A 54-year-old woman was referred to our emergency department by an out-of-hours general practitioner. Her friend, who accompanied her, gave the history. She had been forgetful and anxious for two weeks, first noticed the day after her return from a bridge-playing holiday. She constantly checked the clothes she was wearing, had forgotten that she had recently had solar panels fitted to the roof of her house, and that she had been on holiday. She had had one episode of visual disturbance a few days before admission; although unable to describe her symptoms in detail, she had consulted an optician who had found a left superior homonymous quadrantanopia (she brought the results of her visual field test with her). She had a history of hypertension, treated with losartan and hydrochlorthiazide, and was an ex-smoker. She had recently retired from a professional career in continental Europe.

On examination she was hypertensive (160/100 mmHg) and had a left superior homonymous quadrantanopia. She was in discomfort from low back pain, which her friend had not mentioned. She scored 27/30 on a Folstein’s mini-mental status examination losing points on recall, day and year. The rest of the physical examination was normal.

Urgent blood tests revealed normal urea and electrolytes, full blood count and glucose, with an erythrocyte sedimentation rate of 21 mm/h and alkaline phosphatase of 142 units/l (normal range 40–125 units/l). An electrocardiograph showed sinus rhythm and her chest x ray was normal.

We requested a CT brain scan without contrast. Figures 1 and 2 show the significant abnormalities.