Hu Y, Guo P, Lian TH, et al. - Researchers conducted the study for examining the clinical features, iron metabolism, and neuroinflammation in Parkinson disease (PD) patients with excessive daytime sleepiness (EDS). The sample consisted of 379 patients with PD and 30 age-matched controls. The Epworth sleepiness scale (ESS) and a series of rating scales were used to evaluate all participants, and they were divided into PD-EDS and PD-NEDS groups based on their ESS score. In PD patients, EDS was a common symptom. PD patients with EDS exhibited more severe motor and some non-motor symptoms. An underlying mechanism of PD-EDS could be overloaded iron-relevant inflammation in the brain.