Condition- Wernicke's Encephalopathy

Question 1

What is Wernicke’s encephalopathy? A deficiency in what vitamin/ mineral causes it and which group of the population is more at risk?

Answer 1

A neuropsychiatric disorder caused by thiamine (B1) deficiency commonly seen in alcoholics

Question 2

List three ways in which chronic alcoholism may lead to thiamine deficiency

Answer 2

• Inadequate nutritional thiamine intake + storage due to cirrhosis of liver where thiamine is stored
• Decreased thiamine absorption due to decreased gene expression for thiamine transporter-1
• Impaired thiamine utilisation by cells due to impaired conversion of thiamine to active form

Question 3

Other than chronic alcoholics list some other risk factors for developing Wernicke’s encephalopathy

Answer 3

• Eating disorders
• Malnutrition
• Prolonged vomiting e.g. with chemotherapy
• GI malignancy
• Chronic subdural haematoma
• AIDS
• Hyperemesis gravidarum
• Thyrotoxicosis

Question 4

List two areas of the brain which are commonly affected in Wernicke’s encephalopathy

Answer 4

• Mamillary bodies
• Cerebellum

Question 5

What is the role of the mamillary bodies?

Answer 5

Memory

Emotion

Behaviour

Question 6

List some of the presenting symptoms of Wernicke’s encephalopathy…

Answer 6

werNICke mnemonic

1. Nystagmus/ opthalmoplegia
2. Incoordination/ ataxia
3. Confusion/ memory impairement- inability to form new memories

Other symptoms:

*

Question 7

Korsokoff psychosis may also develop- what two additional symtpoms does this condition involve?

Answer 7

• Antero- and retrograe amnesia
• Confabulation
• • werNICke’s symptoms

Question 8

List some signs of Wernicke’s on clinical examination

Answer 8

• cachexia
• tachycardia, hypotension, hypothermia
• Nystagmus
• Abnormal, unsteady gait
• May show decreased reflexes and polyneuropathy

Question 9

List some investigations you could carry out on someone with suspected Wernicke’s encephalopathy…

Answer 9

• Based on clinical examination and hx
• Could conduct bloods to exclude other causes:
  
  • FBC (high MCV is a common feature amongst alcoholics)
  • U&Es (exclude metabolic imbalances as a cause of confusion), LFTs, Glucose, ABG (hypercapnia and hypoxia can cause confusion)
  • Serum thiamine
  • Red cell transketolase activity is decreased – rarely done
• MRI head: degeneration of mamillary bodies

Question 10

If an alcoholic patient presents to hospital with ataxia, nystagmus and confusion what is the most important step that should be taken?

Answer 10

• Administer thiamine infusion urgently to prevent progression of Wernicke’s encephalopathy to Wernicke’s-Korsokoff syndrome (Korsokoff psychosis) which has irreversibe implications
• Also give glucose afterwards