Acupuncture is a commonly used therapy for treating functional diarrhea (FD), although there is limited knowledge on the mechanism. The objectives of this study were to investigate the differences in brain activities elicited by acupuncture between FD patients and healthy controls (HC) so as to explore the possible mechanism. Eighteen FD patients and eighteen HC received 10 sessions of acupuncture treatment at ST25 acupoints. Functional magnetic resonance imaging (fMRI) scans were, respectively, performed before and after acupuncture. The defecation frequency, Bristol stool form scale (SBFS), and MOS 36-item Short Healthy Survey (SF-36) were employed to evaluate the clinical efficacy. After acupuncture, the FD patients showed a significant decrease in defecation frequency and BSFS score. The regional homogeneity (ReHo) map showed a decrease in the paracentral lobule and postcentral gyrus, and an increase in the angular gyrus, insula, anterior cingulate cortex (ACC), and precuneus in the FD group. Moreover, the changes in ReHo values in the ACC were correlated with the reduction in defecation frequency. Decreasing functional connectivity among the ACC, insula, thalamus, and orbital frontal cortex only existed in the FD group. Conclusively, acupuncture alleviated defecation frequency and improved stool formation in FD patients. The efficacy might result from the regulation of the homeostasis afferent processing network. 1. Introduction Functional diarrhea (FD), one of the functional gastrointestinal disorders (FGID), is characterized by chronic diarrhea in the absence of structural or biochemical abnormalities that explain the symptoms . According to the 2006 Rome III criteria, FD is defined as loose or watery stools without pain occurring in at least 75% of the stools . The prevalence of FD ranges from 1.72% to 3.7% [3–5]. FD significantly influences the quality life of patients and consumes many healthcare resources . Because of the unclear etiology and pathogenesis, the therapeutic options for FD are limited. As a result, complementary or alternative therapies are attractive to both patients and practitioners. Acupuncture, an important traditional Chinese medicine (TCM) therapy, has been used to treat gastrointestinal symptoms for centuries in China. Now it has been increasingly accepted as a complementary and alternative treatment for functional gastrointestinal disorders in western countries [7, 8]. ST25 (Tianshu), an important acupoint in the stomach meridian of the Foot Yangming, is commonly used to treat intestinal illnesses, such as
C. K. Porter, R. Gormley, D. R. Tribble, B. D. Cash, and M. S. Riddle, “The incidence and gastrointestinal infectious risk of functional gastrointestinal disorders in a healthy US adult population,” American Journal of Gastroenterology, vol. 106, no. 1, pp. 130–138, 2011.
I. Perveen and M. Hasan, “Prevalence and health-care seeking pattern of patients with functional diarrhoea in an urban community of Bangladesh,” Mymensingh Medical Journal, vol. 19, no. 1, pp. 85–88, 2010.
J.-J. Wang, W.-H. Wang, and X.-M. Ruan, “Effect of abdominal needling in treating post-cardiosurgical operational gastrointestinal dysfunction,” Chinese Journal of Integrated Traditional and Western Medicine, vol. 28, no. 4, pp. 310–313, 2008.
H.-R. Liu, X.-M. Wang, E.-H. Zhou et al., “Acupuncture at both ST25 and ST37 improves the pain threshold of chronic visceral hypersensitivity rats,” Neurochemical Research, vol. 34, no. 11, pp. 1914–1918, 2009.
M. Xiao-Peng, L.-Y. Tan, Y. Yang et al., “Effect of electro-acupuncture on substance P, its receptor and corticotropin-releasing hormone in rats with irritable bowel syndrome,” World Journal of Gastroenterology, vol. 15, no. 41, pp. 5211–5217, 2009.
E. A. Mayer, B. D. Naliboff, and A. D. B. Craig, “Neuroimaging of the brain-gut axis: from basic understanding to treatment of functional GI disorders,” Gastroenterology, vol. 131, no. 6, pp. 1925–1942, 2006.
M. P. Jones, J. B. Dilley, D. Drossman, and M. D. Crowell, “Brain-gut connections in functional GI disorders: anatomic and physiologic relationships,” Neurogastroenterology and Motility, vol. 18, no. 2, pp. 91–103, 2006.
K. K. S. Hui, O. Marina, J. Liu, B. R. Rosen, and K. K. Kwong, “Acupuncture, the limbic system, and the anticorrelated networks of the brain,” Autonomic Neuroscience, vol. 157, no. 1-2, pp. 81–90, 2010.
B. Biswal, F. Z. Yetkin, V. M. Haughton, and J. S. Hyde, “Functional connectivity in the motor cortex of resting human brain using echo-planar MRI,” Magnetic Resonance in Medicine, vol. 34, no. 4, pp. 537–541, 1995.
Y. Yuan, Z. Zhang, F. Bai et al., “Abnormal neural activity in the patients with remitted geriatric depression: a resting-state functional magnetic resonance imaging study,” Journal of Affective Disorders, vol. 111, no. 2-3, pp. 145–152, 2008.
K. J. Friston, C. D. Frith, P. F. Liddle, and R. S. J. Frackowiak, “Functional connectivity: the principal-component analysis of large (PET) data sets,” Journal of Cerebral Blood Flow and Metabolism, vol. 13, no. 1, pp. 5–14, 1993.
D. Cordes, V. M. Haughton, K. Arfanakis et al., “Mapping functionally related regions of brain with functional connectivity MR imaging,” American Journal of Neuroradiology, vol. 21, no. 9, pp. 1636–1644, 2000.
S. Lui, W. Deng, X. Huang et al., “Association of cerebral deficits with clinical symptoms in antipsychotic-naive first-episode schizophrenia: an optimized voxel-based morphometry and resting state functional connectivity study,” American Journal of Psychiatry, vol. 166, no. 2, pp. 196–205, 2009.
C. M. Portas, G. Rees, A. M. Howseman, O. Josephs, R. Turner, and C. D. Frith, “A specific role for the thalamus in mediating the interaction of attention and arousal in humans,” Journal of Neuroscience, vol. 18, no. 21, pp. 8979–8989, 1998.
Z. Cao, X. Wu, S. Chen et al., “Anterior cingulate cortex modulates visceral pain as measured by visceromotor responses in viscerally hypersensitive rats,” Gastroenterology, vol. 134, no. 2, pp. 535–543, 2008.
U. Blankstein, J. Chen, N. E. Diamant, and K. D. Davis, “Altered brain structure in irritable bowel syndrome: potential contributions of pre-existing and disease-driven factors,” Gastroenterology, vol. 138, no. 5, pp. 1783–1789, 2010.
K. D. Davis, G. Pope, J. Chen, C. L. Kwan, A. P. Crawley, and N. E. Diamant, “Cortical thinning in IBS: implications for homeostatic, attention, and pain processing,” Neurology, vol. 70, no. 2, pp. 153–154, 2008.
R. L. Buckner, J. R. Andrews-Hanna, and D. L. Schacter, “The brain's default network: anatomy, function, and relevance to disease,” Annals of the New York Academy of Sciences, vol. 1124, pp. 1–38, 2008.
M. D. Greicius, G. Srivastava, A. L. Reiss, and V. Menon, “Default-mode network activity distinguishes Alzheimer's disease from healthy aging: evidence from functional MRI,” Proceedings of the National Academy of Sciences of the United States of America, vol. 101, no. 13, pp. 4637–4642, 2004.
A. G. Garrity, G. D. Pearlson, K. McKiernan, D. Lloyd, K. A. Kiehl, and V. D. Calhoun, “Aberrant “default mode” functional connectivity in schizophrenia,” American Journal of Psychiatry, vol. 164, no. 3, pp. 450–457, 2007.
S. Grimm, P. Boesiger, J. Beck et al., “Altered negative BOLD responses in the default-mode network during emotion processing in depressed subjects,” Neuropsychopharmacology, vol. 34, no. 4, pp. 932–943, 2009.
L. Q. Uddin, A. M. C. Kelly, B. B. Biswal et al., “Network homogeneity reveals decreased integrity of default-mode network in ADHD,” Journal of Neuroscience Methods, vol. 169, no. 1, pp. 249–254, 2008.
M. N. Baliki, P. Y. Geha, A. V. Apkarian, and D. R. Chialvo, “Beyond feeling: chronic pain hurts the brain, disrupting the default-mode network dynamics,” Journal of Neuroscience, vol. 28, no. 6, pp. 1398–1403, 2008.
L. Koski and T. Paus, “Functional connectivity of the anterior cingulate cortex within the human frontal lobe: a brain-mapping meta-analysis,” Experimental Brain Research, vol. 133, no. 1, pp. 55–65, 2000.