Many years later, a scourge returns
Post-polio syndrome afflicts many who thought they’d left disease behind
MONDAY, NOVEMBER 16, 2009 AT 1:29 A.M.
In 1950, when he was 31⁄2 years old, Rick Kneeshaw contracted polio.
Within days, the healthy toddler was crippled, paralysis quickly numbing and immobilizing his left leg, hip and parts of his back. Over the next 12 years, Kneeshaw would endure many operations, each attempting to restore at least partial muscle and nerve function. Between surgeries, Kneeshaw would spend hours in physical therapy, going and growing through countless braces, crutches and other supports.
“By the time I was 16, I figure I’d spent a quarter of my life in hospitals,” he said.
The payoff was partial recovery. He was able to walk without braces or crutches — at least on level surfaces for short distances. “It gave me nighttime mobility at least. I could get out of bed, go to the bathroom. That was something.”
But something changed in 1971. At age 25, Kneeshaw’s joints on his polio-damaged left side began to ache and act up, forcing him to resume wearing a leg brace. He would never again be without it. He took up using crutches again. And in 1984, his right leg — the healthy one — began to progressively weaken. It got to the point where he could only stand for brief periods. He began using a wheelchair.
Kneeshaw knew he had never actually conquered polio, but he thought he had put it behind him. He had moved on, becoming an electrical engineer, marrying, having children. Polio caught up.
In the late 1940s and 1950s, paralytic poliomyelitis was a scourge and nightmare, the most terrifying public health threat in post-World War II America. The causative agent — a virus that inhabits the gastrointestinal tract — had been identified only a few decades earlier. It was extraordinarily infectious, easily transmitted via contaminated food or water. Epidemics were annual occurrences, each seemingly worse than the last. By 1952, polio was killing more Americans than any other communicable disease: More than 300,000 cases and 58,000 deaths in that year alone. Most of the victims were children, their young immune systems unprepared for the viral onslaught.
After infecting a body and incubating for several days in gastrointestinal cells, the poliovirus spreads along key nerve fiber pathways, replicating in and destroying motor neurons in the spinal cord and brain stem. With their nerve connections destroyed, affected muscles atrophy from lack of stimulation, weakening until permanent paralysis sets in. The damage can be limited to a single finger joint or affect almost the entire body. During one of his stays in a hospital ward occupied entirely by teens with polio, Kneeshaw recalls a girlfriend who was completely paralyzed except for her left arm.
To be sure, the majority of infected children escaped relatively unscathed, acquiring lifelong immunity while suffering only temporary, flu-like symptoms or no symptoms at all. But a small percentage were devastated, the disease exacting permanent, crippling damage. In the worst cases, the virus destroyed motor neurons that control breathing. Many of these polio victims, if they survived, spent the rest of their shortened lives inside “iron lungs” — ungainly, tubular tanks that inflated and deflated their paralyzed lungs by alternating air pressure inside the device.
The polio vaccine, developed by Jonas Salk and introduced in 1955, profoundly changed the equation. The Salk vaccine, which used a killed virus to generate immunity, and a subsequent oral vaccine developed by Albert Sabin (using an attenuated live virus), dramatically reduced the incidence of polio in the United States. New cases declined to less than 1,000 in 1962 and just 121 in 1964. The last reported case of “wild polio” in the United States occurred in 1979. The infrequent infections reported since have all been imported cases or the result of a rare immunological response to the vaccine, which remains one of the major inoculations of childhood.
It’s estimated that up to 600,000 Americans today once had polio. Many are like Kneeshaw, “polio survivors” who labored to rebound from the disease. With treatments and hard work, their bodies overcame at least some of the effects of polio. Motor neurons that survived the initial infection sprouted new and additional fibers, extending into damaged areas to restore at least limited muscle function.
Such was the case with Nan Kaufman, who was 6 years old and living in Texas when she came down with polio in 1954. Her parents thought she had a bad case of the flu until Kaufman collapsed on the way to the doctor, suddenly unable to stand or walk. The disease permanently disabled her right side, stunting growth in her arm and leg, though Kaufman learned to compensate and to persevere.
“I was pretty determined to do what I wanted to do, which was be like other children,” she said. “I learned to ride a bike. I ran, even though my right leg was thinner and shorter. I swam competitively, even though my right hand and arm were chronically weak. There was a good deal of denial and magical thinking. People with polio often become overachievers.”
Kaufman, who now lives in Point Loma, became a pediatrician. She retired in 2006 after years of escalating pain, weakness and fatigue convinced her that she could no longer do her job effectively or safely. “It’s hard to say when symptoms first emerged. I had spent my life pushing pretty hard, raising four children, working long hours as a doctor. I had always had bad days, but I thought it was just that I was tired. Then I started having trouble with my ankle. I fell a lot. I dropped things. I became afraid I might one day drop a baby.”
Kaufman saw doctor after doctor, but no one could pinpoint the problem. She worried she had amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease, a progressive and fatal neurodegenerative disease that destroys voluntary muscle control. A neurologist finally identified the real problem: post-polio syndrome. Like Kneeshaw, an old nemesis had come back.
Very little is known about post-polio syndrome, or PPS. No one knows why the condition seems to emerge 30 to 40 years after the original infection. The working hypothesis is that years of overcompensation takes its toll, that surviving, functional, motor neurons and muscles are overworked and simply begin to wear out and shut down. There is evidence that people who had milder cases of polio, who had more surviving motor neurons, are at greater risk of developing PPS than those who suffered significant, permanent damage.
“People who essentially had no recovery from the original polio are much less likely to have PPS symptoms than those with good recovery,” said Dr. Susan Perlman, a neurologist at the University of California Los Angeles.
It is confoundingly difficult to identify PPS. Symptoms such as fatigue, breathing difficulties and muscle weakness tend to be subtle and gradual. They may be associated with many other conditions, from simple exhaustion to other serious neurodegenerative diseases. The situation is further complicated by likely pre-existing health problems and aging.
“Remember, this condition arises in the context of someone who has probably already suffered some degree of paralysis or disability for most of their lives, so it can be hard to separate new symptoms from old ones,” said Dr. Sam Pfaff, a neurobiologist at the Salk Institute for Biological Studies in La Jolla. “Plus, the syndrome is superimposed upon the aging process.”
It doesn’t help that most doctors have never treated an active case of polio or that there’s no definitive diagnostic test.
“There are no biomarkers,” said Pfaff. “Identifying the condition means doing a careful work-up of the patient, knowing and understanding the patient’s history. Post-polio syndrome is the answer you get after you’ve excluded all other possibilities.”
There is no cure for PPS. Treatment consists of ameliorating symptoms and limiting circumstances and behaviors that can accelerate or exacerbate health problems. “The only thing you can do to prevent the disease from progressing is to pace yourself,” said Kaufman. “Telling yourself to push through it, to just get on with life, only makes it worse.”
Not surprisingly, people like Kaufman and Kneeshaw, who was actually a poster child for anti-polio efforts in the 1950s, are strong advocates for more and better research into PPS. They would like to see new therapies, a cure if possible. But they also recognize a harsh reality: Theirs is an affliction that strikes only a distinct and shrinking population of people, particularly in the United States. Unless polio re-emerges as a major public health threat, post-polio syndrome will inevitably decline and disappear as polio survivors do the same.
“We’re a dying breed,” said Gladys Swensrud, who got polio as a 3-year-old living in Escondido in 1951 and now suffers from muscle weakness and breathing problems that require her to use a respirator at night when sleeping.
Swensrud would like to feel better. She argues, as do others with PPS, that it is shortsighted and foolish to simply (and cruelly) write off post-polio syndrome as a health problem that will solve itself as PPS patients pass away. Pfaff at the Salk Institute agrees:
“Polio is not a big public health problem anymore, but it hasn’t been completely eliminated. There are still occasional outbreaks in other parts of world, particularly Africa and Asia. There are thousands of other polio survivors in the world.”
A better understanding of PPS could improve treatments and ease the burden upon survivors around the world. It might also fill in knowledge gaps about the basic biology and pathology of the human body, providing “information that’s relevant to other neurological diseases and other biological systems.”
And that, said Kneeshaw, sitting in his wheelchair, is always a step in the right direction