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What is Parkinson’s Disease?

What is Parkinson’s Disease?

Parkinson’s Disease (PD) is a chronic, neurodegenerative disorder that affects 10 million people worldwide, with 60,000 Americans diagnosed each year. The average age of onset is 60, with incidences of the disease increasing with age. 

Although the cause of PD is unknown, symptoms result from a loss of cells in the brain, particularly in a region called the substantia nigra, where cells produce dopamine. Dopamine is a neurotransmitter that regulates movement and emotion. According to the Parkinson’s Foundation, most people begin experiencing symptoms later in the disease’s progression because at that point a significant amount of the substantia nigra neurons have been lost, resulting in the low levels of dopamine that affect a person’s movement. 


“Early signs of Parkinson’s disease include tremor, slowed movement and stiffness, as well as balance problems. Some people may notice that their handwriting has become smaller or that they have a “masked face,” making them look more serious or depressed,” said Dr. Anupama Kale, Attending Neurologist and Parkinson’s Disease Specialist in DENT Neurologic Institute’s Movement Disorders Clinic.

As the disease progresses, symptoms can include:

  • Tremor
  • Limb Rigidity
  • Gait and Balance Problems 

According to the Parkinson’s Foundation, in addition to movement-related or “motor” symptoms, Parkinson’s symptoms may be unrelated to movement or “non-motor”.

Non-motor symptoms can include: apathy, depression, constipation, sleep behavior disorders, loss of sense of smell and cognitive impairment.


“PD is a chronic disease that is managed over time, with treatment tailored to each individual based on his or her symptoms. Most people with Parkinson’s disease can lead productive and fulfilling lives,” said Dr. Kale. “And while there is currently no cure for Parkinson’s disease, there are several treatments available, with more and more new and promising treatments in the pipeline. 

The content of this post is intended for general educational and informational purposes only; it does not constitute medical advice.  Readers should always consult with a licensed healthcare professional for diagnosis and treatment.