What is Parkinson disease?

Parkinson disease is a degenerative neurological disorder. It occurs when certain nerve cells (neurons) in a part of the brain called the substantia nigra die or become impaired. Normally, 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 disease appear.

What are the signs and symptoms of Parkinson disease?

The loss of dopamine production in the brain causes the primary symptoms of Parkinson disease. The key signs of Parkinson disease are:

Tremor (shaking) and/or
Slowness of movement and/or
Rigidity (stiffness)

Other signs of Parkinson disease may include:

Difficulty with balance
Small, cramped handwriting
Stiff facial expression
Shuffling walk
Muffled speech
Depression   

Who gets Parkinson disease?

Parkinson 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 1.5 million Americans who currently have Parkinson disease. While the condition usually develops after the age of 65, 15% of those diagnosed are under 50.

How is Parkinson disease diagnosed?

The process of making a Parkinson disease diagnosis can be difficult. There is no X-ray or blood test that can confirm Parkinson disease. A physician arrives at the diagnosis only after a thorough examination. Blood tests and brain scans known as magnetic resonance imaging (MRI) may be performed to rule out other conditions that have similar symptoms. People suspected of having Parkinson disease should consider seeking the care of a neurologist who specializes in movement disorders.

What is the treatment for Parkinson disease?

There are a number of effective medicines that help to ease the symptoms of Parkinson 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 disease. Several new medicines are being studied that may slow the progression. Many promise to improve the lives of people with Parkinson disease.