Parkinson's Disease Information

What is Parkinson's Disease?

Parkinson’s disease (PD) is a brain disorder associated with a loss of dopamine nerve cells in a brain region called the basal ganglia. The basal ganglia consist of a network of nuclei or nerve circuits involved in motor control. The figure below illustrates key regions of the basal ganglia. Dopamine nerve cells are located in the substantia nigra. This nucleus, in turn, projects to other regions within the motor circuit including the caudate nucleus, putamen, thalamus and subthalamic nuclei. One of the primary tasks for these nerve cells is the planning, initiation, and control of movement.

Motor Symptoms

Motor symptoms of PD emerge as these nerve cells degenerate. In fact it is estimated that between 60 to 70% of dopamine nerve cells are lost before the initial motor symptoms are noticed.

Motor symptoms typically begin on one side of the body and over time ‘spread’ to the other side. These include:

Are there non-Motor Symptoms?

Non-motor symptoms are listed below. These symptoms can precede the earliest motor symptoms:

Occur after diagnosis throughout the disease:

Parkinson’s medications can also worsen non-motor symptoms: