O081 Neural aperiodic activity as a novel objective measure of wakefulness in patients undergoing a maintenance of wakefulness test

Abstract Background The maintenance of wakefulness test (MWT) measures the ability of an individual to stay awake and is used to assess treatment response for conditions of hypersomnolence. The MWT is a laborious test with a strict and standardised protocol. The interpretation of a MWT and what is deemed ‘normal’ is also fraught with debate. Wake and sleep states are characterised by oscillatory activity on EEG namely delta, theta, alpha, beta and gamma. There is also a less utilised non-oscillatory component of background neural activity (aperiodic activity) which can be calculated from the EEG. There is emerging evidence that shows clinical associations of aperiodic activity with cognition, visuomotor learning, schizophrenia and anaesthesia. We aim to determine if there is a relationship between EEG aperiodic activity and the ability of an individual to maintain wakefulness. Methods All patients who underwent a MWT from 2010 to 2023 will be included. Clinical data including demographics, comorbidities and mean sleep latency will be extracted from the sleep study database of the Royal Adelaide Hospital. Raw EEG data will be obtained from the ProFusion Study Manager software. Statistical analysis (linear mixed models) will be performed to determine if there is a correlation between the aperiodic exponent and the mean sleep latency. Progress Awaiting ethics committee approval Intended outcome To demonstrate that a longer mean sleep latency in the MWT will be associated with a higher aperiodic exponent which could lead to further research into the utility of aperiodic activity as a novel measure of wakefulness.