There are three major types of multiple system atrophy (MSA). They affect different areas of the body and can produce different symptoms. The three MSA types are:

• Striatonigral degeneration (SND). Degeneration that affects the corpus striatum and substantia nigra in the brain, both of which are part of the basal ganglia – which is involved in motion control and memory. SND produces symptoms similar to those of Parkinson’s disease, including slow movements, stiff muscles, rigidity and tremors. This type of MSA is sometimes also referred to as the Parkinsonian type.
  
  
• Olivopontocerebellar atrophy (OPCA). Degeneration that affects three areas of the brain: the lower pair of olives (oval structures in the medulla oblongata), the pons and the cerebellum – all of which work together to control movement. Thus, the predominant symptoms of OPCA are a lack of balance and inability to coordinate movement and speech. There are many different types of OPCA, including several hereditary forms. However, the hereditary forms are not considered a type of MSA, according to the National Organization for Rare Disorders. The severity of OPCA symptoms and age of symptom onset may vary significantly, depending on the type of OPCA involved. OPCA is also sometimes referred to as the cerebellar type.
  

  

• Multiple system atrophy with orthostatic hypotension (formerly called Shy-Drager syndrome). As its contemporary name indicates, orthostatic hypotension (sudden drop in blood pressure upon standing) is the predominant symptom of this type of MSA. This type of MSA affects the autonomic nervous system, which regulates involuntary body functions (e.g., blood pressure, heart rate, sweating, erectile function, bowel and bladder control). This MSA is sometimes referred to as the combined type, since it may also include symptoms typically associated with OPCA and/or SND.