Wernicke's encephalopathy Flashcards
Define Wernicke’s encephalopathy
Presence of neurological symptoms caused by biochemical lesions of the CNS following exhaustion of vitamin B (particularly thiamine) reserves
Aetiology of Wernicke’s encephalopathy
Thiamine deficiency results in abnormal cellular function in the cerebral cortex, hypothalamus & cerebellum
Causes of Wernicke’s encephalopathy
5
Chronic alcohol consumption Chronic subdural haematoma AIDS Hyperemesis gravidarum Thyrotoxicosis
Chronic alcohol consumption causes…
3
Inadequate nutritional thiamine intake
Decreased thiamine absorption
Impaired thiamine utilisation by cells
Epidemiology of Wernicke’s encephalopathy
3
10-24% dementia caused by alcohol-related brain damage
Prevalence higher in areas of socio economic deprivation
Higher prevalence in 50-60 yr olds
Presenting symptoms of Wernicke’s encephalopathy
5
Visions changes
diplopia
eye movement abnormalities
ptosis
Loss of muscle coordination
unsteady gait
Loss of memory
Inability to form new memories
Hallucinations
Signs of Wernicke’s encephalopathy on physical examination
triad +8
Triad of:
Confusion
Ophthalmoplegia
Ataxia
Usually mentally alert (vocabulary, comprehension, motor skills maintained) Some 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 Rapid pulse Some are cachectic
Investigations for Wernicke’s encephalopathy
general +7
Diagnosis mainly based on history & examination
Potentially useful: FBC - high MCV common in alcoholics U&Es - exclude metabolic imbalance as cause LFTs Glucose ABG - hypercapnia & hypoxia can cause confusion Serum thiamine CT head
Deterioration of Wernicke’s encephalopathy
state + 2 extra symptoms
Korsakoff’s psychosis
Amnesia
Confabulation
