Brain Atrophy of Secondary REM-Sleep Behavior Disorder in Neurodegenerative Disease

Abstract

Background Rapid eye movement sleep behavior disorder (RBD) may present as an early manifestation of an evolving neurodegenerative disorder with alpha-synucleinopathy. Objective We investigated that dementia with RBD might show distinctive cortical atrophic patterns. Methods A total of 31 patients with idiopathic Parkinson’s disease (IPD), 23 with clinically probable Alzheimer’s disease (AD), and 36 healthy controls participated in this study. Patients with AD and IPD were divided into two groups according to results of polysomnography and rated with a validated Korean version of the RBD screening questionnaire (RBDSQ-K), which covers the clinical features of RBD. Voxel-based morphometry was adapted for detection of regional brain atrophy among groups of subjects. Results Scores on RBDSQ-K were higher in the IPD group (3.54 ± 2.8) than in any other group (AD, 2.94 ± 2.4; healthy controls, 2.31 ± 1.9). Atrophic changes according to RBDSQ-K scores were characteristically in the posterior part of the brain and brain stem, including the hypothalamus and posterior temporal region including the hippocampus and bilateral occipital lobe. AD patients with RBD showed more specialized atrophic patterns distributed in the posterior and inferior parts of the brain including the bilateral temporal and occipital cortices compared to groups without RBD. The IPD group with RBD showed right temporal cortical atrophic changes. Conclusion The group of patients with neurodegenerative diseases and RBD showed distinctive brain atrophy patterns, especially in the posterior and inferior cortices. These results suggest that patients diagnosed with clinically probable AD or IPD might have mixed pathologies including α-synucleinopathy.

Altered Brain Functional Network in Parkinson Disease With Rapid Eye Movement Sleep Behavior Disorder

“…Some researchers successively explored structure changes in PD-RBD patients using voxel-based morphometry, diffusion tensor imaging and structural correlation network methods. They found PD-RBD has decreased volume in more or less cortical and subcortical structures such as thalamus, hippocampus, and cingulate cortex (6)(7)(8)(9)(10)(11)(12). In addition to brain structure, a few researchers also used the resting-state functional MRI (rs-fMRI) to search changes of brain function in PD-RBD.…”

Brain atrophy in Parkinson’s disease with polysomnography-confirmed REM sleep behavior disorder

“…Few studies have used voxel-based morphometry (VBM) to investigate RBD-related gray matter abnormalities in PD, with the most consistent finding being volume loss in the temporal lobes but with other findings including change in the cingulate cortex, posterior regions, and thalamus [7][8][9][10][11]. Another study used deformation-based morphometry (DBM), a technique shown to detect volume changes occurring in PD with better accuracy [12], and found abnormal volume in several cortical (anterior cingulate, olfactory areas) and subcortical (brainstem, cerebellum, thalamus, putamen, amygdala) regions in people with PD with RBD [13].…”

“…Another study used deformation-based morphometry (DBM), a technique shown to detect volume changes occurring in PD with better accuracy [12], and found abnormal volume in several cortical (anterior cingulate, olfactory areas) and subcortical (brainstem, cerebellum, thalamus, putamen, amygdala) regions in people with PD with RBD [13]. However, these studies have some methodological limitations, notably the use of screening questionnaires for RBD diagnosis [10,11,13], the use of statistical thresholds uncorrected for multiple comparisons [8,10,11], and absence of a healthy control group [10]. Furthermore, the techniques (VBM or DBM) used for analysis were limited by voxel-based resolution, resulting in a partial overview of structural abnormalities in this population.…”

Obstructive Sleep Apnea in Neurodegenerative Disorders: Current Evidence in Support of Benefit from Sleep Apnea Treatment

“…One recent study found that RBD is associated with changes in brain morphology similar to those found with OSA, namely cortical thinning in the frontal, temporal, and parietal cortices and the hippocampal region [187]. Earlier studies observed volume loss in the temporal lobes, cingulate, thalamus, and posterior regions of patients with PD and RBD [188][189][190][191]. However, most of these studies lacked a robust diagnostic method for RBD and comparisons with healthy controls.…”