Parkinson's disease (PD)
A neurodegenerative disorder that affects predominately the dopamine-producing (“dopaminergic”) neurons in a specific area of the brain called substantia nigra.
Symptoms generally develop slowly over years. The progression of symptoms is often a bit different from one person to another due to the diversity of the disease. People with PD may experience:
- Tremor, mainly at rest and described as pill rolling tremor in hands; other forms of tremor are possible
- Slowness and paucity of movement (called bradykinesia and hypokinesia)
- Limb stiffness (rigidity)
- Gait and balance problems (postural instability)
In addition to movement-related (“motor”) symptoms, Parkinson’s symptoms may be unrelated to movement (“non-motor”). People with PD are often more impacted by their non-motor symptoms than motor symptoms. Examples of non-motor symptoms include: depression, anxiety, apathy, hallucinations, constipation, orthostatic hypotension, sleep disorders, loss of sense of smell, and a variety of cognitive impairments.
The cause remains largely unknown. Scientists believe a combination of genetic and environmental factors are the cause.
Although there is no cure, treatment options vary and include medications, lifestyle adjustments and surgery. While Parkinson’s itself is not fatal, disease complications can be serious. The Centers for Disease Control and Prevention (CDC) rated complications from PD as the 14th cause of death in the U.S.
The first step to living well with Parkinson’s disease is to understand the disease and the progression.
It is possible to have a good to great quality of life with PD. Working with your doctor and following recommended therapies are essential in successfully treating symptoms by using dopaminergic medications. People with PD need this medication because they have low levels or are missing dopamine in the brain, mainly due to impairment of neurons in the substantia nigra.
It is important to understand that motor symptoms of PD only become evident later in the course of the disease, after 60% to 80% of the substantia nigra neurons have already been lost or impaired. Lewy bodies (accumulation of abnormal alpha-synuclein) are found in substantia nigra neurons of people with PD.
The Parkinson’s Foundation research has led to breakthroughs in treatment and improved care that bring hope to the Parkinson's community. The field of Parkinson’s research is ongoing and ever evolving as we learn more about this disease.
Scientists are exploring ways to identify biomarkers for PD that can lead to earlier diagnosis and more tailored treatments to slow down the disease process. Currently, all therapies used for PD can improve symptoms but do not slow or halt the disease progression.
Page reviewed by Dr. Jun Yu, Movement Disorders Fellow at the University of Florida, a Parkinson’s Foundation Center of Excellence.