Cell-based therapies for Parkinson disease—past insights and future potential

Dopaminergic drugs were established as an effective treatment for Parkinson disease (PD) in the 1960s, and are still the mainstay of therapy for this conditionExperiments that heralded the modern era of neural grafting for PD began in the 1970s in SwedenDespite limited preclinical data, adrenal medullary transplantation was adopted by many groups during the 1980s, with largely disappointing resultsHuman fetal ventral mesencephalic (fVM) allografts have been shown to survive and function for over 20 years in some patientsThe protocol for neural transplantation in patients with PD remains to be optimizedHuman fVM grafts are currently being revisited, and stem cell-based dopamine replacement therapies are close to clinical trials