Increased neural motor activation and functional reorganization in patients with idiopathic rapid eye movement sleep behavior disorder. (November 2021)

• Record Type: Journal Article
• Authors: Brcina, Nikolina; Hohenfeld, Christian; Heidbreder, Anna; Mirzazade, Shahram; Krahe, Janna; Wojtala, Jennifer; Binkofski, Ferdinand; Schulz, Jörg B.; Schiefer, Johannes; Reetz, Kathrin; Dogan, Imis
• Is Part Of: Parkinsonism & related disorders. Volume 92(2021)
• Page Start: 76
• Page End: 82
• Publication Date: 2021-11
• Subjects: RBD -- REM sleep behavior disorder -- fMRI -- Neuroimaging -- Connectivity -- VBM; Parkinson's disease -- Periodicals; Movement disorders -- Periodicals; Movement Disorders -- Periodicals; Nerve Degeneration -- Periodicals; Nervous System Diseases -- Periodicals; Parkinson Disease -- Periodicals; Tremor -- Periodicals; Parkinson, Maladie de -- Périodiques; Parkinson's disease; 616.833
• DOI: 10.1016/j.parkreldis.2021.10.019
• Languages: English
• ISSNs: 1353-8020

Abstract

Abstract: Introduction: Altered brain activity and functional reorganization patterns during self-initiated movements have been reported in early pre-motor and motor stages of Parkinson's disease. The aim of this study was to investigate whether similar alterations can be observed in patients with idiopathic REM-sleep behavior disorder (RBD). Methods: 13 polysomnography-confirmed male and right-handed RBD patients and 13 healthy controls underwent a bilateral hand-movement fMRI task including internally selected (INT) and externally-guided (EXT) movement conditions for each hand. We examined functional activity and connectivity differences between groups and task-conditions, structural differences using voxel-based morphometry, as well as associations between functional activity and clinical variables. Results: No group differences were observed in fMRI-task performance or in voxel-based morphometry. Both groups showed faster reaction times and exhibited greater neural activation when movements were internally selected compared to externally-guided tasks. Compared to controls, RBD patients displayed stronger activation in the dorsolateral prefrontal cortex and primary somatosensory cortex during INT-tasks, and in the right fronto-insular cortex during EXT-tasks performed with the non-dominant hand. Stronger activation in RBD patients was associated with cognitive and olfactory impairment. Connectivity analysis demonstrated overall less interregional coupling in patients compared to controls. In particular, patients showed reduced temporo-cerebellar, occipito-cerebellar and intra-cerebellar connectivity, but stronger connectivity in fronto-cerebellar and fronto-occipital pathways. Conclusion: The observed stronger activation during hand-movement tasks and connectivity changes in RBD may reflect early compensatory and reorganization patterns in order to preserve motor functioning. Our findings may contribute to a better understanding and prognosis of prodromal stages of α-synucleinopathies. Highlights: RBD patients vs. controls showed increased brain activation in hand movement tasks. Greater brain activation in RBD correlated with cognitive and olfactory impairment. Patients showed reduced task-based connectivity, but increased long-range coupling. Our findings indicate compensation strategies in RBD similar to Parkinson's disease. This study provides new insight into prodromal stages of α-synucleinopathies.