From the Introduction:

Sudden and unexpected loss of communication is a terrifying, dehumanizing experience that tears away at the essence of life itself.

For decades, speech and language pathologists have sought to better understand it. The term aphasia is used to generally describe a condition whereby speech and language skills are partially or totally lost. Aphasia is the result of damage to or disturbance of those areas in the brain responsible for speech and language functions.

A tremendous variety of specific impairments can occur to plague the individual with aphasia....