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Parkinson’s Disease
Historical Perspective
 First described by British
doctor James Parkinson
 Identified its major
symptoms and called it
“the shaking palsy”
 Research progressed
slowly until the 1960’s
 60’s linked the disease to
the loss of cells that
produce dopamine
Initial Symptoms
 First signs can be
mistaken for another
condition.
 Can be considered by
the patient as a
normal part of the
aging process.
 Persistent mild fatigue
 Handwriting might
become “shaky”
 Person might feel
unbalanced or have
difficulty performing
sit-to-stands
 Agitation, irritability,
& depression
 Lack of affect
(masked face
phenom)
 Initial symptoms can
go on for years
Movement Disorders
 Hand tremors
 Muscles associated
with movement all
 Typically involves a
have opposing
rhythmic back-andmuscles - when one is
forth motion of the
activated, the other is
thumb at 3 bpm.
relaxed.
 Most evident when
 Brain’s signals in PD
the limb is at rest or
patients become
under stress
confused causing both
 Patients report rigidity
sets
of
muscles
to
or resistance to
remain engaged and
movement
contracted.
Movement Disorders cont’d
 Spontaneous
movements can
become progressively
slower and may
actually cease.
 This is known as
bradykinesia
 Impaired balance and
coordination (known
as postural instability)
 Causes PD pt.’s to
lean unnaturally
backward or forward
 Common to see
someone with head
down, stooped stance
Movement Disorders cont’d
 Become vulnerable to
falls
 Those who tend to
lean backward have to
step step backward
first before they begin
walking (known as
retropulsion)
 Some develop a midstride halting which
creates a risk for falls.
 Most common gait
characteristics are
short, quick steps.
 Can appear as if they
are scrambling
forward to keep their
balance.
Secondary Symptoms
 Depression
 Emotional Changes
(Irritable, pessimistic,
fearful, become
dependent or isolated)
 Memory Loss (slower
thought processes)
 Swallowing
Difficulties




Speech Problems
Bladder/Bowel Prob’s
Excessive sweating
Sleep Disturbance
Causes
 Basal Ganglia and
 Dopamine is
Substantia Nigra cell
responsible for the
death or dysfunction
transmission of
signals associated
 These neurons
with smooth,
produce the
controlled, muscular
neurotransmitter
activity from the
(neuro-chemical)
substantia nigra to the
dopamine
corpus striatum
Causes cont’d
 PD “occurs” when
these neurons die or
fail to function
properly.
 Without enough
dopamine, neurons in
the corpus striatum do
not function in the
usual coordinated
manner.
 The result is an
inability to direct or
control the body’s
movements normally.
 Typical PD pt. has an
80% reduction of
dopamine producing
cells.
Theories about cell death
 Nerve cells are
 Damage is normally
damaged by free
controlled by other
radicals - unstable
chemicals called
molecules generated
antioxidants.
by normal chemical
 Not understood yet
reactions.
what mechanistic
 Free radicals lack one
event prevents this
electron and attempt
“checks and balances”
to replace it by
reacting with nearby
procedure to take
molecules in a process
place.
called oxidation.
Theories about cell death cont’d
 Toxins destroy
 Genetic factors
dopamine producing
 1/5th of PD pt.s have
neurons.
at least 1 relative with
 Exposure to pesticides
parkinsonian
or a toxic substance in
symptoms
the food supply.
 Investigating the
 Not proven
theory that the roots
conclusively.
of PD are in a facet of
DNA.
Incidence
 500,000 Americans
have the diagnosis of
PD
 50,000 new cases
each year (in the U.S.
alone)
 Numbers are higher
because of dismissal
of symptoms or
misdiagnosis.
 Not gender-specific
 Avg. age of onset is
60 yrs. Old
 Estimated that 5-10%
of pt.s experience
symptoms before the
age of 40.
Diagnosis
 Neuropsychological
tests
 CAT (computerized
tomography)
 MRI (magnetic
resonance)
 These are used to rule
out other diagnosis
 Side effects of
medications
 Multiple Strokes
 Progressive
Supranuclear Palsy
 Shy-Drager
Syndrome
 Wilsons Disease
Treatment
 Cure does not exist
 Tx is usually
comprised of
medications and
therapies that relieve
symptoms.
 Levodopa (Sinemet)
 First used in the
1960’s
 Delays the onset of
symptoms for 75% of
PD pt.s
 Used to make
dopamine, which
itself cannot be
injected into the body
because it cannot pass
the blood-brain
barrier.
Treatment cont’d
 When Levodopa is
combined with
Carbidopa, L-dopa
holds back the
conversion of
levodopa into
dopamine until it
reaches the brain.
 Effective in treating
bradykinesia and
rigidity
 Less effective in
reducing tremor
 Often ineffective in
relieving problems
related to balance.
Levodopa Side Effects





Nausea
Vomiting
Low Blood Pressure
Restlessness
Twitching, nodding,
jerking (large doses)
 Lower dosage limits
the side effects but
symptoms then
reoccur.
 Long-term use
diminishes
effectiveness
 Taking frequently but
in smaller amounts is
an occasionally
effective solution.
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