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Wernicke’s Encephalopathy

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Overview

Wernicke’s encephalopathy is a medical emergency characterised by neurocognitive changes due to thiamine deficiency. It is commonly seen in people with alcohol abuse.

Thiamine deficiencies can be due to reduced intake, deficiency due to increased demand or malabsorption.

Epidemiology

  • Higher prevalence in those at risk for alcohol abuse/malnutrition/malabsorption
  • Higher prevalence in the homeless, older individuals living in isolation, and psychiatric inpatients

Risk Factors

  • Alcohol abuse and dependence
  • Malignancy
  • Malnutrition
  • Previous gastrointestinal surgery – may be a risk factor for thiamine malabsorption
  • AIDS

Presentation

Any patient who is known to misuse alcohol with confusion or an altered level of consciousness should be considered at high risk of Wernicke’s encephalopathy. Features may be:

  • Nystagmus and diplopia
  • Ophthalmoplegia
  • Eyelid drooping
  • Ataxia
  • Reduced GCS
  • Confusion

Differential Diagnoses

Alcohol withdrawal

  • Patients have tachycardia, hypertension, and sweating
  • They may have hallucinations and seizures
  • There may be a history of chronic alcohol use and sudden withdrawal 

Korsakoff syndrome

  • Memory problems are more predominant
  • Often occurs due to untreated Wernicke’s encephalopathy
  • Anterograde and retrograde amnesia present

Encephalitis

  • Patients may have fevers
  • There may be focal neurological deficits
  • There may be seizures

Investigations

  • Thiamine level followed by therapeutic thiamine trial – should improve symptoms
  • Capillary blood glucose – to rule out hypoglycaemia
  • FBC – usually normal but there may be leukocytosis in infection
  • U&Es – to rule out electrolyte derangements and renal dysfunction
  • LFTs – usually elevated if there is chronic alcohol consumption
  • Serum ammonia – usually normal unless there is co-existent alcoholic liver disease
  • Urine and serum drug toxicology – if drug abuse suspected

Management

  • 1st-line: IV thiamine

Patient Advice

  • Patients should be educated on alcohol avoidance and should be helped with this
  • The patient should be informed about the progression of Wernicke’s encephalopathy to Korsakoff syndrome

Complications and Prognosis

Complications

  • Progression to Korsakoff’s syndrome
  • Persistent ataxia
  • Permanent nystagmus
  • Persisting learning difficulties and memory impairment

Prognosis

  • If untreated it can lead to death in 20% of cases
  • For those that develop Korsakoff’s syndrome, 25% of patients require long-term institutionalisation

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