Conclusions.
This is first study showing the influence of orthostatic stress on pain
perception in ME/CFS patients. After orthostatic stress PPT is decreased
in ME/CFS patients, with or without fibromyalgia, whereas in healthy
controls PPT did not change. In contrast, after orthostatic stress
windup is unchanged in both HC and the two patient groups, but
significantly increased in the two patient groups compared to HC.