0894 Impulsivity across early stages of synucleinopathy: from high-risk relatives, REM sleep behavior disorder to Parkinson’s disease

Abstract Introduction Increased impulsivity is a common neuropsychiatric feature in patients with Parkinson’s disease (PD), especially attributed to the use of dopaminergic medications. Interestingly, emerging evidence suggested that had changed drug-naïve PD patients. However, it remains unclear whether has been altered prodromal stage PD, namely isolated rapid eye movement sleep behavior disorder (iRBD) and their high-risk relatives. Methods This was cross-sectional study four groups subjects, including early drug-naive patients, iRBD first-degree relatives (iRBD-FDRs, group potential RBD features), controls. A panel neuropsychological computerized tasks, go/no-go task, four-choice serial reaction time task (4CSRTT), beads balloon analogue risk (BART) delay/effort discounting would measure various dimensions motor decisional impulsivity. Results total 331 subjects were recruited, 27 (mean age ± SD: 70.1 5.8 years, 77.8% man), 152 (67.2 6.6 77.6% 68 iRBD-FDRs (63.2 6.4 51.5% 84 controls (67.4 8.1years, 61.9% man). Early fewer numbers extracted 1 (P< 0.001) 2 making decisions pumps unexploded blue balloons BART than iRBD-FDRs, suggesting higher level reflection lower taking, respectively. In addition, more no-go errors (P=0.023), marginally response inhibition groups. premature responses 4CSRTT (P=0.008). The delay effort indexes comparable among Conclusion While taking decreased, actually increased These novel findings indicated complex construct already occurred at earlier (at iRBD) α-synucleinopathy, which will have implications for pathophysiology clinical management. Support (if any) supported by General Research Fund (14116119).