Event-related potentials in idiopathic rapid eye movements sleep behaviour disorder

Objective To assess psychophysiological parameters in idiopathic rapid eye movements sleep behaviour disorder (RBD), in order to identify possible markers for pre or sub-clinical cognitive abnormalities. Methods Sixteen consecutive unmedicated patients with idiopathic RBD and 16 age- and sex-matched controls performed active and passive auditory oddball paradigms and an attentional test. Results There were no significant between-group latency and amplitude differences. The two groups showed a difference in the inter-peak interval between N100 and P200 in the active condition. A significant correlation between attentional matrices scores and N100 amplitude at Fz and Cz to standard stimuli in the passive condition was found in controls but not in patients. Conclusions In RBD there are minimal event-related potentials (ERPs) abnormalities involving the early stages of information processing. Significance ERPs are not sensitive to pre or sub-clinical cognitive abnormalities in RBD. In alternative, these findings might support the existence of a truly idiopathic RBD syndrome.