Medical update: post-polio syndrome

Medical update: post-polio syndrome

Thousands of polio survivors are experiencing the late-effects of their childhood disease, decades after they had poliomyelitis (polio for short). Having believed it was all “behind them,” many who had polio during the epidemics of the 1950s are experiencing fresh problems, known as Post-Polio Syndrome or PPS. The symptoms associated with PPS usually surface 30-40 years after the development of polio, following a long plateau of stable recovery. Symptoms of PPS include unaccustomed fatigue, pain and new muscle weakness (often in parts previously affected by the disease, but also elsewhere). Breathing difficulties may also occur and – most troubling of all – an overall decline in energy and efficiency.

While the precise number likely to develop PPS cannot be accurately predicted, specialists estimate that as many as half of those who had polio are at risk. Although many polio survivors know about PPS, “there are still many,” according to one expert at the Montreal Neurological Institute, “who may not recognize its onset. Muscle weakness can be gradual with a functional loss of only one per cent a year.” At first, PPS was thought be an entirely new disease or perhaps a re-activation of the old polio. But today’s most widely accepted theory is that it’s an “overuse syndrome,” resulting from the way people reacted to and overcame the disease. Paradoxically, those who were most severely afflicted by polio but recovered well, seem to be worst hit. Typically, people who had polio were encouraged to “persevere” in combatting the disease and many afflicted youngsters struggled hard to overcome the disability – strengthening damaged muscles, putting up with pain, some even refusing to wear their prescribed braces. In fighting a devastating disease, these people learnt to surmount hardships and “keep a stiff upper lip.” Many developed into hard working over-achievers. Some who pushed themselves to the limit – overworking weakened muscles – are now suffering fresh disabilities such as a dropped foot and extensive muscular fatigue.

The polio virus destroys motor nuerons or anterior horn cells in the spinal cord which determine movement. If sufficient horn cells are damaged, muscular disability and perhaps paralysis ensue. During recovery, the surviving spinal cord cells put out “sprouts” to enervate or connect with those muscles whose anterior horn cells were destroyed. But the new nerve to muscles junctions are diffuse and less effective than the original ones. Hence, the intact (undamaged) horn cells must do both their own work and that of the destroyed spinal cells. Being overworked, they ultimately wear out or die. PPS may occur because the normal aging process is speeded up by overwork. Treatment of PPS is with specific exercise routines (and aids such as canes and scooters). Specialists advocate a careful balance of exercise and rest for affected muscles. Toronto’s West Park Polio Clinic promotes gentle, non-fatiguing exercises. Any pain during exercise is a signal to slow down or stop. Such fitness programs help many post-polio sufferers who may have over-exerted themselves for decades. Other strategies include Therapeutic Electrical Stimulation (TES) to increase the strength of weakened muscles with gentle electrical stimulation done overnight (while asleep). Magnetic Resonance Imaging (MRI) helps to reveal the post-polio deterioration and assess the possible benefits of different therapies.

For more information contact: the Ontario March of Dimes, Post-Polio Syndrome, 60 Overlea Blvd. Toronto, M4H 1B6 (416) 425-0501. They offer a complete information kit and registry program for those who had polio.

COPYRIGHT 1993 Strategic Inc. Communications Ltd.

COPYRIGHT 2004 Gale Group