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A Pilot Study of Functional Magnetic Resonance

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A Pilot Study of Functional Magnetic Resonance THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE Volume 8, Number 4, 2002, pp. 411–419 © Mary Ann Liebert, Inc. ORIGINALPAPERS A Pilot Study of Functional Magnetic Resonance Imaging of the Brain During Manual and Electroacupuncture Stimulation of Acupuncture Point (LI-4 Hegu) in Normal Subjects Reveals Differential Brain Activation Between Methods JIAN KONG, M.S., Lic.Ac., 1,2 LIN MA, M.D., Ph.D., 3 RANDY L. GOLLUB, M.D., Ph.D., 2 JINGHAN WEI, Ph.D., 4 XUIZHEN YANG, M.D., 1 DEJUN LI, Ph.D., 3 XUCHU WENG, Ph.D., 4 FUCANG JIA, Ph.D., 4 CHUNMAO WANG, Ph.D., 4 FULI LI, Ph.D., 5 RUIWU LI, M.D., 1 and DING ZHUANG, M.D. 1 ABSTRACT Objectives: To characterize the brain activation patterns evoked by manual and elec- troacupuncture on normal human subjects. Design: We used functional magnetic resonance imaging (fMRI) to investigate the brain re- gions involved in electroacupuncture and manual acupuncture needle stimulation. A block de- sign was adopted for the study. Each functional run consists of 5 minutes, starting with 1-minute baseline and two 1-minute stimulation, the interval between the two stimuli was 1 minute. Four functional runs were performed on each subject, two runs for electroacupuncture and two runs for manual acupuncture. The order of the two modalities was randomized among subjects. Dur- ing the experiment, acupuncture needle manipulation was performed at Large Intestine 4 (LI4, Hegu) on the left hand. For each subject, before scanning started, the needle was inserted per- pendicular to the skin surface to a depth of approximately 1.0 cm. Electroacupuncture stimula- tion was delivered using a continuous rectangular wave form (pulse width 30 ms) at a frequency of 3 Hz. For manual acupuncture, the needle was rotated manually clockwise and counter- clockwise at a rate of about 180 times per minute (3 Hz). Subjects: Eleven right-handed, normal, healthy volunteer adults, 6 male and 5 female, ages 21–64 participated in the experiment. Results: Results showed that electroacupuncture mainly produced fMRI signal increases in precentral gyrus, postcentral gyrus/inferior parietal lobule, and putamen/insula; in contrast, manual needle manipulation produced prominent decreases of fMRI signals in posterior cingu- late, superior temporal gyrus, putamen/insula. Conclusion: These results indicate that different brain networks are involved during manual and electroacupuncture stimulation. It suggests that different brain mechanisms may be recruited during manual and electroacupuncture. 1Institute of Acupuncture and Moxibustion, China Academy of Traditional Chinese Medicine, Beijing, People’s Re- public of China. 2Department of Psychiatry, Massachusetts General Hospital East, Charlestown, MA, and Harvard Medical School, Boston, MA. 3Department of Radiology, PLA General Hospital, Beijing, People’s Republic of China. 4Institute of Psychology, Chinese Academy of Science, Beijing, People’s Republic of China. 5Department of Physics, Capital Moral University, Beijing, People’s Republic of China. 411 412 KONG ET AL. INTRODUCTION et al., 1999). These studies indicate that fMRI, a noninvasive imaging method that can detect cupuncture, an ancient therapeutic tech- the rapid changes in neural activity in discrete Anique, is emerging as an important modal- brain regions that accompany acupuncture ity of complementary medicine in Western stimulation in human subjects, can provide countries (Diehl et al., 1997; Eisenberg et al., valuable information about the scientific basis 1993, 1998). Acupuncture treatments for post- of acupuncture. operative and chemotherapy-induced nausea No fMRI studies comparing the patterns of and vomiting and for postoperative dental pain brain activation induced by the two commonly are promising, and acupuncture can be a ben- used clinical acupuncture treatment modali- eficial adjunct or alternative treatment for drug ties, manual and electroacupuncture, have addiction, stroke rehabilitation, asthma and been reported. Investigation of the pattern of chronic pain (NIH, 1998). In ancient times, regional brain activation produced by manual acupuncturists used manual manipulation acupuncture and electroacupuncture stimula- methods to achieve clinical benefits. Today, tion will not only provide more information electroacupuncture is becoming more and about the biologic basis of acupuncture, but more popular. Both acupuncture modalities are may also be helpful in explaining the different believed to have clinical efficacy, however, effects of the acupuncture modalities on the many research studies suggest that they work central nervous system. Ultimately, the infor- through different neural mechanisms. For in- mation gained by imaging studies may help stance, the two modalities have significantly refine acupuncture treatment protocols to different effects on electroencephologram achieve maximal clinical efficacy. In this ex- (EEG), salivary flow rate, and neurotransmitter periment, we utilized fMRI using both manual release in the central nervous system (Bucin- acupuncture and electroacupuncture at LI4 in skaite et al., 1994; Dawidson et al., 1997; Saletu the same subjects, to investigate the brain net- et al., 1975). works that are involved in these two modali- Recently, functional magnetic resonance ties of acupuncture. The acupoint LI4 was se- imaging (fMRI) has been used to investigate lected because it is the most frequently used the neurobiologic mechanism underlying acupoint in Chinese acupuncture, especially for acupuncture needle manipulation (Cho et al., analgesia and sedation, and because there are 1998; Hui et al., 2000; Wu et al., 1999). In these previous fMRI studies using this point, facili- studies, researchers investigated correlations tating comparison of results with those of other between brain activities as reflected by fMRI research groups (Hui et al., 2000; Wu et al., signal changes and acupuncture stimuli. For 1999). example, in one study, it has been reported that manual acupuncture needle manipulation for 2 minutes at Large Intestine 4 (LI4) produced few fMRI signal increases, but widespread MATERIALS AND METHODS signal decreases in the nucleus accumbens, Subjects amygdala, hippocampus, parahippocampus, hypothalamus, ventral tegmental area, anterior The Academic and Ethical Committee in the cingulate gyrus (BA24), caudate, putamen, Institute of Acupuncture, China Academy of temporal pole, and insula in all subjects who Traditional Chinese Medicine, approved the experienced acupuncture sensation (Hui et al., imaging study, which was performed after ob- 2000). The authors interpret this result as evi- taining informed consent. Eleven (11) right- dence that acupuncture needle manipulation handed normal, healthy volunteer adults, 6 can modulate the activity of the limbic system male and 5 female, ages 21–64 (32 6 16.1) par- and subcortical structures. Two other reports ticipated. None had a history of psychiatric or also found that manual acupuncture needle neurologic disorders or head trauma with loss manipulation can produce corresponding tem- of consciousness, nor intake of tranquilizing poral fMRI signal changes (Cho et al., 1998; Wu drugs in the previous 3 days. All subjects had fMRI STUDY ON MANUAL AND EAP 413 received acupuncture before and had some ported by subjects were different for the two knowledge of acupuncture (they were either modalities. No quantitative measures were students in acupuncture school or acupuncture used to compare the two acupuncture modali- research scientists). Thus, it was easy for them ties because of the inherent difficulties in ex- to detect different acupuncture sensations. actly matching stimulation. A block design was adopted for each func- Experimental protocol tional run. We adopted a 5-minute scan time for each functional run. This started with 1 minute Each subject was put into the scanner and in- of rest, followed by 1 minute of acupuncture structed to close his or her eyes and relax stimulation, then 1 minute of rest, followed by throughout the imaging session. Four MRI scan 1 minute of acupuncture stimulation, then 1 runs were performed, two runs for elec- minute of rest again. The acupuncture stimula- troacupuncture and two for manual acupunc- tion was either manual or electroacupuncture ture. The order of the two modalities was ran- during any functional run. The interval be- domized among subjects. tween two functional runs was approximately Acupuncture was performed at acupoint LI4 3 minutes for the same acupuncture modality on the left hand only. Intermittent acupuncture and at least 5 minutes between different stimulation was delivered using a sterile dis- acupuncture modalities. Acupuncture was per- posable #32 stainless steel needle (0.26 mm in formed by the same acupuncturist on all sub- diameter). The frequency of stimulation was jects. After scanning was completed, subjects matched as closely as possible across subjects. were questioned as to the sensation that they For manual acupuncture, the needle was ro- experienced when acupuncture stimuli were tated manually clockwise and counterclock- applied during each run. wise at a rate of about 180 times per minute (3 cycles per second, 3 Hz). An electroacupunc- Apparatus and scanning procedures ture instrument (ZYZ-20GZ1, Institute of Acupuncture and Moxibustion, China Acad- fMRI scanning was conducted on a 1.5 T emy of Traditional Chinese Medicine, Beijing) General Electric (GE Medical Systems, Mil- was used to administer electroacupuncture waukee, WI) Signa scanner at PLA General with continuous
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