148 Longitudinal resting state changes in parkinson’s disease

Introduction There is currently no objective method of monitoring progression of Parkinson’s disease (PD). We demonstrate resting-state magnetic resonance imaging (rs-MRI) as a potential biomarker of PD progression. Methods 15 patients with idiopathic PD (age at baseline: mean±std, 66.43±7.16 years; follow-up: 69.46±7.09; Male, 10; HY follow-up: 2.2±1.08) were recruited. Baseline and follow-up visits occurred 3.03± 0.18 years apart (Disease duration baseline: 3.61±1.33; follow-up: 6.64±1.38). (Disease severity: MDS-UPDRS-III baseline 27.17±15.28; follow-up: 35.53±16.45). Image acquisition rs-MRI was performed using 3T GE 750 MRI; 32-channel head coil; TR=2000ms; TE=30ms; Eyes open, medicated. Analysis An in-house optimised standardised pipeline was used based on FSL (1), MRIQC algorithm (2). Functional connectivity (FC) was derived from the following seeds (5 mm radius): primary motor cortex (M1), anterior and posterior putamen, caudate, supplementary motor area (SMA) and substantia nigra (SN). (Coordinates determined using AAL template and FSL atlas). Z score >2.3 used to report significance in a paired t test. Results Overall, we found greater FC at baseline vs follow-up in the motor cortex and SN, while FC with the posterior putamen and SMA showed a dissociated pattern of increased and decreased FC changes with disease progression. Conclusion Our preliminary analysis of a longitudinal dataset of >2 years mean duration show promising change patterns in line with progressive motor cortex and SN disconnection and complex putaminal and SMA disconnection.