Parkinson’s (PD) is a progressive neurological brain disorder caused by the death of cells in a certain part of the brain known as the substantia nigra that produces dopamine. Dopamine is a neurotransmitter, or chemical messenger, that sends information to the parts of the brain that control movement and coordination. When approximately 70% of the dopamine-producing brain cells are damaged, the motor symptoms of Parkinson’s disease appear. This process of impairment of brain cells is called neurodegeneration.

Parkinson’s is the 2nd most common neurodegenerative disorder after Alzheimer’s. It is estimated that 1.5 million Americans are affected, more people than those suffering from Multiple Sclerosis, Muscular Dystrophy, and ALS combined. Estimates range from 60,000 to 70,000 on how many are diagnosed each year. Parkinson’s affects one of every 100 people over 60. That number will increase as the population ages.

Parkinson’s is chronic and progressive, meaning that the symptoms continue to worsen over time. Some of the most common motor symptom are: tremor of the hands, arms, legs, jaw or face; stiffness of the limbs and trunk; slowness of movement; and impaired balance and coordination. Symptoms typically begin on one side of the body and progress to include both sides. In addition, there are other secondary and non-motor symptoms affecting many systems in the body.

At this time, no single diagnostic test for PD is available. For that reason, it can be difficult to diagnose. Physicians rely on a patient’s descriptions of symptoms and a neurological examination. Other tests may be conducted to rule out other conditions.

The cause of Parkinson’s disease is not known. Scientists suspect that for most people, the cause is probably a combination of genetic and environmental factors. They believe these factors may vary from person to person. There is currently no known cure for Parkinson’s. Physicians treat PD with medications that treat the symptoms of the disease. Levodopa is the most widely prescribed Parkinson medication, and people often take several other medications to manage the disease. Surgical options, such as deep brain stimulation, may help alleviate a person’s PD symptoms when they stop responding to medication.

Additional resources

Parkinson’s Disease Foundation

American Parkinson Disease Association

National Parkinson Foundation

Parkinson’s Action Network

Michael J. Fox Foundation