Point specificity of acupuncture in the light of recent clinical and imaging studies.

One fundamental question that is still not resolved is whether acupuncture needles must be inserted in specific points to have their greatest effects. In the majority of large RCTs recently conducted in Germany, acupuncture was significantly more effective than doing nothing but not than sham acupuncture. Only for one study of chronic knee pain was acupuncture superior to sham. Brain imaging with functional magnetic resonance (fMRI) and positron emission tomography (PET) may be helpful but is still in its early stages. Several studies have shown differences between the way the deep central areas of the brain respond to genuine acupuncture compared with sham. Acupuncture can clearly produce complex changes that are relevant to pain transmission and perception, though it is still uncertain how specific these are. Similar changes have been seen after the application of placebo cream and after hypnosis. A previous paper discussed the likely central role of the limbic system in acupuncture, evidenced by euphoria and out of body experiences. There may be a good deal of common ground between acupuncture, placebo treatments, hypnosis, and even manipulative treatments. This understanding could offer a way out of the sterile debate about whether acupuncture is merely a placebo: acupuncture could be one effective way of stimulating responses within these deep areas of the brain, though not the only way.

Royal London Homeipathic Hospital, London, UK. ac@campbell.org.uk