological and imaging aspects. Despite all the progress in the past 25 years, the mechanisms that determine how neuronal death is mediated by these unstable expansions are still unclear. The aim of this article is to review, from an historical point of view, the first CAG-related ataxia to be genetically described: SCA 1.

RESUMO As ataxias espinocerebelares (SCA) são um grupo clínico e geneticamente heterogêneo de doenças monogênicas que compartilham ataxia e herança autossômica dominante como características principais. Uma proporção importante de SCAs é causada por expansões de repetição de trinucleotídeos CAG na região de codificação de diferentes genes. Além da heterogeneidade genética, os aspectos clínicos transcendem os sintomas motores, incluindo aspectos cognitivos, eletrofisiológicos e de imagem. Apesar de todo o progresso feito nos últimos 25 anos, os mecanismos que determinam como se dá a morte neuronal mediada por essas expansões instáveis ainda não estão claros. O objetivo deste artigo é revisar, de um ponto de vista histórico, a primeira ataxia geneticamente relacionada com o CAG descrita: SCA 1.