Is there a BOLD response of the visual cortex on stimulation of the vision-related Acupoint GB 37?

Purpose: To determine whether or not acupuncture of guangming (GB 37) produces a significant response of the visual cortex detectable by means of functional magnetic resonance imaging (fMRI). Materials and Methods: This study investigates the activation of the visual cortex elicited by a soft and an intensified stimulation of GB 37, an acupoint documented to influence vision-related disorders. Three different paradigms were carried out to detect any possible modulation of the Blood Oxygenation Level Dependent (BOLD)-response in the visual cortex to visual stimulation through acupuncture. Results: The percentage signal changes in the visual stimulation cycles did not significantly differ before vs. during acupuncture. Conclusion: Whereas no BOLD-response correlating with acupuncture was detected in the visual cortex, BOLD-signal-changes in response to needle twisting were detected in different cortical areas. Further studies are necessary to clarify whether these clusters correlate to inevitable somatosensory stimulation accompanying acupuncture or represent an acupuncture-specific response.