Multiple System Atrophy (MSA)
The parts of the brain that control movements and many internal body processes degenerate.
Symptoms include symptoms that resemble those of Parkinson disease, low blood pressure when a person stands (orthostatic hypotension), problems with urination, and constipation.
Doctors base the diagnosis on a person's response to levodopa (used to treat Parkinson disease) and results of magnetic resonance imaging and tests of autonomic function.
Simple measures and drugs can help lessen symptoms, but the disorder is progressive and ultimately fatal.
(See also Overview of the Autonomic Nervous System.)
Multiple system atrophy usually begins when people are in their 50s. It affects about twice as many men as women.
There are two types of multiple system atrophy (MSA), based on which symptoms occur first:
Both types involve autonomic nervous system dysfunction. Although multiple system atrophy begins as one of these types, symptoms of the other type eventually develop. After about 5 years, symptoms tend to be similar regardless of which disorder developed first.
Multiple system atrophy results from degeneration of several parts of the brain and spinal cord:
The basal ganglia (collections of nerve cells at the base of the cerebrum, deep within the brain), which help control voluntary muscle movements by balancing the actions of muscle groups that move the same muscles in opposite ways (for example, a group that bends an arm and a group that straightens the arm)
The cerebellum, which coordinates voluntary movements (particularly complex movements done simultaneously) and helps maintain balance
Areas that control the autonomic nervous system, which regulates involuntary body processes, such as how blood pressure changes in response to changes in posture
The cause of the degeneration is unknown, but degeneration in multiple system atrophy probably results when synuclein changes shape (misfolds) and accumulates in support cells in the brain. Synuclein is a protein in the brain that helps nerve cells communicate, but whose function is not yet fully understood. Abnormal synuclein can also accumulate in people with pure autonomic failure, Parkinson disease, or dementia with Lewy bodies.
Rapid eye movement (REM) sleep behavior disorder often occurs in people with disorders that involve accumulation of synuclein, including multiple system atrophy.
Locating the Cerebellum and Basal Ganglia
Multiple system atrophy is a progressive disorder. Early symptoms of multiple system atrophy vary, depending on which part and how much of the brain is affected first. The disorder causes three groups of symptoms.
Parkinsonism—symptoms that resemble those of Parkinson disease—may occur. These symptoms result from degeneration in the basal ganglia. Muscles are stiff (rigid), and movements become slow, shaky, and difficult to initiate. When walking, people may shuffle and not swing their arms. People feel unsteady and off balance, making them more likely to fall. Posture may be stooped. Limbs may tremble jerkily, usually when they are held in one position. But people with multiple system atrophy are less likely to have tremors during rest than people with Parkinson disease. Articulating words is difficult, and the voice may become high-pitched and quaver.
Loss of coordination may occur. It results from degeneration in the cerebellum. People lose their balance. Later, they may be unable to control movements of their arms and legs. Consequently, they have difficulty walking and take wide, irregular steps. When reaching for an item, they may reach beyond it. When sitting, they may feel unstable. People may have difficulty focusing their eyes on and following objects. Tasks that require rapidly alternating movements, such as turning a door knob or screwing in a light bulb, also become difficult.
Malfunction of internal body processes, controlled by the autonomic nervous system, may also occur. Blood pressure may decrease dramatically when a person stands up, causing dizziness, light-headedness, or fainting—a condition called orthostatic hypotension. Blood pressure may increase when a person lies down.
People may need to urinate urgently or frequently or may pass urine involuntarily (urinary incontinence). They may have difficulty emptying the bladder (urinary retention). Constipation is common. Vision becomes poor. Men may have difficulty initiating and maintaining an erection (erectile dysfunction).
Other symptoms of autonomic malfunction may include the following:
Less sweat, tears, and saliva are produced. As a result, people may become intolerant of heat and have dry eyes and mouth.
People may have difficulty swallowing and breathing.
Breathing may be noisy and high-pitched.
During sleep, breathing may stop repeatedly or become inadequate (sleep apnea).
If REM sleep behavior disorder develops, people speak (often profanely) and may wave their arms or legs violently during sleep, possibly because they are acting out vivid, frightening dreams.
People may lose control of bowel movements (fecal incontinence).
Many people are confined to a wheelchair or are otherwise severely disabled within 5 years after symptoms begin. The disorder results in death 9 to 10 years after symptoms begin.
The diagnosis of multiple system atrophy is based on a doctor's evaluation and results of certain tests. For example, doctors may suspect multiple system atrophy if parkinsonian symptoms are rapidly worsening and levodopa (used to treat Parkinson disease) has little or no effect on symptoms.
Magnetic resonance imaging (MRI) is usually done to check for certain changes in the brain.
Tests to evaluate the autonomic nervous system are done. They include the thermoregulatory sweat test and measurement of blood pressure while the person is sitting and after the person stands to check for orthostatic hypotension.
If MRI shows changes that suggest multiple system atrophy and test results are abnormal, multiple system atrophy is likely.
No treatment can cure multiple system atrophy. However, a combination of simple measures and drugs may help relieve symptoms.
Parkinsonism: Continuing to do as many daily activities as possible helps maintain muscle strength and flexibility. Stretching and exercising regularly may also help. Drugs used to treat Parkinson disease, such as levodopa plus carbidopa, taken by mouth, may be tried, but this combination usually has little effect or is effective for only a few years.
Orthostatic hypotension: Measures are taken to stabilize the sudden changes in blood pressure. Consuming more salt and water may increase the volume of blood and thus help increase blood pressure. Standing up slowly may help prevent blood pressure from decreasing too much or too fast when a person stands, as may wearing an abdominal binder or compression stockings. These garments help maintain blood pressure by promoting blood flow from the legs to the heart and thus prevent too much blood from staying (pooling) in the legs. Raising the head of the bed by about 4 inches (10 centimeters) can help prevent blood pressure from increasing too much when the person lies down. Fludrocortisone may be taken by mouth. It helps the body retain salt and water and thus may increase blood pressure as needed when a person stands. Other drugs, such as midodrine or droxidopa, taken by mouth, may also help.
Decreased production of body fluids: If sweating is reduced or absent, people should avoid warm environments to avoid overheating the body. Good dental care and regular check-ups are essential for people with dry mouth. Artificial tears (eye drops containing substances that resemble real tears) applied every few hours may relieve dry eyes.
Urinary retention: If needed, people can learn to insert a catheter (a thin rubber tube) into the bladder themselves. They insert it several times a day. It is inserted through the urethra, allowing urine in the bladder to drain out. People remove the catheter after the bladder is empty. This measure helps prevent the bladder from stretching and urinary tract infections from developing. Washing the hands, cleansing the area around the urethra, and using a sterile or clean catheter also help prevent infections. Inserting a catheter becomes more difficult as coordination deteriorates. Sometimes drugs such as bethanechol are used to stimulate contractions of the bladder and thus help the bladder empty.
Urinary incontinence: Oxybutynin, mirabegron, tamsulosin, or tolterodine, taken by mouth, may be used to relax the muscles of an overactive bladder. If incontinence persists, using a catheter inserted into the bladder may help. People may learn to insert it themselves.
Constipation: A high-fiber diet and stool softeners are recommended. If constipation persists, enemas may be necessary.
Erectile dysfunction: Usually, treatment consists of drugs such as sildenafil, tadalafil, vardenafil, or avanafil, taken by mouth.
As the multiple system atrophy progresses, people may need a breathing tube, feeding tube (usually surgically inserted), or both.
Physical, occupational, and speech therapists can teach people ways to compensate when walking, doing daily activities, and speaking become difficult. Social workers can help people find support groups and, when symptoms become disabling, home health care or hospice services.
Because the disorder is progressive and ultimately fatal, people should prepare advance directives soon after the disorder is diagnosed. These directives should indicate what kind of medical care people want at the end of life.