Understanding drug-induced parkinsonism: separating pearls from oy-sters.

Maria Victoria G. Alvarez, MD Virgilio Gerald H. Evidente, MD In 1817, James Parkinson described the shaking palsy now known as Parkinson disease (PD). Descriptions evolved until the term “parkinsonism” now refers to a syndrome characterized by the presence of tremor, rigidity, and bradykinesia in addition to loss of postural reflexes and freezing. The most common cause of parkinsonism is PD. However, in any parkinsonian patient, onemust obtain a careful medical and medication history, as druginduced parkinsonism (DIP) is often reversible, especially if the offending drug is discontinued early.