Polio and motor Peripheral Neuropathy have much in common. They both involve the motor nerve fibers that carry impulses from the brain to our muscles. These nerve fibers are responsible for movement. Without them the brain signals that direct movement would never be able to communicate with our muscles.
In the case of Polio, the polio virus infected a cell body within the spinal cord named the Anterior Horn Cell. The anterior horn cell is the starting point — the life generator — of the motor nerve fiber. The anterior horn cell relays information from the brain, via the spinal cord, to the rest of the motor nerve that then communicates with the muscle.
The part of the nerve that travels from the anterior horn cell and the muscle is called the peripheral part of the nerve. In the case of Polio, when the anterior horn cell dies, so does the peripheral motor nerve. In the case of Peripheral Neuropathy, the peripheral nerve itself dies back, without any disease of the anterior horn cell itself.
Think of it like a tree, where the trunk is the anterior horn cell and the branches are the peripheral nerves. The leaves are the muscles. Sometimes trees get infected in the trunk (Polio). When this happens, it is no surprise if the branches get sick as well. Other times the trunk is healthy, but the branches are not (Peripheral Neuropathy). For example, they may have become overgrown or infected; maybe a drought starved the branches or a storm broke one.
In the case of Polio, there is another striking similarity with Peripheral Neuropathy. After all of the anterior horn cells that were going to die had done so, the ones that were left tried to make up the difference. The surviving tree trunks grew more new branches and leaves than they normally would. While this helped out quite a bit, over time the tree trunk could no longer support such heavy growth.
The branches started to die back, just like with motor Peripheral Neuropathy. Medicine calls this event the Late Effects of Polio. Unlike those with Peripheral Neuropathy, however, when those with Polio (also referred to as Polios) start to suffer from the late effects, they have very little reserve to fall back upon. They were over-extended to begin with.
For those with Peripheral Neuropathy, the Polios can serve as a wonderful role model for what can happen in the more severe forms of their illness. The Polios provide a helpful example of how to cope with peripheral neuropathy diseases. Polios have learned how to adapt both physically and emotionally over the course of their lives. They are strong-willed people who, as survivors, now wish to become teachers for those with Peripheral Neuropathy.
At Piedmont Physical Medicine & Rehabilitation, P.A. we take a wholistic approach to health care. We specialize in the diagnosis and treatment of pain, weakness, numbness, immunological compromise, and functional impairment. We believe in disease management. By offering a full battery of diagnostic studies to evaluate the level of involvement of peripheral neuropathy, as well as the complicating factors that affect its progression and recovery, we are able to offer a wider range of therapeutic interventions that put quality into life.
Dr. Robert G. Schwartz is the medical advisor for the Palmetto Polio Peripheral Neuropathy Support Group of SC and a contributing editor to its web site.