Israeli soldiers captured during the 1973 Yom Kippur War were subjected to brutal torture in Egypt and Syria. Researchers have tried to study the effects of torture on the human pain system.
Held alone in tiny, filthy spaces for weeks or months, sometimes handcuffed and blindfolded, they suffered severe beatings, burns, electric shocks, starvation, and worse. And rather than receiving treatment, additional torture was inflicted on existing wounds.
Forty years later, research by Prof. Ruth Defrin of the Department of Physical Therapy in the Sackler Faculty of Medicine at Tel Aviv University shows that the ex-prisoners of war (POWs), continue to suffer from dysfunctional pain perception and regulation, likely as a result of their torture.
"The human body's pain system can either inhibit or excite pain. It's two sides of the same coin," Prof. Defrin said.
"Usually, when it does more of one, it does less of the other. But in Israeli ex-POWs, torture appears to have caused dysfunction in both directions. Our findings emphasize that tissue damage can have long-term systemic effects and needs to be treated immediately," she said.
The study focused on 104 combat veterans of the Yom Kippur War. Sixty of the men were taken prisoner during the war, and 44 of them were not.
In the study, all were put through a battery of psychophysical pain tests - applying a heating device to one arm, submerging the other arm in a hot water bath, and pressing a nylon fiber into a middle finger. They also filled out psychological questionnaires.
The ex-POWs exhibited diminished pain inhibition (the degree to which the body eases one pain in response to another) and heightened pain excitation (the degree to which repeated exposure to the same sensation heightens the resulting pain).
Based on these novel findings, the researchers conclude that the torture survivors' bodies now regulate pain in a dysfunctional way.
The study is published in the European Journal of Pain.