aphasia

n. Aphasia is an acquired impairment to the language processing skills (production and comprehension) after brain damage. Aphasia follows damage to the brain resulting from traumatic brain injury, cerebrovascular accident (stroke), dementia, tumor, and infectious disease. Patterns of aphasia are divided according to fluency. The characteristic feature of Broca's aphasia is telegraphic speech, in which articles, conjunctions, prepositions, auxiliary verbs, and pronouns (function words) and morphological inflections (e.g., plurals, past tense) are omitted. However, nouns, verbs, adjectives, and adverbs (content words) may be retained. The characteristic feature of Wernicke's aphasia is preserved speech with empty content. This may vary from the insertion of a few incorrect or nonexistent words (neologisms) to a profuse outpouring of jargon or word salad. In fluent aphasia lesions are usually in brain regions that are posterior to the fissure of Rolando (the central sulcus). In nonfluent aphasia lesions are anterior to the fissure of Rolando.  -BW