Excerpted from "The Language of Aphasia," Stroke Connection Magazine, May/June 2003 (Science Update August 2009)
Language is much more than words. It involves our ability to recognize and use words and sentences. Much of this capability resides in the left hemisphere of the brain. When a person has a stroke or other injury that affects the left side of the brain, it typically disrupts their ability to use language.
Through language, we:
- Communicate our inner thoughts, desires, intentions and motivations.
- Understand what others say to us.
- Ask questions.
- Give commands.
- Comment and interchange.
A stroke that affects the left side of the brain may lead to aphasia, a language impairment that makes it difficult to use language in those ways. Aphasia can have tragic consequences.
- May be disrupted in their ability to use language in ordinary circumstances.
- May have difficulty communicating in daily activities.
- May have difficulty communicating at home, in social situations, or at work.
- May feel isolated.
Scientists and clinicians who study how language is stored in the brain have learned that different aspects of language are located in different parts of the left hemisphere. For example, areas in the back portions allow us to understand words. When a stroke affects this posterior part of the left hemisphere, people can have great difficulty understanding what they hear or read.
Imagine going to a foreign country and hearing people speaking all around you. You would know they were using words and sentences. You might even have an elemental knowledge of that language, allowing you to recognize words here and there, but you would not have command of the language and couldn’t follow most conversation. This is what life is like for people with comprehension problems.
- Know that people are speaking to them.
- Can follow some of the melody of sentences — realizing if someone is asking a question or expressing anger.
- May have great difficulty understanding specific words.
- May have great difficulty understanding how words go together to convey a complete thought.
- Often say many words that don’t make sense.
- May fail to realize they are saying the wrong words; for instance, they might call a fork a “gleeble.”
- May string together a series of meaningless words that sound like a sentence but don’t make sense.
- Have challenges because our dictionary of words is shelved in a similar region of the left hemisphere, near the area used for understanding words.
When a stroke injures the frontal regions of the left hemisphere, different kinds of language problems can occur. This part of the brain is important for putting words together to form complete sentences. Injury to the left frontal area can lead to what is called Broca’s aphasia. Survivors with Broca's aphasia:
- Can have great difficulty forming complete sentences.
- May get out some basic words to get their message across, but leave out words like “is” or “the.”
- Often say something that doesn’t resemble a sentence.
- Can have trouble understanding sentences.
- Can make mistakes in following directions like “left, right, under, and after.”
“Car…bump…boom!” This is not a complete sentence, but it certainly expresses an important idea. Sometimes these individuals will say a word that is close to what they intend, but not the exact word; for example they may say “car” when they mean “truck.”
A speech pathologist friend mentioned to a patient that she was having a bad day. She said, “I was bitten by a dog.” The stroke survivor asked, “Why did you do that?” In this conversation, the patient understood the basic words spoken, but failed to realize that the words of the sentence and the order of the words were critical to interpreting the correct meaning of the sentence, that the dog bit the woman and not vice versa.
When a stroke affects an extensive portion of the front and back regions of the left hemisphere, the result may be global aphasia. Survivors with global aphasia:
- May have great difficulty in understanding words and sentences.
- May have great difficulty in forming words and sentences.
- May understand some words.
- Get out a few words at a time.
- Have severe difficulties that prevent them from effectively communicating.
- It is important to make the distinction between language and intelligence.
- Many people mistakenly think they are not as smart as they used to be.
- Their problem is that they cannot use language to communicate what they know.
- They can think, they just can’t say what they think.
- They can remember familiar faces.
- They can get from place to place.
- They still have political opinions, for example.
- They may still be able to play chess, for instance.
The challenge for all caregivers and health professionals is to provide people with aphasia a means to express what they know. Through intensive work in rehabilitation, gains can be made to avoid the frustration and isolation that aphasia can create.