• PDtrials - Parkinson's Disease Clinical Trials
• /PD Research & You

Parkinson's disease  Parkinson's DiseaseA chronic, slowly progressive disease of the nervous system characterized by the combination of tremor, rigidity, bradykinesia and stooped posture, among other symptoms. (PD) is a movement disorder that is chronic and progressive, meaning that symptoms continue and worsen over time. As many as one million Americans suffer from PD. While approximately 15 percent of people with Parkinson's are diagnosed before the age of 50, incidence increases with age. PD occurs when a group of cells in an area of the brain called the substantia nigra  Substantia Nigra (SN)A small region in the brain stem, just above the spinal cord. Cells within the SN produce and release a chemical called dopamine, a neurotransmitter that controls movement and balance and is essential to the proper functioning of the central nervous system (CNS). begin to malfunction and die. These cells in the substantia nigra produce a chemical called dopamine.  DopamineA "chemical messenger" that regulates movement by assisting in the effective communication (transmission) of electrochemical signals in the brain from one nerve cell (neuron) to another. As dopamine producing cells degenerate with advancing PD, they no longer produce enough to regulate neurons elsewhere in the brain, resulting in a loss of control of movements, leading to symptoms such as slowed movements, tremor, and rigidity. Dopamine is a neurotransmitter,  NeurotransmitterA chemical that carries signals between nerves, sometimes called a chemical messenger. Dopamine is a neurotransmitter. or chemical messenger, that sends information to the parts of the brain that control movement and coordination. When a person has PD, their dopamine-producing cells begin to die and the amount of dopamine produced in the brain decreases. Messages from the brain telling the body how and when to move are therefore delivered more slowly, leaving a person incapable of initiating and controlling movements in a normal way.

PD can also cause several different symptoms. The specific group of symptoms that an individual experiences varies from person to person. Some of the most common symptoms of PD are:

• tremor  TremorShaking or rhythmic movement, especially in the hands but in other parts of the body. Often occurs when at rest, such as in the RESTING TREMOR. of the hands, arms, legs, jaw and face
• rigidity  RigidityA symptom in which muscles feel stiff and display resistance to movement even when another person tries to move the affected part of the body. or stiffness of the limbs and trunk
• bradykinesia  BradykinesiaSlowness of movement. or slowness of movement
• postural instability  Postural InstabilityImpaired balance and coordination often causing patients to lean forward or backward and to fall easily. or impaired balance and coordination

The cause of PD remains unknown. Although there is presently no cure, there are many treatment options such as medication and surgery to manage the symptoms.

There are many professionals and organizations dedicated to helping people with Parkinson’s, and devoted to finding a cure. There are also many opportunities for you to meet and learn from others who have experienced what you are going through, and to raise public awareness and commitment to research through advocacy, fundraising and other initiatives. You may find a listing of such organizations on the PDtrials Partners page.