Topiramate as an Adjunct to Amantadine in the Treatment of Dyskinesia in Parkinson's Disease

Inclusion Criteria: 1. Parkinson's disease patient, defined by United Kingdom (UK) Brain Bank criteria 2. Current age between 30-90 3. Clinically pertinent dyskinesias defined by Clinical Global Impression - Severity (CGI-s) score (see attachment) \> 3 (mild) established by clinician's total assessment of patient including objective observation during the screening process. \* 4. Stable doses of all antiparkinsonian medications for at least 4 weeks 5. Stable treatment with at least 200 mg amantadine for at least 4 weeks. 6. Presence of a caregiver willing to participate in the study 7. In the opinion of the enrolling investigator, the subject will be able to maintain current dosing schedule of antiparkinsonian drugs for the duration of the trial. 8. Subjects must be free of dementia, depression and psychosis as determined by clinical examination. 9. The subject must be willing to participate in all study related activities and visits. Exclusion criteria: 1. Any subjects with clinical evidence suggestive of an atypical or secondary form of Parkinson's Disease 2. Any subject who, in the opinion of the Principal Investigator, has a concomitant medical illness which would preclude them from being treated with amantadine, 3. Any subject who, in the opinion of the Principal Investigator, will be unable to maintain current stable dosing of their anti-parkinsonian medications for the duration of the trial, 4. Any subject with evidence for dementia, depression, or psychosis, as determined by clinical examination. 5. Any subject who has not signed informed consent, or unable or unwilling to participate in all of the study related activities.