Parkinson's disease is a progressive nervous system disorder that affects movement.
Symptoms start gradually, sometimes starting with a barely noticeable tremor in just one hand.
Tremors are common, but the disorder also commonly causes stiffness or slowing of movement.
In the early stages of Parkinson's disease, your face may show little or no expression. Your
arms may not swing when you walk. Your speech may become soft or slurred. Parkinson's
disease symptoms worsen as your condition progresses over time.
Although Parkinson's disease can't be cured, medications might significantly improve your
symptoms. Occasionally, your doctor may suggest surgery to regulate certain regions of your
brain and improve your symptoms.
Symptoms
Parkinson's disease signs and symptoms can be different for everyone. Early signs may be mild
and go unnoticed. Symptoms often begin on one side of your body and usually remain worse on
that side, even after symptoms begin to affect both sides.
Parkinson's signs and symptoms may include:
Tremor. A tremor, or shaking, usually begins in a limb, often your hand or fingers. You
may a rub your thumb and forefinger back-and-forth, known as a pill-rolling tremor. Your
hand may tremor when it's at rest.
Slowed movement (bradykinesia). Over time, Parkinson's disease may slow your
movement, making simple tasks difficult and time-consuming. Your steps may become
shorter when you walk. It may be difficult to get out of a chair. You may drag your feet as
you try to walk.
Rigid muscles. Muscle stiffness may occur in any part of your body. The stiff muscles
can be painful and limit your range of motion.
Impaired posture and balance. Your posture may become stooped, or you may have
balance problems as a result of Parkinson's disease.
Loss of automatic movements. You may have a decreased ability to perform
unconscious movements, including blinking, smiling or swinging your arms when you walk.
Speech changes. You may speak softly, quickly, slur or hesitate before talking. Your
speech may be more of a monotone rather than with the usual inflections.
Writing changes. It may become hard to write, and your writing may appear small.
Causes
In Parkinson's disease, certain nerve cells (neurons) in the brain gradually break down or die.
Many of the symptoms are due to a loss of neurons that produce a chemical messenger in your
brain called dopamine. When dopamine levels decrease, it causes abnormal brain activity,
leading to symptoms of Parkinson's disease.
The cause of Parkinson's disease is unknown, but several factors appear to play a role,
including:
Your genes. Researchers have identified specific genetic mutations that can cause
Parkinson's disease. But these are uncommon except in rare cases with many family
members affected by Parkinson's disease.
However, certain gene variations appear to increase the risk of Parkinson's disease but
with a relatively small risk of Parkinson's disease for each of these genetic markers.
Environmental triggers. Exposure to certain toxins or environmental factors may
increase the risk of later Parkinson's disease, but the risk is relatively small.
Researchers have also noted that many changes occur in the brains of people with Parkinson's
disease, although it's not clear why these changes occur. These changes include:
The presence of Lewy bodies. Clumps of specific substances within brain cells are
microscopic markers of Parkinson's disease. These are called Lewy bodies, and
researchers believe these Lewy bodies hold an important clue to the cause of Parkinson's
disease.
Alpha-synuclein is found within Lewy bodies. Although many substances are found
within Lewy bodies, scientists believe an important one is the natural and widespread
protein called alpha-synuclein (a-synuclein). It's found in all Lewy bodies in a clumped form
that cells can't break down. This is currently an important focus among Parkinson's
disease researchers.
