Wernicke’s Encephalopathy and Korsakoff’s Syndrome

Acute and chronic phase (respectively) of the same disease process.

Wernicke’s Encephalopathy

A clinical tetrad of:

• Acute confusional state
• ophthalmoplegia- commonly CN VI palsy
• nystagmus
• ataxic gait

with associated features including:

• peripheral neuropathy
• resting tachycardia
• nutritional deficiency
• sluggish pupillary reflexes
• Anisocoria (unequal pupils)

It is caused by a thiamine deficiency, resulting in microhaemorrhages and secondary gliosis of periaqueductal grey matter.

Treat with parenteral thiamine as soon as diagnosis is suspected.  There is a high mortality (15%) if untreated.

Korsakoff’s syndrome

Characterised by:

• Anterograde amnesia (inability to form new memories)
• Retrograde amnesia (inability to remember old memories)
• Confabulation (fabricating/false perceptions of memories)
• Hallucinations

The damage to the memory is mostly irreversible (75% never regain full function).

Treat with thiamine for 2 years.