Olivopontocerebellar atrophy

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

The term was originally coined by Joseph Jules Dejerine and André Thomas.

Current uses of the term
The term "olivopontocerebellar atrophy" currently applies only to two hereditary disorders whose genetic basis remains unknown:

Obsolete uses of the term
In the past, the term "olivopontocerebellar atrophy" extended to both the sporadic (non-hereditary) cases of the disease, which have been currently reclassified as a form of multiple system atrophy, as well as to four hereditary types, which have been currently reclassified as four different forms of spinocerebellar ataxia: