What is aphasia, the brain condition sidelining Bruce Willis?

The veteran Hollywood actor’s retirement has drawn attention to the little-known illness that has many causes.

The announcement by American actor Bruce Willis that he will be “stepping away” from the big screen has drawn attention to aphasia, a little-known condition with many causes.

Willis’s family said on Wednesday he had recently been diagnosed with the condition, which they said is “impacting his cognitive abilities”.

“As a result of this and with much consideration, Bruce is stepping away from the career that has meant so much to him,” the family said in a statement.

The cause of the 67-year-old’s condition was not revealed.

What are the symptoms?

Aphasia can affect the ability to produce and comprehend both written and spoken communication.

Because the condition relates to complex language systems in the brain, it can take many forms. Doctors typically split aphasia into broad clinical categories.

In expressive aphasia, people “usually understand fairly well but have trouble getting words out”, speech pathologist Brooke Hatfield, of the American Speech-Language-Hearing Association (ASHA), told AFP news agency.

In receptive aphasia “the words come easily, but they might not be the right words. And it’s difficult for that person to understand what they’re hearing,” Hatfield added.

So-called global aphasia has components of expressive and receptive aphasia.

Aphasia usually does not affect a person’s intelligence.

What causes aphasia?

There are many possible causes to aphasia, which affects about two million Americans, according to the National Aphasia Association.

Most commonly, it is caused by a stroke that cuts off blood to part of the brain. The lack of oxygen and nutrients causes brain cells to die which can lead to difficulty retrieving words.

Tumors, head injuries, and other trauma can also affect the language centers of the brain.

Is it permanent?

Some people show dramatic improvement of the impediments caused by aphasia within a few months.

Others can recover through long-term speech therapy, which can help the brain find new pathways to communicate ideas.

Some people diagnosed with aphasia rely on assistive devices to communicate.

Researchers are looking into new types of speech therapy and noninvasive methods such as a procedure that uses magnetic pulses to stimulate brain cells.