Station 3.21: Parkinson's disease

Question 1

Clinical signs

What are the clinical signs of Parkinson’s disease?

Parkinson’s disease

This man complains of a persistent tremor. Examine him neurologically

Answer 1

• Expressionless face with an absence of spontaneous movements.
• Coarse, pill‐rolling, 3–5Hz tremor. Characteristically asymmetrical.
• Bradykinesia (demonstrated by asking patient to repeatedly oppose each digit onto thumb in quick succession).
• Cogwheel rigidity at wrists (enhanced by synkinesis – simultaneous movement of the other limb (tap opposite hand on knee, or wave arm up and down)).
• Gait is shuffling and festinant. Absence of arm swinging – often asymmetrical.
• Speech is slow, faint and monotonous.

Question 2

Additional clinical signs

What are the additional clinical signs of Parkinson’s disease?

Parkinson’s disease

This man complains of a persistent tremor. Examine him neurologically

Answer 2

• BP looking for evidence of multisystem atrophy: Parkinsonism with postural hypotension, cerebellar and pyramidal signs.
• Test vertical eye movements (up and down) for evidence of progressive
• supranuclear palsy.
• Dementia and Parkinsonism: Lewy‐body dementia.
• Ask for a medication history

Question 3

Discussion - Causes of Parkinsonism

What are the casues of Parkinson’s disease?

Parkinson’s disease

This man complains of a persistent tremor. Examine him neurologically

Answer 3

Parkinson’s disease (idiopathic)
Parkinson plus syndromes:
————Multisystem atrophy (Shy–Drager)
————Progressive supranuclear palsy (Steele–Richardson–Olszewski)
————Corticobasal degeneration; unilateral Parkinsonian signs
Drug‐induced, particularly phenothiazines
Anoxic brain damage
Post‐encephalitis
MPTP toxicity (‘frozen addict syndrome’)

Question 4

Discussion - Pathology

Pathology for Parkinson’s disease?

Parkinson’s disease

This man complains of a persistent tremor. Examine him neurologically

Answer 4

• Degeneration of the dopaminergic neurones between the substantia nigra and basal ganglia.

Question 5

Discussion - Treatment

What is the Treatment for Parkinson’s disease?

Parkinson’s disease

This man complains of a persistent tremor. Examine him neurologically

Answer 5

• l‐Dopa with a peripheral Dopa‐decarboxylase inhibitor, e.g. Madopar/co‐beneldopa:
  ⚬ Problems with nausea and dyskinesia
  ⚬ Effects wear off after a few years so generally delay treatment as long as possible
  ⚬ End‐of‐dose effect and on/off motor fluctuation may be reduced by modified release
• preparations
• Dopamine agonists, e.g. Pergolide:
  ⚬ Use in younger patients: less side effects (nausea and hallucinations) and save l‐Dopa until necessary
  ⚬ Apomorpine (also dopamine agonist) given as an SC injection or infusion; rescue therapy for patients with severe ‘off’ periods
• MAO‐B inhibitor, e.g. Selegiline, inhibit the breakdown of dopamine
• Anti‐cholinergics, can reduce tremor, particularly drug‐induced
• COMT inhibitors, e.g. Entacapone, inhibit peripheral breakdown of l‐Dopa thus reducing motor fluctuations
• Amantadine, increases dopamine release
• Surgery; deep‐brain stimulation (to either the subthalamic nucleus or globus pallidus) helps symptoms

Question 6

Discussion - Causes of tremor

What is the Causes of tremor for Parkinson’s disease?

Parkinson’s disease

This man complains of a persistent tremor. Examine him neurologically

Answer 6

• Resting tremor: Parkinson’s disease
• Postural tremor (worse with arms outstretched):
  ⚬ Benign essential tremor (50% familial) improves with EtOH
  ⚬ Anxiety
  ⚬ Thyrotoxicosis
  ⚬ Metabolic: CO2 and hepatic encephalopathy
  ⚬ Alcohol
• Intention tremor: seen in cerebellar disease