Parkinson's Disease Flashcards
Parkinson’s Disease is _______, ___________, and ___________________
chronic, progressive, neurodegenerative
What is the pathophysiology of PD?
Progressive death of dopamine-producing neurons in the substantia nigra (part of the basal ganglia)
Why is dopamine important in terms of movement? (3)
- Important for smooth, coordinated, controlled movements
- Death of dopaminergic neurons -> messages telling the body how and when to move are delivered slowly or incompletely
- Individual is unable to initiate and control movements in a normal way
What are the 2 components that make up the substantia nigra? What does each component produce?
- Pars compacta - dopamine producing
- Pars reticulata - GABA neurons
What are 3 risk factors for PD?
- Family history -> genetic component
- Pesticide exposure (rural, farmer, drink well water)
- Repeated head injuries
What are 3 protective factors against PD?
- Cigarette smoking
- High coffee consumption
- Intensive exercise
For the hallmark movement symptoms of PD, remember TRAP. What is that?
Tremor
Rigidity
Akinesia/Bradykinesia
Postural instability
The key motor features of PD can be remembered as the 3S’s. What are they?
Slow
Stiff
Shaky
What is the Movement Disorder Society Clinical Diagnostic Criteria for PD?
(What must be present? Need at least 1 of what? What are the supportive criteria?)
- Must be present - bradykinesia
- At least 1 of - rest tremor or rigidity
- Supportive criteria:
- Clear response to dopaminergic treatment
- Levodopa-induced dyskinesias
- Olfactory loss
What are 2 subtypes of PD?
- Tremor-predominant subtype
- Often younger PD patients
- Typically have a slower, more benign course of progression - Akinetic/rigid subtype
- Often have a more rapid rate of progression of motor symptoms
- Particularly in older patients – more likely to develop dementia
What are some medications classes that cause secondary Parkinsonism? (4)
- Typical APs
- Atypical APs
- Antinauseants/prokinetics
- Miscellaneous
- Lithium
- DVP
What are 3 typical APs that can cause secondary Parkinsonism?
- Chlorpromazine
- Haloperidol
- Prochlorperazine
What are 4 atypical APs that can cause secondary Parkinsonism?
- Risperidone
- Olanzapine
- Aripiprazole
- Ziprasidone
What are 3 alternative atypical APs that are less likely to cause secondary Parkinsonism?
- Quetiapine
- Clozapine
- Pimavanserin
What antinauseant/prokinetic agent can cause secondary Parkinsonism? What is a safer alternative?
- Metoclopramide
Safer alternative = domperidone
What are the non-motor symptoms of PD that often precede motor symptoms? (5)
Hyposmia – loss of sense of smell
Constipation
Depression
Fatigue
REM Sleep Behaviour Disorder
What are the non-motor symptoms of PD that are seen early in the disease course? (4)
“Flat affect”
Micrographia
Hypophonia – soft speech
Dry eyes
What are some of the later non-motor PD symptoms? (5)
- Psychiatric disturbances – delusions and hallucinations
- Sialorrhea (drooling)
- Sexual dysfunction
- Autonomic dysfunction
- Orthostatic hypotension
- Urinary and fecal incontinence - Cognitive impairment and dementia
True or False? PD treatment modifies disease progression
False - no PD treatment modifies disease progression - symptomatic treatment only
What are the goals of therapy for PD? (4)
- Reduce signs and symptoms of PD (both motor and non-motor)
- Minimize complications of drug therapy
- Maintain independence
- Improve/maintain quality of life
What are the non-pharm treatment options for PD? (6)
- Physical Therapy: Help maintain motor function
- Occupational Therapy: Adaptive equipment, home safety
- Speech Therapy:
- Assist with soft speech
- Assess swallowing safety - Hearing, vision, and dental care
- Psychological Support
- Surgery
What does PD pharmacotherapy primarily focus on?
Increasing dopamine levels (directly or indirectly)
What are the 6 pharmacological classes of medications for PD management?
- Levodopa
- Dopamine Agonists
- MAO-B Inhibitors (MAOIs)
- Amantadine
- COMT Inhibitors
- Anticholinergics
Which PD med is the effective cornerstone of therapy?
Levodopa
Levodopa is always used in combination with?
A peripheral decarboxylase inhibitor (carbidopa or benserazide)
Why is levodopa given in combination with a peripheral decarboxylase inhibitor? (2)
- Prevents conversion of levodopa to dopamine outside of the brain
- Enhances efficacy
- Reduces adverse effects - Both carbidopa and benserazide cannot cross BBB
- Levodopa → crosses BBB → converted to dopamine via decarboxylase
Initially, levodopa treatment is universally effective for: (2 - symtpoms)
- Bradykinesia
- Usually start seeing response within days - Rigidity
- Maximal improvement in ~2 weeks
Levodopa has variable effect on which PD symptom?
Tremor
Which symptoms of PD is levodopa less likely to help with? (2)
- Poor balance
- Non-motor symptoms
What 3 things decrease bioavailability of levodopa?
- Protein
- Iron
- Antacids
What are the adverse effects of levodopa? (5)
- Nausea, stomach upset
- Dizziness
- Fatigue
- Vivid dreams
- Confusion/hallucinations –> usually not until later stages
After ~5 years of treatment, complications of levodopa therapy develop. What are they? (4)
- Wearing off - meds not lasting as long as they used to
- On-off phenomena
- Freezing - inability to move
- Dyskinesias - abnormal, uncontrollable, involuntary movements
What is on-off phenomena?
Fine one minute, drug effect has totally worn off the next
New formulations of levodopa have been developed to address some of the limitations with oral administration. What are they?
- Duodopa - levo/carbidopa intestinal gel
- Vyalev - foslevodopa/foscarbidopa SQ infusion
- Levodopa inhaled capsules (not in Canada, don’t worry about this one)
How is duodopa gel infusion administered?
Via enteral PEG-J tube
- Connected to a pump, which delivers low and constant doses of Duodopa
What is the benefit of Duodopa gel infusion?
Reduces off-time by ~2 hours/day without increasing dyskinesias
How is Vyalev SQ infusion administered?
Administered via continuous subcutaneous infusion
- Connected to a pump, which delivers low and constant doses of Vyalev
- Does NOT require surgery to initiate (i.e. insertion of PEJ tube)
The most common adverse reactions of Vyalev SQ infusion are? (3)
- Injection-site reactions
- Dyskinesias
- Psychosis