By Mark Sauer, The San Diego Union-Tribune
(Conducted via E-Mail)
October 10, 2000
Dear Dr. Perlman:
I believe Mary Clare Schlesinger has told you I'm doing a feature for our science page on PPS. She said you graciously agreed to an interview.
I'd like to do this by e-mail, since it allows you to not only answer at your convenience but also a bit of time to think about your answers in relation to my lay audience -- plus I don't have to furiously scribble (type) your answers.
Right now, I see three basic themes to my story: the genetic research being done at Salk by Sam Pfaff, the clinical research being done by you at UCLA and the view of those locally suffering from PPS. I have written about this subject before and happen to be a polio survivor myself (contracted in 1958 at age 6, suffered temporary weakness in ankles and lower legs and was unable to walk for a time; no noticeable lasting effects), so I have some background.
My audience is the general newspaper reader with an interest in science.
Mark Sauer (MS)
By way of background, please describe how you got interested in PPS and what your work in this area entails.
Dr. Perlman (DR)
When I finished my training in general neurology, I began specialty work in chronic diseases of the neuromuscular system (muscular dystrophy, spinal cord diseases, cerebral palsy). I had a multidisciplinary clinic (neurologists, psychologist, social worker, physical therapist, occupational therapist, brace maker, nutritionist) that focused on proper diagnosis, rehabilitation treatment, and clinical research into causes and drug treatments. My chairman was approached by a couple of members of our local polio support group to see if he would start a clinic for polio survivors. They brought a stack of articles with them. He agreed and gave the articles to me with a mandate to start such a clinic. I knew nothing about post-polio, but with the help of the patients, quickly learned. My existing clinic was well set up to deal with their needs of proper diagnosis, rehabilitation treatments, and medication management, which is what we continue to do. The clinic itself briefly moved into the Neuro-rehabilitation section of my department and is now a free-standing clinic, separate from my muscular dystrophy clinic, but utilizing the same interventions as before. We teach the basics of post-polio to neurology and rehabilitation residents and see about 200 patients a year, for evaluation and treatment.
MS Since PPS is not widely recognized by front-line physicians and is difficult (impossible?) to diagnose precisely, how can we be sure when a patient has PPS?
DR Post-polio syndrome is a diagnosis of exclusion. Although the diagnostic criteria are quite specific, so many other diseases can mimic them that a thorough evaluation is necessary. Just because a person survived polio, it doesn't mean they're immune to everything else.
MS What are the symptoms?
DR Post-polio is suspected when someone has survived a documented case of acute polio, has had a period of at least 15 years of stable recovery (at whatever level they recovered to), and is now experiencing gradual onset of new/recurrent muscle atrophy, weakness, generalized fatigue or decreased endurance, and secondary pain in the old polio limb (occasionally in limbs that weren't known to be affected originally).
MS Who's at risk?
DR Risk status corellates with (1) severity of original polio and level of recovery (more complete paralysis or bulbar polio originally, with either excellent recovery suggesting a lot of remodelling of nerves or poor recovery suggesting little reserve), (2) aging, (3) overuse (repeated painful muscle use), and (4) recent injuries or weight gain. Even so, only 40% of polio survivors have been found to develop post-polio symptoms. The others may never develop them.
MS Why do some polio survivors contract it and others do not?
DR The risk factor profile may be more favorable in some of them.
MS Is this a problem in other countries?
DR Developed countries share similar patterns of post-polio. The developing countries (eg. India) may have much less post-polio, due to a higher mortality rate with the original infection (only those with very mild cases survived) or due to less rehabilitation available, so recovery to an artificial "remodelled" plateau may not have occurred (sparing those patients the future decline from that plateau, ie. "post-polio").
MS What in your opinion has constituted important progress (breakthroughs?) in our knowledge of PPS in recent years?
DR The biggest breakthroughs are in our understanding of the role of rehabilitation and in the research on the role of the immune system. The first has already led to better treatments and the latter may as well. We now know that energy conservation (not pushing to the point of pain or fatigue, modifying life-style to avoid this), gentle conditioning exercises, and appropriate equipment when needed (braces, electric mobility) can stop progression of post-polio and even give improvement in all but 5% of sufferers. This is so predictable, that it almost becomes part of the definition of post-polio. If you can't stabilize using these techniques, something else may have been missed. There continues to be evidence suggestive of the role of the immune system in causing post-polio--more research is ongoing in the US and other countries to nail this down.
MS How is PPS treated? Therapies, medications, etc.
DR Energy conservation, lifestyle modification, gentle exercise (stretch, pool, resistive work, aerobic), appropriate equipment (canes, braces, electric mobility), and symptomatic medication for pain and fatigue, in that order. Popular anti-fatigue medications for other neurologic diseases may not work as well in post-polio, but are often tried (pyridostigmine, amantadine, selegeline, amphetamine-like agents, selective serotonin drugs like Prozac). Supplements like creatine and carnitine have helped some patients and have shown benefits in research trials. Nerve growth factor and stem cell research may yield additional treatment options in the future.
MS Is there any hope for a "cure"?
DR Yes. A cure could come through the nerve growth factor and stem cell research, but the best way to live with post-polio now is with rehabilitation.
MS It occurs to me that those of us who contracted polio are well into middle age now. There cannot be much money behind researching a disease that, given a few more years, will go away on its own. Is PPS unique in this regard?
DR Acute polio is still occurring and will result in a continuing reservoir of post-polios for a while. Many other infectious diseases were thought to be phased out, but have continued to plague mankind (Tb, syphillis). Because of the relationship of post-polio to aging and the burden it places on those aging with it (as does rheumatoid arthritis, cerebral palsy, mid-life stroke), research in aging will continue to provide resources for post-polio research. The whole area of neural regeneration directly impinges upon post-polio, post-Guillan Barre, and other motor nerve diseases, and will also power future research beneficial to polios.
MS Heartless as it sounds, would we be better off simply comforting those afflicted and invest our research elsewhere?
DR Certainly, those with symptoms need to be encouraged and treated, even if not cured, but I would say NO to investing research dollars elsewhere. Post-polio is a model disease for some key questions in neurology about nerve regrowth, the reaction of the immune system in old injury, viral diseases of the nervous system. It has a lot to teach us.
MS Has society/the medical community at large already done that?
DR I think the errors of society and the medical field are more of ignorance rather than rejection. More education is definitely needed. In the US there are more polio survivors at risk for post-polio syndrome than there are people with MS, so the risk of misdiagnosis and non-diagnosis are much greater given the numbers.