A 61-year-old man of no fixed abode suffers a head injury during a fall. You organise a full set of bloods and a CT scan of the head as part of his work up. The bloods show deranged liver function tests and a macrocytic anemia. The CT scan of the head is reported as normal, but an MRI is performed later and shows the presence of small petechial haemorrhages in the mamillary bodies.
During hospitalization he is administered a treatment that causes his condition to deteriorate and he becomes acutely confused. On examination the presence an ataxic gate, peripheral neuropathy, and bilateral abducens nerve palsies are noted.
1. Which condition has been precipitated by the medication in this case?
This patient has developed Wernicke’s encephalopathy, a condition associated with alcohol abuse and other causes of thiamine deficiency.
Classically, Wernicke’s encephalopathy is characterized by the triad of:
- Acute confusion
Other possible features include papilloedema, hearing loss, apathy, dysphagia, memory impairment, and hypothermia. Peripheral neuropathy, usually confined to the legs, also occurs in the majority of cases.
The condition is characterised by acute capillary haemorrhages, astrocytosis and neuronal death in the upper brainstem and diencephalon. These can be seen on MRI scanning, but CT scanning appears to be of very little diagnostic value.
2. Which treatment is most likely to have precipitated this?
The infusion of glucose containing intravenous fluids without thiamine in a patient with chronic thiamine deficiency can precipitate Wernicke’s encephalopathy, and this appears to be what has happened in this case.
3. What is the most likely diagnosis?
Patients with suspected Wernicke’s encephalopathy should be given parenteral thiamine (e.g. Pabrinex) for a minimum of 5 days. Oral thiamine should follow on from the parenteral therapy.
4. What is the most likely diagnosis?
Most untreated patients proceed to develop a Korsakoff psychosis, which is characterised by a retrograde amnesia, an inability to memorise new information, disordered time appreciation, and confabulation.
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