Improving Outcomes in Parkinson's Disease

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that results from the loss of dopamine containing cells from specific regions of the brain. The disease affects approximately 0.3% of the U.S. population, or about 1 million people. PD onset most commonly occurs between the ages of 60 and 70 years and the incidence increases rapidly after 75 years of age; however, up to 10% of cases may develop before 45 years of age. PD is more common in men than women, but affects people of all races and ethnicity.

There is no known cause of PD. A small proportion of cases are linked to specific genetic alterations, but the majority of cases appear to have at least some environmental component. Some suggested environmental risk factors include rural living or exposure to pesticides, well-water, or solvents.

PD is primarily characterized by the four cardinal motor symptoms: bradykinesia (slowness of movement), resting tremor, postural instability, and rigidity (difficulty in initiating movement). These symptoms will often first appear on only one side of the body, but may affect both sides as the disease progresses. Although these motor symptoms are the most easily recognizable, many non-motor symptoms often exist, such as olfactory impairment, sleep disturbances, cognitive impairment, and psychiatric problems including depression, anxiety, and psychosis.

As the disease progresses, PD symptoms can substantially interfere with patients’ abilities to perform daily tasks and often result in the loss of employment. Coupled with medical costs and the loss of productivity of patients and primary caregivers, this presents a significant burden on patients, their caregivers, and society. While therapies are available to treat the motor symptoms of the disease, no medicine addresses the underlying cause, and there is no cure.