The Effects of the Rivastigmine Patch on Parkinson's Disease With Memory and/or Thinking Problems

Participation in this study requires four visits: a screening visit to ensure eligibility, an initial/baseline visit where the medication is distributed at a dosage lower than the optimal recommended dosage, a four week follow-up visit where the dosage of the medication is increased to the optimal amount, and a final twelve week follow up visit. * In the screening visit the patient will undergo a neurological exam (including a review of their medical history and short physical exam), electrocardiogram ( a painless procedure that measures electrical activity of your heart), cognitive testing (such as memory and thinking tests), and a blood draw. * At the Baseline/Initial visit the patient will receive a brief physical exam, additional cognitive testing, and an MRI scan. Afterwards, the study drug will be distributed. * At the four week follow up visit the patient will be asked to do some abbreviated cognitive and neurological testing and the study drug will be re-distributed at the target dosage. * At the final twelve week visit the patient will receive additional cognitive and neurological testing, and an MRI scan. * Study compliance and adverse events will be reviewed every two weeks throughout the study, whether in person or over the phone.