Wednesday, March 5, 2014

Aphasia: Broca's vs. Wernicke's

Aphasia is a disorder caused by damage to the area of the brain that controls language. It can cause difficulty speaking, comprehending speech, writing, gesturing, and reading. Specific types of aphasia are characterized by the different areas of the brain that are damaged and the slight differences in symptoms. There are two types of aphasia that are very similar but have profound differences. They are Broca's aphasia and Wernicke's aphasia. Broca's aphasia involves damage to Broca's area. This is in the  left frontal lobe. Wernicke's area is in the left temporal lobe. They are connected via the arcuate fasciculus.

 Broca's aphasia, also known as nonfluent aphasia, is difficulty in forming or comprehending coherent, complex sentences. People with this type of aphasia often speak awkwardly, in very simple sentences because they can no longer understand complex grammar. They often leave out helping verbs, prepositions, and other flowery words. They only speak with nouns and verbs, and sometimes have trouble with even that. They also have trouble with sentences like "the man was bitten by the dog". This seems simple, but the inversion of the noun and the verb throw them off.

This video shows a patient with damage to Broca's area trying to describe a picture. A simple description of this picture is  "a mother is washing dishes while two children use a stool to steal cookies from a cookie jarYou can see how difficult this is for her.

Wernicke's aphasia, on the other hand,  is also known as fluent aphasia. The real problem is speech comprehension. They don't really understand what they hear. They also have speech impairment but in a different way. They speak fluently, unlike the woman in the Broca's aphasia video. However, they cannot recall words so they make up words instead. There are two different types of made-up words and patients use either or both of them. One type is  paraphasia. An example of this is if the patient wanted to say "cook", but said "took" or "sook" instead. The other type is neologism. This is a total made up word. For example, if they wanted to say "cook" and said "skucker" instead. Also, unlike patients with Broca's aphasia, they don't even notice that their speech is impaired, or that they don't understand something. This type of aphasia can be difficult to treat since the patient doesn't even realize that something is wrong.
In this video, you can see that the man with Wernicke's aphasia doesn't realize that he is answering the questions wrong. He doesn't seem to even understand what is being asked of him. 

As you can see, these disorders seem similar but are actually very different. People with these disorders usually respond well to speech therapy. 

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