Olivopontocerebellar atrophy (OPCA) is a term used for a progressive condition characterized by the degeneration of nerve cells (neurons) in specific areas of the brain. OPCA can be viewed as a finding of several diseases, and indicates a form of progressive ataxia (abnormal or uncontrolled movements) distinguished by characteristic findings in brain imaging studies and at autopsy (pontine flattening and cerebellar atrophy). It was traditionally divided in hereditary or genetic OPCA and sporadic OPCA. Currently, most of the major forms of hereditary OPCA refer to disorders that overlap with spinocerebellar ataxia (SCA), which is a neurological disorder characterized by ataxia. The sporadic forms are considered now to be a form of multiple system atrophy (MSA). OPCA may also occur in people with prion disorders and inherited metabolic diseases. The main symptom is clumsiness that slowly gets worse. Other symptoms may include problems with balance; speech or swallowing problems; difficulty walking; abnormal eye movements; muscle spasms; and neuropathy. Whether OPCA is inherited (and the inheritance pattern) depends on the underlying cause, if known.