August 2017 | Volume 8 | Article 374 1 ORIGINAL RESEARCH published: 03 August 2017 doi: 10.3389/fneur.2017.00374 Frontiers in Neurology | www.frontiersin.org Edited by: Mark Richardson, King’s College London, United Kingdom Reviewed by: Qianfa Long, Xi’an Jiao Tong University, China Luiz Eduardo Betting, Universidade Estadual Paulista Júlio Mesquita Filho, Brazil *Correspondence: Qian Chen chenqian68@126.com; Wenhua Huang huangwenhua2009@sina.com † These authors have contributed equally to this work. Specialty section: This article was submitted to Epilepsy, a section of the journal Frontiers in Neurology Received: 11 March 2017 Accepted: 17 July 2017 Published: 03 August 2017 Citation: Li Y, Tan Z, Wang J, Wang Y, Gan Y, Wen F, Chen Q, Abbott D, Wong KKL and Huang W (2017) Alterations in Spontaneous Brain Activity and Functional Network Reorganization following Surgery in Children with Medically Refractory Epilepsy: A Resting-State Functional Magnetic Resonance Imaging Study. Front. Neurol. 8:374. doi: 10.3389/fneur.2017.00374 Alterations in Spontaneous Brain Activity and Functional Network Reorganization following Surgery in Children with Medically Refractory Epilepsy: A Resting-State Functional Magnetic Resonance Imaging Study Yongxin Li 1† , Zhen Tan 2† , Jianping Wang 3 , Ya Wang 1 , Yungen Gan 2 , Feiqiu Wen 2 , Qian Chen 2 *, Derek Abbott 4 , Kelvin K. L. Wong 5 and Wenhua Huang 1 * 1 Guangdong Provincial Key Laboratory of Medical Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China, 2 Department of Pediatric Neurosurgery, Shenzhen Children’s Hospital, Shenzhen, China, 3 The Second Afiliated Hospital of Guangzhou Medical University, Guangzhou, China, 4 Centre for Biomedical Engineering, School of Electrical and Electronic Engineering, University of Adelaide, Adelaide, SA, Australia, 5 School of Medicine, Western Sydney University, Campbelltown, NSW, Australia For some patients with medically refractory epilepsy (MRE), surgery is a safe and effective treatment for controlling epilepsy. However, the functional consequences of such sur- gery on brain activity and connectivity in children remain unknown. In the present study, we carried out a longitudinal study using resting-state functional magnetic resonance imaging in 10 children with MRE before and again at a mean of 79 days after surgery, as well as in a group of 28 healthy controls. Compared with the controls, children with epilepsy exhibited abnormalities in intrinsic activity in the thalamus, putamen, pallidum, insula, hippocampus, cerebellum, and cingulate gyrus both before and after surgery. Longitudinal analyses showed that the amplitude of low frequency luctuations (ALFF) increased in the parietal–frontal cortex and decreased in the deep nuclei from pre- to post-surgery. The percentage changes in ALFF values in the deep nuclei were positively correlated with the age of epilepsy onset. Functional connectivity (FC) analyses demon- strated a reorganization of FC architecture after surgery. These changes in brain activity and FC after surgery might indicate that the previously disrupted functional interactions were reorganized after surgery. All these results provide preliminary evidence that the age of epilepsy onset may have some potential to predict the outcome of brain functional reorganization after surgery in children with MRE. Keywords: medically refractory epilepsy, children, surgery, amplitude of low-frequency luctuation, functional connectivity INTRODUCTION Epilepsy is the second most common neurological disease worldwide. Currently, the mainstay of epilepsy management is therapy with antiepileptic drugs. However, previous studies have shown that up to one-third of all patients with epilepsy are resistant to medical treatment (1). It is now widely accepted that epilepsy surgery is a safe and efective treatment in children diagnosed with