Multiple system atrophy (MSA): Year of the Zebra 2025

Multiple system atrophy, or MSA for short, is a neurodegenerative disorder that affects a person’s movement, sense of balance, and regulation of body functions like blood pressure, bowel and bladder control, and breathing. It’s part of a group of movement disorders called parkinson-plus syndromes, which cause parkinsonism, plus other clinical features.

The exact mechanism why it happens isn’t completely understood, but it’s believed to result from the abnormal build-up of a protein called alpha-synuclein within glial cells, which are cells that support and protect the central nervous system. This build-up mainly affects the areas of the brain responsible for voluntary movement, balance, and coordination, as well as the autonomic nervous system, which is responsible for involuntary processes like blood pressure, breathing, and digestion. Ultimately, this build-up leads to widespread brain damage.

Now, symptoms of MSA typically begin around the age of 50 and tend to progress rapidly over the course of 5 to 10 years. Clinically, MSA can present in two different ways. Most individuals experience symptoms that resemble those of Parkinson disease, including resting tremor, rigidity, slowness of movement, and postural instability, which often leads to a stooped posture and an increased frequency of falls.

Other people experience symptoms related to the loss of cerebellar function. This can manifest as poor hand-eye coordination; difficulty with fine motor tasks, like buttoning a shirt; involuntary eye movements, known as nystagmus; and a wide-based gait due to poor balance.

Both subtypes of MSA share signs of autonomic system failure, which may include fainting or dizziness when standing due to low blood pressure, known as orthostatic hypotension; impotence; and urinary incontinence or retention.

In advanced stages, individuals may develop voice-tone changes, as well as difficulty speaking and swallowing due to weakness in the muscles in the mouth and throat. In general, MSA tends to progress more rapidly than Parkinson disease; and most people require walking aids, such as a cane or walker, within a few years of symptoms beginning.