OBJECTIVEWith functional magnetic resonance imaging (fMRI), cerebral function imaging of acupuncture and sham acupuncture at Taichong (LR 3) in patients with essential hypertension (EH) was observed to analyze central mechanism of Taichong (LR 3) to treat EH.

METHODSEighteen EH patients were divided into a twisting acupuncture group (10 cases) and a sham acupuncture group (8 cases), which were treated with twisting manipulation and sham acu- puncture at right Taichong (LR 3), respectively. The treatments were both given with 30-second manipulation and 30- second interval for totally 5 min. During the acupuncture, fMRI was adopted to scan the cerebral function imaging of EH patients on resting state, and the acquired data were analyzed with SPM2 module in Matlab software.

RESULTSAcupunc- ture at Taichong (LR 3) in EH patients mainly increased opposite-side oxygen consumption, which generally activated left anterior cingulated gyrus (BA 32), left inferior parietal lobule (BA 40), left inferior temporal gyrus (BA 19), left middle temporal gyrus (BA 37) and right anterior central gyrus (BA 6). The activated areas were related to motor, vision and cognition of emotion. Stimulation region of sham acupuncture mainly included right anterior cingulated gyrus (BA 24), left inferior parietal lobule (BA 40) and left inferior frontal gyrus (BA 7).

CONCLUSIONThe central mechanism of Tai- chong (LR 3) on antihypertensive effect and symptom improvement is not in thalamus and medulla that are traditionally believed to control blood pressure. Taichong (LR 3) could activate anterior cingulated gyrus to regulate parasympathetic nerve and lower blood pressure, and through anterior cingulated gyrus, the connection with the surrounding areas is strengthened to improve the cognitive impairment caused by long-term hypertension.