Chronic Fatigue, Fainting and Autonomie Dysfunction

To test the hypothesis that fatigue and fainting occur together, 1,047 polio survivors and 419 non-disabled control subjects were asked about the frequency and cause of fainting and asked to rate their typical daily fatigue severity. Fatigue severity was significantly higher in polio survivors as compared to controls, and in both polio survivors and controls who had fainted, as compared to those who had not. Daily fatigue severity also increased in both groups as the number of lifetime faints increased. Fatigue was significantly higher in controls who fainted one time and three times as compared to controls who had never fainted. Daily fatigue severity was significantly higher in polio survivors who had fainted three, four and five times as compared to those who had never fainted. These findings suggest a physiological relationship between fatigue and fainting, possibly attributable to the close proximity of cardiovascular regulation and brain activation centers within the brain stem. Fatigue and hypotension in patients with chronic fatigue syndrome and in polio survivors with late-onset fatigue may result from damage to brain stem and hypothalamic neurons.