Olivopontocerebellar atrophy

Olivopontocerebellar atrophy (OPCA) is a term used to define neuronal degeneration in the cerebellum, pontine nuclei, and inferior olive. The use of the term has changed considerably in recent years thanks to the progressing knowledge of the genetic bases of the disease.

Sporadic OPCA
Sporadic (non-hereditary) OPCA is considered a form of multiple system atrophy.

Hereditary OPCA
Four types of hereditary OPCA have disappeared from medical nomenclature, as they have been found to be the same as an already classified form of spinocerebellar atrophy. Type 2, autosomal recessive and Type 5 are still classified as olivopontocerebellar atrophy, though when their genetic associations are identified they may be renamed or combined with other conditions.