Enhanced sensitivity of the peripheral cholinergic vascular response in patients with chronic fatigue syndrome
Acetylcholine is a chemical found in the nervous system which helps transmit nerve impulses from the brain around the body. Brain scans have shown that people with ME/CFS may be abnormally sensitive to acetylcholine, and this could help explain many of the symptoms they experience.
Acetylcholine is also found in the lining of blood vessels, and can influence the flow of blood through an artery by relaxing its walls so that its diameter increases. By stimulating the skin with small amounts of acetylcholine, and measuring the resulting changes in blood flow, it was possible to test the sensitivity of blood vessels in the forearm. People with ME/CFS were found to be more sensitive to acetylcholine than were healthy people of the same age.
Sensitivity to acetylcholine may be an important feature of ME/CFS, and this abnormality may have an impact on the health of the heart and circulation of people with the condition.