Poliomyelitis or infantile paralysis is an endemic disease of humans first recorded in paralytic form in 1300 BC. It is an acute infectious disease caused by an enteric virus with world wide distribution. Transmission is by human contact and most people ingest the virus. (1) One the virus enters the mouth primary multiplication occurs in lymphoid tissues in the oropharynx and intestinal tract, mainly the ileum. (2)

The spinal cord and brain are the only sites of significant virus-induced pathology. Approximately 90% of the poliomyelitis virus infections are nonparalytic. The minor illness, called abortive type, occurs chiefly in young children, is mild, and does not involve the central nervous system. Symptoms are slight fever, malaise, headache, sore throat, and vomiting, which develop 3 to 5 days after exposure. Recovery occurs within 24 to 72 hours. (2)

In the paralytic form, the virus selectively attacks the motor neuron cell bodies with resulting flaccid muscle paresis or paralysis. Poliomyelitis (polio) is caused by the infection of human hosts with the neurotropic poliovirus, which is known to infect a large percentage (2% to 100%) of the motor neuron pool at various levels of the neuroaxis (anterior horn cells, motor nuclei of the brainstem, hypothalamus and thalami nuclei, and cells in the precentral gyrus). (1) Anterior horn cells in the spinal cord are responsible for transmitting nerve impulses to the muscles. During infection the polio virus attacked these cells destroying some and damaging others. The uninvolved and partially injured anterior horn cells multiplied their connections to the muscle cells through terminal splitting of axons. This branching appears to be an attempt to save nearby abandoned muscle fibers. Through the years, fewer, weakened anterior horn cells begin to wear out. Each of these cells is performing the duties of the many cells damaged by polio. Eventually they wither and die, leaving more muscles cells without impulse and the person with a greater residual muscle weakness. (1)

In paralytic poliomyelitis, less than 25% of patients suffer severe permanent disability, about 25% have mild disabilities, and greater than 50% recover with no residual paralyses. The greatest return of muscle function occurs in the first six months, but improvement and recovery may continue over the next two years. (2)

When the Salk and Sabin vaccines brought an end to the annual summer nightmare of polio epidemics, most Americans forgot about polio. Salk introduced the inactivated vaccine in 1955 and then Sabin in 1960 introduced the live attenuated oral vaccine. (1) Unfortunately, polio has again forced itself into the nations consciousness. Over the past several years, many of those who had polio have been experiencing new and unexpected symptoms that range in severity from being merely unpleasant to severely debilitating. Unaccustomed fatigue, new joint and muscle pain, new weakness in muscles affecting and in those apparently unaffected by polio, new respiratory difficulties, cold intolerance where exposure to even mild cold temperature results in noticeable muscle weakness marked with coldness and discoloration of the limbs and burning pain. (3)