Propofol, an intravenous general anaesthetic, has been reported to rel
ieve some forms of pruritus at subhypnotic doses. We assessed its effe
ctiveness in 32 patients with several kinds of non-malignant chronic p
ain, in a placebo-controlled, double-blind study. We found that centra
l pain, but not neuropathic pain, is at least partially controlled by
propofol at subhypnotic doses, without major side-effects. In particul
ar, allodynia associated with central, but no neuropathic, pain has be
en completely controlled. Propofol analgesia leads to renormalization
of brain metabolism as seen on single photon emission computed tomogra
phy. We conclude that propofol may help in the diagnosis of central pa
in, particularly in unclear cases, and also in treatment. Possible mec
hanisms of action are discussed.