Post-Polio Syndrome
What is Post-Polio Syndrome (PPS)?
PPS is a condition that affects polio survivors years after recovery from an initial acute attack of the poliomyelitis virus.
Most often, polio survivors start to experience gradual new weakening in muscles that were previously affected by the polio infection.
(14)
The most common symptoms include slowly progressive muscle weakness, fatigue, and muscle atrophy, a decrease in the size of muscles. Some individuals experience only minor symptoms while others develop visible muscle weakness and atrophy.
(10)
The poliovirus is a picornavirus and a member of the group of enteroviruses, which inhabit the human digestive tract. Poliomyelitis attacks certain cells in the spinal cord and brainstem. (1)
The number of nerve cells that are destroyed and where the virus strikes have a significant impact on the extent of paralysis. If cells are not severely injured, they will recover their normal function. If cells are destroyed, they cannot be replaced because nerve cells are not able to regenerate. (2)
(11)
Motor neurons control voluntary muscle movement and are located in the spinal cord along the long axons. When motor neurons are infected by the poliovirus, some of them die, leaving paralyzed muscle cells. The recovering motor neurons grow new terminal axon sprouts to strengthen the muscle cells, creating a motor unit. This motor unit is constantly growing new sprouts and losing old ones. (3)
Discovery
In the 1970s, there were several reports that people who had recovered from paralytic polio decades earlier began to develop unexpected health problems such as pain in muscles and joints and even new muscle weakness. (4)
By the early 1980s, the medical community came up with the term post-polio syndrome. (6)
(12)
This "flaccid paralysis" affects the motor impulses, blocking their movement along the nerve fibers from the spinal cord to the muscles. These muscles cannot contract, so they become limp. (5)
At the time, it was widely believed that adults were more susceptible than children to get paralysis from the poliovirus. Today, the data from Nathanson and Martin suggests that there is a lack of correlation between the age of an infected person and paralytic attack rates. (7)
The polio epidemic lead to the development of rehabilitation medicine, which focused on rebuilding body functions and learning skills for independent living. The principles that were developed to treat polio patients are similar to the ones used today for the rehabilitation of patients with strokes, spinal injuries, and degenerative disorders. (8)
(13)
Footnotes
1. Britannica School, s.v. "Poliomyelitis," accessed January 16, 2019, https://school.eb.com/levels/high/article/polio/60621.
2. Ibid.
3. Lauro S. Halstead. "Post-Polio Syndrome." Scientific American278, no. 4 (1998): 42-47. http://www.jstor.org/stable/26057741.
4. Ibid.
5. "Poliomyelitis"
6. "Post-Polio Syndrome"
7. Darrell Salk. "Eradication of Poliomyelitis in the United States. I. Live Virus Vaccine-Associated and Wild Poliovirus Disease." Reviews of Infectious Diseases 2, no. 2 (1980): 228-42. http://www.jstor.org/stable/4452429.
8. "Post-Polio Syndrome"
9. Ibid.
10. U.S. Department of Health & Human Services. "Polio Disease and Poliovirus." Centers for Disease Control and Prevention. Accessed May 3, 2019. https://www.cdc.gov/cpr/polioviruscontainment/diseaseandvirus.htm.
11. "Post-Polio Syndrome"
12. LarryHand. "Post-Polio Syndrome: It Takes a Team Approach." Lower Extremity Review. Last modified October 2015. Accessed May 3, 2019. https://lermagazine.com/article/post-polio-syndrome-it-takes-a-team-approach.
13. "Physical Therapy." Baptist Health. Accessed May 3, 2019. https://www.baptistjax.com/services/rehabilitation-services/physical-therapy.
14. "Post-Polio Syndrome Fact Sheet." National Institute of Neurological Disorders and Stroke. Accessed May 17, 2019. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Post-Polio-Syndrome-Fact-Sheet.