Aphasias Flashcards
What are four domains that aphasia can affect?
Talking, listening (comprehension), writing, and reading.
Also can be considered association, storage, retrieval, and rule implementation
What are some common causes of aphasia?
Stroke (hemorrhagic or ischemic), trauma (brain injury), tumors and their removal, infection, neurodegenerative disease.
What is a hemorrhagic stroke?
A blood vessel bursts and releases blood into the brain tissue (5-10% of strokes)
What is an ischemic stroke?
Blockage in a blood vessel deprives the brain of oxygen and nutrients (75-85% of strokes)
Can you be born with an aphasia?
No. By definition they are acquired
What are some implications about the formal definition of aphasia?
There’s no loss of anything. Language isn’t happening, but the area of the areas are not altogether gone.
Linguistic representations are still present in a strict representational/dynamical systems sense.
Rules that are used to assemble these representation into coherent units of language are also still present
The problem is an impairment of access all of the above or activating/inhibiting information in properly timed and regulated ways to build representations.
Language doesn’t have to be relearned. It’s still sensitive to priming for example.
Are aphasias associated with dementias?
No. The definitions do not cover dementias.
Primary progressive aphasia may be an exception.
What is aphasia not?
It’s not associated with other cognitive impairment like dementia, delirium or psychiatric disorder, coma, sensory loss, motor dysfunction (apraxia of speech-problems planning motor movements or dysarthria-weak muscles and slurred speech).
What are some common linguistic aphasic deficits and characteristics?
Anomia, auditory comprehension, agrammatism, dysgraphia, dyslexia
What is anomia?
Difficulty finding words (tip of the tongue) or semantic/phonological errors when finding words.
What is agrammatism?
Omission of function words so that speech sounds like it is a telegram (Telegraphic speech).
Difficulty with verbs/verb morphology
What are some common linguistic/performance aphasic deficits and characteristics?
Variable performance, slowed processing times, reliance on situational context to understand or convey meaning, reduced sentence length/complexity, perseverative speech, reduced verbal STM and WM span, reduced gestures and co-verbal behaviors.
What kind of problem is variable performance?
access problem
What is STM and WM?
Short-term and working memory.
What are the three most common classification systems used for aphasia diagnosis today?
The Centers and Pathways (Wernicke/Lichtheim Model) aka “the Boston Classification System” (most common)
The fluent/nonfluent classification
No classification - aphasia is one
What is fluency?
measure of utterance length and prosody.
What are the four centers-and-pathway domains of measurement in the Boston Classification system?
Fluency, Auditory Comprehension, Repetition, Aphasia Type
Explain Broca’s aphasia
Very slow and non-fluent speech.
Nonfluent output, good comprehension, poor repetition, effortful speech, distorted articulation, short phase length.
Agrammatic production and comprehension
Often hemiparetic
Lesion site: Posterior 2/3 of the inferior frontal gyrus; pars triangularis and pars opercularis; BA44,45
What constitutes agrammatic comprehension?
Trouble with non-standard sentence order, like passive tense
Which type of aphasia is helped by singing?
Aphasias that affect motor speech, like Broca’s aphasia
What does hemiparetic mean?
Weak on one side of the body.
What are the 8 domains for measuring aphasia?
Articulatory agility, phrase length, grammatical form, melodic line (prosody), paraphasia in running speech, word finding relative to fluency, sentence repetition, auditory comrehension
How is articulatory agility measured?
Ability to articulate phonemes and syllables from unable to produce speech sounds, to clumsy, to unimpaired
How is phrase length measured?
By longest occasional uninterrupted word runs. 1 word-7 words.
How is grammatical form measured?
Variety of construction and use of grammatical morphemes. No syntactic word groupings -> simplification and omission of required grammatical morphemes -> normal
How is melodic line measured?
no prosody, intonation of only short phrases, normal melody
How is paraphasia in running speech measured?
It’s only considered if phrase length is more than 4 words.
Present in every utterance -> 1-2 instances per minute of conversation -> absent
How is word finding measured?
As relative to fluency.
Fluent but empty speech -> informational relative to fluency -> words with content are common
How is sentence repetition measured?
as a percentile from 0-100
How is auditory comprehension measured?
as a percentile from 0-100 with a mean percentile of the three standard subtests
What scores might Broca’s aphasia receive?
Articulatory agility: 1-4 Phrase Length: 1-4 Grammatical Form: 1-4 Melodic Line: 1-4 Paraphasia in running speech: 5-7 Word finding: 4-7 Sentence repetition: 30-60% Auditory comprehension: 50-100%
What is true about predicting recovery?
It’s difficult. Total size of lesion is probably most diagnostic of recovery rather than location, but recovery is still possible even with full hemispheric removal.
How would Broca’s aphasia score on the Boston Classification System?
Nonfluent, good auditory comprehension, poor repetition
How would Wernicke’s aphasia score on the Boston Classification System?
Fluent, poor auditory comprehension, poor repetition.
How would Anomic aphasia score on the Boston Classification System?
Fluent, good auditory comprehension, good repetition
How would Conduction aphasia score on the Boston Classification System?
Fluent, good auditory comprehension, poor repetition
How would Transcortical Sensory aphasia score on the Boston Classification System?
Fluent, poor auditory comprehension, good repetition
How would Transcortical Motor aphasia score on the Boston Classification System?
Nonfluent, good auditory comprehension, good repetition
How would Mixed Transcortical (Isolation) aphasia score on the Boston Classification System?
Nonfluent, poor auditory comprehension, good repetition
How would Global aphasia score on the Boston Classification System?
Nonfluent, poor auditory comprehension, poor repetition
Explain Wernicke’s aphasia
Good prosody
Empty content (lots of this and that references)
Use of non-words/anomia neologisms
Long syntactically varied utterances
Poor self-monitoring (lack of awareness of most errors)
Lexical-semantic/conceptual-semantic impairments
Not usually motor deficits
Lesion site: posterior superior temporal gyrus BA22
What is anomia neologism
non words
What is a neologism
A newly coined word
What scores would Wernicke’s aphasia receive?
Articulatory agility: 6.3-7 Phrase Length: 5.5-7 Grammatical Form: 5.5-7 Melodic Line: 6.5-7 Paraphasia in running speech: 1-4 Word finding: 1-3 Sentence repetition: 0-60% Auditory comprehension: 0-45%
Describe Global Aphasia
May have varied, often neologistic output or recurrent stereotypy
Usually hemiparetic or hemiplegic
Lesion site: Large, perisylvian
What is stereotypy?
Repetition of an act without obvious purpose
What does hemiplegic mean?
Paralysis of half the body
Perisylvian
Around the sylvian fissure (Lateral sulcus)
Divides the thumb from the fist if the hand is used to model the brain
Describe Conduction aphasia
Able to accurately paraphrase sentences that they cannot correctly repeat
Frequent phonemic or literal paraphasias
Conduite d’approche: mult. production attempts that progressively more closely approximate the target
Between Broca and Wernicke in fluency
motor deficits are uncommon
Lesion sites: Arcuate fasiculus and/or supramarginal gyrus (BA40)
How does Conduction aphasia score?
Articulatory agility: 5.2-7 Phrase Length: 4.8-7 Grammatical Form: 4.4-7 Melodic Line: 5.8-7 Paraphasia in running speech: 2-4 Word finding: 2-4 Sentence repetition: 0-50% Auditory comprehension: 50-100%
Describe Anomic aphasia
Circumlocution and semantic paraphasias may be the predominant error types
Mild case or end result in recovery
Motor deficits are uncommon
Lesion site: Classically angular gyrus BA 39
More recently: Temporal lobe lesions have been associated with category-specific naming deficits
Temporal pole with proper names
Anterior ITG and MT: animal names
Temporo-occipital junction: Tool names
How does aphasia affect bilingualism?
Bilingual people tend to recover faster. Whether or not both languages are affect depends and varies
How does Anomic aphasia rate?
Articulatory agility: 6.5-7 Phrase Length: 6-7 Grammatical Form: 6.5-7 Melodic Line: 6.5-7 Paraphasia in running speech: 5-7 Word finding: 2-4 Sentence repetition: 70-100% Auditory comprehension: 60-100%
What is circumlocution?
Inefficiency in word use. Could use fewer words to say the same thing
Describe Transcortical Motor aphasia
May have generally akinetic or bradykinetic presentation
LE > UE hemiparesis (lateral and unilateral)
Lesion site: watershed region between MCA and ACA; SMA (BA6); anterior & superior to Broca’s area
Describe Transcortical Sensory aphasia
May be echolalic
Lesion site: watershed region between MCA and PCA; temporo-occipital junction
Akinetic
Slowness or loss of normal movement
Bradykinetic
Pertaining to slowed ability to start and continue movements, and impaired ability to adjust the body’s position
What is a watershed area?
Regions of the body that receive dual blood supply from the most distal branches of two large arteries.
What are some outdated assumptions of the Wernicke-Lichtheim classification system?
Language representations are stored in discrete “centers”
Centers are connected to one another by unique and discrete pathways
Lesions in specific centers or pathways created specific, differentiable types of aphasia
The behavioral dimensions of fluency, comprehension, and repetition are unitary, localizable, and bimodally distributed.
Because of outdated assumptions, the Wernicke-Lichtheim suffers what limitations?
Linguistic and communicative behaviors are missing from the classification
Treatment planning has little predictive value
Prognosis has little predictive value
Lesion locations only offer general predictive value
What’s a problem with scoring fluency?
It can interact with motor speech problems (like apraxia) or language impairment
What’s a problem with scoring repetition?
There are different impairments that can lead to the same problem.
What’s the repetition model?
Hear the word -> Acoustic analysis -> Acoustic to phonological conversion -> Response buffer -> speech
Hear the word -> Acoustic analysis -> Auditory input lexicon -> phonological output lexicon -> response buffer -> speech
The middle of the model loops with cognitive/semantic components
How often does Broca’s aphasia predict anterior lesions?
35% (17/48)
How often does an anterior lesion predict Broca’s aphasia?
59% (17/29)
How often does Wernicke’s aphasia predict posterior lesions?
48% (23/48)
How often does a posterior lesion predict Wernicke’s aphasia?
90% (23/26)
How often does Global aphasia predict a large lesion?
75% (59/79)
How often does a large lesion predict Global aphasia?
83% (59/71)
What is one hard fact about aphasia and lesions?
It usually co-occurs with a perisylvian legion of the left hemisphere.
What is true about localization of apraxia?
It’s usually localizable to Broca’s area.
How often does Apraxia of speech predict Broca’s lesion/hypoperfusion?
87% (26/30)
How often does a lesion Broca’s area/hypoperfusion predict Apraxia?
84% (26/31)
How often does Apraxia of speech predict insular lesions/hypoperfusion?
41% (12/29)
How often does an insular lesion/hypoperfusion predict apraxia of speech?
39% (12/31)
What is hypoperfusion?
Sounds like a stroke or shock to the brain. The inadequate perfusion of body tissues, resulting inadequate supply of oxygen and nutrients
What is perfusion?
Passage of fluid through the circulatory system to tissue.
How can imaging be used to help study and rehabilitation in aphasia?
Neuroplastic changes can be detected as a response to treatment.
Structural imaging can predict aphasia treatment success.
TMS and tDCS as adjuncts to behavior therapy
What are some structural changes found in relation to aphasia treatment?
Increased activation of right-hemisphere homologues in post-acute phase of recovery.
Re-activation of peri-lesional areas in chronic phase among patients showing best response to therapy
What are some ways structural imaging has been shown to predict rehabilitation in aphasia?
Intact RH homologues and basal ganglia associated
Intact LH hippocampus and surrounding white matter
Intact peri-lesional LH cortex
All associated with positive treatment response
Is aphasia isolated to language?
It also overlaps with other cognitive deficits such as attention, working memory, and executive functioning deficits. The more these are impaired the greater language impairment.
These are co-morbid but independent
What’s an open question from the lecture?
Are there functional relationships between language and control deficits?
What’s one area of research about language and control deficits?
How long do they spend search for a word? Speed-accuracy tradeoffs.
Define aphasia
A central, multimodal impairment in symbolic language processing performance independent of possibly co-morbid cognitive or sensory impairments
What are problems with the classification model?
Clinical utility
Criteria for classification
Lesion-symptom correlations
What are three cardinal features of aphasia?
Word finding difficulty, comprehension impairment, and moment-to-moment variability
Explain the dorsaw stream of speech
Auditory input leads to acoustic phonetic speech codes which goes dorsal to auditory-motor interface and on to articulatory-based speech codes.
Explain the ventral stream of speech
Auditory input leads to acoustic phonetic speech codes which goes ventral to sound-meaning interfaces
What areas are associated with articulatory-based speech codes?
pIF/dPM (left)
What area is associated with auditory-motor interface?
Area Spt (left) sylvian parietal temporal
What area is associated with acoustic-phonetic speech codes?
STG (bilateral)
What area is associated with sound-meaning interface?
pITL (left)
What is lemma?
Word meaning without the utterance or sound
What area is associated with a lemma?
The association areas between STS and pITL (MTG and ITG)
Where are sound based representations?
STG
What does Spt do?
maps between auditory representations of speech and motor representations of speech.
Does sub-lexical speech perception performance correlate with auditory comprehension
no. They doubly disassociation and are therefore performed by different areas of the brain.
What are three theories that diverge from classical associate connectionist models that posit distinct regions for language features?
Brown’s microgenetic theory, cognitive neuropsychological perspective, and computational approaches
What are paraphasias?
symptoms of aphasia
Describe Brown’s microgenetic theory.
Paraphasias represent reemergence of previous stages of linguistic development. Also more basic language structures are possible through more primitive areas of the brain.
Describe cognitive neuropsychological perspective.
Looks at brain damage for evidence, but double disassociation is rare and the interactions between systems hard to track.
Describe computational approaches.
A model can be created and interactions tested to see if they produce aphasic like data.
