Wernicke's encephalopathy

Last reviewed: 22 Feb 2023
Last updated: 19 Aug 2020



History and exam

Key diagnostic factors

  • history of GI surgery
  • mental slowing, impaired concentration, and apathy
  • frank confusion
  • ocular motor findings
  • mental status changes, ophthalmoplegia, and gait dysfunction
More key diagnostic factors

Other diagnostic factors

  • alcohol dependence
  • pre-existing conditions that predispose to malnutrition: for example, AIDS, cancer, prolonged vomiting, or diarrhoea
  • mild irritability
  • delirium
  • acute psychosis
  • coma
  • miosis, anisocoria, light-near dissociation
  • papilloedema, retinal haemorrhages
  • tachycardia or hypotension
  • hypothermia or hyperthermia
  • hearing loss, seizures, and spastic paraparesis
  • ataxia
Other diagnostic factors

Risk factors

  • alcohol dependence
  • AIDS
  • cancer and treatment with chemotherapeutic agents
  • malnutrition
  • history of gastrointestinal surgery
  • genetics
  • bone marrow transplantation
  • infants who have been fed formula milk deficient in thiamine
  • male sex
More risk factors

Diagnostic investigations

1st investigations to order

  • therapeutic trial of parenteral thiamine
  • finger-prick glucose
  • FBC
  • serum electrolytes
  • renal function
  • LFTs
  • urinary and serum drug screen
  • serum ammonia
  • blood alcohol level
  • blood thiamine and its metabolites
  • serum magnesium
More 1st investigations to order

Investigations to consider

  • lumbar puncture
  • MRI of brain
  • CT of brain
More investigations to consider

Treatment algorithm


moderate or high suspicion of Wernicke's encephalopathy

low suspicion of Wernicke's encephalopathy or mimics: at high risk for Wernicke's encephalopathy


poor dietary intake and/or chronic alcoholism: at risk for Wernicke encephalopathy



Abhay Moghekar, MB BS

Assistant Professor

Department of Neurology

Johns Hopkins Hospital




AM is a medical advisory board member of the Hydrocephalus Association and was reimbursed for travel and airfare. AM was a consultant to Quest Diagnostics and Orbees Incorporation for market research, receiving payment for consulting. AM undertook research for Fujirebio Diagnostics and received a research grant to his lab at Johns Hopkins University.

Peer reviewers

Adrian Priesol, MD, FRCPC


Massachusetts Eye and Ear Infirmary

Harvard Medical School




AP declares that he has no competing interests.

  • Wernicke's encephalopathy images
  • Differentials

    • Alcohol intoxication
    • Alcohol withdrawal
    • Viral encephalitis
    More Differentials
  • Guidelines

    • Alcohol-use disorders: diagnosis and management of physical complications
    • Guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy
    More Guidelines
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