Poliomyelitis (Polio) is a contagious viral illness that attacks the central nervous system and can cause paralysis.   Polio penetrates the body through the mouth, and lives in the throat and intestinal tract.   In most cases, a person will not exhibit any symptoms. In others, symptoms of slight fever, upper respiratory tract infection, or a mild disturbance of the gastrointestinal tract may last for about three or four days.

In still another small group of cases, fever, headache, a stiff neck, vomiting (i.e. so-called meningitis) may occur. This is called the non-paralytic stage of the disease, or non-paralytic poliomyelitis.

In some cases, the disease progresses to the paralytic stage, or paralytic poliomyelitis.  This stage causes either permanent or temporary paralysis of the muscles, depending on the depth of paralysis.  When the paralysis effects the extremities, almost full recovery can be expected.  This is because the polio virus only partially affects the anterior horn cells of the central nervous system.

The extent of paralysis depends upon the degree of involvement of the spinal cord, i.e., of the motor nerve cells lying in the anterior horns of the spinal cord.  Therefore, the paralysis may be confined to only one small group of muscles of any of the limbs, i.e., only a part of the limb may be involved. While in others, either the whole limb, or even all four limbs may be involved.

Furthermore, the paralysis due to poliomyelitis is a highly irregular or asymmetrical/variable, to the extent that in a particular patient, if on one side the foot is involved, on the other side, either the whole or part of the arm may be involved, etc.

As stated above, in spite of the full recovery of most of the muscles that have been paralyzed, some residual paralysis may persist, leading to permanent paralysis of these affected muscles. The worst case is that these muscles soon start wasting (atrophy) very quickly.  Contractures in these muscles may develop, which become responsible for various deformities in a growing child.

There is no specific treatment that can stop the paralysis of the muscles, once it occurs, or bring about the full recovery of the muscles that are going to be affected permanently. Since in some of these paralyzed muscles, contractures are likely to occur, and one cannot say which of the muscles will be permanently damaged, all the paralyzed limbs must be kept in their proper positions.

Early mobility/physiotherapy is the most important part of the treatment, to avoid contractures. However, surgical intervention may be required in some of the cases, so that the paralyzed limb can be functional. Finally, orthopedic appliances may also be required so that the person is able to live independently with the highest functional capability.

Polio immunization is now available throughout the world, and the reported cases of polio and its devastating consequences have diminished over the past years.