Are there several different types of Parkinson’s disease or parkinsonism?

Parkinsonism is a broad term used to describe any condition in which a person’s movements are impaired by rigidity, tremor, or the slowness of motion known as bradykinesia. Parkinson’s disease, the most common form of parkinsonism, results from the selective death of cells in the brain’s substantia nigra . But parkinsonism can result from other types of brain damage caused by another type of neurological disease, side effects from antipsychotic drugs, and a rare form of viral encephalitis.