Self-assessment questions Reversible confusional state in an elderly man

A 76-year-old man was noted by his sister, with whom he lived, to have become increasingly confused for 6 months. He gradually became more dependent on her, even for basic activities of daily living such as dressing, but he remained fully ambulant and was not unsteady. He had no headaches or other specific symptoms, there was no relevant medical history, and he was not receiving any regular medications. When referred to hospital he was disorientated in time and place. His gait was normal, there was no evidence of cranial nerve or limb deficit. His visual fields and fundal examination were normal, and there were no cardiorespiratory or other abnormalities on physical examination. Full blood count, erythrocyte sedimentation rate, renal and liver function tests were normal, as were thyroid-stimulating hormone (TSH), vitamin B12 and blood glucose levels. Chest X-ray and electrocardiogram were unremarkable. Computed tomography (CT) of the brain suggested a cause for the confusional state which was confirmed by magnetic resonance imaging (MRI) of the brain (figures 1 and 2).