Adult patients affected by PD and suffering from motor fluctuations will be screened for participation.~If the inclusion and exclusion criteria are met, the participant will enter in the baseline assessment phase and undergo 1 night baseline PSG and 1 week baseline actigraphy. The patient will then start the treatment with 50 mg/day of Safinamide per os for 2 weeks (escalation phase). Then, safinamide will be increased up to 100 mg/day and, if tolerated, the treatment will last for 10 weeks (maintenance phase). At week 12 (end of treatment), the questionnaires, actigraphy and PSG will be repeated. A safety follow-up visit is scheduled 4 weeks after study treatment completion.~The treatment will be continued thereafter in all patients if medically indicated.
Patients suffering of Parkinson's Disease will be treated with 50 mg/day of Safinamide per os for 2 weeks (escalation phase). Then, safinamide will be increased up to 100 mg/day and, if tolerated, the treatment will be taken for 10 more weeks (maintenance phase). Total treatment 12 weeks.