About Parkinson's Disease

Parkinson's disease affects 1.5 million Americans.¹ If you're one of them, you probably know this neurological movement disorder has no cure. What you may not know is that Medtronic has developed a therapy that has been proven to reduce some of the symptoms associated with Parkinson's disease.²

Definition and Symptoms

Parkinson's disease is a progressive, degenerative neurological movement disorder that affects approximately 1.5 million Americans.¹ Although it typically develops after the age of 65, about 15% of people with the condition develop "young-onset" Parkinson's disease before reaching age 50.¹

As Parkinson's disease progresses, it becomes increasingly disabling, making daily activities like bathing or dressing difficult or impossible. Many of the symptoms of Parkinson's disease involve motor control, the ability to control your muscles and movement.

The four primary symptoms of Parkinson's disease are:

• Tremor (involuntary, rhythmic shaking of a limb, head, or entire body) – The most recognized symptom of Parkinson's disease, tremor often starts with an occasional tremor in one finger that eventually spreads to the whole arm. The tremor may affect only one part or side of the body, especially in the early stages of the disease. Not everyone with Parkinson's disease has tremor.
• Rigidity (stiffness or inflexibility of the limbs or joints) – The muscle rigidity experienced with Parkinson's disease often begins in the legs and neck. Rigidity affects most people. The muscles become tense and contracted, and some people may feel pain or stiffness.
• Bradykinesia or akinesia (slowness of movement or absence of movement) – Bradykinesia is one of the classic symptoms of Parkinson's disease. Over time, a person with Parkinson's disease may develop a stooped posture and a slow, shuffling walk. They eventually also may lose their ability to start and keep moving. After a number of years, they may experience akinesia, or "freezing," and not be able to move at all.
• Postural Instability (impaired balance and coordination) – A person with postural instability may have a stooped position, with head bowed and shoulders drooped. They may develop a forward or backward lean and may have falls that cause injuries. People with a backward lean have a tendency to "retropulsion," or stepping backwards.

Causes and Risk Factors

Parkinson's disease is caused by the degeneration of a small part of the brain called the substantia nigra. As brain cells in the substantia nigra die, the brain becomes deprived of the chemical dopamine.

Dopamine enables brain cells involved in movement control to communicate, and reduced levels of dopamine lead to the symptoms of Parkinson's disease. According to the National Parkinson Foundation, 80% of dopamine-producing cells are lost even before the motor symptoms of Parkinson's disease appear.³

Parkinson's disease often becomes increasingly disabling over time. If you suffer from Parkinson's disease you may have trouble performing daily activities such as rising from a chair or moving across a room. As the disease progresses, some people need to use a wheelchair or may become bedridden.

References

1. Basic Information About Parkinson's Disease. Available at: apdaparkinson.org. Accessed July 15, 2008.
2. Activa Therapy Clinical Summary, 2003.
3. Parkinson Primer. Available at: www.parkinson.org. Accessed July 14, 2008.

Section Navigation

• About Parkinson's Disease

Additional information