Parkinson's

Question 1

What is Idiopathic Parkinson’s disease (PD)?

Answer 1

• Neurodegenerative disorder
• Cardinal features:
  
  • Resting tremor, rigidity, bradykinesia, postural instability
• +/- non-motor symptoms

Question 2

Epidemiology of PD?

Answer 2

• Prevalence of disease increases with age
• Mean age of onset is 65 years

Question 3

Aetiology of PD?

Answer 3

• Loss of dopaminergic neurons in the substantia nigra
• Lewy bodies in the basal ganglia, brainstem and cortex
• Most cases are sporadic, but genetic loci have been identified in familial cases:
  
  • eg genes coding for alpha synuclein, PINK-1, parkin

Question 4

Classification of PD?

Answer 4

• Age of onset
  
  • Juvenile parkinsonism: under 21 years
  • Young-onset parkinsonism: 21 to 40 years
  • PD: 40+ years

Question 5

What is the extrapyrimidal triad of Parkinsonism?

Answer 5

• Tremor
  
  • Worse at rest, pill rolling
• Hypertonia
  
  • Rigitiy + tremor gives cogwheel rigidity
  • Felt by examiner during pronation and supination
• Bradykinesia
  
  • Slow to intiate movement
  • Shuffling, leaning forward gait - Marche a petit pas
  • Micrographia

Question 6

Clinical features of Parkinsons?

Answer 6

• Parkinsonian triad
• Non-motor symptoms:
  
  • Autonomic dysfuction: postural hypotension, constipation
  • Sleep disturbance
  • Reduced sense of smell
  • Depression, dementia, psychosis

Question 7

Describe the diagnosis of PD?

Answer 7

• Clinical
• Based on bradykinasia with resting tremor and/or hypertonia
• Cerebellar disease and frontotemporal dementia should be excluded
• Clinical response to dopaminergic therapy
• If signs are NOT worse on one side, look for another cause:
  
  • MRI for structural pathology

Question 8

Risk factors for PD?

Answer 8

• Increasing age
• History of familial PD in younger-onset disease
• Mutation in gene encoding glucocerebrosidase
• MPTP exposure

Question 9

What is the first test to order for a patient with suspected PD?

Answer 9

• Dopaminergic agent trial
  
  • Should be improvement in symptoms in PD

Question 10

What other tests should be considered in a patient with suspected PD?

Answer 10

• MRI brain
  
  • May show other causes: trauma, stroke
• Fluorodopa PET
  
  • Decreased basal ganglia dopamine uptake
• Olfactory testing
  
  • Hyposmia or anosmia
• Genetic testing

Question 11

Name some differentials for PD?

Answer 11

• Progressive supranuclear palsy (PSP)
  
  • Midbrain atrophy on MRI supportive of PSP
• Lewy body dementia
  
  • Neuropsychometric testing may distinguish cognitive defect domains
• Drug-induced parkinsonsim
  
  • History of specific drug usage

Question 12

What drugs can cause drug-induced parkinsonism?

Answer 12

• Lithium
• Neuroleptic
• Metoclopramide
• Calcium channel blocker

Question 13

Describe the treatment for mild parkinsonism?

Answer 13

Question 14

Describe the treatment for moderate parkinsonism?

Answer 14

Question 15

Describe the treatment for advanced parkinsonism?

Answer 15

Question 16

Examples of monoamine oxidase-B (MAO-B) inhibitors?

Answer 16

• Rasagiline
• Selegiline

Question 17

Examples of dopamine agonists?

Answer 17

• Ropinorole
• Rotigotine
• Pramipexole

Question 18

Describe the use of Levadopa for PD?

Answer 18

• Dopamine precursor
  
  • Combined with dopa-decarboxylase inhibitor
• SEs: dyskinesia, painful dystonia, psychosis, N/V
  
  • Give domperidone for N/V

Question 19

Describe the use of dopamine agonists in PD?

Answer 19

• Can delay starting levadopa in early PD
• Allow lower doses of levadopa as disease progresses
• SEs: drowsiness, nausea, hallucinations, compulsive behavioue

Question 20

Describe the use of MAO-B inhibitors in PD?

Answer 20

• Alternatice to dopamine agonists in early PD
• SEs: postural hypotension, AF

Question 21

Describe the use of COMTinhibitors in PD?

Answer 21

• May help with motor complications in late disease
• Requires monitoring of LFTs

Question 22

Examples of COMT inhibitors?

Answer 22

• Entacapone
• Tollecapone