The common therapeutic strategy in practice at the Movement Disorders Unit over the period of the study was to delay levodopa treatment mainly in patients with young age of symptoms onset, to add dopamine agonist drugs only if daily dose of 500mg levodopa did not give satisfactory relief or if response fluctuations appeared. Amantadine was prescribed in many cases throughout the entire disease course. Selegiline was introduced in the late 1980’s or early 1990 in most patients and was continued unless side effects developed.