Multiple System Atrophy
What Is It, Causes, Symptoms, and More
Author:Anna Hernández, MD
Editors:Alyssa Haag,Ian Mannarino, MD, MBA,Kelsey LaFayette, DNP, ARNP, FNP-C
Illustrator:Jessica Reynolds, MS
Copyeditor:David G. Walker
What is multiple system atrophy?
Multiple system atrophy (MSA) is a rare and rapidly progressive neurodegenerative disorder characterized by symptoms that affect both the autonomic nervous system (i.e., the part of the nervous system that controls involuntary body functions) and movement and balance. These symptoms reflect the progressive loss of function of nerve cells in the brain and spinal cord.
The term multiple system atrophy includes three neurologic conditions that were previously recognized individually—namely olivopontocerebellar atrophy, Shy-Drager syndrome, and striatonigral degeneration—as they all appear to be manifestations of the same disease.
What causes multiple system atrophy?
While the exact cause of multiple system atrophy is unknown, most proposed mechanisms suggest that MSA is caused by the accumulation of the protein alpha-synuclein within glial cells, a group of cells that supports neurons in the brain. Other mechanisms, including mitochondrial dysfunction and inflammation, have also been proposed. However, what is apparent is the deposits of alpha-synuclein occur in oligodendroglia (i.e., a type of glial cell that produces myelin) and result in glial inclusion bodies that can be seen under a microscope. Because they both result from a build-up of alpha-synuclein in cells, MSA and Parkinson disease are known as synucleinopathies. A possible risk factor for the disease is mutations in the synuclein gene (i.e., SCNA), which provides instructions for producing alpha-synuclein.
What are the signs and symptoms of multiple system atrophy?
Signs and symptoms of multiple system atrophy typically appear around 50 and rapidly progress for five to ten years. Although symptoms of MSA can vary between individuals, they generally include a combination of autonomic symptoms, parkinsonism, and cerebellar ataxia. The different symptoms can be used to classify MSA into the Parkinsonian subtype (MSA-P) and the cerebellar subtype (MSA-C).
Autonomic dysfunction is an essential manifestation of multiple system atrophy that causes symptoms related to involuntary bodily functions. Individuals may experience dizziness or fainting due to orthostatic hypotension where blood pressure drops when rising from a seated or lying position. Other symptoms may include erectile dysfunction, urinary incontinence, constipation, and decreased sweating. There may also be breathing problems, like sleep apnea and stridor (i.e., a high-pitched, whistling sound made when breathing).
Abnormal postures, including contractures in the hands or feet, bent spine, and antecollis (i.e. severe forward neck flexion that interferes with eating, speaking, and vision), may be part of the motor symptoms in a few individuals with MSA.
In the parkinsonism type of multiple system atrophy (MSA-P), individuals mainly experience Parkinson-like symptoms, such as slowness of movements (i.e., bradykinesia), shuffling gait, rigidity, slurred speech, and a tendency to fall. Unlike Parkinson’s classic “pill-rolling” resting tremor, MSA usually has a kinetic tremor, which occurs when the individual is in a specific position (e.g., extending their arms out) or moving. Another typical feature of MSA is a poor response to levodopa, a medication that is commonly used in the treatment of Parkinson disease.
The cerebellar type of multiple system atrophy (MSA-C) is characterized by progressive loss of coordination and balance. Symptoms can include a wide-based gait, uncoordinated limb movements, action tremors, and unusual eye movements (known as nystagmus).
In advanced stages, individuals may develop frequent falls, voice-tone changes, difficulty articulating words, and difficulty swallowing due to muscle weakness. This may lead to potentially life-threatening complications, like aspiration pneumonia. Generally speaking, 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 after symptoms begin.
How is multiple system atrophy diagnosed?
In most cases, diagnosis relies on a combination of clinical history and neurological findings as there is currently no specific laboratory tests or imaging studies that can accurately diagnose multiple system atrophy. Diagnosis of multiple system atrophy can be challenging as the initial symptoms are often difficult to distinguish from those of Parkinson disease. However, additional tests like a brain MRI or PET scan may be done to rule out alternative causes and confirm the diagnosis.
How is multiple system atrophy treated?
Treatment of multiple system atrophy is aimed at helping individuals cope with the symptoms of the disease as there is currently no cure for MSA. Levodopa, a medication that stimulates the dopamine receptor, is sometimes used to improve motor function in the early stages of the disease; but its efficacy generally decreases over time. There is no specific treatment available for cerebellar dysfunction. However, benzodiazepines, like clonazepam, may be used to reduce jerking movements and action tremors. Contractures and abnormal postures may be managed with physical therapy and injections of botulinum toxin to relax the affected muscles.
Orthostatic hypotension can be controlled by compression stockings and lifestyle changes, such as increasing salt and fluid intake and avoiding standing up too quickly. In severe cases, a corticosteroid medication called fludrocortisone may increase blood volume and blood pressure. Other alternatives include droxidopa and midodrine, two FDA-approved medications for the treatment of neurogenic orthostatic hypotension. Other autonomic problems, like urinary incontinence, may be treated with anticholinergic medications (e.g., oxybutynin, tolterodine), whereas urinary retention can be managed with intermittent catheterization or an indwelling urinary catheter. In addition, individuals with neurogenic bladder symptoms should be screened regularly for urinary tract infections.
Individuals can use a continuous positive airway pressure (CPAP) device for sleep apnea. This machine forces the airways open with a steady stream of pressurized air administered through a mask or nasal prongs. In more severe cases, botulinum toxin injections to the vocal cords may be done to prevent airways from collapsing. Finally, a tracheostomy (i.e., a surgical opening in the trachea) may provide an alternative way of breathing in severely affected individuals.
In advanced stages, individuals may have significant difficulties with swallowing and may need a feeding tube for nutritional support. Likewise, individuals may require assistive devices, such as walkers and wheelchairs. Physical therapy may be helpful throughout the progression of the disease to maintain mobility, reduce contractures, and decrease muscle spasms and abnormal postures.
What are the most important facts to know about multiple system atrophy?
Multiple system atrophy (MSA) is a rare neurodegenerative condition that causes autonomic system dysfunction and symptoms of parkinsonism or cerebellar ataxia. Like Parkinson disease, MSA is associated with the accumulation of the protein alpha-synuclein within nerve cells, causing damage to the areas of the brain that control movement and involuntary body functions. Diagnosis of MSA can be challenging and often involves a combination of clinical history, physical examination, and neuroimaging tests. Treatment focuses on managing the symptoms as there is currently no treatment available to prevent the progression of the disease.
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Resources for research and reference
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Fecek C, Nagalli S. Shy Drager Syndrome. PubMed. Published 2022. Accessed 2023. https://www.ncbi.nlm.nih.gov/books/NBK560502/
Wiener C, Fauci AS, Hauser SL, et al. Harrison’s Principles of Internal Medicine Self-Assessment and Board Review, 20th Edition. McGraw Hill Professional; 2021.
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