Bruce Willis diagnosed with aphasia: The science behind the disorder

msn.com:

brain, typically the left side, according to Johns Hopkins Medicine. That damage can be the result of stroke, head injury, a brain tumor, some sort of infection or dementia.

Symptoms — which involve difficulty with speech and comprehension — can come on suddenly after a stroke or head trauma, or gradually as a result of brain tumor or progressive disease. "To Bruce's amazing supporters, as a family we wanted to share that our beloved Bruce has been experiencing some health issues and has recently been diagnosed with aphasia, which is impacting his cognitive abilities," his ex-wife and fellow actor Demi Moore said in a statement on Instagram. "As a result of this and with much consideration Bruce is stepping away from the career that has meant so much to him. " There are two broad categories of aphasia, called fluent and non-fluent; within these categories are different groups distinguished both by the area damaged and by symptoms.

The most common type of non-fluent aphasia is called Broca aphasia, which occurs when a part of the frontal lobe, typically on the left side, is damaged, according to Johns Hopkins Medicine.

Symptoms of Broca aphasia — also called expressive aphasia — include speech issues in which the person eliminates certain words from their language and talks in short sentences; a person with this disorder can generally understand some of what others are saying.