Regional homogeneity abnormalities in patients with interictal migraine without aura: a resting-state study Dahua Yu a,b , Kai Yuan a , Ling Zhao c , Limei Zhao a , Minghao Dong a , Peng Liu a , Guihong Wang a,d , Jixin Liu a , Jinbo Sun a , Guangyu Zhou a , Karen M. von Deneen a , Fanrong Liang c , Wei Qin a * and Jie Tian a,e * Previous studies have provided evidence of structural and task-related functional changes in the brains of patients with migraine without aura. Resting-state brain activity in patients with migraine provides clues to the pathophys- iology of the disease. However, few studies have focused on the resting-state abnormalities in patients with migraine without aura. In the current study, we employed a data-driven method, regional homogeneity (ReHo), to analyze the local features of spontaneous brain activity in patients with migraine without aura during the resting state. Twenty-six patients with migraine without aura and 26 age-, education- and gender-matched healthy volunteers participated in this study. Compared with healthy controls, patients with migraine without aura showed a significant decrease in ReHo values in the right rostral anterior cingulate cortex (rACC), the prefrontal cortex (PFC), the orbitofrontal cortex (OFC) and the supplementary motor area (SMA). In addition, we found that ReHo values were negatively correlated with the duration of disease in the right rACC and PFC. Our results suggest that the resting-state abnormalities of these regions may be associated with functional impairments in pain processing in patients with migraine without aura. We hope that our results will improve the understanding of migraine. Copyright © 2011 John Wiley & Sons, Ltd. Keywords: migraine without aura; regional homogeneity (ReHo); resting state; functional MRI (fMRI); supplementary motor area (SMA); prefrontal cortex (PFC); rostral anterior cingulate cortex (rACC); orbitofrontal cortex (OFC) INTRODUCTION Migraine is an idiopathic headache disorder and causes a significant individual and social burden. Frequent migraine attacks may produce pain, sensitivity and productivity loss, and even increase the risk of subtle lesions in certain brain regions (1–3). With the help of neuroimaging technology, our perception of migraine has transformed from a vascular to a neurovascular and, most recently, to a central nervous system disorder (4). Advanced neuroimaging approaches have been employed to investigate structural and functional brain changes in patients with migraine (4,5). Voxel-based morphometric studies of migraine have reported significant gray matter reduction in the cingulate cortex, insula, superior temporal gyrus, orbitofrontal cortex (OFC), inferior frontal gyrus and precentral gyrus in patients with migraine (6–9). Furthermore, gray matter reduction is correlated with both attack frequency and headache duration in patients with migraine (6,9). Facilitated by the diffusion tensor imaging technique, DaSilva et al. (10) reported lower fractional anisotropy in the ventroposterior medial thalamus and the corona radiate of the trigeminal somatosensory and modulatory pain systems in patients with migraine with and without aura and in the periaqueductal gray matter in patients with migraine without aura. Moreover, task-related functional MRI (fMRI) studies have also revealed abnormal activation of some brain regions associated with pain-related information processing in patients with migraine, such as the anterior cingulate cortex * Correspondence to: J. Tian, Life Sciences Research Center, School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi 710071, China. E-mail: tian@ieee.org W. Qin, Life Sciences Research Center, School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi 710071, China. E-mail: chinwei@mail.xidian.edu.cn a D. Yu, K. Yuan, L. Zhao, M. Dong, P. Liu, G. Wang, J. Liu, J. Sun, G. Zhou, K. M. Deneen, J. Tian Life Sciences Research Center, School of Life Sciences and Technology, Xidian University, Xi’an, Shaanxi, China b D. Yu Information Processing Laboratory, School of Information Engineering, Inner Mongolia University of Science and Technology, Baotou, Inner Mongolia, China c L. Zhao, F. Liang The 3 rd Teaching Hospital, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China d G. Wang Department of Applied Mathematics, Xidian University, Xi’an, Shaanxi, China e J. Tian Institute of Automation, Chinese Academy of Sciences, Beijing, China Abbreviations used: ACC, anterior cingulate cortex; fMRI, functional MRI; FWE, family-wise error; KCC, Kendall’s coefficient of concordance; OFC, orbitofrontal cortex; PFC, prefrontal cortex; rACC, rostral anterior cingulate cortex; ReHo, regional homogeneity; SMA, supplementary motor area; SPM5, Statistical Parametric Mapping 5. Research Article Received: 15 July 2011, Revised: 27 August 2011, Accepted: 9 September 2011, Published online in Wiley Online Library: 2011 (wileyonlinelibrary.com) DOI: 10.1002/nbm.1796 NMR Biomed. (2011) Copyright © 2011 John Wiley & Sons, Ltd.