Introduction: Non-progressive congenital ataxias (NPCA) constitute a heterogeneous group of processes linked to diverse aetiological factors that can be either environmentally or genetically determined. The signs of cerebellar compromise, which are preceded by unspecific signs such as early hypotonia, difficulty in sucking or chewing or retarded motor acquisition, become apparent with development or may remain absent when the disorder is very severe.
Development: NPCA can be accompanied by a number of pathologies and their diagnosis can be made easier by the concurrence of symptoms or signs of extra-cerebellar involvement, such as dysmorphic features or abnormalities affecting the skin, heart, bones, blood, eyes or other areas of the central or peripheral nervous system. Neuroimaging usually reveals vermian hypoplasia and/or hypoplasia of the cerebellar hemispheres, but can be normal in certain situations. The article includes a review of the NPCA following the classification proposed by Steinlin in 1998.
Conclusions: The difficulties inherent in diagnosing these processes makes it necessary to deploy a wide range of complementary examinations, especially metabolic tests, before a generic diagnosis of NPCA can be established. Although the progress made in molecular genetics has made it possible to categorise NPCA better, both their causation and their hereditary or sporadic nature remain unknown in about 50% of cases.