TUESDAY, Aug. 26 (HealthDay News) -- Imagine you're in a foreign country where learning the language is incredibly hard, if not impossible.
No one understands what you're saying. You can't comprehend a word. The best you can do is point and gesture, and hope the other person understands what you're trying to get across.
You're now in a position to better understand what a person suffering from aphasia goes through on a daily basis. Caused by injury to the brain, often due to stroke, aphasia affects the production or comprehension of speech, be it verbal or written.
People with mild cases can blend in easily with the world, the only clue a verbal miscue here or there. But those with severe cases can find themselves completely alienated from everyone.
The worst part is, cognition is not affected. People think as clearly as they ever did. They simply can't communicate.
"There are patients who can fluently say something that sounds like a sentence, but it's just garbage," said speech language pathologist Paul Rao, vice president of clinical services, quality improvement and corporate compliance at the National Rehabilitation Hospital in Washington, D.C. "It's one of the least understood disabilities in the world, because these people cannot communicate for themselves.
Aphasia is believed to affect about one million people in the United States, according to the National Aphasia Association. Stroke is the most common cause of brain injuries that result in the disorder.
Aphasia affects everyone differently, depending on the sort of brain damage a person has sustained. Some may be able to speak but can't understand what is said to them. For others, the reverse is true.
"What makes the science very difficult in this field is that no two brain injuries are identical and, therefore, no two aphasias are identical," said Dr. Steven Small, professor of neurology and psychology at the University of Chicago and medical director of the Comprehensive Aphasia Center of Chicago.
Several major defined forms of aphasia include:
Broca's aphasia, in which damage to the frontal lobe of the brain severely limits speech. People with this form of the disorder frequently speak in short, meaningful phrases produced with great effort that usually consist of fewer than four words. They are able to understand the speech of others, more or less.
A person with Broca's aphasia may say, "Walk dog" meaning, "I will take the dog for a walk," according to the U.S. National Institutes of Health (NIH). However, the same sentence could also mean, "You take the dog for a walk," or "The dog walked out of the yard."
Wernicke's aphasia, in which damage to the temporal lobe results in speech that contains long sentences with no meaning, or additional, unnecessary or newly created words. People with this type of aphasia usually have great difficulty understanding speech and are often unaware of their mistakes.
An example of Wernicke's aphasia speech, according to the NIH: "You know that smoodle pinkered and that I want to get him round and take care of him like you want before," meaning, "The dog needs to go out so I will take him for a walk."
Global aphasia, which results from severe damage to extensive portions of the language areas of the brain. People struggling with global aphasia have severe communication difficulties and can be extremely limited in their ability to speak or comprehend.