title: Cerebral hemodynamic responses induced by specific acupuncture sensations during needling at trigger points: a near-infrared spectroscopic study.
abstract: Acupuncture stimulation at specific points, or trigger points (TPs), elicits sensations called "de-qi". De-qi sensations relate to the clinical efficacy of the treatment. However, it is neither clear whether de-qi sensations are associated with TPs, nor clear whether acupuncture effects on brain activity are associated with TPs or de-qi. We recorded cerebral hemodynamic responses during acupuncture stimulation at TPs and non-TPs by functional near-infrared spectroscopy. The acupuncture needle was inserted into both TPs and non-TPs within the right extensor muscle in the forearm. Typical acupuncture needle manipulation was conducted eight times for 15 s. The subjects pressed a button if they felt a de-qi sensation. We investigated how hemodynamic responses related to de-qi sensations induced at TPs and non-TPs. We observed that acupuncture stimulations producing de-qi sensations significantly decreased the Oxy-Hb concentration in the supplementary motor area (SMA), pre-supplementary motor area, and anterior dorsomedial prefrontal cortex regardless of the point stimulated. The hemodynamic responses were statistically analyzed using a general linear model and a boxcar function approximating the hemodynamic response. We observed that hemodynamic responses best fit the boxcar function when an onset delay was introduced into the analyses, and that the latency of de-qi sensations correlated with the onset delay of the best-fit function applied to the SMA. Our findings suggest that de-qi sensations favorably predict acupuncture effects on cerebral hemodynamics regardless of the type of site stimulated. Also, the effect of acupuncture stimulation in producing de-qi sensation was partly mediated by the central nervous system including the SMA.
authors.affiliation: System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan.
authors.forename: Kouich
authors.initials: K
authors.lastname: Takamoto
authors.forename: Etsuro
authors.initials: E
authors.lastname: Hori
authors.forename: Susumu
authors.initials: S
authors.lastname: Urakawa
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Sakai
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ishikawa
authors.forename: Satoru
authors.initials: S
authors.lastname: Kohno
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Ono
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishijo
mesh_terms: D026881:Acupuncture / Q000379:methods*; D015669:Acupuncture Points; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism; D012684:Sensory Thresholds / Q000502:physiology; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins