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(詳細はaphasia. Expressive aphasia differs from dysarthria, which is typified by a patient's inability to properly move the muscles of the tongue and mouth to produce speech. Expressive aphasia also differs from apraxia of speech which is a motor disorder characterized by an inability to create and sequence motor plans for speech. Comprehension is typically only mildly to moderately impaired in expressive aphasia due to difficulty understanding complex grammar.〔〔Appendix: Common Classifications of Aphasia. (n.d.). Retrieved from http://www.asha.org/Practice-Portal/Clinical-Topics/Aphasia/Common-Classifications-of-Aphasia/〕 This contrasts with receptive aphasia, which is distinguished by a patient's inability to comprehend language or speak with appropriately meaningful words. Expressive aphasia is also known as Broca's aphasia in clinical neuropsychology and agrammatic aphasia in cognitive neuropsychology and is caused by acquired damage to the anterior regions of the brain, including (but not limited to) the left posterior inferior frontal gyrus or inferior frontal operculum, also described as Broca's area (Brodmann area 44 and Brodmann area 45)〔 Expressive aphasia is also a symptom of some migraine attacks. ==Signs and symptoms== Broca's aphasia is a type of expressive aphasia because speech production is halting and effortful. Damage is typically in the anterior portion of the left hemisphere. Typically, writing is at least as severely impaired as speech. Persons with Broca's aphasia are usually aware of their communication deficits, and are more prone to depression and sometimes catastrophic reactions that are patients with other forms of aphasia.〔 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 ... Good ... Good ... "''Content words (nouns, verbs) may be used in speech, but sentences are difficult to produce due to problems with grammar, resulting in "telegraphic speech." In its more severe form, spoken utterances may be reduced to single words. "The prosody of those with Broca's aphasia is compromised by shortened length of utterances and the presence of self-repairs and disfluencies.〔Manasco, H. (2014). The Aphasias. In Introduction to Neurogenic Communication Disorders (Vol. 1, p. 91). Burlington, MA: Jones & Bartlett Learning.〕" 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. Patients who communicated with sign language before the onset of the aphasia experience analogous symptoms.〔http://pages.slc.edu/~ebj/IM_97/Lecture10/L10.html〕 Severity of expressive aphasia varies among patients. In the most extreme cases, patients may be able to produce only 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〔(【引用サイトリンク】 work=Neuropathologies of Language and Cognition )〕—for instance, some patients can count from one to ten, but cannot produce the same numbers in ordinary conversation. Meanwhile, in general, word comprehension is preserved; making most Broca's aphasia patients receptive language functional. Individuals with Broca's aphasia understand most of the everyday conversation around them, but higher-level deficits in receptive language can also occur.Individuals with Broca's aphasia can often respond to simple questions. For more complex sentences, with many steps 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 man is bitten by the dog" by switching the subject and object.〔(【引用サイトリンク】 work=Behavioral and Brain Sciences 23 (1) )〕 Note this element is a problem with receptive language, not expressive language, and is one reason why the problem is referred to as agrammatic aphasia. Because patients with Broca's aphasia have good receptive language, their reading skills are also functional. 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Expressive aphasia」の詳細全文を読む スポンサード リンク
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