What is post polio syndrome

Post polio syndrome is a poorly understood condition that affects polio survivors years after recovery from an initial acute attack of the poliomyelitis virus. Post polio syndrome usually develops 15 to 40 years after the polio infection. Post polio syndrome symptoms and severity vary among affected people and may include muscle weakness and a gradual decrease in the size of muscles (atrophy); muscle and joint pain; fatigue; difficulty with gait; respiratory problems; and/or swallowing problems. The most common symptoms include slowly progressive muscle weakness, fatigue (both generalized and muscular), and a gradual decrease in the size of muscles (muscle atrophy). Pain from joint degeneration and increasing skeletal deformities such as scoliosis (curvature of the spine) is common and may precede the weakness and muscle atrophy. Some individuals experience only minor symptoms while others develop visible muscle weakness and atrophy.

Only a polio survivor can develop post polio syndrome. While polio is a contagious disease, post polio syndrome is not.

Post-polio syndrome is rarely life-threatening, but the symptoms can significantly interfere with an individual’s ability to function independently. Respiratory muscle weakness, for instance, can result in trouble with proper breathing, affecting daytime functions and sleep. Weakness in swallowing muscles can result in aspiration of food and liquids into the lungs and lead to pneumonia.

The severity of weakness and disability after recovery from poliomyelitis tends to predict the relative risk of developing post polio syndrome. Individuals who had minimal symptoms from the original illness are more likely to experience only mild post polio syndrome symptoms. A person who was more severe polio and who attained a greater recovery may experience a more severe case of post polio syndrome, with greater loss of muscle function and more severe fatigue.

The exact incidence and prevalence of post polio syndrome is unknown. The U.S. National Health Interview Survey in 1987 contained specific questions for persons given the diagnosis of poliomyelitis with or without paralysis. No survey since then has addressed the question. Results published in 1994-1995 estimated there were about 1 million polio survivors in the U.S., with 443,000 reporting to have had paralytic polio. Accurate statistics do not exist today, as a percentage of polio survivors have died and new cases have been diagnosed. Researchers estimate that the condition affects 25 to 40 percent of polio survivors.

The exact cause of post polio syndrome years after the first episode of polio is unclear, although several theories have been proposed. Treatment focuses on reducing symptoms and improving quality of life.

Post polio syndrome life expectancy

The best actuarial assumption about the life expectancy of polio survivors in the US seems to be that, on average, it now matches average life expectancy for the general population in the US ¹.

Post-polio syndrome complications

Post-polio syndrome is rarely life-threatening, but severe muscle weakness can lead to complications:

• Falls. Weakness in your leg muscles makes it easier for you to lose your balance and fall. You then might break a bone, such as a hip, leading to other complications.
• Malnutrition, dehydration and pneumonia. People who’ve had bulbar polio, which affects nerves leading to muscles involved in chewing and swallowing, often have difficulty with these activities as well as other signs of post-polio syndrome. Chewing and swallowing problems can lead to inadequate nutrition and to dehydration, as well as to aspiration pneumonia, which is caused by inhaling food particles into your lungs (aspirating).
• Chronic respiratory failure. Weakness in your diaphragm and chest muscles makes it harder to take deep breaths and cough, which can cause fluid and mucus to build up in your lungs. Obesity, smoking, curvature of the spine, anesthesia, prolonged immobility and certain medications can further decrease your breathing ability, possibly leading to a sharp drop in blood oxygen levels (acute respiratory failure). You might then need treatment to help you breathe (ventilation therapy).
• Osteoporosis. Prolonged inactivity and immobility are often accompanied by loss of bone density and osteoporosis in both men and women. If you have post-polio syndrome, talk to your doctor about bone-density screening.

Post polio syndrome causes

The cause of post polio syndrome is unknown but experts have offered several theories to explain the phenomenon—ranging from the fatigue of overworked nerve cells to possible brain damage from a viral infection to a combination of mechanisms. The leading theory is that it’s the result of the gradual deterioration of nerve cells in the spinal cord (motor neurons) that were damaged by the polio virus. This would explain why the condition can take years to appear.

The new weakness of post polio syndrome appears to be related to the degeneration of individual nerve terminals in the motor units. A motor unit is formed by a nerve cell (or motor neuron) in the spinal cord or brain stem and the muscle fibers it activates. The polio virus attacks specific neurons in the brain stem and spinal cord. In an effort to compensate for the loss of these motor neurons, surviving cells sprout new nerve-end terminals and connect with other muscle fibers. These new connections may result in recovery of movement and gradual gain in power in the affected limbs.

Years of high use of these recovered but overly extended motor units adds stress to the motor neurons, which over time lose the ability to maintain the increased work demands. This results in the slow deterioration of the neurons, which leads to loss of muscle strength. Restoration of nerve function may occur in some fibers a second time, but eventually nerve terminals malfunction and permanent weakness occurs. This hypothesis explains why post polio syndrome occurs after a delay and has a slow and progressive 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 progresses very slowly. It is marked by periods of relative stability, interspersed with periods of decline.

Risk factors for post polio syndrome

Factors that can increase your risk of developing post-polio syndrome include:

• Severity of initial polio infection. The more severe the initial infection, the more likely that you’ll have signs and symptoms of post-polio syndrome.
• Age at onset of initial illness. If you developed polio as an adolescent or adult rather than as a child, your chances of developing post-polio syndrome increase.
• Recovery. The greater your recovery after acute polio, the more likely it seems that post-polio syndrome will develop, perhaps because greater recovery places additional stress on motor neurons.
• Excessive physical activity. If you often exercise to the point of exhaustion or fatigue, you might overwork already stressed-out motor neurons and increase your risk of post-polio syndrome.

Post polio syndrome prevention

Polio survivors often ask if there is a way to prevent the development of post polio syndrome. Presently, no intervention has been found to stop the deterioration of surviving neurons. Physicians recommend that polio survivors get a good night’s sleep, maintain a well-balanced diet, avoid unhealthy habits such as smoking and overeating, and follow a prescribed exercise program. Lifestyle changes, such as weight control, the use of assistive devices, and taking certain anti-inflammatory medications, may help with some of the symptoms of post polio syndrome.

Post polio syndrome symptoms

Post-polio syndrome can cause a wide range of symptoms that can severely affect everyday life.

Post-polio syndrome tend to develop gradually and get worse very slowly over time.

Post-polio syndrome can include a wide range of symptoms that develop gradually over time, including:

• persistent fatigue (extreme tiredness)
• muscle weakness
• shrinking muscles
• muscle and joint pain
• sleep apnea

The condition can have a significant impact on everyday life, making it very difficult to get around and carry out certain tasks and activities.

The symptoms tend to get gradually worse over many years, but this happens very slowly and treatment may help slow it down further.

The condition is rarely life-threatening, although some people develop breathing and swallowing difficulties that can lead to serious problems, such as chest infections.

Post polio syndrome common symptoms

Fatigue

Fatigue is the most common symptom of post-polio syndrome. It can take many forms, including:

• muscle fatigue – where muscles feel very tired and heavy, particularly after physical activity
• general fatigue – where you feel an overwhelming sense of physical exhaustion, as if you’ve not slept for days
• mental fatigue – where you find it increasingly difficult to concentrate, have problems remembering things and make mistakes you would not usually make

Organizing your activities so that you don’t over-exert yourself and taking regular rests will help to reduce your fatigue.

Muscle weakness

Increasing muscle weakness is another common symptom of post-polio syndrome. It can be easy to confuse muscle weakness with muscle fatigue, but they are different.

Muscle weakness means that you’re increasingly unable to use affected muscles, whether you feel tired or not. Weakness can occur in muscles that were previously affected by a polio infection, as well as in muscles that were not previously affected.

There may also be associated shrinking of affected muscles, known as atrophy.

Muscle and joint pain

Muscle and joint pain are also common in post-polio syndrome. Muscle pain is usually felt as a deep ache in the muscles or muscle cramps and spasms.

The pain is often worse after you’ve used the affected muscles. It can be particularly troublesome during the evening after a day’s activities.

Joint pain is similar to arthritis and consists of soreness, stiffness and a reduced range of movement.

Associated symptoms

As well as the common symptoms of post-polio syndrome, several associated symptoms can arise from the combination of fatigue, muscle weakness, and muscle and joint pain.

Weight gain

Because of the symptoms mentioned above, most people with post-polio syndrome become less physically active than they used to be.

This can often lead to weight gain and, in some cases, obesity. This in turn can make any fatigue, muscle weakness and pain worse.

Walking difficulties

As well as weight gain, the combination of fatigue, weakness and pain can lead to walking difficulties and increasing difficulty with mobility.

Many people with post-polio syndrome will require a walking aid such as crutches or a stick at some stage, and some people may eventually need to use a wheelchair.

Breathing difficulties

In some people with post-polio syndrome, breathing can be difficult because the breathing muscles become weaker.

This can cause problems such as shortness of breath, interrupted breathing while you sleep (sleep apnea), and an increased risk of chest infections.

If you have post-polio syndrome, it’s important to seek medical advice as soon as possible if you experience symptoms of a possible chest infection. These can include coughing up discolored phlegm or blood, chest pain and wheezing.

Sleep apnea

Sleep apnea affects many people with post-polio syndrome. The walls of the throat relax and narrow during sleep, interrupting normal breathing.

This can cause problems such as feeling very sleepy during the day, headaches and increased fatigue.

Swallowing problems

Weakness in the muscles you use for chewing and swallowing may lead to problems swallowing (dysphagia), such as choking or gagging when you try to swallow.

You may experience changes in your voice and speech, such as hoarseness, low volume or a nasal-sounding voice, particularly after you’ve been speaking for a while or when you are tired.

Swallowing problems are usually mild and progress very slowly. A speech and language therapist may be able to help.

Sensitivity to cold

Some people with post-polio syndrome find they become very sensitive to cold temperatures or a sudden drop in temperature as a result of poor blood supply.

Because of this intolerance to cold, people with post-polio syndrome may need to wear extra layers of clothing to try to stay comfortable.

Post polio syndrome diagnosis

The diagnosis of post polio syndrome relies nearly entirely on clinical information and can be difficult to diagnose because there are no specific tests for it and symptoms can be mistaken for other conditions.

There are no laboratory tests specific for this condition and symptoms vary greatly among individuals. Physicians diagnose post polio syndrome after completing a comprehensive medical history and physical examination, and by excluding other disorders that could explain the symptoms.

Physicians look for the following criteria when diagnosing post polio syndrome:

• Prior paralytic poliomyelitis with evidence of motor neuron loss. This is confirmed by history of the acute paralytic illness, signs of residual weakness and atrophy of muscles on neuromuscular examination, and signs of motor neuron loss on electromyography (EMG). Rarely, people had subtle paralytic polio where there was no obvious deficit. In such cases, prior polio should be confirmed with an EMG study rather than a reported history of nonparalytic polio.
• 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.
• Slowly progressive and persistent new muscle weakness or 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 skeletal abnormalities as causes of symptoms.

Post polio syndrome may be difficult to diagnose in some people because other medical conditions can complicate the evaluation. Depression, for example, is associated with fatigue and can be misinterpreted as post polio syndrome. A number of conditions may cause problems in persons with polio that are not due to additional loss of motor neuron function. For example, shoulder osteoarthritis from walking with crutches, a chronic rotator cuff tear leading to pain and disuse weakness, or progressive scoliosis causing breathing insufficiency can occur years after polio but are not indicators of post polio syndrome.

Polio survivors with new symptoms resembling post polio syndrome should consider seeking treatment from a physician trained in neuromuscular disorders. It is important to clearly establish the origin and potential causes for declining strength and to assess progression of weakness not explained by other health problems. Magnetic resonance imaging (MRI) and computed tomography (CT) of the spinal cord, electrophysiological studies, and other tests are frequently used to investigate the course of decline in muscle strength and exclude other diseases that could be causing or contributing to the new progressive symptoms. A muscle biopsy or a spinal fluid analysis can be used to exclude other, possibly treatable, conditions that mimic post polio syndrome. Polio survivors may acquire other illnesses and should always have regular check-ups and preventive diagnostic tests. However, there is no diagnostic test for post polio syndrome, nor is there one that can identify which polio survivors are at greatest risk.

Tests you may have to rule out other conditions, or to confirm whether it’s likely you have post-polio syndrome, may include:

• Electromyography (EMG) tests to determine whether polio has damaged your nerves and muscles – an EMG measures the electrical activity in your muscles and nerves. In a variation of EMG called nerve conduction studies, two electrodes are taped to your skin above a nerve to be studied. A small shock is passed through the nerve to measure the speed of nerve signals. These tests help identify and exclude conditions such as an abnormal condition of your nerves (neuropathy) and a muscle tissue disorder (myopathy).
• Sleep studies if you are having problems sleeping (such as sleep apnea) or are feeling unusually tired – read more about diagnosing sleep apnea
• Tests to check your heart rate and function
• A magnetic resonance imaging (MRI) scan or computerized tomography (CT) scan of your bones and muscles
• Lung function tests to measure how well you can breathe, such as spirometry
• Tests to investigate swallowing problems (dysphagia)
• Muscle biopsy. A muscle biopsy might be done to help your doctor look for evidence of another condition that could be causing the weakness.
• Blood tests. People with post-polio syndrome usually have normal blood test results. Abnormal blood test results could indicate another underlying problem that’s causing your symptoms.
• Muscle ultrasound, which uses sound waves to create images of muscles, shows promise for evaluating the severity of post-polio syndrome and monitoring its progression. However, more study is needed.

It’s possible to have post-polio syndrome alongside other conditions, so not every health problem or symptom you experience may be related to the condition.

Post polio syndrome treatment

There’s currently no cure for post-polio syndrome, but support and a range of treatments are available to help manage the symptoms and improve quality of life.

There are currently no effective pharmaceutical treatments that can stop deterioration or reverse the deficits caused by the syndrome itself. However, a number of controlled studies have demonstrated that nonfatiguing exercises may improve muscle strength and reduce tiredness. Most of the clinical trials in post polio syndrome have focused on finding safe therapies that could reduce symptoms and improve quality of life.

Researchers have tried treating persons having post polio syndrome with high doses of the steroid prednisone and demonstrated a mild improvement in their condition, but the results were not statistically significant. Also, the side effects from the treatment outweighed benefits, leading researchers to conclude that prednisone should not be used to treat post polio syndrome.

Preliminary studies indicate that intravenous immunoglobulin may reduce pain and increase quality of life in post-polio survivors.

A small trial to treat fatigue using lamotrigine (an anticonvulsant drug) showed modest effect but this study was limited and larger, more controlled studies with the drug were not conducted to validate the findings.

Although there are no effective treatments, there are recommended management strategies. Patients should consider seeking medical advice from a physician experienced in treating neuromuscular disorders. Patients should also consider judicious use of exercise, preferably under the supervision of an experienced health professional. Physicians often advise patients on the use of mobility aids, ventilation equipment, revising activities of daily living activities to avoid rapid muscle tiring and total body exhaustion, and avoiding activities that cause pain or fatigue lasting more than 10 minutes. Most importantly, patients should avoid the temptation to attribute all signs and symptoms to prior polio, thereby missing out on important treatments for concurrent conditions.

Learning about post polio syndrome is important for polio survivors and their families. Managing post polio syndrome can involve lifestyle changes. Support groups that encourage self-help, group participation, and positive action can be helpful. Counseling may be needed to help individuals and families adjust to the late effects of poliomyelitis. Experiencing new symptoms of weakness and using assistive devices may bring back distressing memories of the original illness.

People with post polio syndrome are often treated by a team of different healthcare professionals working together. This is known as a multidisciplinary team.

Members of your multidisciplinary team may include:

• a neurologist – a specialist in problems affecting the nervous system
• a respiratory consultant – a specialist in problems affecting breathing
• a consultant in rehabilitation medicine – a specialist in managing complex disabilities
• a physiotherapist – who helps people improve their range of movement and co-ordination
• a speech and language therapist – who can help people with swallowing difficulties
• an occupational therapist – who helps people improve the skills needed for daily activities, such as washing and dressing
• a mobility specialist – who can give advice about mobility aids, such as walking sticks and wheelchairs

Some of the ways that symptoms of post-polio syndrome may be managed include with:

• rest and exercise – such as learning to stop activities before becoming exhausted
• mobility aids – such as walking sticks or scooters
• weight control and healthy eating – to avoid putting unnecessary strain on muscles and joints
• painkilling medication – to help relieve muscle or joint pain
• psychological support – such as discussions with a doctor, on an online forum, or in a local support group.

Rest and exercise

Being active is thought to be beneficial for most people with post-polio syndrome, as it may slow down the progressive muscle weakness.

However, this can be difficult to achieve if you have the condition because your symptoms may feel worse after a period of activity.

To overcome this problem, “pacing” techniques may be recommended. This involves:

• planning and prioritizing tasks
• finding alternative ways of doing exhausting tasks and getting help from others when you need it
• taking regular breaks and having rest periods during the day
• doing regular gentle exercise – this should be built-up gradually and stopped before you become exhausted or experience pain

For example, several smaller trips to a supermarket may be easier than one large shop. If driving to the supermarket and back is tiring, you may want to consider having home deliveries.

Pacing can mean you don’t wear yourself out and are able to accomplish more activities over the space of a day than if you tried to do things without taking a break.

Many people with post-polio syndrome find it hard to adapt to pacing at first. This is because when they had polio as a child, they may have been told to make every effort to use their muscles, even if it caused pain and fatigue.

Nowadays, the advice is the opposite. It’s now thought that making effective and efficient use of your strength and muscle function will help them last longer.

Post polio syndrome exercise

Pain, weakness, and fatigue can result from the overuse of muscles and joints. These same symptoms also can 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 with 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, especially when activities are paced to allow for frequent breaks and strategies are used to conserve energy. Heavy or intense resistive exercise and weight-lifting using polio-affected muscles may be counterproductive, as this 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 it causes additional weakness, excessive fatigue, or unduly prolonged recovery time that is noted by either the individual with post polio syndrome or the professional monitoring the exercise. As a general rule, no muscle should be exercised to the point of causing ache, fatigue, or weakness.

Post polio syndrome physical therapy

Your doctor or therapist may prescribe exercises for you that strengthen your muscles without fatiguing them. These usually include less strenuous activities, such as swimming or water aerobics, that you perform every other day at a relaxed pace.

Speech therapy

A speech therapist can show you ways to compensate for swallowing difficulties. Voice strengthening exercises might also be helpful.

Painkillers

While pain and fatigue can often be reduced using pacing, various medications to help relieve pain are available if you need them. These include over-the-counter painkillers such as aspirin, paracetamol or ibuprofen, and stronger anti-inflammatory drugs and opiates.

Over-the-counter medicines should not be used on a long-term basis without first talking to your doctor. This is because some of them can cause complications, such as stomach ulcers, if taken over long periods.

Opiates, such as codeine, may cause drowsiness or depressed breathing (slow, shallow breathing) as well as other side effects, including constipation.

If these medications don’t work, your doctor may consider prescribing gabapentin for your pain. This medication was originally developed for epilepsy, but has also proved useful for post-polio syndrome pain when other types of painkillers haven’t helped.

If you are taking medication to control your pain, you may not be aware of damage that could be caused to your muscles and joints by too much activity. It’s therefore important to stick to your pacing regimen, even if you don’t feel tired or in pain.

Mobility aids

Mobility aids may make it possible to do many of the activities that were becoming difficult or impossible.

Mobility aids that may be of benefit to people with post-polio syndrome include:

• braces that can support weakened muscles and joints, improve posture and prevent falls
• walking sticks
• electric scooters
• wheelchairs

Treating breathing and sleeping problems

If you have breathing difficulties as a result of post-polio syndrome, a number of treatments and lifestyle measures may be useful.

These can include:

• using a machine that delivers pressurized air into your lungs via a mask as you sleep – this can help to stop your airways closing if you have sleep apnea
• exercises to increase the strength of your breathing muscles
• having the pneumococcal vaccination and annual flu jab – this can reduce your risk of getting serious chest infections

If you smoke, stopping smoking can also help.

Post polio syndrome diet

Being overweight can put further strain on weakened muscles and can have a negative effect on your energy levels and general health. Losing weight, if you need to, may make your symptoms better.

While regular exercise is a good way of controlling your weight, it may not be possible because of your physical condition. You care team may be able to give you specific advice about this.

Following a sensible healthy eating plan will help you reduce and control your weight, as well as improve your health. It’s important to eat a healthy, balanced diet, including foods that provide energy that are released slowly over long periods.

Trying new foods, new food combinations or new ways of cooking to widen the variety of tastes and textures and stimulate the appetite can be an enjoyable way to lose weight and improve your health. Your doctor can refer you to a dietitian, if necessary.

You can also apply the pacing principles mentioned above to eating and cooking. For example, it may help to:

• plan your meals in advance
• break down cooking tasks into smaller, more manageable ones
• use days when you have more energy to prepare food and cook extra amounts to freeze for less energetic days
• use cookery books that contain simple, healthy meals that are quick to prepare, such as pasta or salads
• use kitchen equipment, such as food processors, microwaves and slow cookers, that can help you save time and energy
• try ready meals and tinned and packet foods if you feel too tired to cook a meal from scratch; however, you should avoid eating these too often, as they are usually high in salt, sugars and fats, and low in vitamins and minerals

Managing the psychological impact

Post-polio syndrome can often have a significant psychological impact. The symptoms can be distressing, and developing post-polio syndrome can often bring back painful childhood memories of living with polio.

It can often feel very cruel that, having struggled to overcome a polio infection during childhood, you’re affected by polio again. This can lead to feelings of anxiety, isolation and stress, which can sometimes trigger depression.

If you have been feeling very down during the past month and you no longer take pleasure in things that you used to enjoy, you may be depressed. See your doctor if this is the case. A number of treatments are available that can help.

It’s important not to neglect your mental wellbeing if you have post-polio syndrome. As well as the impact on your quality of life, feelings of depression and anxiety can also interfere with your treatment.

You may find it useful to talk to other people who are living with post-polio syndrome.

Post polio syndrome alternative treatment

Having to deal again with an illness you thought was in the past can be discouraging, even overwhelming at times. Recovering from the initial illness required drive and determination, but now the late effects of polio require you to rest and conserve your energy.

Here are some suggestions:

• Limit activities that cause pain or fatigue. Moderation is key. Overdoing it on a good day can lead to several subsequent bad days.
• Be smart. Conserving your energy through lifestyle modifications and assistive devices doesn’t mean you’re giving in to the illness. It just means you’ve found a smarter way to deal with it.
• Stay warm. Cold increases muscle fatigue. Keep your home at a comfortable temperature and dress in layers, especially when you go out.
• Avoid falls. Get rid of throw rugs and loose clutter on the floor, wear good shoes, and avoid slippery or icy surfaces.
• Maintain a healthy lifestyle. Eat a balanced diet, stop smoking and decrease caffeine intake to keep fit, breathe easier and sleep better.
• Protect your lungs. If your breathing is impaired, watch for signs of a developing respiratory infection and have it treated promptly. Don’t smoke, and stay current with your flu and pneumonia vaccines.

Coping and support

Dealing with the fatigue and weakness of post-polio syndrome can be difficult physically and psychologically. You might need to lean on your friends and family. Don’t hesitate to tell them what kind of help you need.

Consider joining a support group for people with post-polio syndrome. Sometimes talking things over with people who have similar problems can help you cope. Ask your doctor about support groups in your area.

1. http://www.post-polio.org/PolioSurvivorsInTheUS1915-2000.pdf[↩]