Parkinson Disease Flashcards
Parkinson’s Disease – Clinical Features
Cardinal signs
Diagnosis requires 2 of 3
Bradykinesia, rigidity, tremor (primarily at rest)
Other signs
Masked face, decreased arm swing, hypovolemic speech, swallowing difficulty, micrographia, stooped posture, shuffling gait, start hesitancy, festination and freezing.
Postural instability (later)
Parkinson’s Disease Risk Factors
Definite: Old age
Highly likely: MZ co-twin with early-onset PD
Probable: Positive family history
Possible: Herbicides, pesticides, heavy metals, proximity to
industry, rural residence, well water, repeated head trauma,
etc.
Possible protective effect: smoking, caffeine
Parkinson’s Disease – Diagnosis
No definitive diagnostic test for PD is currently available
PD is diagnosed clinically from history taking and neurological
examination
MRI brain/spine
Positron emission tomography (PET), single photon emission
computed tomography (SPECT)
Parkinson’s Disease – Treatment
There are no known cure for PD at this time and the goal of
treatment is to control symptoms
Complementary and supportive therapy
Surgery
major drugs available for the treatment of PD motor
symptoms include:
●Levodopa
●Dopamine agonists
●Monoamine oxidase (MAO) B inhibitors
●Anticholinergic agents
●Amantadine
●Catechol-O-methyl transferase (COMT) inhibitors
Treatment: Neuroprotective Therapies
No definite medication yet
Selegiline – Monoamine Oxidase (MAO-B) enzyme inhibitors
reduce the rate of progression of PD in laboratory settings
Improves the symptoms of the disease
Coenzyme Q-10 – a powerful antioxidant (1200 mg)
Preliminary studies suggested reduced rate of
progression of the disease
Treatment: Early Symptomatic Therapies
When symptoms has adverse effects
and interfere with daily activities
Selegiline
Amantadine – anti-viral agent that
relieve symptoms in 2/3 of patients
Benzhexol (pharm class & side effects)
anti-cholinergics – useful
in treating tremors
Side effects – dryness of the mouth,
urinary retention, memory problems and hallucinations
Treatment: Main Symptomatic Therapies
When symptoms of PD become more significant – replace the dopamine deficiency
Dopamine agonists and levodopa
Dopamine agonists – act like
– act like dopamine in the brain and
stimulate the brain cells to function normally
Egs of dopamine agonists
Bromocriptine, Pramipexole (Sifrol), Ropinorole (Requip)
Side effects of dopamine agonists
Start at a low dose and increased gradually to reduce side effects –
nausea, vomiting, giddiness on standing, hallucinations may
occur especially in older patients with dementia
Levodopa MOA
converted to dopamine in the brain, hence restoring the reduced dopamine levels
Madopar or Sinemet with
enzyme inhibitor (dopadecarboxylase inhibitor) –
reduce side effects of nausea
and vomiting and more
levodopa to get into the brain
Treatment: Main Symptomatic Therapies
Side effects similar to dopamine agonists
Domperidone may be used to counter the side effects of nausea and vomiting
> 5 years on levodopa
Wearing-off effect – beneficial effects of medication wear off after a
few hours
Levodopa-related dyskinesias – abnormal involuntary movements
related to the peak dose of levodopa in the body
when to take levodopa
Take levodopa on empty stomach
Amantadine
reduce the severity of dyskinesias
may have ankle swelling, skin rashes and hallucinations
