Levetiracetam Treatment in Adult Subjects With Parkinson's Disease Experiencing Troublesome Dyskinesias

Inclusion criteria

• Male / female adult, 30 years old or more;
• Subject suffering from Idiopathic Parkinson's Disease, diagnosed according to the UK Brain Bank Criteria (see Appendix 14.8) (1) , since a minimum of 3 years, and stabilized with regard to the motor function (ratio .on./.off. over the day);
• Subject treated with levodopa whether or not combined with any other antiparkinsonian drugs (except apomorphine) for minimum one year;
• Subject experiencing during .on. periods, despite several attempts of treatment adjustment, persistent troublesome dyskinesias:

• with a minimum score of 2 on item 33 of the UPDRS-Part IV (moderately disabling dyskinesias);
• with a minimum score of 2 on item 32 of the UPDRS-Part IV (dyskinesias present during more than 25% of the waking day).

Exclusion criteria

• Dyskinesias that cannot reliably be characterized on a regular basis by the subject himself/herself (more than 5 .errors. on DRC per 24 hours after repeated training);
• Subject currently treated with apomorphine or neuroleptic drugs either typical or atypical such as clozapine, olanzapine or risperidone;
• Subject currently treated with dopamine antagonists such as but not limited to metoclopramide, alizapride or phenothiazine derivatives (e.g. metopimazine). If necessary, the use of the dopamine antagonist domperidone is allowed.
• Subject Who had undergone or who was scheduled for functional neurosurgery for Parkinson's disease during the trial period;