Energy conservation slows deterioration in PPS
Post-polio syndrome often misdiagnosed
An estimated 2 million polio survivors in the United States are at risk for developing a debilitating condition known as post-polio syndrome (PPS). The general symptoms such as fatigue, new muscle weakness, and pain are experienced in varying degrees and are often dismissed by physicians as normal signs of aging.
"Patients can be as young as their late 30s or early 40s. There was one last very bad polio outbreak in 1957 and not everyone was routinely vaccinated against polio until 1960," says Robby B. Leonard, MS, PT, program coordinator for the Medical University of South Carolina Physical Therapy Program in Greenville. "Most polio survivors are Type A personalities who have been active and functioning well for years. When they begin to experience muscle weakness and fatigue, it’s not the first thing that pops into the mind of either the patient or the doctor."
Many patients with PPS move from physician to physician, receiving a variety of misdiagnoses, says Leonard. There are several reasons for this tendency to misdiagnose the condition. First, few physicians have any experience with polio because for many it is a disease of the past eradicated before they were out of elementary school. Second, there are a wide range of symptoms that can mimic a number of other medical conditions, says Leonard. PPS symptoms include:
• unaccustomed fatigue, either rapid muscle tiring or a feeling of total body exhaustion;
• new weakness in muscles, both those previously affected and those seemingly unaffected during original infection;
• pain in muscles or joints;
• sleeping problems;
• breathing difficulties;
• decreased ability to tolerate cold temperatures;
• decline in ability to conduct customary activities such as walking and bathing;
• swallowing problems.
"I had one patient in the clinic in Warm Springs, GA, where she was treated for polio as a child. Her only problem was she was choking when she ate," says Leonard. "Her doctor sent her to a psychologist, because he couldn’t find any clear cause for her swallowing difficulties. Her childhood chart showed she had been completely paralyzed and in an iron lung and later completely recovered. We did swallowing studies and respiratory studies and found she was having dysphagia." (For further discussion of symptoms, see PPS patient checklist on p. 213. For a look at who’s at risk for PPS, see story, p. 214.)
Patients often experience other health problems resulting from polio-caused impairments and overstressed joints due to compensatory body mechanics. These problems are called late effects of polio, or polio sequelae. They include:
• degenerative arthritis of the overused joints;
• carpal tunnel syndrome;
• tendinitis;
• bursitis.
To obtain a correct diagnosis of PPS, it’s important for case managers to insist on a thorough evaluation to rule out any other conditions. "Sometimes, patients may have had polio and such a young age that if their parents are no longer living they might not even be sure they had the virus," says Leonard. "There are no definitive tests for PPS. However, an electromyleogram (EMG) will confirm that the patient had polio. In polio survivors, an EMG shows the giant motor neurons associated with PPS."
In fact, the current theory is that PPS is related to the gradual loss of individual nerve cells that make contact with muscle fibers, says Leonard. This leads to eventual loss of nerve transmission to these fibers. During initial polio infection, the virus attacks motor neurons, causing injury or death to nerve cells. In polio survivors, the body compensated for lost function by causing surviving nerve cells to sprout extra branches, called axonal sprouts, which attached to muscle fibers that had lost their original nerve supply. The muscle fibers then worked again often as good as new. Unfortunately, over time these overextended nerve cells cannot hold such a large number of extra axonal sprouts and instead undergo degeneration due to overextension.
"It’s as if instead of walking five miles an hour, these polio survivors have been running at 30 miles an hour for years," says Leonard. "The huge metabolic demands of these large motor neurons can no longer be met, and if polio survivors continue to overuse their muscles we see new problems occurring."
The key to proper management of PPS is conservation, says Leonard. "What the patient needs to do is stop the progression of the degeneration and maintain an acceptable function level." It takes teamwork and problem solving to find the right combination of energy conservation techniques, she adds. "This is patient-driven process. The patient has to accept the measures you suggest for the energy conservation plan to work," says Leonard. "Most of these people have been very successful. They have jobs and families. It’s difficult to tell them they have to cut back."
Finding the middle ground
Compromise sometimes works best, notes Leonard. "If a patient is reluctant to use a scooter or wheelchair all the time, see if they will agree to use the scooter on trips to the grocery store. I had one patient who lived on a farm and hated the idea of a scooter, but agreed to use a golf cart to get around her property." Other conservation measures Leonard suggests case managers discuss with PPS patients include:
• taking regular rest periods or daytime naps;
• regular breaks during physical activities;
• cutting back to part-time work, or finding a job that is less physically demanding;
• using assistive devices in the home;
• ceasing all noncritical daily activities, such as bed making.
"There is no cure for PPS, and any functional losses cannot be regained. What we can do is decrease the digression caused by continued overuse of these motor neurons. When that happens, some people do begin to feel less fatigue and pain."
Perhaps an even tougher problem case managers may have to help PPS patients manage is the depression experienced when patients realize they may have to begin using assistive devices they thought were part of their past, says Leonard. "It’s hard to tell these people they have to cut back. It causes some tough psychological issues, especially if you add the fact that many doctors tell PPS patients the symptoms are all in their head,’" says Leonard.
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