Multiple system atrophy (MSA) is a neurological disorder in which patients experience degenerative symptoms that can affect movement, speech, blood pressure and other bodily functions.

MSA affects the central nervous system (CNS) and the autonomic nervous system (ANS). The CNS includes the brain and spinal cord. It coordinates the body’s responses to sensory impulses received from the peripheral nervous system (PNS). The ANS is a part of the PNS that controls involuntary functions of the body, such as blood pressure, heart rate, digestion, sweating, sexual function, and bowel and bladder control.

MSA is characterized by symptoms of parkinsonism (e.g., slow movements, rigidity and tremors), ataxia (loss of muscle coordination) and autonomic dysfunction (e.g., drop in blood pressure, breathing difficulties). These symptoms may occur in a variety of combinations. The type of MSA a person has may be determined by the predominant symptoms – that is, whether symptoms are primarily those of parkinsonism, ataxia or autonomic dysfunction.

The prevalence of MSA is unclear, although it is considered to be a relatively rare disorder. According to The Parkinson’s Institute, there are an estimated 25,000 to 100,000 people in the United States who have MSA.

MSA occurs in adults and symptoms get progressively worse over a number of years. As the disease progresses, patients are likely to experience more widespread and severe symptoms. In some cases, dementia may develop during later stages of the disease. Complications of MSA may include injury from falls (due to orthostatic hypotension or impaired balance), breathing problems and cardiac arrhythmias (irregular heart rhythms).

The speed with which MSA progresses can vary from person to person, and may differ depending on the type of MSA involved. For example, according to the National Institute of Neurological Disorders and Stroke (NINDS):

• Patients with predominant parkinsonism (striatonigral degeneration) may have a normal life expectancy.
  
  
• Patients with predominant ataxia symptoms (olivopontocerebellar atrophy) may experience symptoms that progress slowly, with death occurring about 20 years after symptom onset.
  
  
• Patients with autonomic dysfunction as their primary symptom (MSA with orthostatic hypotension) usually die within 10 years after onset of symptoms.

Although statistics vary, the average life expectancy after diagnosis with MSA appears to be approximately 10 years.