Expressive aphasia
Template:DiseaseDisorder infobox
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Expressive aphasia, known as Broca's aphasia in clinical neuropsychology and agrammatic aphasia in cognitive neuropsychology, is an aphasia caused by damage to anterior regions of the brain, including (but not limited to) the left inferior frontal region known as Broca's area (Brodmann area 44 and Brodmann area 45).
Presentation
Sufferers of this form of aphasia exhibit the common problem of agrammatism. For them, speech is difficult to initiate, non-fluent, labored, and halting. Intonation and stress patterns are deficient. Language is reduced to disjointed words and sentence construction is poor, omitting function words and inflections (bound morphemes). A person with expressive aphasia might say "Son ... University ... Smart ... Boy ... Good ... Good ... "
For example, in the following passage, a Broca's aphasic patient is trying to explain how he came to the hospital for dental surgery:
- Yes... ah... Monday... er... Dad and Peter H... (his own name), and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah.[1]
In extreme cases, patients may be only able to produce a single word. The most famous case of this was Paul Broca's patient Leborgne, nicknamed "Tan", after the only syllable he could say. Even in such cases, over-learned and rote-learned speech patterns may be retained[2]—for instance, some patients can count from one to ten, but cannot produce the same numbers in ordinary conversation.
While word comprehension is generally preserved, meaning interpretation dependent on syntax and phrase structure is substantially impaired. This can be demonstrated by using phrases with unusual structures. A typical Broca's aphasic patient will misinterpret "the dog is bitten by the man" by switching the subject and object.[3] Patients who recover go on to say that they knew what they wanted to say but could not express themselves. Residual deficits will often be seen.
Classification and diagnosis
Expressive aphasia is also a classification of non-fluent aphasia, as opposed to fluent aphasia. Diagnosis is done on a case by case basis, as lesions often affect surrounding cortex and deficits are not well conserved between patients.
See also
- Broca's area
- aphasia
- Compare with receptive aphasia (Wernicke's aphasia).
References
- ↑ Goodglass, H. (1976). "Language disorders". In E. Carterette and M.P. Friedman. Handbook of Perception: Language and Speech. Vol VII. New York: Academic Press. Unknown parameter
|coauthors=ignored (help) - ↑ "Specific Syndromes: The Nonfluent Aphasias". Neuropathologies of Language and Cognition. Retrieved 2006-05-10.
- ↑ "Neurology of Syntax". Behavioral and Brain Sciences 23 (1). Retrieved 2006-05-10.