Influence of Piribedil (Clarium®) on Vigilance and Cognitive Function in Patients With Parkinson's Disease Compared to Other Non-Ergot Dopamine Agonists

Oral application of piribedil at an equivalent dose of pramipexole or ropinirole according to a defined equivalence scheme (dose range 100 - 300 mg per day) for 11 weeks.

continuation of pre-study treatment regimen