Acupuncture Continuing Education

MRI Acupuncture Research on Point Specificity

New acupuncture research concludes that, “Recent evidence shows that stimulation of different points on the body causes distinct responses in hemodynamic, fMRI and central neural electrophysiological responses.” The researchers note that fMRI and laboratory studies demonstrate unique changes within the body when specific acupuncture points are stimulated. The study demonstrates that specific acupuncture points have specific biophysiological effects. As a result, the researchers suggest further research to investigate these measurable, quantifiable and objective phenomena.

Researchers from the Department of Medicine at the University of California, Irvine, examined the specific effects of needling different acupuncture points as compared with stimulation of non-acupuncture points and placebo simulated stimulation. The researchers note that “... many well-controlled studies do support the principle of point specificity.” They cite as example multiple studies of cardiovascular disease and note that real acupuncture points “elicit(s) significantly greater responses than stimulation of both non-acupoints and inactive acupoints.” They also conclude that stimulation of different acupoints “produces differential input to regions of the brain that regulate sympathetic outflow and cardiovascular function.”

The researchers note that a hemodynamic study of acupoint P6 showed that this acupuncture point “decreased heart rate and increased the high-frequency HRV index of cardiac vagal modulation….” A sham acupoint (a point not located on a traditional acupoint location) was able to decrease the heart rate but did not change the vagal outflow as did P6. These differing mechanisms suggest that sham acupuncture studies may obscure the true medical benefits of acupuncture. In the case of P6 stimulation, only the true acupuncture point increased the high-frequency HRV index. HRV (heart rate variability) is the variance in time interval between heart beats. Reduced HRV is linked to mortality after myocardial infarction and a lowering of HRV is also linked to congestive heart failure, diabetic neuropathy and low survival rates in premature babies. Both true and sham acupuncture decrease heart rates but only true acupuncture increases HRV. Examination of other true acupuncture points (across numerous studies) compared with non-acupuncture points and non-relevant acupuncture points confirms that hemodynamic responses are specific to exact acupuncture points and that true acupoints elicit sympathoexcitatory responses relevant to their traditional medical indications.

Neurological investigations support the specificity of acupuncture points. The researchers examined MRI studies of the brain and note that “stimulation of different sets of acupoints leads to disease-specific neuronal responses, even when acupoints are located within the same spinal segment.” The researchers also note, “The point-specific actions resulting from stimulation of different acupoints in controlled laboratory trials confirm that needling different points on the body produces more than just placebo responses, given that placebo acupuncture is not associated with differential or acupoint-specific responses in anesthetized animals.”

Point specificity in acupuncture. Chinese Medicine 2012, 7:4 doi:10.1186/1749-8546-7-4. Emma M Choi, Fang Jiang, John C Longhurst.
Susan Samueli Center for Integrative Medicine, Department of Medicine, School of Medicine, University of California, Irvine CA.
Medical Science, School of Medicine, University of California, Irvine, CA.