Language Disorders Flashcards
In which hemisphere do most right-handed adults have their speech centers?
The left one.
Review: What important area for speech is in the left inferior frontal lobe? Lesion causes?
Broca’s region -> afluent aphasia
Review: What important area for speech is in the superior (usually left) temporal lobe? Lesion causes?
Wernicke’s aphasia -> fluent aphasia.
Review: What structure connects Wernicke’s and Broca’s areas?
Arcuate fasciculus.
In most right-handers, what difference can be grossly seen in left vs. right Wernicke’s, Broca’s etc.?
Bigger on left where speech centers are.
Why do strokes causing aphasia have better prognoses for left-handed people?
Speech tends to be bilateral in left-handers. (it’s also just tends to be better in right hemisphere strokes)
What’s one piece of evidence that environmental factors affect the lateralization of speech?
Illiterate people don’t have as strongly lateralized speech: lesion on either side will cause aphasia.
Asking a patient to point to a pencil tests…
comprehension
What kind of lesion might you suspect if the patient only had problems with repetition (in a cursory exam for aphasia)? Possible site of lesion?
Conductive. Arcuate fibers.
3 things wrong in afluent aphasia due to Broca’s lesion?
Difficulty producing speech (labored, simple grammar)
Poor repetition
Mildly impaired naming.
(Comprehension / ability to follow commands tends to be mostly intact)
4 things wrong in fluent aphasia due to lesion to Wernicke’s area?
Fluent speech, circumlocutory (if mild) to meaningless (if severe)
Poor single word comprehension (may be able to approximate meaning)
Impaired repetition
Poor naming
4 signs of global aphasia? Does it often evolve?
Non-fluent speech Poor comprehension Impaired repetition Poor naming -Yes, it often evolves to be more focal.
What speech area would an anterior MCA stroke most affect?
Broca’s
What speech area would a posterior MCA stroke most affect?
Wernicke’s
What kind of vascular lesion could produce global aphasia?
MCA, internal carotid.
What is prosody?
Melodic pitch variation in speech -> loss of prosody produces flat, boring speech
3 right hemisphere language disorders that might occur in right-handers?
Impaired prosody
Poor comprehension of metaphor, humor
Limited grasp of extended discourse
Name 2 subcortical language disorders?
Striatal (caudate-putamen) aphasia -apparently quite rare.
Thalamic aphasia - effects vary with location in thalamus
Would Broca’s aphasics have a problem with grammatical comprhension and expression?
Yes. Broca’s isn’t all production. Recall “Fran showed her baby the pictures” vs. “Fran showed her the baby pictures.”
What kind of aphasia can frontotemporal degeneration lead to? Underlying cause?
Progressive, non-fluent aphasia (PNFA) -often accompanied by personality change. Most commonly caused by Tau buildup.
What makes progressive non-fluent aphasia different from isolated Broca’s lesion?
Really poor grammar comprehension. (can’t follow command of “Point at the floor after you point at the ceiling.”)
3 characteristics of semantic dementia?
Fluent, empty speech (like Wernicke’s)
Poor single word comprehension
Object comprehension difficulty
(it’s thought to more about losing the concept of the object that causes poor naming, not the loss of the word itself)
What areas are most affected in semantic dementia (roughly)?
Anterior and ventral temporal lobes.
What is a sign of peripheral alexia?
Letter-by-letter reading
What are 2 signs of central alexia?
Pronouncing sight vocab, such as “choir”
Pronouncing novel words, such as “gub”
(i.e. things where the pronunciation doesn’t necessarily follow the usual sounds associated with the letters)
How does the localization of peripheral and central alexia differ?
Peripheral: ventral occipito-temporal region…
Central: above and slightly anterior to the peripheral alexia region
Contrast the two kinds of agraphia.
Central agraphia: Spelling of site vocab like “choir” or novel words like “gub” (similar to central alexia
Peripheral: loss of automaticity of writing, must take time with each letter, letters often flipped
Does amusia (disorder of music) often go along with disorders of language?
Yup.