Neurology

Wernicke-Korsakoff syndrome

Wernicke-Korsakoff syndrome is a spectrum of thiamine deficiency: acute Wernicke's encephalopathy is a treatable medical emergency, while Korsakoff's syndrome is a chronic amnesic disorder requiring abstinence support, rehabilitation and tailored long-term care.

In a nutshell

Wernicke's encephalopathy is a thiamine-deficiency emergency. In an at-risk person, confusion, an eye-movement abnormality or ataxia is enough to treat with parenteral thiamine; do not wait for the full triad, blood tests or MRI. Give thiamine promptly before or alongside carbohydrate and refeeding where feasible, but never delay life-saving glucose for hypoglycaemia. Screen for magnesium and refeeding abnormalities. Korsakoff's syndrome is chronic amnesia requiring abstinence support, rehabilitation and tailored long-term care.

Classic presentation

A person with alcohol dependence and poor nutrition develops confusion, nystagmus or ophthalmoplegia and an unsteady gait. Treat immediately with parenteral thiamine in hospital while checking glucose, electrolytes, magnesium and competing causes.

Key points

Wernicke's is a clinical diagnosis and the full triad is not required; one compatible feature in an at-risk person warrants treatment.
Give parenteral thiamine promptly for suspected Wernicke's, following current local and BNF protocol, then continue with oral therapy.
Do not delay life-saving glucose for hypoglycaemia; give thiamine before or alongside carbohydrate where feasible.
Check and correct magnesium because deficiency can impair thiamine activation and treatment response.
Screen for refeeding risk and monitor phosphate, potassium, magnesium, calcium and fluid status when nutrition is restored.
MRI may support the diagnosis but a normal scan does not exclude it and imaging must not delay treatment.
Korsakoff's causes severe short-term memory impairment and possible confabulation; abstinence and multidisciplinary rehabilitation can support improvement.

First-line investigation

Immediate clinical assessment and glucose, with electrolytes including magnesium and phosphate, while investigating withdrawal, infection, liver disease, trauma, stroke and other causes of confusion.

Management

Treat suspected Wernicke's

In an at-risk patient with confusion, an eye-movement abnormality or ataxia, give parenteral thiamine in hospital immediately and do not delay for MRI or laboratory confirmation.^1,3,5

Correct glucose and deficiencies safely

Check glucose and treat hypoglycaemia immediately; give thiamine before or alongside carbohydrate where feasible, check magnesium and other electrolytes, and assess refeeding risk.^3,4,5

Manage alcohol and acute comorbidity

Treat alcohol withdrawal, infection, liver disease, trauma, stroke, hypoglycaemia and electrolyte disturbance in parallel, with dietetic and alcohol-care input and safe hospital refeeding when required.^1,3

Rehabilitate Korsakoff's and prevent recurrence

Support abstinence, continue appropriate thiamine, provide adapted cognitive rehabilitation, reassess cognition and capacity, involve carers and arrange long-term support or care matched to functional need.^6,2

Exam traps

Do not wait for the classic triad; it is often incomplete.
Do not wait for MRI or a thiamine result before treating suspected Wernicke's.
Do not delay emergency glucose for hypoglycaemia; thiamine should be given promptly before or alongside it where feasible.
Oral thiamine is not adequate initial treatment for suspected acute Wernicke's; use parenteral treatment.
Hypomagnesaemia can make thiamine treatment ineffective, and refeeding can cause dangerous electrolyte shifts.
Korsakoff's is not simply intoxication: severe memory impairment and confabulation require adapted rehabilitation, capacity and care planning.

Illustrations

Bilateral thalamic signal in Wernicke's encephalopathyAxial FLAIR brain MRI showing symmetric hyperintense signal in the medial thalami, with a caption emphasising that MRI can support but never exclude the diagnosis and must not delay parenteral thiamine.Jto410, Wikimedia Commons · CC-BY-SA-3.0

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.