Causes

There's no known cause for multiple system atrophy (MSA). Some researchers are studying a possible inherited component or involvement of an environmental toxin in the disease process, but there's no substantial evidence to support these theories.

MSA causes deterioration and shrinkage (atrophy) of portions of your brain (cerebellum, basal ganglia and brainstem) that regulate internal body functions, digestion and motor control.

Under a microscope, the damaged brain tissue of people with MSA shows nerve cells (neurons) that contain an abnormal amount of a protein called alpha-synuclein. Some research suggests that this protein may be overexpressed in multiple system atrophy.