**6.18 Olivopontocerebellar atrophy**

The term (OPCA) is used to describe neurological degeneration in the cerebellum, pontine nuclei, and inferior olive. OPCA can also originate in the brains of an individual with prion disorders and inherited metabolic diseases. The distinctive regions of the damaged brain by OPCA can be seen by imaging the brain using CT scan or MRI studies.

#### **6.19 O'Sullivan-McLeod syndrome**

Also known as "Monomelic Amyotrophy" (MMA) and is illustrated by progressive degeneration and loss of motor neurons, the nerve cells of the brain and spinal cord, responsible for controlling voluntary muscles.
