My husband had polio (infantile paralysis) at the age of three. He is now 66 years old. I would like to know the signs and symptoms of post-polio syndrome and/or related syndromes of poliomyelitis.

K.

Paralytic poliomyelitis, or polio, was common in the United States and the remainder of the Western Hemisphere in the 1940s and 1950s. After an extensive immunization campaign, naturally occurring polio is no longer seen in the United States. However, there are rare cases of children developing full-blown paralytic polio following administration of the live, oral vaccine. To avoid those cases, the U.S. Centers for Disease Control and Prevention now recommends using only the killed (injection) vaccine in most circumstances.

Most infections with the poliomyelitis virus do not result in paralysis. The infection usually causes a mild, nonspecific illness or no symptoms at all. In about one in every 1,000 infections, however, the patient develops paralysis. That occurs when the virus invades the nerve cells in the spinal cord responsible for movement. The patient develops fever, headache, stiff neck, muscle pain and then weakness. This weakness can affect virtually any muscle, even the respiratory muscles, which is why some patients in the 1940s and 1950s needed breathing machines called iron lungs. The death rate for paralytic polio at that time was approximately 5 to 10 percent, but intensive care was not as good then as it is today. Some degree of residual muscle weakness occurs in most people who survived the illness, but more often than not, it is not severe. After recovery, the patient's condition usually remains stable for the rest of his or her life.

The post-poliomyelitis syndrome occurs when a patient manifests a variety of signs and symptoms 15 to 20 years after a full or nearly full recovery from polio. The most common symptoms are fatigue, weakness (usually of the muscles involved in the original bout of polio), cold intolerance, pain in the muscles and joints and interference with activities of daily living. Post-polio syndrome is not a relapse of infection. It is thought to be due to the following mechanism: The original bout of polio causes denervation (loss of nerve stimulation) to various muscle groups. Although there is some recovery, the muscle is left with fewer nerves and nerve stimulation than before. Over the years, natural aging causes the loss of more nerve input. Eventually, this loss of nerves causes the symptoms of post-polio syndrome. Everyone loses nerve input to our muscles over time, but we do not develop symptoms such as those seen in post-polio syndrome because we start with more nerves than we need. This explanation is a bit simplistic, but it is thought to be the primary mechanism involved in the illness.

Most of the treatment regimens for post-polio syndrome are designed to support the patient rather than cure the symptoms. First, patients must be educated about their illness and learn what they can or cannot do. Several studies have evaluated pyridostigmine (trade name Mestinon), a drug used to treat myasthenia gravis, in these patients. The results have been erratic, but many experts believe this drug can combat the fatigue seen in this illness. For most of the other manifestations of post-polio syndrome, there is no specific therapy. A multidisciplinary approach including physical therapy and psychological counseling may help minimize the effect post-polio syndrome has on the daily life of the patient.