Harvey's Garden

Wernicke encephalopathy and Korsakoff syndrome

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Epidemiology

Etiology

  • Wernicke encephalopathy and Korsakoff syndrome are caused by a severe deficiency of thiamine (vitamin B1).
  • Thiamine deficiency can be due to:
    • Chronic heavy alcohol use (most common): due to inadequate intake, absorption, and hepatic storage of thiamine
    • Inadequate intake
      • Thiamine-deficient diets
      • Anorexia nervosa, starvation
        • In patients with low glucose intake, thiamine deficiency may be asymptomatic. However, this patient ingested a large quantity of glucose, which likely rapidly depleted her limited thiamine stores.
    • Malabsorption

Pathophysiology

  • Core Pathophysiology
    • Caused by Thiamine (Vitamin B1) deficiency, which is a critical cofactor for several key enzymes involved in glucose metabolism. t
    • Most common cause is chronic alcoholism due to poor nutrition, malabsorption, and impaired thiamine storage/utilization.
  • Key Affected Enzymes
    • Pyruvate dehydrogenase: Links glycolysis to the TCA cycle (Pyruvate → Acetyl-CoA).
    • α-ketoglutarate dehydrogenase: A rate-limiting enzyme in the TCA cycle.
    • Transketolase: An enzyme in the pentose phosphate pathway (HMP shunt).
  • Cellular & Anatomic Consequences
    • Impairment of these enzymes leads to a severe ↓ in ATP production, particularly affecting brain regions with high metabolic demand.
    • This energy deficit causes neuronal injury, cell death, and focal lactic acidosis.
    • Selectively damages specific brain structures:
      • Mamillary bodies t
      • Medial dorsal nuclei of the thalamus
      • Periaqueductal and periventricular gray matter
      • Cerebellum

Clinical features

Wernicke encephalopathy (acute, reversible)

  • Should be suspected in any patient with a history of chronic heavy alcohol use who presents with one/more symptoms of the classic triad of Wernicke encephalopathy
  • Classic Triad (“ACE” or “COA”):
    1. Ataxia (Gait instability)
    2. Confusion (Encephalopathy/Global confusion)
    3. Eye abnormalities (Ophthalmoplegia, nystagmus, conjugate gaze palsy) t (most specific)
  • Note: Only ~30% of patients present with the full triad.

When to suspect

Wernicke encephalopathy should be suspected in any patient with chronic alcohol abuse or any form of malnutrition and any of the following: acute altered mental status, ophthalmoplegia, ataxic gait, delirium, and hypotension.

Korsakoff syndrome (chronic, irreversible)

  • Results from neuronal death due to chronic/untreated WE.
  • Anterograde Amnesia: Inability to form new memories (hallmark).
  • Retrograde Amnesia: Loss of existing memories.
  • Confabulation: Fabricating events to fill memory gaps (patients are not lying intentionally; they believe the false memories).
  • Personality changes (apathy).

Diagnostics

Treatment

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