Acupuncture stimulation for motor cortex activities: A 3T fMRI study

The acupoint, GB34, located in the back of the knee, is known to be effective in recovering motor function after a stroke. This study uses a functional magnetic resonance imaging (fMRI) study with 3T scanner to investigate whether or not acupuncture of GB34 produces a significant response of the modulation of somatomotor areas. A fMRI of the whole brain was performed in ten normal healthy subjects during two task stimulations of acupuncture manipulation on GB34 and sham points, inserting and twisting the needle for 25 seconds at a rate of approximately 120 times per minute; the needle manipulation was paused for a duration of 25 seconds as a control state. The process was repeated four times to have four epochs of stimulation. Bilateral sensorimotor areas (BA 3, 4, 6 and 7) showed approximately 6% of stimulation-related BOLD signal contrast, whereas very few areas were activated when sham stimulation was given. Acupuncture stimulation in GB34 modulates the cortical activities of the somatomotor area in humans. The present findings may shed light on the CNS mechanism of motor function by acupuncture, and form a basis for future investigations of motor modulation circuits in stroke patients.