disease is a progressive neurological disease involving deterioration
of neurons in a
region of the brain called the substantia
nigra. It affects approximately a million Americans, most
of them over the age of 60, although sometimes the disease
can appear in people as young as 35 or 40. The causes of Parkinson's
disease are unknown. It is named after James Parkinson (1755-1824),
an English neurologist who studied the disease.
Parkinson's disease is characterized by
motor symptoms, including tremor
in muscles that are at rest, rigidity, slowness of movement,
difficulty initiating movement, and problems maintaining posture.
The onset of these symptoms is usually gradual, and patients
may go for a long time without appreciable worsening. Symptoms
are usually intermittent in the early stages of the disease,
but may become continual late in the course of the disease.
In late stages of Parkinson's disease, the face becomes expressionless,
eye blinking is infrequent, speech is slow, and the patient
may find it difficult to stand upright without falling.
In addition to the motor symptoms in Parkinson's disease,
there are also cognitive symptoms which may be evident even
in the early stages of the disease. These may include deficits
function (especially planning and attention), set-shifting
(ability to alternate between two or more tasks), and memory.
Approximately 25%-30% of Parkinson's patients develop dementia.
It is not yet known whether dementia is actually a symptom
of Parkinson's disease or whether patients with Parkinson's
disease are for some reason also at higher risk for dementia.
A large number of Parkinson's patients also experience psychiatric
disorders such as depression,
anxiety, or sleep disorders.
Because Parkinson's disease damages neurons
in the substantia nigra which produce dopamine,
treatment usually involves drugs which work to counteract
this shortage of dopamine. For example, levodopa (L-dopa,
for short) may be used to help boost brain production of dopamine;
L-dopa is a component of the widely-used Parkinson's drug
Sinemet. Other medications such as selegiline (also known
as deprenyl or Eldepryl) work to increase the efficacy of
existing dopamine in the brain. Parkinson's patients may benefit
from treatment with several kinds of drugs simultaneously.
These drugs can often combat the motor symptoms for a long
time, but as the disease progresses and the substantia nigra
continues to degrade, the drugs eventually become less effective.
Some patients whose motor symptoms cannot
be controlled by medication undergo brain surgery to destroy
portions of the brain regions responsible for some of the
motor symptoms in Parkinson's disease, or benefit from deep
brain stimulation (DBS) -- using thin wires to stimulate electrical
activity in the brain. There has also been controversial research
involving implantation of cells from aborted fetuses into
the brains of Parkinson's patients in an attempt to regrow
neurons in the substantia nigra; more recently, scientists
are exploring the possibility of using stem cells isolated
from healthy adults or grown in the laboratory. As yet, this
work is still highly experimental.
Article : "DANCING
by Catherine E. Myers. Copyright © 2006 Memory Loss and
Article : "How Parkinsonís disease affects the mind"