Wernicke's encephalopathy (N) Flashcards
Define Wernicke’s encephalopathy.
Acute (reversible) neurological emergency resulting from thiamine (vitamin B1) deficiency
What are the causes of Wernicke’s encephalopathy? (3)
- chronic heavy alcohol consumption - most common
- inadequate intake or malabsorption of thiamine (EDs, malnutrition, prolonged vomiting etc)
- bariatric surgery predisposes to thiamine malabsorption
What is the most common cause of Wernicke’s encephalopathy?
Chronic alcohol consumption
What demographic does Wernicke’s encephalopathy happen most commonly in?
M>F - due to increased frequency of alcoholism in men
How does Wernicke’s encephalopathy typically present?
Varied neurological manifestations, typically involving mental status changes, oculomotor dysfunction and gait
What are the clinical features of Wernicke’s encephalopathy? (5)
- confusion + mental status changes
- oculomotor signs - ophthalmoplegia (weakness/paralysis of eye muscles), nystagmus, diplopia, ptosis
- gait ataxia - wide-based, small steps
- mental slowing, impaired concentration and apathy
- memory loss
What oculomotor signs are seen in Wernicke’s encephalopathy? (4)
- ophthalmoplegia - weakness/paralysis of eye muscles:
- nystagmus
- diplopia
- ptosis
What might you find on examination of Wernicke’s encephalopathy (rarer findings)? (5)
- patient usually mentally alert with vocabulary, comprehension, motor skills, social habits and naming ability maintained
- reflexes may be decreased
- papilloedema, retinal haemorrhages
- hypothermia
- tachycardia / hypotension
What is the classic triad of Wernicke’s encephalopathy?
- mental status changes
- ophthalmoplegia (nystagmus, diplopia, ptosis, impaired VOR)
- gait dysfunction
What is Wernicke’s COAT?
- Confusion
- Ophthalmoplegia
- Ataxia
- Thiamine IV administration
What is it called when Wernicke’s encephalopathy progresses into a chronic, irreversible condition?
Korsakoff’s Psychosis
(Wernicke’s encephalopathy = acute and reversible)
What are the main features of Korsakoff’s Psychosis?
CART:
- Confabulation (making things up)
- Anterograde + Retrograde Amnesia
- Temper (altered)
(CART for Korsakoff’s, COAT for Wernicke’s encephalopathy)
What is the difference between Wernicke’s encephalopathy and Korsakoff’s psychosis?
- Wernicke’s encephalopathy - acute, reversible, COAT
- Korsakoff’s psychosis - chronic, irreversible, CART (confabulation and amnesia added)
What are the risk factors for Wernicke’s encephalopathy? (5)
- alcohol-use disorder
- HIV infection and AIDS
- cancer and treatment with chemotherapeutic agents
- malnutrition
- Hx of GI surgery
How is Wernicke’s encephalopathy usually diagnosed?
Clinical diagnosis
What are some other investigations done for Wernicke’s encephalopathy? (4)
- therapeutic trial of parenteral thiamine - clinical response within hours/days
- bloods - decreased thiamine
- MRI - atrophy of mamillary bodies
- screening tool for alcohol withdrawal = Clinical Institute Withdrawal Assessment for Alcohol (CIWA)
What electrolyte may be low in Wernicke’s encephalopathy?
Magnesium - deficiency common in alcohol misuse, and it impairs thiamine therapeutics
What might MRI show in Wernicke’s encephalopathy?
Atrophy of mamillary bodies
What are some differential diagnoses for Wernicke’s encephalopathy? (5)
- alcohol intoxication
- alcohol withdrawal - delirium tremens = tachycardia, hypertension, agitation, diaphoresis, mydriasis, hallucinations, seizures
- viral encephalitis
- toxic encephalopathies - phenytoin, aspirin, carbamazepine, BZs
- metabolic encephalopathies (hepatic and uraemic)
What is the first-line treatment for Wernicke’s encephalopathy?
Immediate IV thiamine (IV Pabrinex) + vitamin/mineral supplementation
Pabrinex (yellow-coloured fluid) contains vitamins B and C
How do we manage moderate/high suspicion Wernicke’s encephalopathy?
IV thiamine (Pabrinex) + magnesium sulfate + multivitamins
How do we manage those at high risk of Wernicke’s encephalopathy (but do not have it yet)?
Supplement diet with thiamine + vitamin/mineral supplementation
How do we manage chronic Wernicke’s encephalopathy?
Dietary supplementation with thiamine (oral or IM)
When should thiamine be administered (Wernicke’s encephalopathy)?
Before carbohydrate administration
What do we give if delirium tremens and hallucinations (Wernicke’s encephalopathy)?
Benzodiazepine (Chlordiazepoxide)
What are some complications of Wernicke’s encephalopathy? (5)
- ataxia + ophthalmoplegia
- Korsakoff’s psychosis (confabulations, amnesia)
- hearing loss
- seizures
- spastic paraparesis
Describe the prognosis of Wernicke’s encephalopathy.
If not recognised and treated early, can lead to permanent brain injury and death
