Pain Sensitivity
Question: I've NEVER understood this. You say polio survivors are more sensitive to pain than nonpolio survivors but have a higher pain tolerance. How is it that I can have a high pain tolerance and be more sensitive? It feels contradictory to me.
Dr. Bruno’s Response: It has been known since the 1970s that the body produces its own morphinelike, painkilling opiates called endorphins and enkephalins. The problem for polio survivors is that the poliovirus killed off brain and spinal cord neurons that produce the body's own opiates. So polio survivors can't "medicate" themselves against pain, which is why polio survivors need more pain medication than do non-polio survivors.
Our 1984 study showed that polio survivors are TWICE as sensitive to pain as non-polio survivors, likely due to the lack of endorphins and enkephalins (1) “Normal” levels of pain would be doubled in polio survivors and likely intolerable if polio survivors hadn't developed a higher pain tolerance.
Here’s another example of sensitivity and developed tolerance. Think about many polio survivors’ emotional hypersensitivity to childhood hospital smells (e.g., rubbing alcohol, the smell of wet wool from hot packs). As adults, polio survivors had to develop an increased tolerance to these emotional triggers or they never would have allowed themselves to enter a hospital again. Sadly, many polio survivors have indeed refused to get medical treatment because they didn't develop an increased tolerance for hospitals and medical facilities. (2)
For more information, please read these two articles under the topic of “Psychology” in the Encyclopedia of Polio and PPS:
Trauma and Illness as Precipitants of Post-Polio Sequelae and
Psychology of Polio as Prelude to Post-Polio Sequelae.
References:
(1) Bruno RL, et al. Motor and sensory functioning with changing ambient temperature in post-polio subjects. Late Effects of Poliomyelitis. Miami: Symposia Foundation, 1985.
(2) Bruno RL, Frick NM. The psychology of polio as prelude to Post-Polio Sequelae: Behavior Modification and Psychotherapy. Orthopedics, 1991;14 (11):1185-1193.