Polyneuropathy in Patients with Spinocerebellar Ataxias Types 2, 3, and 10: A Systematic Review.

Spinocerebellar ataxia (SCA) is an autosomal dominant hereditary disease with a low prevalence, for which more than 50 types have been described. This group of neurodegenerative diseases can present as different phenotypes with varying progression rates and clinical manifestations of different severities. Herein, we systematically reviewed existing medical literature to describe the main characteristics of polyneuropathy in patients with SCA types 2, 3, and 10. Using relevant keywords, 16,972 articles were identified from the databases. Of these, 5,329 duplicate studies were excluded before screening. Subsequently, 11,643 studies underwent title and abstract review, of which only 49 were selected for full-text review. Among these, 24 studies were included. The medical literature suggests peripheral neuropathy - probably in a polyneuropathy phenotype - in SCA types 2 and 3. It is not possible to determine whether there is peripheral neuropathy in patients with SCA type 10, as there is only one case series in Mexico that described peripheral neuropathy in this group. Further studies are required to investigate peripheral neuropathy in patients with SCA types 2, 3, and 10. The study and description of a possible statistical association between CAG repeats and SARA scale scores with the presence of peripheral neuropathy are important points requiring assessment in future research.