Parkinson's or Multiple System Atrophy? 5 Clues Doctors Look For
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Parkinson's or Multiple System Atrophy? 5 Clues Doctors Look For
A man is diagnosed with Parkinson's disease in his late fifties. He is slow and stiff, and his medication helps for a few months. Then the picture starts to shift. He gets dizzy and nearly faints when he stands up from the couch. His wife notices he is getting up several times a night to urinate, and that his voice has begun to strain when he speaks.
A movement disorders specialist reviews the whole history and raises a different possibility: multiple system atrophy, or MSA. It looks like Parkinson's disease in the early years, and the differences show up as a pattern. This story is a composite of conversations we have had with families.
Why MSA and Parkinson's Disease Can Look Alike
MSA belongs to a group called atypical parkinsonism. The word parkinsonism describes slowness, stiffness, and sometimes tremor, which Parkinson's disease causes and which several other conditions can also cause.
The National Institute of Neurological Disorders and Stroke (NINDS) describes MSA as a progressive neurodegenerative disorder affecting both movement and the body's automatic functions. It is rare, affecting potentially 15,000 to 50,000 people in the United States, and symptoms usually begin in a person's fifties. In Parkinson's disease, the protein alpha-synuclein builds up in nerve cells. In MSA, it builds up in support cells called glial cells.
MSA has two main forms. In the parkinsonian type, called MSA-P, slowness and stiffness dominate, so it is the form most easily mistaken for Parkinson's disease. In the cerebellar type, MSA-C, balance and coordination problems come first.
How often does the mix-up happen? In a 2021 study in the journal Brain, researchers reviewed 218 people whose MSA was confirmed at autopsy. Sixteen of them, about 7 percent, had been diagnosed with Parkinson's disease during life.
Clue 1: Blood Pressure and Bladder
The first clue involves the body's automatic functions. The Movement Disorder Society's 2022 criteria require autonomic dysfunction for a diagnosis of clinically established MSA. That means unexplained bladder problems, such as trouble emptying the bladder or sudden urgency with leaking, or a significant blood pressure drop on standing, called neurogenic orthostatic hypotension. The criteria define it as a drop of at least 20 over 10 within three minutes of standing.
Parkinson's disease can cause these problems as well. In the Brain study, autonomic dysfunction within the first three years of symptoms was more frequent in the MSA cases diagnosed as Parkinson's than in people with confirmed Parkinson's disease. The timing matters as much as the symptom itself.
Clue 2: The Response to Levodopa
Levodopa is the main Parkinson's medication. The 2022 criteria describe the parkinsonism of MSA as poorly levodopa-responsive. NINDS says levodopa may improve movement in some people with MSA, but the benefits are often short-lived. The criteria list a substantial and persistent benefit from dopamine medications as an exclusion for MSA.
One caution belongs here. In the Brain study, people with MSA who had been diagnosed with Parkinson's more often had a sustained levodopa response than typical MSA patients did. A strong early response does not rule MSA out.
Clue 3: Balance and Coordination
The third clue is a cerebellar pattern, which means trouble with balance and coordination out of proportion to the slowness and stiffness. NINDS lists balance and coordination problems, called ataxia, along with trouble swallowing, speech changes, and abnormal eye movements.
The 2022 criteria describe a cerebellar syndrome as including at least two of the following: unsteady walking, clumsiness in the limbs, slurred or scanning speech, and abnormal eye movements. A person with MSA-C may have this picture from the start. A person with MSA-P may develop it alongside parkinsonism.
Clue 4: Red Flags in Voice, Breathing, and Posture
The fourth clue is a set of features the 2022 criteria call red flags. They are not required for a diagnosis, but they lend support when they appear together with the features above.
On the movement side, the list includes rapid progression within three years, significant balance trouble or severe speech or swallowing problems within three years, a jerky, myoclonic tremor, and a bent or twisted posture. On the non-movement side, the list includes noisy breathing called stridor, sighing breaths during inhalation, cold and discolored hands and feet, and sudden crying or laughing that does not match how the person feels.
Clue 5: The Pace
NINDS states that MSA progresses faster than Parkinson's disease. Symptoms often advance over about five to 10 years, and most people need a walking aid within a few years of symptom onset.
There is currently no cure for MSA, according to NINDS, but treatment addresses the symptoms. That includes medicines and compression stockings for blood pressure drops, botulinum toxin injections for abnormal muscle postures, speech and physical therapy, and mobility aids. An accurate diagnosis matters because the safety plan, including fall prevention and swallowing, looks different.
How Doctors Diagnose MSA, and What Remains Uncertain
There is no single test that confirms MSA during life. According to NINDS, diagnosis rests on the history, the examination, and sometimes autonomic testing, bladder assessment, and brain imaging.
The 2022 criteria also list findings that point elsewhere, including unexplained loss of smell, hallucinations or dementia early on, and a strong and lasting response to dopamine medication. The authors state that the criteria still need prospective and autopsy-based validation.
Most people with Parkinson's symptoms have Parkinson's disease. Dizziness on standing or bladder trouble does not mean MSA. These clues exist to help a family ask better questions at an evaluation.
What to Bring and What to Ask
If several of these clues sound familiar, ask for a referral to a movement disorders specialist, a neurologist with extra training in these conditions.
- A dated log of dizziness or fainting when standing
- Any bladder symptoms
- Falls and their dates
- A medication log showing when each dose was taken and what changed
- A short phone video of the person walking and speaking
Then ask two questions. How confident are you in the current diagnosis, and what findings would make you reconsider it? Anyone who faints or nearly faints should tell their care team promptly.
This article is educational and does not replace medical advice. The opening story is a composite of conversations with families.
Sources: National Institute of Neurological Disorders and Stroke, Multiple System Atrophy. Movement Disorder Society criteria for the diagnosis of multiple system atrophy (2022), Movement Disorders, doi 10.1002/mds.29005. Miki, Y., et al. (2021). Identification of multiple system atrophy mimicking Parkinson's disease or progressive supranuclear palsy. Brain, 144(4), 1138-1151.