Silverdale MA, et al. - A large clinical study was conducted to examine potential factors that may contribute to pain in early/moderate Parkinson's disease (PD). One thousand, nine hundred fifty-seven PD patients were enrolled who had detailed assessments of pain, motor and non-motor symptoms. Researchers in this investigation used the King's Parkinson's Pain scale to quantify different subtypes of pain. Peripheral factors cannot explain pain in early/moderate PD; central factors were a more important cause of pain in these patients than previously considered.