Post Polio Muscle Atrophy (PPMA)
Some people, who had polio, are finding that after 30, 40 or even 50 years their muscles are getting weaker, smaller in size, are having more difficulty breathing or are experiencing pain in muscles that were thought to be unaffected by the original polio. This new finding of weakness and shrinkage (atrophy) in muscles, along with pain, many years after having had polio is called Post Polio Muscle Atrophy. Some polio survivors with these symptoms may not necessarily have PPMA, but after some medical evaluation may be diagnosed with arthritis, tendonitis and cartilage damage, all of which are more common when movement and weight bearing have been altered by the effects of weakened muscles.
What is Post Polio Muscle Atrophy?
Some patients who had paralytic polio many years ago have recently experienced deterioration in their muscle strength after having been stable for a long time. In addition to increasing weakness in muscles known to be previously damaged, loss of strength and fatigue in muscles which had been functioning well has also been found. Some survivors of polio have experienced increasing difficulty in breathing due to weakness of the chest muscles. Very frequently, pain previously absent, has been reported in muscles and joints. This condition is Post Polio Muscle Atrophy or PPMA.
What Causes PPMA?
Post Polio Muscles Atrophy is not a reinfection of the polio virus or a reactivation of the virus many years after the initial attack. The disease is not starting up again. The most likely explanation is an acceleration of the aging process in polio survivors. As we age, our bodies experience a decrease in the number of cells in the spinal cord called anterior horn cells which transmit nerve impulses to the muscles and cause them to move as we want them to. These cells are the ones which are destroyed or damaged in an acute attack of poliomyelitis.
Persons who have not had polio can lose a considerable number of anterior horn cells as they age without experiencing any serious muscular weakness. Polio survivors have already lost some cells in the acute disease process, and cells, which have not been destroyed, may have been damaged and have a shortened life span. The surviving cells and the muscles they innervate are put under unusual stress as they are required to take over the functions of the cells which were destroyed. This may cause them to wear out much sooner than would be expected.
Who is most likely to be Affected?
The average age of patients with PPMA is 50. Symptoms appear 30 to 40 years after the acute attack of polio. Person developing the new symptoms seem to be those who had a severe case of polio. Most were over ten years of age when they contracted polio, required hospitalization, had paralysis or weakness of all four limbs, and needed respiratory assistance (ventilator)
What Should Survivors Do If They Are Losing Strength or Experiencing Pain?
Polio Survivors who believe they have PPMA symptoms (weakness, fatigue and pain) should be thoroughly evaluated by experts at a center for rehabilitative medicine. It may be that a change of bracing, a decrease in activity or treatment of conditions such as arthritis will lessen or eliminate the symptoms. One should not increase their activities in daily living in the hope that this will strengthen their muscles. This might place an additional strain on the anterior horn cells and the muscles, causing them to become weaker. A collaborative effort between you, your physician and physical therapist can be helpful in determining what course of action is to be taken by you to maintain your current physical mobility level as well as provide information for bracing, ventilation and other physical needs for your personal health and wellness.