Parkinson’s Disease

Parkinson's disease is a brain disorder that occurs when certain nerve cells (neurons) in a part of the brain called the substantia nigra die or become impaired. Under normal circumstances, these cells produce a vital chemical known as dopamine. Dopamine allows smooth, coordinated function of the body's muscles and movement. When approximately 80% of the dopamine-producing cells are damaged, the symptoms of Parkinson's disease appear.

Parkinson's disease affects both men and women in almost equal numbers. It shows no social, ethnic, economic or geographic boundaries. In the United States, it is estimated that 60,000 new cases are diagnosed each year, joining the 1 million Americans who currently have Parkinson's disease. While the condition usually develops after the age of 65, 15% of those diagnosed are under 50.

At this time no treatment has been shown to slow or stop the progression of this disease. Instead, therapy is directed at treating the symptoms that are most bothersome to an individual with Parkinson's disease. For this reason, there is no standard or “best” treatment for Parkinson's disease. There are a number of effective medicines that help to ease the symptoms of Parkinson's disease. Most symptoms are caused by lack of dopamine. The medicines most commonly used will attempt to either replace or mimic dopamine, which improves the tremor, rigidity and slowness associated with Parkinson's disease. Several new medicines are being studied that may slow the progression. Many promise to improve the lives of people with Parkinson's disease.

With progression of PD symptoms and increasing dopaminergic therapy, the benefits from levodopa or dopamine agonist dosing become less effective and the duration of action declines. In this setting, patients start to experience off periods during the day before their next dose of medication. This phenomenon, wearing-off, affects 30 – 50% of patients within 5 years of starting levodopa therapy [1] . In addition to wearing-off, patients may awaken each morning in the off-state due to a long duration between dopaminergic dosing intervals. Apart from these predictable off periods, random on/off may also occur, despite optimal medical management. With disease progression a delay in time-to-on after levodopa dosing may also appear.

Download Recent Parkinson's Disease Survey Results here.

LINKS

National Parkinson’s Foundation: www.parkinson.org
The Parkinson’s Foundation of Canada: www.parkinson.ca
Parkinson’s Disease Foundation: www.pdf.org
Micheal J Fox Foundation: www.michaeljfox.org
National Institute of Neurological Disorders and Stroke: www.ninds.nih.gov