Sietske N. Heyn is a medical writer with a PhD in neuroscience. Dr. Heyn's education includes a BS with honors from the University of Oregon, and a doctoral degree in neuroscience from the University of California at Davis. After completing postdoctoral training at the University of California, San Francisco, and many years of working as a medical writer at the Stanford University Center for Down Syndrome Research, Dr. Heyn now runs her own medical writing business.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Most individuals with Parkinson's disease are diagnosed when they are 60
years old or older, but early-onset Parkinson's disease also occurs.
With proper treatment, most individuals with Parkinson's disease can lead
long, productive lives for many years after diagnosis.
What is Parkinson's disease?
Parkinson's disease is the second most common neurodegenerative disorder and
the most common movement disorder. It is characterized by progressive loss of
muscle control, which leads to trembling of the limbs and head while at rest,
stiffness, slowness, and impaired balance. As symptoms worsen, it may become
difficult to walk, talk, and complete simple tasks.
The progression of Parkinson's disease and the degree of impairment vary from
individual to individual. Many people with Parkinson's disease live long
productive lives, whereas others become disabled much more quickly. Premature
death is usually due to complications such as falling-related injuries or
In the United States, about 1 million people are affected by Parkinson's
disease and worldwide about 5 million. Most individuals who develop Parkinson's
disease are 60 years of age or older. Parkinson's disease occurs in
approximately 1% of individuals aged 60 years and in about 4% of those aged 80
years. Since overall life expectancy is rising, the number of individuals with
Parkinson's disease will increase in the future. Adult-onset Parkinson's disease
is most common, but early-onset Parkinson's disease (onset between 21-40 years),
and juvenile-onset Parkinson's disease (onset before age 21) also exist.
Descriptions of Parkinson's disease date back as far as 5000 BC. Around that
time, an ancient Indian civilization called the disorder Kampavata and treated
it with the seeds of a plant containing therapeutic levels of what is today
known as levodopa. Parkinson's disease was named after the British doctor James
Parkinson, who in 1817 first described the disorder in great detail as "shaking