Author Affiliation: Department of Neurology, Universitätsklinikum Schleswig-Holstein, Kiel Campus, Kiel, Germany.
The treatment of advanced stages of Parkinson disease (PD) is a major challenge for modern medicine. This devastating movement disorder is characterized by severe fluctuations of the patient's mobility between a state of sometimes complete akinesia and dyskinetic hypermobility often being equally bothersome for the patient. These symptoms frequently are accompanied by wide fluctuating nonmotor symptoms such as anxiety, depression, hallucinations, and autonomic disturbances. While the early stages of PD usually can be sufficiently treated, this condition presents an ongoing therapeutic problem. After the revolutionary discovery of levodopa as the most efficient drug therapy1 during the early stages of the disease, it has been found that long-term complications limit the use of this drug.2 The great hope for transplantation of embryonic cells to restore endogenous L-dopa production was met with initial success3 but has turned into a disappointment, with 2 double-blind studies demonstrating lack of efficacy when rigorously tested against sham surgery.4,5 The proof-of-principle studies of gene therapy for PD likewise created much hope6 but also failed to show benefit in a sham surgery–controlled trial, based on release of preliminary data.7 A preliminary conclusion for many experts is that placebo effects are overwhelming for the invasive therapies of PD.
Deuschl G. Neurostimulation for Parkinson Disease. JAMA. 2009;301(1):104-105. doi:10.1001/jama.2008.938