TY - JOUR T1 - <strong>Regional brain cholinergic system changes in Parkinson disease with RBD: an <sup>18</sup>F-FEOBV PET study</strong> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1496 LP - 1496 VL - 60 IS - supplement 1 AU - Prabesh Kanel AU - Martijn Muller AU - Nicolaas Bohnen Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/1496.abstract N2 - 1496Objectives: To apply spatial covariance analysis (SCA) and voxel-based analysis of 18F-FEOBV vesicular acetylcholine transporter (VAChT) brain PET to understand the regional brain cholinergic system changes associated with REM sleep behavior disorder (RBD) in patients with Parkinson disease (PD). Methods: A total of 93 PD subjects without dementia (71M/22F; age:67.7±7.9y; modified Hoehn &amp; Yahr stage: 2.4±0.6; duration of disease: 5.9±4.5y; MoCA total score: 26.3±3.3; MDS-UPDRS Part III total score: 32.9±12.0) underwent clinical assessment and 18F-FEOBV brain PET imaging. The presence of RBD symptoms was determined using the Mayo Sleep Questionnaire. RBD and non-RBD groups were compared using multivariate spatial covariance analysis based on the scaled subprofile model (SSM) using covariance analysis software module (http://www.nitrc.org/projects/gcva_pca/) and voxel-based independent t-test using software suite (https://www.fil.ion.ucl.ac.uk/spm/software/spm12/) on a spatially normalized parametric image. Results: Fifty PD subjects reported a history of RBD symptoms. There was no difference between the groups in term of age, disease duration, and gender. There was a borderline significant difference in Hoehn &amp; Yahr stage (t=-1.96; p=0.0534). The subject scaling factor, a measure of overall SSM/PCA expression was significantly different between the two groups (t =-6.032; p&amp;lt;0.0001). SSM/PCA covariance analysis showed relatively reduced VAChT binding in bilateral peri-Sylvian regions (|z|&amp;gt;2) in the RBD compared to non-RBD group. In contrast, relatively increased binding was observed in the right putamen, bilateral anterior cingulum, and right insula in RBD subjects (|z|&amp;gt;2). We observed similar results in a voxel-based independent t-test comparing absolute binding between the groups (uncorrected p&amp;lt;0.01). Conclusions: Our findings identify distinct brain regions with relatively increased or decreased VAChT binding in the RBD compared to the non-RBD PD group. These bidirectional changes may represent areas of compensatory and/or degenerating cholinergic terminal changes in RBD. Areas of decreased activity may explain the increased risk of dementia in PD patients with this parasomnia. ER -