fMRI review on brain responses to acupuncture: the limitations and possibilities in traditional Korean

Background: Since the late 1990s, imaging studies have allowed the visualization of brain response to acupuncture stimulation with alteration in blood flow. In 1998, the first functional magnetic resonance imaging (fMRI) study for the Korean acupuncture was published and thereafter, many subsequent neuroimaging studies with acupuncture have been published and revealed that acupuncture modulates central nervous system in human being. The purpose of this review is to summarize and evaluate the acupuncture studies using fMRI. Methods: A survey of computerized literature searches for experimental studies of acupuncture studies using fMRI revealed that a total of 19 studies were published from 1998 to 2005. Results: These studies have mainly focused on the correlation between acupoints and corresponding brain cortices, acupoint-specific patterns of brain activity. The analgesic effect of acupuncture implied that the pain network, including the hypothalamus and limbic system, was induced by different kinds of acupuncture stimulation. There are still several limitations in these experimental designs. Conclusion: We reviewed studies that contributed to an understanding of the neurophysiologic mechanisms of acupuncture with the hope that this review will be of benefit to the future traditional Korean acupunctural fMRI studies.