Parkinson’s Disease (PD)

Parkinson’s disease (PD) is a movement disorder that occurs when brain cells that make the chemical messenger (neurotransmitter) called dopamine die over time. This creates a shortage of dopamine in the brain.

Trembling and shaking (called tremor) in an arm or leg, especially when at rest, is often the first symptom of PD. Other common symptoms include:

• Slow movement
• An inability to get started moving, freezing in place
• Stiff limbs
• A shuffling gait
• Stooped posture
  

In some cases, people with PD may not show their usual facial expressions, or may speak in an unusually soft voice.

Diagnosing PD
The cause of PD is not clear. Genes may play a role, but researchers believe the disease's onset also depends on environmental factors.
Currently, no test can clearly identify PD in a person. So, in order to diagnose PD, doctors must carefully evaluate patients' symptoms, including what they are, how severe they are, and when they started.
Neurologists (doctors who specialize in the brain and nervous system) have experience with PD. They are best suited to diagnose the disease.

Treating Parkinson's Disease
There is no cure for PD, but many patients don't require treatment for several years after they are diagnosed. When their symptoms do become severe, their doctors may prescribe drugs that help replace dopamine.

Other approaches to treating severe PD include:

Pallidotomy—a type of brain surgery that can effectively reduce symptoms in many people

Deep-brain stimulation—a procedure in which a pacemaker-like device is placed in the brain to reduce tremors

New Research in Parkinson's Disease
Gene therapy—which uses the brain's own systems for cell growth to fight brain illnesses—is a promising area of brain research. The idea is to introduce properly functioning genes that can help make up for abilities lost through disease or injury.

Scientists hope that this approach may be used to treat many movement disorders (like PD) and other neurodegenerative diseases (like Alzheimer's), which are caused by the ongoing loss of nerve cells in certain areas of the brain.

Researchers have already had some success using gene therapy in animal testing (using models of PD) to help restore lost dopamine-producing cells. In animals, the therapy has helped keep nerve cells alive.

This type of treatment is now being investigated in people. But experts point out that gene therapy is still far from perfect. Much more research is necessary make it safer and more effective.

However, many scientists believe these early PD experiments will open the door to a wider use of gene therapy. For example, it could possibly be used in treating ALS—also known as Lou Gehrig's disease—and Huntington's disease.