Poliomyelitis (infantile paralysis)
Poliomyelitis has been eradicated from nearly every country since the approval of the Salk (1955) and Sabin (1962) vaccines.
In 1997, 5,185 polio cases were reported worldwide; in 1998, 5,867. The increased number of cases is due to improved surveillance and reporting techniques. The World Health Organization (WHO) estimates that there are five to six times as many paralytic cases as reports received. WHO has targeted the year 2000 for the complete eradication of acute poliomyelitis.
WHO estimates there are 12 million people worldwide with some degree of disability caused by poliomyelitis. A 1994 National Center for Health Statistics survey reported a preliminary estimate of one million survivors in the United States. About 433,000 of them reported paralysis, resulting in some form of impairment.
For years, most of these polio survivors lived active lives, their memory of polio long forgotten, and their health status stable. By the late '70s, however, polio survivors were noting new problems of fatigue, pain, and additional weakness. By the mid-'80s, health professionals and policymakers recognized these new problems as accurate and not "only in the patients' minds." Studies on this phenomenon called "post-polio syndrome" have been—and are still being—conducted in research institutions and medical centers.
Symptoms
The survivors of poliomyelitis may experience symptoms that include
- Unaccustomed fatigue – either rapid muscle tiring or feeling of total body exhaustion
- New weakness in muscles, both those affected initially and those seemingly unaffected
- Pain in muscles and/or joints
- Sleeping problems
- Breathing difficulties
- Swallowing problems
- Decreased ability to tolerate cold temperatures
- Decline in ability to conduct customary daily activities such as walking, bathing, etc.
These general symptoms are experienced in varying degrees, and their progression can be insidious. They should not be dismissed simply as signs of aging alone. Current research indicates that the length of time one has lived with the residuals of polio is as much of a risk factor as chronological age. It also appears that individuals who experienced the most severe original paralysis with the most significant functional recovery are having more problems now than others with less severe original involvement.
Diagnosis
The diagnosis of post-polio syndrome is one of exclusion
A definitive test is not yet available. Some confusion and doubt among polio survivors, health professionals, and family members is due to the lack of a shared understanding of terminology. It is helpful to think of post-polio problems in the following categories, remembering that the groupings are not distinct but parts of a continuum.
LATE EFFECTS OF POLIO or POLIO SEQUELAE is the largest and most inclusive category. It is defined as specific new health problems that result from polio-caused chronic impairments, e.g., degenerative arthritis of overused joints, carpal tunnel syndrome and other repetitive motion problems, tendinitis, bursitis, failing joint fusions, overstressed joints due to compensatory body mechanics.
POST-POLIO SYNDROME
Post-polio syndrome is a sub-category of the late effects of polio and is defined as a neurologic disorder characterized by increased weakness and/or abnormal muscle fatigability. The symptoms include new weakness, intense fatigue, and pain in muscles and joints, resulting in decreased endurance and diminished function. Most clinicians use the following criteria to diagnose post-polio syndrome.
- Confirmed history of acute paralytic polio. Some clinicians perform an electromyogram (EMG) to document changes compatible with prior polio
- Recovery followed by 15 years or more of stability preceding the gradual or abrupt onset of new weakness and/or abnormal muscle fatigability (decreased endurance), with or without generalized fatigue, muscle atrophy, and/or pain
- Other conditions that might cause the problems listed above must be excluded
To distinguish new, slowly progressive muscle weakness that is neurologic in origin from musculoskeletal and/or wear-and-tear problems, researchers coined the phrase PROGRESSIVE POST-POLIO MUSCULAR ATROPHY (PPMA). PPMA is defined as progressive new weakness and atrophy in muscles with clinical or subclinical signs of chronic partial denervation/reinnervation compatible with previous acute poliomyelitis. The term is used less often today, giving way to post-polio syndrome.
Polio survivors may experience one or more of the problems described above and should not become unnecessarily concerned about the label for their symptoms.
Polio survivors may experience the same health difficulties as the general population, some with symptoms mimicking post-polio syndrome, some magnified due to neurologic damage from former acute polio.
Current consensus
The current consensus explaining post-polio symptoms focuses on the nerve cells and their corresponding muscle fibers. When the poliovirus destroyed or injured motor neurons, muscle fibers were orphaned, and paralysis resulted. Polio survivors who regained movement did so because nerve cells recovered somewhat. Further recovery is attributed to the ability of non-affected neighboring nerve cells to "sprout" and reconnect to the orphaned muscles. Survivors living for years with this restructured neuromuscular system are now experiencing the consequences – overworked surviving nerve cells and overworked muscles and joints, compounded by the effects of growing older. While the search for a viral cause continues, there is no conclusive evidence to support the concept that post-polio syndrome is a reinfection of the poliovirus.
As the first step in management
Polio survivors should undergo a complete, general medical evaluation by a primary care physician and a specialized neuromuscular assessment by a knowledgeable and experienced polio specialist to establish a baseline for judging future changes and developing an appropriate treatment plan.
Polio survivors should first and foremost take care of their health by seeking periodic, basic medical attention. Be nutrition-wise, avoid or reverse excessive weight gain, and stop smoking or over-indulging in alcohol.
Polio survivors should listen to their bodies. Avoid activities that cause pain—pain is a warning signal. Avoid unrestrained use of painkillers, especially narcotics. Do not overuse muscles; continue activities that do not worsen the symptoms. In particular, do not over-exercise or continue to exercise through pain. Avoid activities that cause fatigue lasting more than ten minutes.
Polio survivors experiencing symptoms should pace themselves in their daily activities, resting when tired. When needed, they should stop for a 15-—to 30-minute rest, perhaps several times a day. Management may include increasing the use of assistive devices. A change of equipment or new bracing may also be recommended.
Polio survivors should educate themselves, their families, and, if necessary, their health professionals. The International Polio Network provides accurate and updated information through its conferences and publications. Polio survivors may also benefit from the support and knowledge of other polio survivors.