Does anyone have any effective treatments for reversing the Parkinson's effect of MPTP "bad drug" toxicity

In 1982, seven people in Santa Clara County, California were diagnosed with Parkinson's after using MPPP contaminated with MPTP. J. William Langston, then a neurologist at Santa Clara Valley Medical Center and faculty member at Stanford Medical School, tracked down MPTP as the cause, researched its effects on primates, and was eventually able to successfully treat motor symptoms of three of the seven patients with neural grafts of foetal stem cells from aborted human foetuses in collaboration with neuroscientists from Lund University Hospital in Sweden. This experience was doented in a book he authored, The Case of the Frozen Addict (ISBN 0-679-42465-2), about his quest for a cure, which was later featured in two NOVA productions by PBS.