- Post-Polio Syndrome Center
- Dementia Slideshow Pictures
- Take the ADHD Quiz
- Brain Foods Slideshow
- Patient Comments: Post-Polio Syndrome - Symptoms
- Patient Comments: Post-Polio Syndrome - Treatment
- Patient Comments: Post-Polio Syndrome - Exercise
- Find a local Neurologist in your town
- What is post-polio syndrome?
- What are the symptoms of post-polio syndrome?
- What causes post-polio syndrome?
- How is post-polio syndrome diagnosed?
- How is post-polio syndrome treated?
- What is the role of exercise in the treatment of post-polio syndrome?
- Can post-polio syndrome be prevented?
- What research is being conducted on post-polio syndrome?
- Where can I get more information?
What is post-polio syndrome?
Post-polio syndrome (PPS) is a condition that affects polio survivors years after recovery from an initial acute attack of the poliomyelitis virus. Post-polio syndrome is mainly characterized by new weakening in muscles that were previously affected by the polio infection and in muscles that seemingly were unaffected.
What are the symptoms of post-polio syndrome?
Symptoms include slowly progressive muscle weakness, unaccustomed fatigue (both generalized and muscular), and, at times, muscle atrophy. Pain from joint degeneration and increasing skeletal deformities such as scoliosis are common. Some patients experience only minor symptoms. While less common, others may develop visible muscle atrophy, or wasting.
Post-polio syndrome is rarely life-threatening. However, untreated respiratory muscle weakness can result in underventilation, and weakness in swallowing muscles can result in aspiration pneumonia.
The severity of residual weakness and disability after acute poliomyelitis tends to predict the development of post-polio syndrome. Patients who had minimal symptoms from the original illness will most likely experience only mild post-polio syndrome symptoms. People originally hit hard by the poliovirus and who attained a greater recovery may develop a more severe case of post-polio syndrome with a greater loss of muscle function and more severe fatigue. It should be noted that many polio survivors were too young to remember the severity of their original illness and that accurate memory fades over time.
According to estimates by the National Center for Health Statistics, more than 440,000 polio survivors in the United States may be at risk for post-polio syndrome. Researchers are unable to establish a firm prevalence rate, but they estimate that the condition affects 25 percent to 50 percent of these survivors, or possibly as many as 60 percent, depending on how the disorder is defined and which study is quoted.
Patients diagnosed with post-polio syndrome sometimes are concerned that they are having polio again and are contagious to others. Studies have shown that this does not happen.
Quick GuideConcussions & Brain Injuries: Symptoms, Tests, Treatment
What causes post-polio syndrome?
The cause is unknown. However, the new weakness of post-polio syndrome appears to be related to the degeneration of individual nerve terminals in the motor units that remain after the initial illness. A motor unit is a nerve cell (or neuron) and the muscle fibers it activates. The poliovirus attacks specific neurons in the brainstem and the anterior horn cells of the spinal cord. In an effort to compensate for the loss of these neurons, ones that survive sprout new nerve terminals to the orphaned muscle fibers. The result is some recovery of movement and enlarged motor units.
Years of high use of these enlarged motor units adds stress to the neuronal cell body, which then may not be able to maintain the metabolic demands of all the new sprouts, resulting in the slow deterioration of motor units. Restoration of nerve function may occur in some fibers a second time, but eventually nerve terminals malfunction and permanent weakness occurs. This hypothesis is consistent with post-polio syndrome's slow, stepwise, unpredictable course.
Through years of studies, scientists at the National Institute of Neurological Disorders and Stroke and at other institutions have shown that the weakness of post-polio syndrome is a very slowly progressing condition marked by periods of stability followed by new declines in the ability to carry out usual daily activities.
How is post-polio syndrome diagnosed?
Physicians arrive at a diagnosis of post-polio syndrome by completing a comprehensive medical history and neuromuscular examination and by excluding other disorders that could explain the symptoms. Researchers and physicians typically use the following criteria to establish a diagnosis:
Criteria for diagnosis of post-polio syndrome*
- Prior paralytic poliomyelitis with evidence ofmotor neuron loss, as confirmed by history of the acute paralytic illness, signs of residual weakness and atrophy of muscles on neuromuscular examination, and signs of nerve damage on electromyography (EMG). Rarely, persons have subclinical paralytic polio, described as a loss of motor neurons during acute polio but with no obvious deficit. That prior polio now needs to be confirmed with an EMG. Also, a reported history of nonparalytic polio may be inaccurate.
- A period of partial or complete functional recovery after acute paralytic poliomyelitis, followed by an interval (usually 15 years or more) of stable neuromuscular function.
- Gradual onset of progressive and persistent new muscle weakness or abnormal muscle fatigability (decreased endurance), with or without generalized fatigue, muscle atrophy, or muscle and joint pain. Onset may at times follow trauma, surgery, or a period of inactivity, and can appear to be sudden. Less commonly, symptoms attributed to post-polio syndrome include new problems with breathing or swallowing.
- Symptoms that persist for at least a year.
- Exclusion of other neuromuscular, medical, and orthopedic problems as causes of symptoms.
*Modified from: Post-Polio Syndrome: Identifying Best Practices in Diagnosis & Care. March of Dimes, 2001.
Post-polio syndrome may be difficult to diagnose in some people because other medical conditions can complicate the evaluation. Depression, for example, also is associated with fatigue and can be misinterpreted as post-polio syndrome or vice versa. For this reason, some clinicians use less restrictive diagnostic criteria, while others prefer to categorize new problems as the late effects of polio—for example, shoulder osteoarthritis from walking with crutches, a chronic rotator cuff tear leading to pain and disuse weakness, or breathing insufficiency due to progressive scoliosis.
Polio survivors with post-polio syndrome symptoms need to visit a physician trained in neuromuscular disorders to clearly establish potential causes for declining strength and to assess progression of weakness not explained by other health problems.
Physicians may use magnetic resonance imaging (MRI), computed tomography (CT), neuroimaging, and electrophysiological studies as tools to investigate the course of decline in muscle strength. Less commonly, they will conduct a muscle biopsy or a spinal fluid analysis. These tests are also important to exclude other, possibly treatable, conditions that mimic post-polio syndrome, but the tests do not identify survivors at greatest risk for new progression of muscle weakness.
It is important to remember that polio survivors may acquire other illnesses and should always have regular check-ups and preventive diagnostic tests, such as mammograms, pap smears, and colorectal exams.
How is post-polio syndrome treated?
There are currently no effective pharmaceutical or specific treatments for the syndrome itself. However, a number of controlled studies have demonstrated that nonfatiguing exercises can improve muscle strength.
Researchers at the National Institutes of Health (NIH) have tried treating post-polio syndrome patients with alpha-2 recombinant interferon, but the treatment proved ineffective. Another study in which post-polio syndrome patients received high doses of prednisone demonstrated a mild improvement in their condition, but the results were not statistically significant. This, in addition to the drug's side effects, led researchers to recommend that prednisone not be used to treat post-polio syndrome.
In an effort to reduce fatigue, increase strength, and improve quality of life in post-polio syndrome patients, scientists conducted two controlled studies using low doses of the drug pyridostigmine (Mestinon). These studies showed that pyridostigmine is not helpful for post-polio syndrome patients.
In another controlled study scientists concluded that the drug amantadine (Symmetrel) is not helpful in reducing fatigue. And other researchers recently evaluated the effectiveness of modafinil (Provigil) on reducing fatigue and found no benefit.
Preliminary studies indicate that intravenous immunoglobin may reduce pain, increase quality of life, and improve strength. Research into its use is ongoing.
The future of post-polio syndrome treatment may center on nerve growth factors. Since post-polio syndrome may result from the degeneration of nerve sprouts, growth factors can target these and help to regenerate new ones. Unfortunately, one small study that NINDS scientists participated in showed that insulin-like growth factor (IGF-1), which can enhance the ability of motor neurons to sprout new branches and maintain existing branches, was not helpful.
Although there is no cure, there are recommended management strategies. Seek medical advice from a physician experienced in treating neuromuscular disorders. Do not attribute all signs and symptoms to prior polio. Use judicious exercise, preferably under the supervision of an experienced professional. Use recommended mobility aids, ventilatory equipment, and revised activities of daily living. Avoid activities that cause pain or fatigue that lasts more than 10 minutes. Pace daily activities to avoid rapid muscle tiring and total body exhaustion.
Learning about post-polio syndrome is important for polio survivors and their families. Management of post-polio syndrome can involve lifestyle changes. Support groups that encourage self-help, group participation, and positive action can be helpful. For some, individual or family counseling may be needed to adjust to the late effects of poliomyelitis, because experiencing new symptoms and using assistive devices may bring back distressing memories of the original illness.
What is the role of exercise in the treatment of post-polio syndrome?
The symptoms of pain, weakness, and fatigue can result from the overuse and misuse of muscles and joints. These same symptoms can also result from disuse of muscles and joints. This fact has caused a misunderstanding about whether to encourage or discourage exercise for polio survivors or individuals who already have post-polio syndrome.
Exercise is safe and effective when carefully prescribed and monitored by experienced health professionals. Exercise is more likely to benefit those muscle groups that were least affected by polio. Cardiopulmonary endurance training is usually more effective than strengthening exercises. Heavy or intense resistive exercise and weight-lifting using polio-affected muscles may be counterproductive because they can further weaken rather than strengthen these muscles.
Exercise prescriptions should include
- the specific muscle groups to be included,
- the specific muscle groups to be excluded, and
- the type of exercise, together with frequency and duration.
Exercise should be reduced or discontinued if additional weakness, excessive fatigue, or unduly prolonged recovery time is noted by either the individual with post-polio syndrome or the professional monitoring the exercise.
Can post-polio syndrome be prevented?
Polio survivors often ask if there is a way to prevent post-polio syndrome. Presently, no intervention has been found to stop the deterioration of surviving neurons. But physicians recommend that polio survivors get the proper amount of sleep, maintain a well-balanced diet, avoid unhealthy habits such assmoking and overeating, and follow an exercise program as discussed above. Proper lifestyle changes, the use of assistive devices, and taking certain anti-inflammatory medications may help some of the symptoms of post-polio syndrome.
What research is being conducted on post-polio syndrome?
Scientists are working on a variety of investigations that may one day help individuals with post-polio syndrome. Some basic researchers are studying the behavior of motor neurons many years after a polio attack. Others are looking at the mechanisms of fatigue and are trying to discover the role played by the brain, spinal cord, peripheral nerves, the neuromuscular junction (the site where a nerve cell meets the muscle cell it helps activate), and the muscles.
Determining if there is an immunological link in post-polio syndrome is also an area of intense interest. Researchers who discovered inflammation around motor neurons or muscles are trying to find out if this is due to an immunological response.
Other investigators have discovered that fragments of the poliovirus, or mutated versions of it, are in the spinal fluid of some survivors. The significance of this finding is not known and more research is being done.
Where can I get more information?
For more information on neurological disorders or research programs funded by the National Institute of Neurological Disorders and Stroke, contact the Institute's Brain Resources and Information Network (BRAIN) at:
P.O. Box 5801
Bethesda, MD 20824
Information also is available from the following organizations:
Post-Polio Health International/
4207 Lindell Blvd.
St. Louis, MO 63108-2930
March of Dimes Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: 914-428-7100 888-MODIMES (663-4637)
Daily Health News
Brain and Nervous System Resources
Last update: 10/29/2008
SOURCE: National Institute of Neurological Disorders and Stroke, National Institutes of Health
Post-Polio Syndrome - Symptoms
What were your symptoms associated with post-polio syndrome?Post View 17 Comments
Post-Polio Syndrome - Treatment
What forms of treatment or therapy have you tried to improve muscle strength lost from post-polio syndrome?Post View 4 Comments
Post-Polio Syndrome - Exercise
What types of exercise or physical therapy are helpful in managing symptoms associated with post-polio syndrome?Post View 7 Comments
Top Post-Polio Syndrome Related Articles
CAT ScanA CT scan is an X-ray procedure that combines many X-ray images with the aid of a computer to generate cross-sectional and three-dimensional images of internal organs and structures of the body. A CT scan is a low-risk procedure. Contrast material may be injected into a vein or the spinal fluid to enhance the scan.
DepressionDepression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
ElectromyogramElectromyogram or EMG is defined as a test that records the electrical activity of muscles. Normal muscles produce a typical pattern of electrical current that is usually proportional to the level of muscle activity. Diseases of muscle and/or nerves can produce abnormal electormyogram patterns.
MammogramMammogram is a test that produces an image of the breast tissue on film. The technique is referred to as mammography. Mammography can visualize normal and abnormal structures within the breast such as cysts, calcifications, and tumors looking for breast cancer. The first baseline mammogram for a woman should be between the ages of 35 to 40.
MRI ScanMRI (or magnetic resonance imaging) scan is a radiology technique which uses magnetism, radio waves, and a computer to produce images of body structures. MRI scanning is painless and does not involve X-ray radiation. Patients with heart pacemakers, metal implants, or metal chips or clips in or around the eyes cannot be scanned with MRI because of the effect of the magnet.
OsteoarthritisOsteoarthritis is a type of arthritis caused by inflammation, breakdown, and eventual loss of cartilage in the joints. Also known as degenerative arthritis. Osteoarthritis can be caused by aging, heredity, and injury from trauma or disease.
OsteoporosisLearn about osteoporosis, a condition characterized by the loss of bone density, which leads to an increased risk of bone fracture. Unless one experiences a fracture, a person may have osteoporosis for decades without knowing it. Treatment for osteoporosis may involve medications that stop bone loss and increase bone strength and bone formation, as well as quitting smoking, regular exercise, cutting back on alcohol intake, and eating a calcium- and vitamin D-rich balanced diet.
Pap SmearA Pap smear (Pap test) is a medical procedure to screen for abnormal cells of the cervix. A woman should have her first Pap smear (in general) three years after vaginal intercourse, or no later than 21 years of age. The risks for women at increased risk for having an abnormal Pap smear include: HPV (genital warts), smoking, a weakened immune system, medications (diethylstilbestrol), and others. Some of the conditions that may result in an abnormal Pap smear include: absence of endocervical cells, unreliable Pap smear due to inflammation, atypical squamous cells (ASCUS), low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), cervical intraepithelial neoplasia (CIN), and carcinoma in situ.
Pneumonia FactsPneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness of breath, and chills. Antibiotics treat pneumonia, and the choice of the antibiotic depends upon the cause of the infection.
ScoliosisScoliosis causes an abnormal curvature of the spine. When the cause of scoliosis is unknown the disorder is described based on the age when the scoliosis develops (infantile, juvenile, or adolescent idiopathic scoliosis). In functional scoliosis, curvature develops due to a problem somewhere else in the body. With neuromuscular scoliosis, there is a problem when the bones of the spine are formed. Treatment typically involves observation, bracing, and surgery and is dependent upon the severity of the curvature.