Parkinson's disease: 10 years of progress, 1997-2007.

Many people with Parkinson's disease (PD) and their family members ask their physicians "What is happening in research on Parkinson's disease? Is there anything new?" As the initial speaker at the symposium organized by the Parkinson's Disease Foundation in celebration of its 50th anniversary, I sought to address these questions, focusing on research published between the years 1997 and 2007. I cataloged the advances I considered most important in the field, recognizing my viewpoint is a subjective one and most likely differs from similar listings that others would put together. Space limitation allows me to discuss only a tiny fraction of the remarkable new findings that have been discovered during this 10-year span. Nevertheless, I expect the readers of this summation of advances in the field to be as impressed as I am on the wealth, breadth, and excitement stirring in the field of PD research. Included in this overview are highlights in both laboratory science and clinical science of PD research. In the former category are advances in knowledge on the genetics of PD; potential etiologic and pathogenic causes, especially the better understanding of endogenous factors within dopaminergic neurons; pathologic changes including deposition of alpha-synuclein aggregates; and the consequences of altered alpha-synuclein on the degradation of proteins by both the ubiquitin-proteasomal pathway and the lysosome. Clinical science has also been very active and impressively productive with important clinical advances. In this category are new information on the epidemiology of PD, including awareness of additional factors (besides smoking) that might slow the onset and worsening of PD, such as caffeine and urate; neuroimaging with positron emission tomography and single photon emission tomography; keener awareness of nonmotor features of PD and their impact on quality of life for the persons with PD and their family; recognition of behavioral complications of medications utilized to treat PD, such as impulse control problems; appreciation of the natural history of PD with the increasing impairments as the disease relentlessly worsens over time; the many controlled clinical trials attempting to slow the progression of the disease and to provide new symptomatic therapies; and surgical approaches to alleviate symptoms and progression, including cellular and gene therapy as well as deep brain stimulation.