蜜芽传媒

Actor Bruce Willis, 67, has been diagnosed with frontotemporal dementia (FTD), a group of brain disorders caused by progressive nerve cell loss in the brain.

His family described receiving the diagnosis as a "relief" because FTD affects people's personalities and behaviours and can sometimes be misdiagnosed as a psychiatric issue.

FTD is not the same as dementia, commonly associated with memory loss in older people. Dr Rosie Ashworth, a dementia researcher, explains its nuances and how best to spot it.

(Photo: Actor Bruce Willis attends the "Looper" press conference during the 2012 Toronto International Film Festival. Credit: Getty Images)