Wernicke's encephalopathy

Question 1

What is WE?

Answer 1

Acute/ reversible stage of the manifestation of Vitamin B1/ Thiamine deficiency

Question 2

What is the role of thiamine in the body?

Answer 2

Thiamine needs to be phosphorylated to become thiamine pyrophosphate (it’s metabolically active form) [ATP  AMP]. Thiamine pyrophosphate:

• Assists other enzymes needed for glucose metabolism
• In the brain, metabolises lipids and carbohydrates and maintains normal amino acids and neurotransmitter levels.
• Helps with propagation of neural impulses too

Question 3

Where is thiamine stored/ absorbed

Answer 3

Liver/ duodenum

Question 4

Therefore, what will a deficiency in thiamine lead to?

Answer 4

will reduce glucose metabolism and impact cellular energy.

Question 5

What are the causes of WE?

Answer 5

1. Alcohol abuse- interferes with the activation (phosphorylation) of thiamine. Excess alcohol also leads to fatty liver/ liver cirrhosis which interferes with thiamine storage. Alcohol is also thought to decrease the gene expression of thiamine 1 transporter in the duodenum.
2. Inadequate intake- anorexia/ malnutrition can lead to thiamine deficiency.
3. GI malabsorption of thiamine in the duodenum- due to stomach cancer or IBS
4. Prolonged vomiting- e.g. with chemotherapy, GI malignancy

Question 6

what are the symptoms of WE?

Answer 6

1. Confusion/ apathy
2. Ataxia- unsteady gait
3. vision changes
4. Also memory disturbance

Question 7

Signs of WE:

Answer 7

• Ophthalmoplegia; weakness/ paralysis of eye muscles
• Nystagmus
• Altered GCS
• Hypotension
• Hypothermia

Question 8

What are the different areas of the brain WE can affect and what symptoms may occur as a result?

Answer 8

1. Cerebellum affected first causing altered movement and balance
2. Brainstem- impact cranial nerve function. If medulla affected, HR and breathing will change
3. Mamillary bodies- haemorrhage, necrosis and complete destruction of the mamillary bodies which are a part of the limbic system (memory, emotion and behaviour)

Question 9

What investigations would you do for WE?

Answer 9

1. Take a good history
2. Bloods- FBC, measure thiamine, U&Es, LFTs, glucose, ABG (for hypercapnia)
3. Red cell transketolase activity will be reduced.
4. CT/ MRI may show degeneration of the mamillary bodies

Question 10

What is the treatment for WE?

Answer 10

• Replacement of the thiamine- infusion (IV) over a few days and continue oral supplements until patient is no longer at risk.
• Infusion also given with glucose (but only when thiamine level are stabilised otherwise it would be pointless).

Question 11

What are the complications of WE?

Answer 11

If left untreated, death occurs in 20% and 85% result in Korsakoff’s syndrome.

This is irreversible/ chronic stage of thiamine deficiency. This is characterised by:

• Anterograde and retrograde amnesia
• Confabulation- when person makes up stories and believes they are true due to the lack of memories

Question 12

Which sort of populations is WE seen in?

Answer 12

Areas with socio-economic depression