Language Systems And Aphasias Flashcards
What are the 2 principle structures of the neurocircuitry of language function
Broca’s Area
Wernicke’s Area
What connects Broca’s area and Wernicke’s area?
Accurate fasciculus and other peri-Sylvia connections
What happens if you disrupt the arcuate fasciculus
Both areas work, but problems connecting the 2 areas
Conscious auditory processing in primary auditory cortex
Lateral lemniscus to the MGN (medial = music)
Then to the
primary auditory cortex: superior temporal gyrus, within lateral fissure
Where is Heschl’s Gyrus
On the inside portion of the temporal lobe near the insula
Where is the temporal plane
On the temporal lobe, kind of a shelf when you pull it back
How are the language areas in each hemisphere connected
Via the corpus callosum
Hemispheric lateralization of language function
One “dominant side” processes the semantic aspects of language, while the “non-dominant” side processes non-verbal aspects of language: tone of voice, emotion, cadence, rhythm, accent
What does the dominant side processes
Semantic aspects of language
That does the non dominant side processes
Non verbal aspects of language: tone of voice, emotion, cadence, rhythm, accent
What side of the brain dominant are most people
Left
Non-verbal aspects: tone of voice, emotion, emphasis, cadence, rhythm, accent
Prosody
In people who are left dominant, what does the left side of the brain processes
Semantic aspects of language: meaning
In left dominant individuals, what does the right side of the brain process
Prosody
Sequence of regions and projections for language circuitry for reading aloud or naming objects
- Primary visual cortex
- Higher order visual cortical areas
- Parietal-temporal-occipital association cortex (angular gyrus)
- Wernicke’s area
- Broca’s area
- Motor region of the face
Fluent speech
- effortless, good articulation, grammatical
- prosody is intact: not a monotone or emotionally flat quality
- grammatical-caution: looking for change from patients own normal pattern
Non fluent
- laborious, inarticulate
- degradation in sentence structure: missing words, adjectives, adverbs
- in severe cases, reduced to telegraphic speech- nouns and verses only
How do you communicate with someone who does not have fluent speech
Switch from patient naming stimuli to asking yes-no questions
Volume of speech
Amount, not volume
Quantity/speed produced
Full sentences: high volume
Few words: low volume
Impaired/absent comprehension, but “fluent” and “high volume” of speech
Wernicke’s Aphasia
Coherency of the speech in Wernicke’s aphasia
May or may not be coherent, but will not understand questioning during exam
What’s another way of describing how the patient forms sentences in Wernicke’s aphasia
Word-Salad
-non-sense sentences with real words, real syllables, or non-words
Patients awareness of having Wernicke’s Aphasie
Typically unaware if deficit; frustrates by interactions until diagnosed
Intact comprehension, but impaired speech production
Broca’s Aphasia
Low fluency/volume of speech
Broca’s Aphasia
Patient awareness of having Broca’s aphasia
Patients may be aware of deficit (and distressed by it), especially before being examined and diagnosed
Damage to Broca’s also does what
Severs projections to ipsilateral (left) premotor cortex
What does the damage to the projections to ipsilateral premotor cortex in Broca’s area damage do
Makes it so patient cannot write with contralteral hand (right)
Spoken/written impairment
What do left sided infarcts do to the premotor cortex
Prevents activation of right premotor cortex (non injured side) thus writing apraxia for left hand
When the patient has a deficit in Broca’s area and the premotor cortex is damaged, what can the patient do to answer questions since they cannot write
They can still point to correctly answer questions (non language motor response, does NOT require Broca’s area)
Instant comprehension and intact speech production when tested separately, but deficit lies in coordinating comprehension and spoken responses
Conduction aphasia due to arcus the fasciculus damage.
How do you confirm comprehension in conduction aphasia due to accurate fasciculus damage
By patient nodding head to answer questions (comprehension and non verbal response)
How can speech production be confirmed in patients with conduction aphasia due to accurate fasciculus damage
By examiner pointing to elicit spoken answers rather than asking spoken questions. Patient can correctly name family members if examiner points to them
What is conduction aphasia due to arcuate fasciculus damage called
Disconnection syndrome
What would an infarct to MCA superior territory cause
Broca’s or conduction aphasia
What would infarct to MCA inferior territory cause
Wrenickes or conduction aphasia
What would MCA superior and inferior infarct cause (proximal to bifurcation)
Global aphasia, combination of Brocas and wernickes
MCA-ACA watershed infarct
-motor transcortical aphasia (mild version of Broca’s)
-isolates an intact Broca’s area from other motor areas
Non fluent or low fluency like Broca’s except the patient can repeat words or doe so spontaneously/repetitively
-other motor defects, especially proximal arm/leg
What’s the difference between regular Broca’s aphasia and the type of aphasia you see with an MCA-ACA watershed infarct
It’s low fluency like broca’s, but the patient can repeat words or does so spontaneously/repetitively
MCA-PCA watershed infarct
- Sensory transcortical aphasia
- isolates an intact Wernicke’s area from visual areas, fluent aphasia like in Wernicke’s bu patient can repeat words or does so spontaneously/repetitively
What’s the main differnce between the symptoms of an MCA-ACA watershed infarct and an MCA-PCA watershed infarct
MCA ACA: like Brocas but can repeat words
MCA-PCA: like Wernicke’s but can repeat words
What is the common theme with the symptoms associated with MCA-ACA and MCA-PCA watershed infarcts
They both have different types of aphasias but in both types of infarct, they can repeat words
What kind of infarct results in a motor transcortical aphasia
MCA-ACA watershed infarct
What kind of infarct results in a sensory transcortical aphasia
MCA-PCA watershed infarct
Classification tree for apshasia and infarcts
- Is patient fluent?
- Comprehends language?
- Can repeat single words?
What are the most common types of aphasias
- broca’s aphasia
- Transcortical motor aphasia
- Wernicke’s aphasia
- transcortical sensory aphasia
Inability to name stimuli presented
Anomic
What’s the difference between Broca’s aphasia and transcortical motor aphasia?
Transcortical motor aphasia the patient repeats words, in brocas they don’t repeat
What is the difference between Wernicke’s aphasia and transcortical sensory aphasia
Transcortical sensory aphasia the patient repeats words, in Wernickes they do not
Wernicke’s and Broca’s areas are intact, but are disconnected from each other. Can comprehend and language output is fluent, but cannot produce desired verbal response to a question.
Conduction aphasia
An infarct along the MCA-PCA watershed or isolated MCA branch occlusion in the parieto-occipital-temporal junction would cause what kind of aphasia
Conduction aphasia
Fluency in Brocas
Nonfuent
Fluency in Wernickes
Fluent
Fluency in conduction aphasia
Fluent
Fluency in global aphasia
Nonfleunt
Expression in Brock’s
Impaired
Expression in Wernickes
Unintelligible
Expression in conduction aphasia
Some paraphrasing (some unintelligible)
Expression in global aphasia
Impaired
Comprehension in Broca’s
Relatively preserved
Comprehension in Wernicke’s
Impaired
Comprehension in conduction aphasia
Preserved
Comprehension in global aphasia
Impaired
Naming in broca’s
Impaired
Naming in Wernickes
Impaired
Naming in conduction aphasia
May be impaired
Naming in global aphasia
Impaired
Lesion site for Broca;s aphasia
Left frontal operculum
Lesion site for Wernickes
Left superior temporal and inferior parietal corticospinal
Lesion site for conduction aphasia
Left accurate fasciculus
Lesion site for global aphasaia
Whole perisylvian region
Loss of ability to read words, typically after PCA infarct
alexia
When do you typically get alexia
After PCA infarct
Alexia without agraphia
Alexia without the loss of ability to write (including written responses to the examiner )
Circuitry affected in alexia without agraphia
Infarct in left primary visual cortex not only induces right homonymous hemianopsia, but also blocks projections from intact right visual cortex from crossing midline and reaching the left angular gyrus
Alexia without agraphia and reading
Loss of reading using wither eye. Also cant see left half of space
