0917 - Disorders of Language and Speech Flashcards
What are the three forms of dysphasia?
Receptive - difficulty understanding/comprehending input.
Expressive - problem with producing output.
Mixed/global - problem with both.
What is the significance of Broca’s area?
language output centre with dedicated area and association cortices. Situated near PMC for mouth and tongue, and connected to Wernicke’s area by arcuate fasciculus.
What are the three elements of language that need to be examined? How do you test them?
Comprehension - testing Wernicke’s area inputs, extracting meaning from other areas too. Test by clear instructions.
Expression - Taking ideas and being able to express them. (Often taken in history)
Repetition - Taking an input and reproducing it as an output. (“No ifs, ands, or buts”)
What are the 4 primary forms of aphasia and the areas damaged?
- Wernicke’s - Loss of comprehension and word meanings
- Broca’s - loss of expression plus grammar
- Arcuate fasciculus - Conductive aphasia - loss of repetition
- Global mixed aphasia - everything.
Outline Broca’s aphasia?
Delay or complete failure of the expression phase of language processing, affecting both expression and repetition. Preferential loss of ‘syntactical’ words (so tested by no ifs ands or buts). Speech is slow, hesitant and telegraphic, with patients usually frustrated by it and comprehension largely, but not completely intact.
Outline Wernicke’s aphasia.
Generally mixed, but dominant Wernicke’s involvement. Hallmark is impaired comprehension - not answering questions appropriately or carrying out command. Repetition difficult or impossible, with some expression difficulties as well due to a lack of lexicon. Less frustration than in Broca’s.
Outline Global aphasia
Damage to both Broca’s and Wernicke’s areas - comprehension and speech are both impaired. The speech problems are more obvious than the comprehension problems.
How does a transcortical aphasia present?
Lesion is in the connections from Wernicke’s or Broca’s to the rest of the cortex. Intact repetition, but difficulties understanding or expressing own thoughts.
Outline conduction aphasia
Lesion is in the arcuate fasciculus. Hallmark is impaired repetition in presence of normal comprehension. Understanding and re-expression is intact but original words are lost (e.g. as if re-telling a story).
How do speech/comprehension disorders due to lesion relate to reading/writing ones?
Reading/writing will often be affected in the same way as speech/comprehension is.
What is dysphasia?
An impairment of the ability to understand (receptive) or produce (expressive) or both (global) language due to a brain injury.
What is dysarthria?
An impairment of the ability of the muscles to produce speech that is otherwise linguistically normal - e.g. from cerebellar injury.
What is dysphonia?
An impairment of the ability of speech organs to produce speech that is unrelated to the muscles - e.g. lost voice in laryngitis.
