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Parkinson’s FOUNDATION
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What Is Parkinson’s
Parkinson’s Disease (PD) is a progressive
neurodegenerative movement disease
affecting over 1% of people by the age of
60 and is the second most commonly
occurring neurodegenerative disease in
the elderly (after Alzheimers), with an esti-
mated 8 million sufferers worldwide.
The disease has been known for over 200
years and is named after an English
doctor, James Parkinson, who published
the first detailed description in ‘An Essay
on the Shaking Palsy’ in 1817.
The loss of dopamine-producing neurons,
in a section of the mid-brain called the
substantia nigra, results in a range of both
motor (that is, referring to motion) and
non-motor symptoms, and someone can
have the disease for 5 to 10 years before
it is diagnosed, by which time the majority
of the neurons in the affected part of the
brain may have already been lost.
The cause of this cell death is poorly
understood, but involves the build-up of
misfolded proteins into Lewy bodies in
the neurons.
The underlying cause of PD is also
unknown, with both inherited and envi-
ronmental factors being believed to play a
role. Those with a family member affected
by PD are at an increased risk of getting
the disease, with certain genes known to
be inheritable risk factors. Other risk
factors are those who have been exposed
to certain pesticides (such as dieldrin and
paraquat) and people who have prior
head trauma.
At present, diagnosis of PD relies on
observation of patient movement and in
a clinical setting it is commonly misdiag-
nosed or missed completely – with
primary care doctors making an incorrect
diagnosis more than half of the time and
only movement disorder specialists
achieving reliable diagnostic accuracies.
PD can cause tremor, slowness, stiffness,
and walking and balance problems, and
hence it is called a ‘movement disorder’.
Even though there are existing treat-
ments to alleviate some of the effects of
the disease, at present there is neither
any cure nor any means of slowing its
progression.
The reason that people with PD may
already have the disease for many years
before it is diagnosed is because they
only start noticing the symptoms later
in the course of the disease, once a
significant proportion of the substantia
nigra neurons have gone.
In addition to movement-related
(‘motor’) symptoms, some
Parkinson’s symptoms are
unrelated to movement (‘non-
motor’), and people with PD
are often more impacted by
their non-motor symptoms.
Examples of the non-motor
symptoms include apathy,
depression, constipation,
sleep behavior disorders, loss
of sense of smell and cogni-
tive impairment.
Treatment aims to reduce the effects of
the symptoms, with initial treatment
typically being with the medications
levodopa (L-DOPA), MAO-B inhibitors, or
dopamine agonists. People with PD
need this medication because they have
low levels or are missing dopamine in
the brain, due to the loss of neurons
that produce it.
On a positive note, it is possible for
someone with PD to have a good quality
of life for many years. Working with
your doctor and following the recom-
mended therapies are essential in
successfully treating symptoms with
dopaminergic medications.