Wernicke's encephalopathy and Korsakoff's psychosis

Question 1

What is Wernicke-Korsakoff syndrome?

Answer 1

A brain disorder caused by neuronal degeneration secondary to thiamine (vitamin B1) deficiency.

Seen most commonly in heavy drinkers.

Question 2

What is the progression of Wernicke-Korsakoff syndrome?

Answer 2

1. Wernicke encephalopathy: acute; reversible
   
   • Medical emergency to prevent progression
2. Korsakoff psychosis: chronic; irreversible

Question 3

Give three presenting features of Wernicke encephalopathy?

Answer 3

• Classical triad (10%):
  
  • Ophthalmoplegia esp. CN VI; lateral nystagmus
  • Ataxia
  • Acute confusional state (80%)
• Peripheral neuropathy
• Resting tachycardia; hypotension
• Nutritional deficiency
• Hypothermia
• Coma; death

Question 4

Why is Wernicke encephalopathy most commonly seen in heavy drinkers?

Answer 4

• Reduced food intake
• Alcohol interferes with activtion of thiamine
• Villus atrophy: poor absorption
• Cirrhosis: impaired storage of thiamine

Question 5

What are the features of Korsakoff syndrome?

Answer 5

• Severe memory impairment:
  
  • Anterograde amnesia: inability to create new memories
  • Retrograde amnesia: inability to recall previous memories
• Confabulation: creates stories to fill in memory gaps

Working, procedural and emotional memories intact

Question 6

What is the implication of working, procedural and emotional memories being intact in Korsakoff syndrome?

Answer 6

Likely to score full marks on the MMSE, despite having severe cognitive impairment.

Question 7

Outline the treatment of Wernicke encephalopathy

Answer 7

Treat if suspected Wernicke’s, do not wait for confirmation

• IV Pabrinex (vitamins C, B₁, B₂, B₃, and B₆)
  
  • Two ampoules for 3-7 days
• IV glucose
  
  • After normalising thiamine to prevent lactic acidosis

Question 8

What is the prophylactic treatment of Wernicke encephalopathy?

Answer 8

• IV Pabrinex: 1 ampoule
• Parenteral vitamins

Question 9

Why is oral thiamine not used to treat Wernicke encephalopathy

What is its indication?

Answer 9

• Very low (1-2%) oral bioavailability
• Indicated for long-term use in active drinkers and detox

Question 10

Outline the management of Korsakoff syndrome

Answer 10

Aim for functional improvement:

• Oral thiamine replacement and vitamins up to 2yrs
• Treat psychiatric comorbidities ^eg. depression
• OT assessment
• Cognitive rehabilitation

Question 11

What is the prognosis of Wernicke encephalopathy?

Answer 11

• Untreated: 84% develop Korsakoff psychosis
• Treated:
  
  • Ophthalmoplegia and confusion resolve in days
  • Ataxia, neuropathy, and nystagmus may be permanent.