Wernicke's Encephalopathy

Question 1

Define:

Answer 1

The presence of neurological symptoms due to biochemical lesions in the CNS caused by s deficiency in thiamine.

This affects the hypothalamus, cerebral cortex and the cerebellum.

Question 2

What is the main cause of wernicke’s encephalopathy:

Answer 2

Chronic alcohol abuse this leads to:

• Decreased thiamine intake
• Malabsorption of thiamine at the duodenum
• Impaired thiamine utilisation

Question 3

Other causes/risk factors:

Answer 3

Malnutrition including anorexia
Malabsorption (IBD)
GI malignancies 
Thyrotoxicosis
AIDS
Prolonged vomiting e.g. due to chemotherapy
Chronic subdural haemotoma

Question 4

Epidemiology:

Answer 4

10-24% of dementia is due to alcohol abuse

More common in 50-60 year olds and in areas of lower socio-economic status

Question 5

Symptoms:

Answer 5

Impairment in vision - diplopia, eye movement abnormalities and ptosis

Loss of muscle co-ordination - unstable gait

Loss of memory

Inability to form new memories

Hallucinations

Question 6

Signs:

Answer 6

Triad:

• Confusion
• Ataxia (wide based gait)
• Ophthalmoplegia (nystagmus, lateral rectus or conjugate gaze palsies)

May have decreased reflexes, low temp, rapid pulse or be cachectic

If it has progressed to Korsakoffs –> Amnesia and confabulation

Question 7

Investigations:

Answer 7

Usually a clinical diagnosis

Tests that may help are:
FBC (alcoholics have an increased MCV)
Serum thiamine levels
U + Es (to exclude metabolic causes)
ABG 
LFTS
Glucose 
Red cell transketolase will be decreases but this is rarely done.

CT head