Bruce Willis has frontotemporal dementia. What is FTD?

Bruce Willis’ family has announced that he has been diagnosed with frontotemporal dementia.

The announcement Thursday came about a year after his family said that Willis would step away from acting after being diagnosed with aphasia, a brain disorder that leads to speaking, reading and writing problems.

There are different types of dementia, and the frontotemporal form affects regions in the front and sides of the brain.

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