Case of the month: What’s causing this patient’s sudden-onset confusion and memory loss?

In the next in our monthly quiz series, Dr Roger Henderson asks what might be the cause of this patient’s sudden-onset confusion and memory loss. Share your thoughts on the diagnosis in the comments below!

A previously well 65-year-old woman attended the GP surgery as an emergency, having been brought there by her family. That morning she had suddenly become confused in time and place, forgetting where she lived, what job she did and who her family members were.

She was repeatedly asking questions about where she was, and who the people around her were, and did not seem to understand she was in a doctor’s surgery. Although she had some recall about events that had happened years previously, she was unable to say what had happened in recent days or weeks. Her family said she had been under severe stress in recent weeks due to concerns she had about the possibility of being made redundant from her job.

There was no history of similar episodes, or any seizures or psychiatric problems. Her family said she did not smoke or take any recreational drugs.

Examination showed her to be confused but fully alert, normotensive, with no clinical evidence of a cerebrovascular event. A full detailed physical examination showed no obvious abnormalities, no fever and her blood glucose level was normal. On MMSE she was unable to answer the year, address or the name of the Prime Minister. She was subsequently admitted to hospital for further investigations.

These showed her to have entirely normal blood tests – including inflammatory markers, thyroid function and toxicology screening – a normal CXR and ECG, and a normal EEG. An MRI scan of her brain did not show any abnormality. She was admitted for observation as she remained extremely confused.

After 24 hours and with no specific treatment, the patient had developed orientation in time, place and person again and she was discharged home feeling well 48 hours later with no obvious adverse effects from the episode.

What do you think is going on?

Put your answers in the comments below! Answer to be revealed soon…