Aphasia is a communication disorder that results from damage to the parts of the brain that contain language (typically in the left half of the brain). Individuals who experience damage to the right side of the brain may have additional difficulties beyond speech and language issues. Aphasia may causes difficulties in speaking, listening, reading, and writing, but does not affect intelligence. Individuals with aphasia may also have other problems, such as dysarthria, apraxia, or swallowing problems.
Aphasia is most often caused by stroke. However, any disease or damage to the parts of the brain that control language can cause aphasia. These include brain tumors, traumatic brain injury, and progressive neurological disorders.
The specific symptoms and severity of aphasia vary depending on the location and extent of brain damage. Individuals with damage to the front part of the brain may have “choppy” or non-fluent speech. However, they can typically understand what people say fairly well. Those with damage to the posterior regions of the brain often have fluent speech—that is, the rate and rhythm of speech may sound normal. However, their speech may contain the wrong words or made-up words. They also typically have difficulty understanding what is spoken.