Light Therapy in Parkinson's Disease

As the most important biologic rhythm timer, exogenous light supplement has certain benefits for the improvement of sleep quality and dementia. At present, it is gradually used in sleep and neuropsychiatric diseases. In an open study, 120 patients with PD received 4000 to 6000 lux of light, for 60 minutes before habitual bedtime. The patients were followed up for several months to 8 years, and it found the patients who persisted in the treatment improved their mood, anxiety and motor function. Clinical studies have confirmed the safety and effectiveness of light in improving insomnia and daytime sleepiness of PD patients. It was found that strong light can significantly improve the patients' motor and non-motor symptoms. However, these findings have not been reported in Chinese PD patients. The aim of this randomized controlled trial (RCT) is to clarify the effect of bright light therapy on motor symptoms and sleep disorders in patients with Parkinson's disease and explore the possible mechanism.