Polio is also known as poliomyelitis and is caused by poliovirus and is an infectious disease. Polio is extremely rare in today’s time and there are vaccines available to prevent polio. Polio disease can be transmitted through contaminated food or water. People suffering from polio can develop paralysis over a period of time. Some other symptoms of Polio shown are muscular pain and headache. Another symptom noticed is decrease in growth rate due to Polio.
Electromyography recording is used to observe muscle activities. A new EMG technique is known as macro electromyography. A single modified electromyography fiber is used as electrode and by observing the spikes in the graph and triggering activities the resulting actions of the muscles are recorded. In a healthy person’s body, different muscles will have a different number of motor units. In tibial anterior and biceps brachii muscles, the value of a number of muscle fibers is different for each motor unit when compared to their standard values. In the case where the reinnervation capacity is high, a loss in percentage of motor neurons was observed in both tibial anterior and brachii muscles, which indicate a similar increase in the size of units of surviving motor.
The muscle, which initially has a greater number of motor units was observed that in a situation of loss of a number of motor neurons in both the muscles, macro MUP amplitude will change less in these muscles. According to researchers, the tibial anterior muscle has a greater number of motor units which is 256; whereas the biceps brachii muscles have 106 motor units. Hence, a result can be concluded that the difference in the number of tibial anterior muscle’s motor units with biceps brachii muscles cannot explain the changes in the tibial muscles. There are no studies that have used the motor unit number estimation technique to compare to muscles.
Changes in Macro EMG Over Time in Patients with a History of Polio
In the process to observe the changes, standard macro EMG methods are applied. The electrode where recording takes place is a fiber electrode with a coating of Teflon cannula. The patients who undergo macro EMG showed symptoms, such as weakness and exhaustion during the investigations that was carried out in two phases. Some patients showed symptoms of cold and perception of pain while in some patients these symptoms were not observed. An increase in motor unit size time in the vastus and tibial muscles indicate a neuronal loss. The main objective was to find that time changes affect differently in less severely used arms than weight-bearing muscles of legs. The muscles that were mainly observed were tibial anterior and biceps brachii in patients with a history of polio. According to a result of testing, 26 out of 28 anterior muscles were seen with elevated macro MUP amplitudes. In around 26 muscles fiber density was found to be increased in patients with a history of polio.
The parameters were found to be in normal condition in case of one muscle only. Observing the results of biceps brachii muscles the researchers came to an inference that out of 28 biceps brachii muscles 23 were found to have elevated amplitudes of macro MUP which were compared to matched age controls. 25 muscles were found to have increased in fiber density when compared to age-matched controls. Only one biceps brachii muscle was found to have normal macro MUP amplitude as well as fiber density.
On an average it was noted that both tibial anterior and biceps brachii muscles showed the identical mark of comparative deviations from the position values of the tibial anterior muscle whose range varies from 1.7 to 35 and whose mean value is 7.2 whereas for biceps brachii muscle the range varies from 1.7 to 35 and its mean value is 6.3. The researchers also inferred that there is no relation of age with macro MUP elevation.[1]
Conclusion
Polio or poliomyelitis is caused by poliovirus and is an infected disease. The disease is extremely rare; however, there are vaccines available to prevent polio. A method of macro EMG was used on the patients suffering from polio to find out changes on the muscles. The researchers observed biceps brachii and tibial anterior muscles and noted that out of the selected muscles, only one muscle in both the categories showed deviation in macro MUP elevation. The deviation was checked from the mean and standard values of the respective muscles in patients with a history of polio.
- Sandberg, A., &Stålberg, E. Changes in macro electromyography over time in patients with a history of polio: a comparison of 2 muscles. Archives Of Physical Medicine And Rehabilitation, (2004). 1174-1182. doi: 10.1016/j.apmr.2003.08.101
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