Meta-analysis Of Voxel-based Morphometry Studies In Rapid Eye Movement Sleep Behavior Disorder

Background:Studies about voxel-based morphometry(VBM)of rapid eye movement sleep behavior disorder(RBD)showed gray matter volume(GMV)changes in recent years.However,several studies of whole-brain VBM analysis yielded contradictory results.Objective:A meta-analysis was conducted on several whole-brain VBM studies of RBD,which could emerge more reliable results.The pathophysiological mechanism and clinical features of RBD deeply were explored by focusing on the brain regions of GMV changes.The correlation was analyzed between RBD and Parkinson's disease(PD)Method:Related studies were searched on PubMed,ISI Web of Science,Embase and Medline databases carefully and comprehensively in the past 10 years.3D coordinates were picked up from clusters with significant differences and their T value.The meta-analysis was conducted on signed differential mapping(SDM;http://www.sdmproject.com/software/)software.The study was divided into two groups.Meta-analysis of whole-brain VBM study in patients with RBD and healthy controls(HC)was performed in Group 1 and patients with PDRBD+and PDRBD-was performed in Group 2Results:Compared with HC,patients with RBD showed significant GMV increasing in left hippocampus an GMV decresing in left middle frontal gyrus,right gyrus rectus and bilateral corpus callosum in group 1.Compared with PDRBD+,PDRBD-showed significant GMV increasing in right corpus callosum an GMV decresing in left middle temporal gyrus,left inferior fronto-occipital fasciculus(IFOF)and right rolandic operculum in group 2Conclusion:1.Prefrontal-hippocampal pathway may closely relate to non-motor symptoms of RBD.The intrinsic pathophysiological mechanism may involve atrophy of prefrontal cortical and excessive activation of hippocampal glutamate signal.Hippocampus abnormal may be early biological predictor for RBD develop into PD.Pathways involved in motor symptoms of RBD still require further investigation.2.Compared with PDRBD-,PDRBD+group showed broader significant GMV changes,which may related to the severity of PD.3.PD and RBD are both involve in multiple systems and exist certain overlap in anatomy and pathophysiology,which may performance different period of the same disease.