How many people are diagnosed with MSA? MSA is considered rare, affecting about two to five individuals for every 100,000 people. Currently, about 13,000 people are diagnosed with MSA in the United States. This compares with about 30,000-40,000 people with progressive supranuclear palsy( PSP), which is a different type of atypical parkinsonism disorder; about 1 million with Parkinson’ s disease; and 5 million with Alzheimer’ s disease. This means that in the U. S., about five people are newly diagnosed with MSA each day. However, these figures for MSA are probably underestimates because many people with MSA are misdiagnosed with another condition, such as Parkinson’ s disease.
At what age does MSA start? People with MSA often begin to have symptoms anywhere from their late 40s through their early 70s. The average age at which the symptoms of MSA begin is 53. Unlike Parkinson’ s disease, where symptoms can begin as early as the 20s and as late as the 90s, symptoms of MSA are very unlikely to begin outside this age range.
What are the symptoms of MSA? MSA involves multiple circuits in the brain, each of which explains one of its several categories of recognizable symptoms. These major symptom groups include:
- Parkinsonism, which refers to slowness, smallness, and stiffness of movement, as well as tremor and changes in gait and balance. Other common problems related to movement in parkinsonism include reduced arm swing with walking, small or cramped handwriting, soft voice, and reduced facial expression.
- Cerebellar ataxia, which is caused by disease in the cerebellum( located at the back of the brain) and its connections. Common symptoms are a staggering, drunken-like gait, imbalance, uncoordinated movements, difficulty reaching for things with the arms, sloppy handwriting, and slurred speech.
- Autonomic nervous system failure, including severe blood pressure fluctuations when changing positions, difficulty with urination, constipation, difficulty swallowing, reduced sweating, and sexual dysfunction.
- Spasticity, which refers to muscle stiffness or tightness that creates resistance to being stretched. When your doctor taps on your arm or leg with a reflex hammer, you may notice that your limb jumps. MSA can exaggerate these reflexes, interfering with voluntary movement.
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Are there different types of MSA? People with MSA may develop some or all of the groups of symptoms listed above. Currently there are two recognized subtypes of MSA, defined by their predominant symptoms. One is the parkinsonian subtype( MSA-P). People with this type of MSA have more parkinsonism symptoms, meaning slow and small movements, tremor, and shuffling gait. Many people with this subtype may be misdiagnosed with Parkinson’ s disease initially. The other subtype of MSA is the cerebellar subtype( MSA-C). This subtype is diagnosed when someone has a predominance of