AUTHOR=Ooi Leon Qi Rong , Wen Ming-Ching , Ng Samuel Yong-Ern , Chia Nicole Shuang-Yu , Chew Isabel Hui Min , Lee Weiling , Xu Zheyu , Hartono Septian , Tan Eng King , Chan Ling Ling , Tan Louis Chew-Seng 

TITLE=Increased Activation of Default Mode Network in Early Parkinson’s With Excessive Daytime Sleepiness

JOURNAL=Frontiers in Neuroscience

VOLUME=Volume 13 - 2019

YEAR=2019

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2019.01334

DOI=10.3389/fnins.2019.01334

ISSN=1662-453X

ABSTRACT=Background and Objectives: The underlying neuropathology of excessive daytime sleepiness (EDS) remains elusive in Parkinson’s disease (PD). We aim to investigate neural network changes that underlie EDS in PD.
Methods: Early PD patients comprising eighty-one patients without EDS (EDS-) and seventeen patients with EDS (EDS+) received a resting state functional MRI scan and the Epworth Sleepiness Scale(ESS). Connectivities within the default mode network(DMN), motor and basal ganglia networks were compared between the EDS+ and EDS- groups. Correlations between network connectivity and the severity of EDS were investigated through linear regression.
Results: EDS+ patients displayed a trend of increased network connectivity of the posterior DMN (pDMN). A significant positive correlation was found between connectivity of the ventromedial prefrontal cortex in the pDMN and ESS.
Conclusion: EDS+ patients are likely to display increased activation in the DMN, suggesting neural compensation in early PD or impaired attentiveness due to mechanisms such as mind-wandering.