The story

A 57-year-old, right-handed housewife was admitted to a general medical ward in September 2005 after being found on the floor by a neighbour. She was unable to provide any indication as to what had happened.

Her family reported cognitive symptoms since July 2004 with occasional lapses of memory—for example, being unable to remember her brother's name at a wedding. In September 2004 she underwent minor laser cosmetic surgery to her face and became uncharacteristically low in mood. She was tearful and refused to leave the house for several weeks. She seemed to improve but relapsed after a similar treatment in early 2005. She and her husband went on holiday to Spain in May 2005. The day after arriving she became agitated, tearful and distracted. During the holiday she had difficulty navigating, on one occasion returning to the wrong hotel. On arriving back in the UK she failed to recognise her sons at the airport. She subsequently declined markedly such that she had difficulty distinguishing between domestic appliances, including the fridge and washing machine, and her husband had to put tapes over the controls to prevent inappropriate use. While family members were familiar, her son felt that she did not recognise them or understand their relationships. Additionally, she confused events on television with reality. Her speech deteriorated such that she responded in conversations only with short phrases. She would wake up at 03:00 in the morning and had been found wandering in the garden. She had nightmares and slept excessively during the day. She developed an obsessional attachment to items such as a teddy bear and became very agitated if these were taken away. She was referred to a psychiatrist by her general practitioner and was assessed in July 2005. An organic diagnosis was considered and investigations were arranged.

Other than …