BDNF and Parkinson disease: For the evaluation of physical exercise on BDNF levels, data were aggregated from two RCTs [56, 57] with a total of 52 ambulatory in- and outpatients with mild to moderate idiopathic PD severity, mean 7.0±1.5 years after PD diagnosis and 68±5.6 years (mean±standard deviation) of age at the time of study enrollment.