Spinocerebellar ataxia type 1 (SCA1), spinocerebellar ataxia type 2 (SCA2) and Machado-Joseph disease or spinocerebellar ataxia type 3 (MJD/SCA3) are three distinctive forms of autosomal dominant spinocerebellar ataxia (SCA) caused by expansions of an unstable CAG repeat localized in the coding region of the causative genes. Another related disease, dentatorubropallidoluysian atrophy (DRPLA) is also caused by an unstable triplet repeat and can present as SCA in late onset patients. We investigated the frequency of the SCA1, SCA2, MJD/SCA3 and DRPLA mutations in 328 Brazilian patients with SCA, belonging to 90 unrelated families with various patterns of inheritance and originating in different geographic regions of Brazil. We found mutations in 35 families (39%), 32 of them with a clear autosomal dominant inheritance. The frequency of the SCA1 mutation was 3% of all patients; and 6% in the dominantly inherited SCAs. We identified the SCA2 mutation in 6% of all families and in 9% of the families with autosomal dominant inheritance. The MJD/SCA3 mutation was detected in 30% of all patients; and in the 44% of the dominantly inherited cases. We found no DRPLA mutation. In addition, we observed variability in the frequency of the different mutations according to geographic origin of the patients, which is probably related to the distinct colonization of different parts of Brazil. These results suggest that SCA may be occasionally caused by the SCA1 and SCA2 mutations in the Brazilian population, and that the MJD/SCA3 mutation is the most common cause of dominantly inherited SCA in Brazil.

RESUMO -Neurocisticercose é condição provocada pela infecção do sistema nervoso pelo Cysticercus cellulosae, a forma larvária da Taenia solium. Ela é, muito provavelmente, a principal responsável pela elevada prevalência de epilepsia no Brasil. Em diversas áreas do país, possui um caráter endêmico, gerando grande dispêndio financeiro para um enfrentamento das diversas complicações neurológicas relacionadas a ela. Sabe-se que por suas peculariedades sócio-econômicas, com suinocultura disseminada, a região sul do Brasil, é considerada pelo ministério da Saúde como uma área de alto risco. Para averiguar sua importância entre nós, um estudo, considerando internações por epilepsia e sua etiologia, foi realizado na cidade de Chapecó, principal cidade do oeste de Santa Catarina. O período coberto pela investigação foi de 1995, entrada em funcionamento de tomógrafo computadorizado no Hospital Regional daquela cidade, até o mês de novembro de 1996. Uma expressiva prevalência de neurocisticercose, aproximada de 24%, foi observada entre os indivíduos internados pelo diagnóstico de epilepsia. Algo em torno de 40% dos infectados apresentava lesões em sua fase ativa, sugerindo uma aquisição recente. Nossos dados sugerem que a despeito desta região sediar agro-indústrias de projeção internacional, a cisticercose grassa endemicamente na área. Um controle deste flagelo terceiro mundista poderia ser obtido com a difusão de mensagens educativas, em linguajar apropriado, para uma sensibilização de toda a população vivendo naquela região. Além disso, todos aqueles indivíduos envolvidos em suinocultura, independentemente de como seja esta classificada, deveriam ser objeto de atenção especial. PALAVRAS-CHAVES: neurocisticercose, epilepsia, suinocultura. Prevalence of neurocysticercosis among epileptic in-patients in the west of Santa Catarina -southern BrazilABSTRACT -Neurocysticercosis (NC) is an endemic condition in several areas of Brazil. It is most likely the major responsible for the high prevalence of epilepsy in our country, estimated in 1-2% of general population. We performed a study to evaluate NC as aetiology of epilepsy in the west of Santa Catarina. This state belong to southern Brazil and it has a very developed economy. However, due the widespread swine farming in the west district, many of them without any sanitary control, the national health authorities have considered all this area at risk to NC. The study was carried out in Chapecó, the main town in that region, where CT Scan service was started in 1995. All patients put on hospital care due epileptic seizures in 1995-96 were considered. Febrile convulsions were excluded of the sample. We found a very expressive prevalence rate of NC among patients suffering from epilepsy. Roughly 24% of these patients, showed unequivocal tomography evidences for the diagnosis of NC. Our data suggest cysticercosis as a real endemic trouble in the area and, overdosis of information in proper language, diffuse to the whole population, seems to be the only remedy to fight against it....

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