Long term treatment with levodopa, the gold standard treatment of Parkinson's disease (PD), can lead to the development of abnormal involuntary movements called levodopa induced dyskinesia (LID). The severity of LID can range from mild to severely debilitating. A majority of PD patients will develop LID in their treatment life-time. In a recent study of the MPTP monkey model of PD, statin use was found to reduce LID (45%) without a worsening of Parkinsonism symptoms1. Another study showed rats treated with lovastatin prior to and with initiation of levodopa after substantia nigra lesioning showed dramatically less LID evolution compared to animals without lovastatin exposure2. In this study, the investigators will examine the association of statin use and dyskinesia in a convenience sample Parkinson's disease patients in the Veterans Administration Health Care System. This study is a retrospective three cohort design and will compare statin exposure BEFORE beginning LD, versus statin exposure AFTER LD is begun, versus NO statin exposure in PD subjects controlling for disease characteristics (severity), gender, and total LD exposure The primary endpoint is the severity of LID between the groups after years of opportunity to develop LID. Levodopa-Induced dyskinesia is a major cause of reduced quality of life for Veterans with PD and, in some cases, leads to costly surgical interventions. This project examines the impact of statin use on the presence of LID, and could lead to a future intervention trial. The reduction, delayed onset, or elimination of LID could improve the quality of life of many Veterans nationwide.
In this study, the investigators will examine the association of statin use and dyskinesia in a convenience sample Parkinson's disease patients in the Veterans Administration Health Care System.