What is Parkinson's disease?
Parkinson's disease is a chronic progressive neurological disease that affects
nerve cells (neurons) in an area of the brain near the neck, known as the
substantia nigra. These cells normally produce dopamine, a chemical
(neurotransmitter) that transmits signals between areas in the brain. These
signals, when working normally, coordinate smooth and balanced muscle movement.
Parkinson's disease, however, causes neurons in the substantia nigra cells to
die, leading to a lack of dopamine in the brain, especially in the part of the
brain known as the basal ganglia. The basal ganglia are responsible for
organizing movement commands from other parts of the brain. The loss of dopamine
causes patients to lose the ability to control their body movements.
Who gets Parkinson’s disease?
Approximately one million Americans have Parkinson's disease. More than 50,000
Americans are diagnosed with Parkinson's disease each year. There is increasing
evidence that Parkinson's disease may be inherited. Men after the age of 60 are
more likely to develop the disease than women. The average age at the onset of
symptoms is 60. However, 10 percent of patients are diagnosed before age 40.
What are the symptoms of Parkinson's?
The major symptoms of Parkinson’s disease include:
- Muscle stiffness (rigidity)
- Tremors
- Bradykinesia (the slowing down of movement and the gradual loss of
spontaneous activity)
- Changes in walking pattern and posture
- Changes in speech and handwriting
- Loss of balance and increased falls
How is Parkinson’s disease diagnosed?
Diagnosing Parkinson's disease is sometimes difficult, since early features may
be difficult to assess and may mimic other disorders. For example, tremor may
not be apparent as a person is sitting at rest, or posture changes may be
written off as osteoporosis or simply a sign of aging.
There are currently no sophisticated blood or
laboratory tests available to diagnose the disease. Some imaging tests, such as
CT (computed tomography) or MRI (magnetic resonance imaging) scans, may be used
to rule out other disorders that cause similar symptoms. Given these
circumstances, a physician may need to observe the patient over time to
recognize signs of tremor and rigidity, and pair them with other characteristic symptoms.
The physician will also compile a comprehensive
history of the patient's symptoms, activity, medications, other medical problems
and exposures to toxic chemicals. This will likely be followed up with a
rigorous physical examination with concentration on the functions of the brain
and nervous system. Tests are conducted on the patient's reflexes, coordination,
muscle strength and mental function.