Neurology - Parkinson's Disease Flashcards
What is Parkinson’s disease?
Progressive reduction in dopamine in the basal ganglia, leading to movement disorders
Symtpoms are typically assymetrical
What is the typical Parkinson’s patient?
Older man around 70
Gradual symptom onset
What are the classic triad features of Parkinson’s disease?
- Resting tremor
- Rigidity
- Bradykinesia
What is the role of dopamine in the basal ganglia?
Essential for coordinating habitual movements and controlling voluntary movements
Describe the characteristics of the tremor in Parkinson’s disease
Worse on one side
4-6 hertz frequency
Improves with voluntary movement
Pill-rolling tremor
More noticeable when resting, imrpoves on movement
Worse when patient is distracted e.g. using other hand
What is rigidity in Parkinson’s disease?
Resistance to passive movement of a joint
Jerking resistance to movement
Ccogwheel rigidity
How does bradykinesia present in Parkinson’s
- Micrographia
- Shuffling gait
- Rapid frequency of steps to compensate for small steps and avoid fallnig Festinating gait
- Difficulty initating movement
- Difficulty in turning around when standing
- Reduced facial movements and expression (hypomimia)
What are some other features associated with Parkinson’s disease?
- Depression
- Sleep disturbance
- Anosmia
- Postural instability
- Cognitive impairment
Complete the table
Name some Parkinson’s-plus syndromes
- Multiple system atrophy
- Dementia with Lewy bodies
- Progressive supranuclear palsy
- Corticobasal degeneration
What is multiple system atrophy?
A rare condition with degeneration of various brain systems, including the basal ganglia, leading to a Parkinson’s presentation
Denergation in other areas leads to autonomic dysfunction and cerebellar dysfunction
What are the symptoms associated with dementia with Lewy bodies?
- Progressive cognitive decline
- Visual hallucinations
- Delusions
- REM sleep disorders
- Fluctuating consciousness
How is Parkinson’s disease diagnosed?
Clinically, based on history and examination findings by an experienced specialist
UK Parkinson’s Disease Society Brain Bank Clinical Diagnostic Criteria
What is the primary focus of treatment for Parkinson’s disease?
Controlling symptoms and minimising side effects
What are the different treatment options for Parkinson’s
- Levodopa (with peripheral decarboxylase inhibitors)
- COMTis
- Dopamine agonists
- Monoamine oxidase-B inhibitors
What is levodopa?
Synthetic dopamine taken orally, usually combined with a peripheral decarboxylase inhibitor (e.g. Carbidopa)
Prevents levodopa being metabolised before reaching the brain
Why is Levodopa not given first line?
Most effective treatment for symptoms
Less effective over time
How is levodopa given?
As a combination drug e.g.
Co-beneldopa (levodopa and benserazie)
Co-careledopa (levodopa and carbidopa)
What are the main side effects of levodopa?
- Dyskinesia
- Dystonia
- Chorea
- Athetosis
What can be given to manage dyskinesia associated with levodopa?
Amantadine
Glutamate antagonist
What are COMT inhibitors?
Inhibitors of catechol-o-methyltransferase that extend the effective duration of levodopa
Slows levodopa breakdown
What do dopamine agonists do?
Mimic the action of dopamine in the basal ganglia, stimulating dopamine receptors
Less effective than levodopa
Used to delay use of levodopa, typically then used in combination
What is a significant side effect of prolonged dopamine agonist use?
Pulmonary fibrosis
e.g. Bromocriptine
Pergolide
Cabergoline
What is the function of monoamine oxidase-B inhibitors?
Block monoamine oxidase-B enzymes to increase circulating dopamine
e.g. Selegiline
Rasagiline
