Differences in functional magnetic resonance imaging following cutaneous and routine acupuncture

NEURAL REGENERATION RESEARCH Volume 6, Issue 15, May 2011

Cite this article as: Neural Regen Res. 2011;6(15):1169-1174.

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Yangjia Lu ☆, Studying for doctorate, Teaching

Research Department of Acupuncture, School of Traditional Chinese

Medicine, Southern Medical University, Guangzhou 510515, Guangdong Province, China

Corresponding author: Yong Huang, Doctor, Professor, Chief physician, Doctoral supervisor, Teaching Research Department of Acupuncture, School of Traditional Chinese

Medicine, Southern Medical University, Guangzhou 510515, Guangdong Province, China nfhy@https://www.sodocs.net/doc/a81836432.html,

Supported by: the National Basic Research Program of China (973 Program), No. 2006CB504505*; the National Natural Science Foundation of China, No. 90709027*

Received: 2011-02-08 Accepted: 2011-04-10 (N 20100123001/WJ)

Lu YJ, Wu JX, Zou YQ, Chen JQ, Shan BC, Chen JR, Huang Y . Differences in functional magnetic

resonance imaging following cutaneous and routine acupuncture at different acupoints. Neural Regen Res. 2011;6(15):1169-1174.

https://www.sodocs.net/doc/a81836432.html,

https://www.sodocs.net/doc/a81836432.html,

doi:10.3969/j.issn.1673-5374.2011.15.009

Differences in functional magnetic resonance imaging following cutaneous and routine acupuncture at different acupoints**☆

Yangjia Lu 1, Junxian Wu 1, Yanqi Zou 1, Junqi Chen 1, Baoci Shan 2, Jiarong Chen 1, Yong Huang 1

1Teaching Research Department of Acupuncture, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, Guangdong Province, China

2Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China

Abstract

Few studies have examined the effects of different stimuli at a single acupoint using functional magnetic resonance imaging. The present study applied acupuncture at the Neiguan (PC 6),

Waiguan (SJ 5), Zhigou (SJ 6) and Yanglingquan (GB 34) acupoints in healthy volunteers. fMRI was used to examine the activation of brain areas in response to different types of acupuncture

(cutaneous or routine acupuncture) at each acupoint. There were no significant differences in the distribution of activation in the regions of interest between cutaneous and routine acupuncture at the Neiguan , Waiguan , and Zhigou acupoints, but some differences were observed between the two methods of acupuncture at the Yanglingquan acupoint. There were no significant differences in the intensity of induced activation between cutaneous and routine acupuncture at the Neiguan , Zhigou and Yanglingquan acupoints, but the activation intensity in the right cerebellum induced by routine acupuncture at the Waiguan acupoint was greater than that induced by cutaneous acupuncture. Results confirmed that cutaneous and routine acupuncture at the Neiguan , Waiguan , Zhigou and Yanglingquan acupoints activated different functional brain areas, and caused activation of different intensities in some areas.

Key Words: functional magnetic resonance imaging; cutaneous acupuncture; routine acupuncture; Neiguan (P C6); Waiguan (SJ 5); Zhigou (SJ 6); Yanglingquan (GB 34); neural regeneration

INTRODUCTION

Functional MRI (fMRI) is commonly used to detect neural activity in the brain in vivo [1]. Recent studies have utilized fMRI to observe brain functional changes following acupuncture, such as comparisons in cerebral functional imaging between acupuncture at acupoints compared with non-acupoints, or between true and sham acupuncture conditions, confirming a close correlation between acupuncture at

acupoints and functional brain activities [2-8]. Most previous studies have focused on

differences in activated brain areas between acupoints or between acupoints and non-acupoints, but little is known about differences in activation caused by different types of acupuncture at one acupoint. Clinical acupuncture at superficial or deep layers has been reported to exert positive therapeutic effects in treating facial paralysis [9-10]. Classical blood oxygenation level

dependent fMRI (BOLD-fMRI) has been utilized to study task-related brain activation, in experiments involving both block designs and event-related designs. Areas of

functional brain activation are typically obtained by subtracting the task condition and task-free condition [11]. Lai et al [12]

reported that the effects of acupuncture at acupoints were highly correlated with

functional integration in the brain, and that specific changes in brain function could explain the differences induced by stimuli in different layers at one acupoint.

Waiguan (SJ 5) and Zhigou (SJ 6) are acupoints in the triple-warmer channel of hand shaoyang. This channel commences at the hand and ends at the head, and is connected with the Neiguan (PC 6) and Yanglingquan acupoints. Based on the hypothesis that applying acupuncture at acupoints along the triple-warmer channel would influence brain function, the present study used fMRI to examine differences between the effects of cutaneous and routine acupuncture at the Neiguan , Waiguan , Zhigou and Yanglingquan acupoints.

RESULTS

Quantitative analysis of subjects

Thirty-one healthy volunteer subjects were

https://www.sodocs.net/doc/a81836432.html,

randomly divided into Neiguan (n = 7), Waiguan (n = 8), Zhigou (n = 8) and Yanglingquan (n = 8) groups. Each group received cutaneous and routine acupuncture. All 31 subjects were included in the final analysis. Activation rate of regions of interest (ROIs) following acupuncture at four acupoints

There were some differences in ROI activation rate between cutaneous and routine acupuncture at each acupoint. Cutaneous acupuncture at the Neiguan mainly activated the bilateral frontal lobe, parietal lobe, left temporal lobe and right occipital lobe (activation rate > 50%; activation rate = number of activated areas/number of subjects in one group), while routine acupuncture mainly activated the bilateral frontal lobe, parietal lobe, temporal lobe and left occipital lobe (activation rate > 50%). Cutaneous acupuncture at the Waiguan mainly activated the bilateral frontal lobe, bilateral parietal lobe, and bilateral cerebellum, while routine acupuncture mainly activated the bilateral frontal lobe, bilateral parietal lobe, bilateral temporal lobe, bilateral occipital lobe, bilateral cingulate gyrus and bilateral cerebellum.

Cutaneous acupuncture at the Zhigou mainly activated the bilateral frontal lobe, parietal lobe, and temporal lobe (activation rate > 50%; activation rate = number of activated areas/number of participants in one group), while routine acupuncture mainly activated the bilateral frontal lobe, parietal lobe, left occipital lobe and temporal lobe (activation rate > 50%).

Cutaneous acupuncture at the Yanglingquan mainly activated the left parietal lobe, left occipital lobe and left basal ganglia, while routine acupuncture mainly activated the right cingulate gyrus (Table 1).

Number of activated ROIs following acupuncture at four acupoints

There were no significant differences in the number of activated areas (sum of the number of activated areas in the ROIs of all subjects in one group) among cutaneous and routine acupuncture at the Neiguan, Waiguan, and Zhigou acupoints (P > 0.05). However, there were some differences in the distribution of activation between cutaneous and routine acupuncture at the Yanglingquan acupoint. The results revealed that the activated areas were mainly distributed in the bilateral frontal lobe, and parietal lobe following cutaneous acupuncture at the Neiguan, whereas they were mainly distributed in the bilateral frontal lobe, parietal lobe, and left occipital lobe (number of areas of activation > 10) following routine acupuncture. Following cutaneous acupuncture at the Waiguan, the areas of activation were mainly distributed in the bilateral frontal lobe, parietal lobe, and cerebellum. In addition, the activated areas were mainly distributed in the bilateral frontal lobe, parietal lobe, and temporal lobe following cutaneous acupuncture at the Zhigou, and in the bilateral frontal lobe, parietal lobe, temporal lobe, and right occipital lobe (number of activated areas > 10) following routine acupuncture. Finally, following cutaneous and routine acupuncture at the Yanglingquan, the activated areas were mainly distributed in the bilateral frontal lobe, parietal lobe, and temporal lobe (number of activated areas > 10, Table 2).

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Mean activation intensity at different ROIs following acupuncture at four acupoints

The mean activation intensity at ROIs = the sum of activation intensity of each area of activation at an

ROI/number of subjects in one group. The results revealed that the mean activation intensity in the right cerebellum was greater following routine acupuncture at the Waiguan compared with cutaneous acupuncture (P < 0.05). There were no other significant differences for the effects of cutaneous and routine acupuncture at the Neiguan, Zhigou and Yanglingquan acupoints (P > 0.05). However, ROI activation intensity was increased in the left cerebellum and decreased in the left occipital lobe and right cerebellum following cutaneous acupuncture at the Neiguan compared with routine acupuncture. ROI activation intensity was greater in the left temporal lobe and right occipital lobe following routine acupuncture at the Zhigou compared with cutaneous acupuncture. ROI activation intensity was increased in the bilateral parietal lobe, basal ganglia and left cerebellum, and reduced in the bilateral cingulate gyrus, left frontal lobe, right occipital lobe and cerebellum following cutaneous acupuncture at the Yanglingquan compared with routine acupuncture (Table 3).

DISCUSSION

In the current study, no significant differences were detected in activation rate, the number of activated areas or the intensity of activation in ROIs between cutaneous and routine acupuncture at the Neiguan acupoint. This suggests that both methods may exhibit similar treatment effects on the heart, chest and stomach. In addition to the occipital lobe and cerebellum, routine acupuncture has been found to cause bilateral temporal lobe activation, which is closely linked to audition, vision and memory, and the regulation of emotion. Therefore, routine acupuncture is recommended in the treatment of disorders related to those functions. There were no significant differences in activation rate or the distribution of activated areas between cutaneous and routine acupuncture at the Waiguan acupoint, but routine acupuncture caused stronger activation in the right cerebellum compared with cutaneous acupuncture. The cerebellum is closely associated with muscular tension, bodily equilibrium, and motor coordination, and is involved in an extensive range of cognitive functions, including sensory perception, learning, attention, language, and emotional control[9]. As such, routine acupuncture can be used to treat disorders in vision, balance and cognition.

Routine acupuncture at the Zhigou acupoint mainly activated the bilateral frontal lobe, parietal lobe, the left occipital and temporal lobes, all of which are related to motor function, learning and memory, emotion, vision and hearing. Following cutaneous acupuncture at the Zhigou acupoint, areas of activation were distributed bilaterally, and activation intensity was weaker than that induced by routine acupuncture. Following cutaneous acupuncture at the Yanglingquan acupoint, many areas of activation were observed in the bilateral frontal lobe, parietal lobe, and temporal lobe, and high-intensity activation was distributed in the bilateral parietal lobe, basal ganglia, left occipital lobe, cerebellum, and right insular lobe.

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In contrast, following routine acupuncture at the Yanglingquan acupoint, areas of activation were mostly distributed at the right cingulate gyrus and cerebellum. The cingulate gyrus and frontal lobe are closely linked to cognitive function. Thus, taken together with previous reports, our findings suggest that cutaneous acupuncture at the Yanglingquan acupoint can be used to treat motor disorders, while routine acupuncture may be more appropriate for treating mental disorders and balance disturbances.

In conclusion, cutaneous and routine acupuncture applied at the Neiguan, Waiguan, Zhigou and Yanglingquan acupoints exhibit similar treatment effects. These results are in accord with previous reports that superficial layer stimulation, such as finger pressing, moxibustion and deep layer stimulation such as routine acupuncture, exert similar effects in treating disease. Moreover, stimulation at the superficial and deep layers possesses respective advantages for treating different conditions. SUBJECTS AND METHODS

Design

This was a randomized, comparative observation experiment.

Time and setting

The experiment was performed in the Imaging Center of Nanfang Hospital, Guangdong Province, China, from June to September 2009.

Su bjects

The subjects were 31 healthy volunteers from different universities in Guangzhou City, China (16 males, 15 females) with an average age of 22.83 ± 2.32 years old, an average weight of 55.33 ± 8.44 kg, and an average height of 165.42 ± 9.61 cm. We used several inclusion criteria to ensure that all participants: (1) were undergraduate/postgraduate students from a

non-medical specialty; (2) ate regular meals, did not smoke cigarettes or consume tea and coffee, had normal sleeping patterns, and had a normal body stature (3) right-handed; (4) exhibited satisfactory results in a screening test conducted 3 months prior to the experiment (all volunteers received a pre-experiment testing the effects of response/sham acupuncture needling at true/sham acupoints).

The exclusion criteria were as follows: subjects (1) suffering from pain (including dysmenorrhea), depression or mental symptoms in the past 3 months; (2) suffering from congenital diseases, psychiatric diseases, central/peripheral nervous system diseases, endocrinal diseases, immunological diseases, and problems with the heart, liver, and kidney; (3) suffering from

plate-reduction, hemophilia or coagulation disorders; (4) receiving acupuncture treatment in the past 3 months; (5) non-responders or over-sensitive-responders screened with true/sham needling at true/sham acupoints. Informed consent was obtained from all volunteers before the experiment, and the protocol was devised in strict accordance with the Administrative Regulations on Medical Institution, formulated by the State Council of the People’s Republic of China[13].

Methods

Needling manipulation

All subjects underwent cutaneous acupuncture at each

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acupoint at the first day of experiment, followed by routine acupuncture 2 weeks later. The acupuncture was performed by one physician.

Routine acupuncture: four acupoints, Neiguan, Waiguan, Zhigou and Yanglingquan, were selected at the right side according to the Science of Acupuncture and Moxibustion[14]. Local skin was routinely sterilized with iodine tincture and ethanol. The base of acupuncture trocar (Dongbang AcuPrime, Birmingham, UK) was attached to the local skin, and the trocar handle was tapped softly using the index finger. The sheath was removed, and the needle was inserted vertically to a depth of 15 ± 2 mm. After needling sensitivity was determined[15], the physician manually stimulated the point with even manipulation of the needle by twirling the needling ± 180° and 60 times/min. The stimulation was designed with the block procedure[16-18] of alternating twirling and non-twirling for 30 seconds each, and the stimulation lasted for a total of 4 minutes[19].

Cutaneous acupuncture: Acupoint selection, location, and skin sterilization were performed as the above description. The sham acupuncture trocar (Dongbang AcuPrime), and 0.3 cm × 40.0 cm silver needles (Beijing Zhongyan Taihe Medicine Co., Ltd., China) were used. The base of trocar was attached to the local skin, and the trocar handle was tapped softly using the index finger, pressed to a depth of 1 mm. After needling sensitivity was determined, the physician manually stimulated the point with even manipulation of the needle by twirling the needling ± 180° and 60 times/min. The stimulation was designed with the block procedure of alternating twirling and non-twirling for 30 seconds each, and the stimulation lasted for a total of 4 minutes.

fMRI scan

At the same time as the acupuncture, scanning experiments were carried out with a 1.5T whole body MRI scanner (GE Signal, Fairfield, CT, USA), with a standard head coil. Each subjects’ eyes were closed and the ears were blocked. The first step was a T1 spin echo (SE) sequence scan, with repetition time (TR) of 500 ms, echo time (TE) of 16 ms, matrix 256 × 256, field of view (FOV) 240 mm × 240 mm and 5.0 mm a layer. The second step comprised a blood oxygenation level-dependent scan, with a gradient echo planar imaging sequence, with TR

3 000 ms/TE 50 ms, flip angle 90°, FOV 240 mm ×

240 mm, matrix 64 × 64 and 5.0 mm per layer.

Data analysis

Functool software (3135 Easton Turnpike Fairfield, CT 06828-0001, GE, USA) was used to process the images, and correlation coefficients were obtained. ROIs used for analyses included the bilateral frontal lobe, parietal lobe, temporal lobe, occipital lobe, insular lobe, hippocampus, parahippocampal gyrus, cingulate gyrus, basic ganglion, pons, and cerebellum. The activating areas (continuous 4 pixels, correlation coefficient ≥ 0.6) were counted in each ROI.

Statistical analysis

Measurement data were expressed as mean ± SD. The rate of activation, the number of activated areas, and the average intensity of the activation in each ROI were compared among the groups using SAS 9.13 software (SAS Institute Inc., Cary, NC, USA). The rate of activation and the intensity of activation were compared with a corresponding rank test. A value of P < 0.05 was considered statistically significant.

Author contributions:Yong Huang conceived and coordinated the study. Yong Huang and Yangjia Lu participated in the design of the study and wrote the paper. Junxian Wu and Yanqi Zou performed the acupuncture stimulation and organized the fMRI scan. Baoci Shan performed the fMRI data analysis with SPM2 and SAS. Yangjia Lu and Jiarong Chen took the charge of correction.

Conflicts of interest:None declared.

Funding:The project was supported by the National Basic Research Program of China (973 Program), No.

2006CB504505; the National Natural Science Foundation of China, No. 90709027.

Ethical approval:This research was granted permission by the Ethics Committee of the First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, China, and registered on a clinical trial website (Trial registration number: ChiCTRNRC00000255).

Acknowledgments:We thank Yanping Chen, Chief physician of MR Department, Nanfang Hospital, Guangdong Province, for technical support. We also thank Junqi Chen, Department of Acupuncture, Traditional Chinese Medicine School of Southern Medical University, Guangdong province, China, for help in enlisting volunteers for the study.

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(Edited by Zhang N, Guo Y/Su LL/Wang L)

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