dyskinesia human 10 Parkinson disease 8 article 8 priority journal 8 Aged 6 Humans 6 Parkinson Disease 6 Parkinson's disease 6 aged 6 clinical trial 6 levodopa 6 male 6 motor performance 6 Double-Blind Method 4 Female 4 Globus Pallidus 4 Male 4 Middle Aged 4 Severity of Illness Index 4 adult 4 clinical article 4 controlled clinical trial 4 controlled study 4 female 4 pallidotomy 4 randomized controlled trial 4 4 aminobutyric acid 2 Adynamic bowel syndrome 2 Antiparkinson Agents 2