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Post-Polio Health (ISSN 1066-5331)

Vol. 11, No. 1, Winter 1995

Read selected articles from this issue ...

Defining Post-Polio Problems
Jacquelin Perry, MD, Pathokinesiology, Rancho Los Amigos Medical Center, Downey, California; Neil Cashman, MD, Neurology, Montreal Neurological Institute, Montreal, Quebec; Lauro S. Halstead, MD, Physical Medicine and Rehabilitation, National Rehabilitation Hospital, Washington, DC; Frederick Maynard, MD, Physical Medicine and Rehabilitation, MetroHealth Center, Cleveland, Ohio

Incidence & Prevalence of Post-Polio Problems
P. Ellen Parsons, PhD, MPH, National Center for Health Statistics, Hyattsville, Maryland
Jonathan M. Ramlow, PhD, MPH, Dow Chemical Company, Midland, Michigan

Post-Polio Research: The Latest from the
Later Life Effects (LLE) Study

Joan L. Headley, MS, Executive Director, GINI

From the Archives

Polio Survivors Remember

The World Will Remember

Presented at Sixth International Post-Polio and Independent Living Conference, Fall 1994

Defining Post-Polio Problems

Jacquelin Perry, MD, DSc (Hon), Pathokinesiology, Rancho Los Amigos National Rehabilitation Center, Downey, California;
Neil Cashman, MD, Center of Research/Neuro Degenerative Diseases, University of Toronto, Toronto, Canada;
Lauro S. Halstead, MD, Physical Medicine and Rehabilitation, National Rehabilitation Hospital, Washington, DC;
Frederick M. Maynard, MD, Physical Medicine and Rehabilitation, Upper Peninsula Rehab Medicine Assoc., PC, Marquette, Michigan
Jacquelin Perry, MD, DSc (Hon)
Pathokinesiology, Rancho Los Amigos National Rehabilitation Center, Downey, California

The term late effects of polio is the umbrella over three subdivisions.

The cause of post-polio problems is neuromusculoskeletal failure from chronic overuse of a polio-altered system. How has that system been altered? The pathology of polio involves destruction of the anterior horn cell, and the only functional residual is weakness. New polio problems are the effects of the functioning of muscle that had less than normal capability.

So, who's under the umbrella? First are the asymptomatic post-polio individuals who have a known history of polio but who are not having troubles now. Their lifestyle and their physical ability are balanced. These persons can, for example, go on running and continue what they are doing as long as they have no symptoms. If symptoms do occur, it is time to become more cautious about their activities.

The second group has symptoms that indicate the lifestyle demands now exceed their muscles' ability to meet those demands. The symptoms of pain, fatigue and new weakness are signs of overuse with a penalty. We have a list of about 1,000 polio survivors and of that group we found 107 who thought they had full recovery. Eighty-nine percent of them lived very active lives while 24% of them had been in athletics. They came to the clinic because they were having symptoms. Ninety-three percent showed weakness with at least one muscle less than grade 5. (See chart below.)

When a muscle creates a force to control or create motion, it also creates a force internally and can cause some damage. It has been demonstrated that as muscles contract they need time to repair and refuel. If the muscles are functioning almost continually, they do not have time to repair. Muscles and their ability to function are the main problem.

Another problem is the neuromuscular junction. This is evidenced by information from Gunnar Grimby, MD, PhD, Sahlgrenska University Hospital, Gôteborg, Sweden. He studied the anterior tibialis and demonstrated that a 3+ muscle, which is about 25% of normal on the Beasely scale, has marked hypertrophy (enlargement) compared to a 4+ muscle that would be about a 45% muscle. Both of them have degrees of weakness, but the 3+ is much more weak than the 4+.

Grimby also found that the 3+ tibialis anterior was not only markedly hypertrophied, but its activational rate was twice normal. One gains new or additional strength either by activating more muscle fibers or making the current muscle fibers work twice as hard. In 3+ muscles there are not very many muscle fibers, so they are worked twice as hard to meet the functional demand.

The individuals most difficult to get in balance are the ones with 3+ and 2 muscles all over. Their muscles are not strong enough to function without overtime use.

The third group, which we often overlook, is the polio survivor with joint degeneration problems. It is just plain wear and tear, either from substitutive posture used to replace inadequate muscles, or by the impact of loading a joint instead of letting it yield on the muscles. For instance, a hyper-extended knee causes bones to hit together with every step, and the joint becomes degenerative and arthritic. Joint degeneration problems do not result in muscle pain. There is pain and tenderness in the specific joint, resulting in deformity and x-ray changes.

Again, feeling that the primary cause is overuse, the principal management is lifestyle modification. No matter what else we do, we find that about 95% of people have to make lifestyle changes in order to make exercise or other devices work.

Out of 250 patients we have studied quantitatively on a scale of 'better, same, worse." The majority of them were "better,' meaning that they lost their symptoms of pain and fatigue by modifying their lifestyle. A small percentage did not make a change because they reject the whole idea of lifestyle modification. Some became worse and are the individuals with all muscles of grades 2 and 3. We have trouble finding a lifestyle for them which does not cause any strain.

Neil Cashman, MD
Center of Research/Neuro Degenerative Diseases, University of Toronto, Toronto, Canada

Today, there is no consensus, no position paper, no diagnostic test, no agreed-upon criteria about this syndrome, so there will be differences of opinion and some overlap.

From a neurologist's point of view, post-polio syndrome has to begin in the spinal cord and brain stem with the original infection and destruction of motor neurons causing paralytic polio. A common question arises: "I had non-paralytic polio. Am I susceptible to the post-polio syndrome?'' A neurologist would have to say "no." There is no evidence that people who had no infection of motor neurons can develop classical post-post syndrome. In fact, the worse the paralytic poliomyelitis, the more likely new symptoms are to develop.

Another common question is: "Am I out of the woods with post-polio syndrome after 40-years?" Burk Jubelt, MD, (SUNY, Syracuse, New York), and I reviewed every recorded case of post-polio syndrome that had been reported up to 1987 and found the mean onset was 36 years. Some people develop new symptoms ten years after polio, and others develop symptoms 60 years after polio. Unfortunately, there is no out-of-the-woods threshold age.

There is a running controversy in the medical literature of "jumpers" and "splatters." Some authorities like to put diseases together under certain rubrics, and others like to break off certain diseases. My opinion is that it is too early to split sub-syndromes off the post-polio syndrome. My conservatism, in part, is based on work with people who had post-polio muscular atrophy. People with atrophy were just as likely to have pain and fatigue as people without new atrophy. There is not enough data to make a distinction and say this is merely musculoskeletal; that is neurogenic. They act differently and, they are treated differently.

The original meaning of the word "syndrome" comes from the Greek – "running together." These symptoms present in polio persons time after time, and the symptoms really do run together. There is something going on and, in my opinion, it is too early to dogmatize sub-groups.

The safest term, to date, is post-polio syndrome, and the safest definition of the post-polio syndrome is a new clinical syndrome of pain, weakness, and fatigue in individuals who recovered from acute paralytic poliomyelitis.  

Lauro S. Halstead, MD
Physical Medicine and Rehabilitation, National Rehabilitation Hospital, Washington, DC

From the point of view of a clinician who sees polio individuals in a clinic, "What diagnosis do I use?" often makes a great deal of difference, because of the implications for insurance and disability payments. We do not have enough information, insight or wisdom to separate specific definitions except for clinical use.

The three major diagnostic terms – the late effects of polio, post-polio syndrome and post-polio muscular atrophy – can be described by imagining three concentric circles. A large outer circle labeled the late effects of polio represents a grab bag. Anyone who has serious involvement with a neuromuscular disease, and it does not have to be polio, will experience a variety of problems, if they live long enough.

The late effects of polio refers to a group of symptoms and signs which people who had polio many years ago now experience and include weakness, fatigue, muscle pain, joint pain, decreased endurance and new atrophy. They also include increased weight gain, osteoporosis, increased risk of fractures, scoliosis, increase in pulmonary problems, sleep difficulties and psychological problems.

People can experience a whole list of problems that are in this big circle as a result of having had polio, but they do not have post-polio syndrome.

Inside the big circle is a smaller circle labeled post-polio syndrome. More narrowly defined, a diagnosis of post-polio syndrome requires the presence of new neurogenic weakness. This new weakness is caused by some dysfunction of the motor neuron that was originally affected. Post-polio syndrome is a neurologic disease which occurs as a result of having had an invasion of the poliovirus to part of the nervous system many years earlier.

There are five elements to make the diagnosis of post-polio syndrome:

Currently, making a diagnosis is difficult because there is no diagnostic test; unfortunately at this stage, diagnosis is still primarily by history and physical examination.

The smallest and most inner circle is post-polio muscular atrophy and is reasonably straightforward. It is post-polio syndrome in someone with new muscle atrophy.

Another better term that might be used for these last two diagnoses is post-polio motor neuron disease that focuses on the motor neuron as the primary source of pathology.

Frederick M. Maynard, MD
Physical Medicine and Rehabilitation, Upper Peninsula Rehab Medicine Assoc., PC, Marquette, Michigan

In the broadest terms, there are many new health problems that persons with a previous history of polio may experience. These health problems can include those that are clearly unrelated to the history of polio, such as glaucoma or gallstones.

For other health problems, such as coronary artery disease, it may be unclear whether there is a relationship to previous paralytic because a sedentary lifestyle in polio survivors may cause an increased risk of developing coronary artery disease.

Systemic health problems, such as heart disease or diabetes, can impact and produce symptoms that overlap and mimic those of post-polio syndrome (fatigue, weakness, and pain). This issue has led to confusion, misunderstanding, and lack of consensus about what is meant by post-polio syndrome.

The term "late effects of polio" implies that new health problems are related to the original polio impairments, such as muscle weakness and related joint deformities. The term "post-polio syndrome" is a looser term which does not specify etiology, or cause of symptoms. Post-polio syndrome commonly develops in people with polio residuals and mild symptoms are almost inevitable in people who are growing older with polio.

As a "syndrome," post-polio is a common symptom cluster – classically, pain, fatigue, and new weakness – that is seen over and over again in post-polio people. The bottom line for having post-polio syndrome is new loss of function.

Individuals with post-polio syndrome have new disability.

Post-polio muscular atrophy (PPMA) refers specifically to people who definitely had old polio weakness and are now having new weakness and atrophy from no other identifiable cause. PPMA is new or additional anterior horn cell disease that appears to be unexplainable.

A slightly different concept has recently been proposed by the Institute of Medicine (see figure below) to describe new disabilities in people with long-standing disability.

This has also been referred to as the development of secondary disability in a person who has always had a primary disability. For example, people with post-polio residuals, after full recovery and rehabilitation, were left with a primary disabling condition. Other health problems may then cause the residuals (weakness, deformity) to become worse and result in additional new functional limitations.

Another new concept is the notion of "life course" of people with a history of polio. As people with paralytic polio histories become older, they can be expected to experience a level of functional decline when they are 70 or 80, similar to what non-polio people experience. However, their expected life course of slowly progressive weakness can be drastically accelerated by other life events, such as injury or the onset of other medical conditions, for example diabetes, heart disease and arthritis.

Figure showing Institute of Medicine's Model of Secondary Disability