Objective: Objective: To assess whether progression from isolated REM sleep behaviour disorder (iRBD), established Parkinson’s disease (PD) and Dementia with Lewy bodies (DLB) are accompanied by a gradient of changes in the power spectra during sleep which may serve as a biomarker of progression and indicator of pathology within the sleep circuitry.

Background: Background: Sleep disturbances are common among patients with Lewy body disorders¹. iRBD has been identified as a prodromal Lewy body condition with a significantly increased risk of conversion to either PD or DLB². Involvement of thalamic and brainstem structures involved in sleep regulation has been pathologically reported in these disorders. Changes in electrophysiological markers in sleep have been reported in iRBD³ and PD, although whether such changes worsen progressively and how they relate to DLB is unknown.

Method: Method: A cross-sectional design was used. 13 controls, 18 early PD, 19 polysomnography confirmed iRBD and 23 DLB underwent overnight polysomnography, neurological and neuropsychological assessment. Spectral power analysis during NREM and REM sleep was undertaken using a previously validated quantitative EEG algorithm and compared between groups. Following artefact and outlier removal, results were analysed using the Cz derivation. Groups were compared with a Jonckheree-Terpstra test for ordered alternatives, controlling for age and sex.

Results:

Results: We found a significant and gradual reduction in power in the spindle frequency band (12-15 Hz) in NREM sleep (Controls > iRBD > early PD > DLB (T_JT = 521.00, z = -2.902. p<0.001). Meanwhile in REM sleep we found a suggestion of a shift in power to slower frequencies with increased power in the theta (4.5-8 Hz) band (T_JT = 950.00, z = 2.253. p=0.024). No differences were found across the other frequency bands in NREM or REM sleep.

Conclusion: Conclusion: Power spectral analysis may be a useful biomarker of progression towards Lewy body dementia from prodromal stages with reduced spindle density correlating to stage of diagnosis.

References: [1] Bohnen NI, Hu MTM. Sleep Disturbance as Potential Risk and Progression Factor for Parkinson’s Disease. J Parkinsons Dis 2019;9(3):603-614.
[2] Postuma RB, Iranzo A, Hu M, et al. Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study. Brain 2019;142(3):744-759.
[3] O’Reilly C, Godin I, Montplaisir J, Nielsen T. REM sleep behaviour disorder is associated with lower fast and higher slow sleep spindle densities. Journal of sleep research 2015;24(6):593-601.

« Back to 2023 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/utility-of-quantitative-eeg-during-sleep-as-a-potential-biomarker-of-lewy-body-disease-progression/