Reliving Polio

Roberta Simon was eight years old when poliomyelitis paralyzed her from the neck down. She spent three months on her back in a Washington hospital and then began a long series of treatments and exercises that slowly, painfully restored full mobility to her limbs. Like many brave polio victims, she pushed herself hard. She was a majorette in junior high school, went to college and eventually became a surgical nurse in a Chicago-area hospital, working long hours on her feet in the operating room. "I was out there doing my thing," she says. "I thought I was over polio."

She was wrong. One day 36 years after the disease disrupted her childhood, she felt some familiar symptoms. They started as muscle fatigue, weakness and pain. Then her legs collapsed under her, and she had to lean against walls to stand up straight. She went to specialists and took test after test. "They all came back negative," says Simon. "One doctor thought I was mentally ill and sent me to a psychotherapist." Finally, four years later, Simon was correctly diagnosed. She had polio. Again.

Forty years after the great polio epidemic of the 1940s and '50s swept through the U.S., infecting millions and leaving some 640,000 (mostly children) with varying degrees of paralysis, survivors are being revisited by a degenerative muscle condition that has precisely the same symptoms as a mild case of polio. The ailment is known as acute paralytic poliomyelitis sequelae, or postpolio syndrome. Doctors aren't certain what causes it or how best to treat it (for many years physicians prescribed exercises that exacerbated the condition), but they believe the problem will get worse before it gets better. Before the end of the decade, by one estimate, postpolio syndrome will strike 40% to 50% of the polio survivors, forcing many in their 50s, 60s and 70s to relive the childhood pain and suffering they thought was behind them.

The symptoms of postpolio mimic those of the original disease, albeit in a less virulent form. They include fatigue and exhaustion, muscle weakness, painful joints and, sometimes, difficult breathing. The discomfort usually begins in the muscles affected by the original infection but can spread. Patients who got polio before age 10 and suffered particularly severe cases seem to be the most susceptible to the aftereffects.

What triggers postpolio syndrome? One possibility is that the polio virus becomes active again after decades of lying dormant in victims' cells. This notion gained support in 1991, when British scientists reported that 58% of the postpolio patients they tested had high concentrations of polio-type antibodies not only in their blood, which is to be expected, but also in their spinal fluid, which suggests a current infection. That does not explain, however, why the disease resurfaces so long after the original infection, and attempts to replicate the British findings have been unsuccessful. Since it's possible that the dormant virus could mutate into active new forms, scientists are searching for such culprits.