Spinocerebellar ataxias.

UNLABELLED Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of neurodegenerative diseases characterized by progressive cerebellar ataxia in association with some or all of the following conditions: ophthalmoplegia, pyramidal signs, movement disorders, pigmentary retinopathy, peripheral neuropathy, cognitive dysfunction and dementia. OBJECTIVE To carry out a clinical and genetic review of the main types of SCA. METHOD The review was based on a search of the PUBMED and OMIM databases. RESULTS Thirty types of SCAs are currently known, and 16 genes associated with the disease have been identified. The most common types are SCA type 3, or Machado-Joseph disease, SCA type 10 and SCA types 7, 2, 1 and 6. SCAs are genotypically and phenotypically very heterogeneous. A clinical algorithm can be used to distinguish between the different types of SCAs. CONCLUSIONS Detailed clinical neurological examination of SCA patients can be of great help when assessing them, and the information thus gained can be used in an algorithm to screen patients before molecular tests to investigate the correct etiology of the disease are requested.