Acupuncture needling sensation: the neural correlates of deqi using fMRI

The needling sensation of deqi is considered by most acupuncturists to be an important component of acupuncture, yet neuroimaging research that investigates this needle sensation has been limited. In this study we have investigated the effect of deqi and acute pain needling sensations upon brain fMRI blood oxygen level-dependent (BOLD) signals. Seventeen right-handed participants who received acupuncture at the right LI-4 (Hegu) acupoint were imaged in a 3T MRI scanner. fMRI datasets were classified, on the basis of psychophysical participants' reports of needling scores, into those that were associated with predominantly deqi sensations versus those with predominantly acute pain sensations. Brain areas showing changes in BOLD signal increases (activations) and decreases (deactivations) were identified. Differences were demonstrated in the pattern of activations and deactivations between groupings of scans associated with deqi versus pain sensations. For the deqi grouping, significant deactivations occurred, whereas significant activations did not. In contrast, the predominantly acute pain grouping was associated with a mixture of activations and deactivations. For the comparison between the predominately deqi sensation grouping and the acute pain sensation grouping (deqi>pain contrast), only negative Z value voxels resulted (mainly from deactivations in the deqi grouping and activations in the pain grouping) in the limbic/sub-cortical structures and the cerebellum regions of interest. Our results show the importance of collecting and accounting for needle sensation data in neuroimaging studies of acupuncture.