Neurological disorder caused by thiamine (vitamin B1) deficiency, manifesting in a triad of specific clinical symptoms: ataxia, confusion, and ocular abnormalities

Aetiology

The primary causes of Wernicke's encephalopathy include:

• Chronic alcohol abuse: alcohol interferes with thiamine absorption and utilisation
• Malnutrition: this can occur due to inadequate dietary intake, malabsorption disorders, or increased requirements
• Bariatric surgery: rapid weight loss and reduced nutrient absorption can lead to thiamine deficiency
• Hyperemesis gravidarum: persistent severe vomiting in pregnancy may lead to nutrient deficiencies, including thiamine

Clinical features

• Characterised by the triad of confusion, ataxia and opthalmoplegia
  • Ataxia: unsteady and uncoordinated movements
  • Confusion: disorientation and difficulty with attention
  • Ocular abnormalities: this can include gaze-evoked nystagmus, spontaneous upbeat nystagmus, and horizontal or vertical ophthalmoplegia
• Only 10% of patients present with all three symptoms so have a high index of suspicion for patients at risk of Wernicke’s

Investigations

• Neurological examination: assessment of the characteristic triad of symptoms
• Bloods: although not definitive, they can reveal low thiamine levels and other signs of malnutrition or alcohol abuse
• MRI head: may show characteristic changes in specific brain regions, such as the mammillary bodies and periaqueductal area

Management

• Replacement of thiamine - high-dose intravenous thiamine, commonly given as Pabrinex IV, is the standard treatment
• Appropriate management of underlying causes e.g. counselling and support to cease alcohol consumption

Complications: Korsakoff's syndrome

• If left untreated, the condition can progress to Korsakoff's syndrome, which affects the mammillary bodies
• It is characterised by is profound anterograde amnesia, limited retrograde amnesia, and confabulation