New research explores the role of de-qi in the field of acupuncture. De-qi is a combination of bodily sensations induced by acupuncture needling techniques combined with physiological responses to the stimulation. The researchers note that de-qi sensation is often described as dull, heavy, deep pressure, pulling, numb, aching, spreading, radiating, electrical, refreshing, relieving and tingling.
The researchers differentiated the different subjective experiences into the types of nerve fibers that carry those responses. It turns out that de-qi related numbness is transmitted by different nerve fibers than heaviness. De-qi related soreness is transmitted by yet another type of nerve fiber. The researchers noted studies showing that these different subjective experiences reflect measurable differing nerve fiber transmissions and consequent differences in brain region stimulation.
The researchers also noted that specific acupuncture points have distinct de-qi characteristics. Intensity of soreness, fullness and heaviness varies according to the specific acupuncture point chosen. These differences persist between acupuncture points that are along the same acupuncture meridian and acupuncture points that have similar tissue structures. Much of the work in this area leads investigators to suggest that nerve innervation has a major influence on de-qi sensation.
The researchers found no correlation between direct nerve stimulation at acupuncture point regions and de-qi sensation. An interesting finding, direct needle stimulation and contact of the median nerve at acupuncture point P6 does not necessarily stimulate a de-qi sensation. Conversely, de-qi is often achieved at P6 without any direct simulation of the median nerve. This and other research finds that de-qi is not caused by direct irritation of a nerve fiber. Rather, de-qi is a physiological response by the central and peripheral nervous system independent of direct contact to nerve fibers.
Another very interesting finding is that achieving de-qi at acupuncture points elicits distinctly different cortical responses than at non-acupuncture points. The researchers suggest that much of these findings point to de-qi having a different effect on the central nervous system dependent on the acupuncture points chosen. Specific acupuncture points demonstrate a consistent and unique ability to stimulate specific brain regions upon de-qi stimulation.
Acupuncture Needle Manipulation
The investigation revealed that many researchers across multiple studies agree that acupuncture needle manipulation affects de-qi. Deep needling and bi-directional rotation were found to be positively correlated with evoking a de-qi response. Needle rotation increased de-qi responses of deep, dull and heavy sensations but did not correlate to prickling and sharp sensations. Needle rotation that stimulated de-qi at LV3 and GB40 elicited brain responses that could not be achieved at non-acupuncture points.
The researchers covered the important topic of the needle grasp sensation. Many acupuncturists were noted in this study as associating the acupuncture needle grasp sensation with the arrival of de-qi. Historically, this sensation was described in Biao You Fu (Song to Elucidate Mysteries) in the Great Compendium of Acupuncture and Moxibustion (Zhen Jiu Da Cheng). The needle grasp sensation was described as “the arrival of qi like a fish biting on a fishing line.”
Several studies were reviewed regarding the arrival of de-qi and its relationship to regulation of the sympathic and parasympathetic divisions of the autonomic nervous system in this meta-analysis. Arrival of de-qi downregulated sympathetic nervous system activity and upregulated parasympathetic activity. This type of response was documented as producing healthy responses in heart rate variability, a measure of cardiac health. Electroencephalogram (EEG) studies also demonstrated unique changes in brain activity upon the arrival of de-qi at verum acupuncture points. Similar findings correlated limbic system activity changes with the arrival of de-qi as verified in numerous fMRI studies.
These were some of the main points in the study performed at the School of Acupuncture, Moxibustion and Tuina at the Beijing University of Chinese Medicine. De-qi is usually described by patients as suan (aching, soreness), ma (tingling, numbness), zhong (heaviness) and zhang (fullness, pressure, distention). De-qi is often perceived by acupuncturists as the needle grasp sensation. The study was a comprehensive meta-analysis of multitudes of studies on de-qi sensations and related physiologic responses. The research across many studies showed a direct and positive correlation between changes in nervous system activity and brain responses to de-qi arrival.