Wernicke's encephalopathy is a neuropsychiatric disorder caused by thiamine deficiency which is most commonly seen in alcoholics. Rarer causes include persistent vomiting, aոοrеxiа nervosa, stomach cancer, and dietary deficiency. A classic triad of ophthalmoplegia/nystagmus, ataxia and encephalopathy may occur.

In Wernicke's encephalopathy, petechial haemorrhages occur in a variety of structures in the brain including the mamillary bodies and ventricle walls.

Features

• oculomotor dysfunction
  • nystagmus (the most common ocular sign)
  • ophthalmoplegia: lateral rectus palsy, conjugate gaze palsy
• gait ataxia
• encephalopathy: confusion, disorientation, indifference, and inattentiveness
• peripheral sensory neuropathy

Classic Triad (in only ~10%):

1. Encephalopathy
2. Ataxic gait, and
3. Some variant of oculomotor dysfunction

Ocular abnormalities are the hallmarks of WE - nystagmus (most common), bilateral lateral rectus palsies, and conjugate gaze palsies reflecting cranial nerve involvement of the oculomotor, abducens, and vestibular nuclei.

Investigations

• decreased red cell transketolase
• MRI

Treatment is with urgent replacement of thiamine

Relationship with Korsakoff syndrome

If not treated Korsakoff's syndrome may develop as well. This is termed Wernicke-Korsakoff syndrome and is characterised by the addition of antero- and retrograde amnesia and confabulation in addition to the above symptoms.