Parkinson's Disease

PARKINSON'S DISEASE (PD) first described by James Parkinson in 1817, is a disorder of the central nervous system (CNS). It is marked by the presence of Lewy bodies (abnormal protein aggregates) and, more importantly, by a progressive loss of dopamine—producing neurons in the substantia nigra region of the brain. Although uncommon in people under age 40 years, the incidence of PD greatly increases with age, affecting approximately 1 percent of individuals older than 60 years.

As of yet, PD is incurable, and current therapies focus only on alleviating symptoms rather than on treating the underlying disease. However, because of the nature of its development, PD is a prime beneficiary candidate of stem cell research.

Traditionally, PD has been regarded as a motor system disorder, with four cardinal ...