Region of Interest Measurements of Structural Volumes in Patients with Parkinson's Disease, Atypical Parkinsonism, and REM Sleep Behavior Disorder: Baseline Measurements from a Prospective Longitudinal Study (P06.076)

Abstract

Objective: Measure baseline Magnetic Resonance Imaging (MRI) volumes of select anatomical structures in patients with Idiopathic Parkinson9s Disease (PD), Atypical Parkinsonism (PS), REM sleep behavior disorder (RBD), and healthy controls in a prospective longitudinal study. Background RBD is considered a subclinical neurodegenerative disorder that precedes the development of PD and PS by decades. Design/Methods: Region of interest baseline volumes of the olfactory bulb (OB), putamen, caudate, amygdala, hippocampus, and entorhinal gray were measured using 3T MRI for PD (N=12), PS (N=10), RBD (N=9), and Control (N=10) groups. OB volumes were measured manually while others were automatically calculated. Volumes were normalized for whole brain volume and converted to a percentage of total brain volume for each individual subject. Intragroup and intergroup differences were analyzed for significance using mean ± s.e.m. Results: Intragroup differences were significant for OB in the RBD group (p=0.050, Left=0.125±0.027, Right=0.102±0.022), putamen in the PD group (p=0.043, Left=2.240±0.085, Right=2.356±0.084), and amygdala in the PD, RBD, and control groups (p=0.010, Left=0.642±0.023, Right=0.697±0.021; p=0.003, Left=0.629±0.030, Right=0.688±0.034; p=0.020, Left=0.632±0.023, Right=0.696±0.029 respectively). There were significant intergroup differences in the normalized left caudate volume of PS versus RBD (p=0.0164, PS =1.839±0.1012, RBD =1.538±0.03923) and versus control (p=0.0318, PS =1.839±0.1012, Control=1.579±0.04756), normalized right caudate volume of PS versus control (p=0.0196, PS =1.828±0.09645, Control =1.536±0.06013), and normalized total caudate volumes of PS versus RBD (p=0.0209, PS =3.667±0.1954, RBD =3.099±0.08852) and versus control (p=0.0205, PS =3.667±0.1954, Control =3.116±0.09428). Conclusions: Preliminary baseline structural volumes are presented with intragroup differences found in the amygdala of PD, RBD, and control groups and also in the OB of RBD patients. Intergroup differences were found in the caudate volumes of the PS group versus RBD and controls. These measurements provide a baseline for evaluation over time and future correlation with behavioral and clinical measures. Disclosure: Dr. Copeland has nothing to disclose. Dr. Ellmore has nothing to disclose. Dr. Beurlot has nothing to disclose. Dr. Liang has nothing to disclose. Dr. Suescun has nothing to disclose. Dr. Furr-Stimming has nothing to disclose. Dr. Castriotta has nothing to disclose. Dr. Schiess has nothing to disclose.