At first, after she began to notice unnerving symptoms – a sudden fall, a foggy brain, exhaustion – Wendy Mitchell did what all of us would do: carry on as normally as possible for as long as possible. A busy NHS manager with a staff of 16 who had brought up two daughters on her own, she was, by her own account, unusually capable and well organised. She was active and fit, a keen runner and walker and prided herself on her memory. For a year or two, she hoped for the best.