Q. A relative has been dizzy for months. Her MRI scan did not find any damage to the brain. She didn’t tell her specialist that she is also forgetful. She forgets, for example, making a cup of tea a few minutes before, then makes another one. Would Alzheimer’s disease have shown up on the MRI scan? And would the specialist have tested her for Alzheimer’s?

A. It’s difficult to spot early Alzheimer’s on any sort of brain scan. It is more easily diagnosed on memory testing. Her GP can do this, so it’s important for her doctor to know about the memory lapses. She should talk to her doctor about her memory loss, or be taken by a relative who can describe what is going on. Alzheimer’s is not the only possible cause of memory loss in the older person. She may be depressed, or even have an underactive thyroid – both of them eminently treatable, so it will be worthwhile seeing the doctor again if only to check on them.