Wernicke's encephalopathy

Question 1

What is Wernicke’s encephalopathy?

Answer 1

Neurological disease characterised by a
triad of ophthalmoparesis with nystagmus, ataxia, + confusion.
Life-threatening
Caused by thiamine deficiency, which primarily affects PNS + CNS

Question 2

What is the main cause of Wernicke’s encephalopathy?

Answer 2

CHRONIC ALCOHOL CONSUMPTION which results in thiamine deficiency by causing:
Inadequate nutritional thiamine intake
Decreased thiamine absorption
Impaired thiamine utilisation by cells

Question 3

List 5 other conditions that cause thiamine deficiency?

Answer 3

Chronic subdural haematoma  
AIDS  
Malnutrition
Hyperemesis gravidarum 
Thyrotoxicosis 
Thiamine deficiency results in abnormal cellular function in the cerebral cortex, hypothalamus + cerebellum

Question 4

Describe the epidemiology of Wernicke’s encephalopathy

Answer 4

Alcohol-related brain damage accounts for 10-24% of all dementia
Higher prevalence in areas of socio-economic deprivation
Higher prevalence in 50-60 yrs

Question 5

List 5 symptoms of Wernicke’s encephalopathy

Answer 5

Vision changes: diplopia, ptosis  
Loss of muscle coordination: unsteady gait  
Loss of memory 
Inability to form new memories 
Hallucinations

Question 6

What are 8 signs of Wernicke’s encephalopathy

Answer 6

Pt is usually mentally alert with vocabulary, comprehension, motor skills, social habits + naming ability maintained  
May show signs of polyneuropathy 
Reflexes may be decreased  
Abnormal gait + coordination  
Eye abnormalities on movement: nystagmus, bilateral lateral rectus palsy, conjugate gaze palsy
Low temperature  
Tachycardia
Some may be cachectic

Question 7

What does deterioration of Wernicke’s encephalopathy result in?

Answer 7

Korsakoff’s Psychosis
In addition, pt presents with:
Amnesia (profound impairment of retrograde + anterograde memory)
Confabulation

Question 8

What is diagnosis of Wernicke’s encephalopathy mainly based on?

Answer 8

Hx + examination

Question 9

What investigations may be useful in Wernicke’s encephalopathy ?

Answer 9

FBC (high MCV common in alcoholics)
U+Es (exclude metabolic imbalances as cause of confusion)
LFTs (high)
Glucose (high or low can cause confusion)
ABG (hypercapnia + hypoxia can cause confusion)
Serum thiamine