Description
An 82 year old female with hearing impairment was admitted to hospital with acute on chronic confusion, and found to be hyponatraemic (serum Na 116 mmol/l). Investigations and history suggested psychogenic polydipsia. The hyponatraemia corrected with f luid restriction. However, she remained more confused than normal in the absence of any other obvious precipitant for delirium. Serum calcium, full blood count, thyroid and liver function tests, serum B12 and red cell folate were normal. Figure 1 shows one of the images obtained from a head CT-scan. Figure 2 shows the view through an auroscope.
