Sleep electroencephalographic asymmetry in Parkinson's disease patients before and after deep brain stimulation

Objective Unilateral manifestation of motor dysfunction is a prominent hallmark of Parkinson’s disease (PD). We investigated how the motor laterality of the disorder affects sleep neural asymmetry before and after Deep Brain Stimulation (DBS). Methods Twenty-seven PD patients of the akinetic-rigid subtype were studied; 11 with right dominant (RD) and 16 with left dominant (LD) motor symptoms. Neuronal sleep asymmetry was computed as the difference of sleep slow-wave energy (SWE) between left and right hemispheres. We used linear mixed models to assess the relationship between symptomatic profile and SWE asymmetry. Results LD PD patients exhibited frontal electroencephalographic (EEG) asymmetry and motor laterality pre-DBS with increased SWE contralateral to their affected body side, which diminished post-DBS. The RD group did not exhibit neither neural asymmetry nor motor laterality pre- and post-DBS. There was a significant negative correlation between the motor laterality and sleep EEG asymmetry. Conclusions Our results suggest evidence for a local use-dependent modulation of SWE as a result of the lateralized pathological motor profile. More bilateral motor symptoms and optimized treatment contribute to diminished sleep EEG asymmetry. Significance These novel findings about the association between symptomatic motor laterality and sleep neural asymmetry may provide targeted therapeutic insights.