Gray Matter Alterations in Parkinson's Disease With Rapid Eye Movement Sleep Behavior Disorder: A Meta-Analysis of Voxel-Based Morphometry Studies

Abstract

Background: Gray matter (GM) alterations in Parkinson's disease (PD) patients with rapid eye movement sleep behavior disorder (RBD) have been demonstrated in many neuroimaging studies using voxel-based morphometry (VBM). However, the inconsistent findings between studies cannot be applied to clinical practice as a neuroimaging biomarker. We performed a meta-analysis of VBM studies at a whole-brain level to investigate GM differences between PD patients with and without RBD. Methods: A systematic search was conducted in PubMed, Embase, and Web of Science from inception to November 2019 to identify eligible VBM studies. We adopted the latest Seed-based d Mapping with Permutation of Subject Images technique to quantitatively estimate the difference of regional GM volume between PD patients with and without RBD. Results: We included five studies comprising 105 PD patients with RBD and 140 PD patients without RBD. The pooled meta-analysis revealed that PD patients with RBD showed a significant reduction of GM volume in the right superior temporal gyrus (STG) compared with those without RBD. This result was confirmed to be robust by the jackknife sensitivity analysis. Conclusion: Our finding shows significantly and robustly reduced GM volume in the right STG in PD patients with RBD, preliminarily suggesting the association of GM atrophy in this brain region with the occurrence of RBD in PD patients.

Neuroanatomical findings in isolated REM sleep behavior disorder and early Parkinson’s disease: a Voxel-based morphometry study

“…Decreased cortical thickness in temporal cortices, including fusiform area, has been found in PD/RBD compared to PD patients without RBD (Rahayel et al, 2019 ) and in iRBD compared to HC (Campabadal et al, 2019 ; Rahayel et al, 2015 , 2018a , b ; Unger et al, 2010 ). Accordingly, a recent voxel-wise metanalysis including VBM studies, showed a significantly reduced GM volume in the right superior temporal gyrus in PD/RBD, compared to PD without RBD, suggesting the association between the occurrence of RBD in PD patients and atrophy in the temporal areas (Yang et al, 2020 ). In agreement with these findings, perfusion and metabolism imaging studies demonstrated the presence of changes in metabolism in temporal areas, in RBD patients compared to HC (Ge et al, 2015 ; Mazza et al, 2006 ; Vendette et al, 2011 ).…”

“…Temporal and limbic areas are found to be significantly activated during physiological REM sleep (Nir & Tononi, 2010 ); thus, these abnormalities could reflect a disruption of the normal atonia circuitry leading to the occurrence of RBD behaviors. On the other hand, temporal GM changes could be associated to the RBD-related clinical characteristics of PD patients, including cognitive impairment, spatial information processing and mood abnormalities (Yang et al, 2020 ). The presence of a similar pattern of structural abnormalities involving temporal regions in iRBD and PD/RBD groups has been previously faced by Pereira and coll (Pereira et al, 2019 ) suggesting the presence of a high prevalence of future iRBD to PD converters in their sample, meaning that subtle changes were already present in patients with iRBD (Pereira et al, 2019 ).…”

Gray Matter Abnormalities in Myotonic Dystrophy Type 1: A Voxel-Wise Meta-Analysis

“…We used SDM-PSI version 6.21 to perform an intelligent voxel meta-analysis of GMV differences in brain regions between patients with DM1 and HCs. The meta-analysis of VBM studies is described in detail in the software tutorial ( www.sdmproject.com ) and previous studies ( 16 , 19 ). In this study, we first established a file containing sample size, clinical data, and statistical thresholds.…”

“…Seed-based d Mapping (SDM) is a statistical technique for meta-analyses studies on differences in brain activity or structure in which neuroimaging technique such as fMRI, VBM, DTI, or PET is used. The methods have been fully validated in many studies ( 15 , 16 ). SDM with Permutation of Subject Images (SDM-PSI) is a new algorithm that can use standard voxel-wise tests and conducts a standard PSI.…”