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Features of Global Aphasia
- Loss of language comprehension and verbal expression
- No sex or age bias
- Most lesions are cortical, extensive, left hemisphere, MCA, thrombosis
- Clinical depression
- Frequent facial and limb apraxia (right side)
- Probably right hemiparesis too
- Isolated areas of preserved comprehension for some clients
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Global Aphasia Expression
- Stereotypic recurring utterances; real word or nonsense
- Continuous syllable string with intonation changes
- Unreliable or absent yes/no
- Nonspecific gestures (looks like communication, but has no meaning)
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Recovery of Global Aphasia
- Lowest recovery rate; variable
- 50% do not evolve to less severe
- Comprehension improves more than expression; nonverbal more than verbal
- Improvement enhanced by treatment within first 12-18 months
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Prognostic Indicators of Global Aphasia
- Age: no proof that younger is better
- Imaging: findings are not reliable
- Language scores: early yes/no response- better outcome at 1 year post stroke
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Treatment Approaches for Global Aphasia
- Greater success when focus on residual skills (skills that were still intact after the stroke)
- 1. Social approaches
- 2. Functional approaches
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Social Approaches (Global Aphasia)
- Partner training
- Conversational coaching
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Functional Approaches (Global Aphasia)
Communication boards
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Communication Boards
- Begin highly structured: matching pictures prior to discrimination (point to) tasks
- Provide high level of support- physical assistance
- Alternative designated boards to keep categories separate
- Train in natural environments
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Modest Goals for Short Term Treatment of Global Aphasia
- Develop reliable yes/no response with speech of gestures
- Develop set of basic messages via speech or gestures or pictures
- Improve comprehension of basic 1 step commands in context with nonverbal cues
- Encourage drawing as form of communication
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Types of Comprehension Processes
- Bottom-up
- Top-down
- Knowledge-based or heuristic
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Bottom-up
- We use only when necessary
- Analysis using piece by piece approach (e.g. phonetic decoding of unfamiliar word)
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Top-down
- Used more often than bottom-up
- Knowledge-based or heuristic (e.g. guess at meaning using your experiences
- Heuristic knowledge is preserved in most aphasic patients
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Knowledge-based or Heuristic
- Used to understand spoken material
- General knowledge
- Expectations
- Intuition
- Guessing
- Does not require continuous word-by-word lexical and syntactic analysis
- Allows for use of SCRIPTS
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SCRIPTS
- Pre-written dialogues between two people
- Ex. social greetings, a waitress taking orders, etc.
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Use of Scripts in Therapy
- Scripts: what we expect to hear based on experience
- Preserved for many people with aphasia
- Context facilitates comprehension
- Appropriate for those with sentence level comprehension skills
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SCRIPTS: Spoken Sentence Comphrension
- SLP modifies length and complexity of stimuli and responses required
- Most daily life utterances are less than 5 words in length (hi, how are you, good to see you, etc.)
- Employs "response switching"
- More functional than working on following 2 and 3 step directions
- No empirical evidence to show improvement in overall language comprehension
- Scripts help people communicate within a public/social setting
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Response Switching
- Deliberate changes in the form of stimulus sentences and required responses from trial to trial
- Ask a question, person replies with statement, follow-up question, joke, etc.
- Purpose: prepare person for day to day conversations out in public
- Requires: memory skills, comprehension
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SCRIPTS: Grammar and Syntax in Spoken Sentence Comprehension
- A. Present tense is easier for clients to comprehend than past or future
- B. Affirmative is easier than negative
- C. Singular is easier than plural
- D. Active voice is eatery than passive
- Start with concrete language and then move to more complex language
- Reducing sentence length may have undesirable consequence of increasing syntactic complexity (making something shorter doesn't necessarily make it better)
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SCRIPTS: Comprehension of Discourse
- Word and sentence comprehension cannot predict comprehension of discourse
- Discourse comprehension is often better than single-sentence comprehension (can use context cues)
- Comprehension is aided by context, redundancy, predictability, extralinguistic cues (ex. salience or emphasis)
- Try not to be condescending/patronizing like you are talking to a child
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Comprehension of Discourse
- Conversational speech = how we communicate naturally
- 1. Context
- 2. Predictability/familiarity
- 3. Redundancy
- 4. Extralinguistic cues
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Context (Comprehension of Discourse)
- Contextually relevant sentences that precede or follow a target sentence can improve processing of key information (e.g. identify topic, setting, or predict relationships)
- Tap into general knowledge and experience
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Predictability/Familiarity (Comprehension of Discourse)
- Use preexisting knowledge
- Scripts organize knowledge of common situations
- Can use overt scripts, then fade
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Redundancy (Comprehension of Discourse)
- Begin treatment using repetition, paraphrasing and elaboration
- Emphasize main ideas and direct information
- Allows clients to use heuristic/knowledge based processes
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Extralinguistic Cues (Comprehension of Discourse)
- Pauses
- Word stress
- Natural gestures
- Facial expressions
- Be careful with humor
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Treatment of Discourse
- Stimulus manipulations
- Patterns of auditory comprehension problems
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Stimulus Manipulations (treatment of discourse)
- Familiarity
- Length
- Redundancy
- Salience
- Directness
- Rate
- Context
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Patterns of Auditory Comprehension Problems (treatment of discourse)
- 1. Slow rise time: miss initial input
- 2. Noise build up: errors increase over time
- 3. Intermittent auditory imperception: comprehension fades in and out (shutter effect); unpredictable errors
- 4. Retention deficit: deterioration with increased length
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Treatment of Auditory Comprehension Problems (treatment of discourse)
- 1. Slow rise time: alerters; redundancy
- 2. Noise build up: insert silent intervals
- 3. Intermittent auditory imperception: use redundancy
- 4. Retention deficit: control stimuli for length; gradually increase message length
- Teach significant others to use these strategies to benefit the client outside of therapy
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Treatment of Wernicke's Aphasia
- Using context to facilitate communication
- Marshall's Context-Based Approach
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Marshall's Context-Based Approach (Wernicke's)
- Best with people who have sentence-level comprehension
- Focuses on message comprehension and message exchange
- Two stages of treatment related to time post onset; early and late
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Early C-B Treatment for Wernicke's Aphasia
- Many patients don't know that they aren't being understood and aren't understanding
- Emotional and behavior effects
- Family confusion
- SLP assumes role of "behavioral engineer" (educates and guides patient, family and treatment team; trains conversational partners)
- Early assessment: patients do poorly on typical tasks
- Marshall uses para-standardized testing, observation, and personal information about patient
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Early C-B Assessment: Para-standardized Testing
- Spark Para-standardized Examination Guidelines for Adult Aphasia (PSE)
- Indicates: Strengths/weaknesses
- What facilitates comprehension and message exchange
- Marshall modified PSE to include assessment of four communication features: Therapeutic Set, Pragmatics, Auditory Comprehension, Verbal Expression
- Each feature includes: Areas of concern, Negative signs/behaviors, and Positive signs/behaviors
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Early C-B Assessment: Observation and Personal History
- Observation: communication in different settings with different partners (add information to PSE)
- Gather personal history: history, background, pre-morbid communication, style and habits (can use questionnaires)
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Early C-B Therapy: Goals
- 1. Establish therapeutic set: positive attitude (if client has negative set, you can find a way to show how working with you is beneficial)
- 2. Create different contexts for communication: need for communication (top-down model)
- 3. Increase comprehension in established context
- 4. Maintain flow of communication in context
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Marshall's Use of Communicative Context
- "Prime the patient" for context
- Use visual stimuli
- Reinforce and encourage patient's requests for repetition
- Use concrete humor and descriptive language
- Alert patient to topic change
- Maximize redundancy
- Use paralinguistic cues
- Manipulate response for short answers
- Fill in necessary words to keep patient focused (very different from traditional therapy)
- Slow rate of speech and pauses at natural intervals
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Early C-B Therapy: Excessive or Restricted Speech Flow
- Excessive flow: "press of speech"
- Defective utterances fed back into impaired auditory comprehension system- lack of comprehension of what is said to them and lack of comprehension of what they are saying ("garbage in, garbage out")
- Stop Strategy: teach the client that when a sign that signals 'stop' is used, the client must stop talking
- Paraphrase, model, reinforce: help the client understand that they don't need to keep talking to get their point across, they can say what they want to say in a more succinct way
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Early C-B Therapy: Restricted Speech Flow
- Patient begins to comprehend problems
- Severe interference of communication of basic needs
- Fill in
- Keep trying
- Acceptance
- Reinforce persistence
- Variability
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Early C-B Therapy: Support and Guidance for Caregivers
- SLP demonstrates how to: increase comprehension, restrict or promote speech flow, create communication opportunities (make sure the caregivers know that they can't restrict communication opportunities)
- Have family members/communication partners observe so they can try using the strategies with the client at home
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Marshall's Later Context-Based Therapy for Wernicke's Aphasia
- ~2-3 months post onset
- Persistent word-finding problems or is considered to have anomic aphasia; less severe comprehension problems; good response to early C-B tx (tend to use circumlocution or interjections as fillers)
- Comprehensive assessment and family completes rating scales (what still seems to be the problem with communication?)- can write therapy goals using this
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Later C-B Therapy: Residual Auditory Comprehension Problems
- 1. Attention deficits- sustained attention, shifting attention from one task to another, multi-tasking is not encouraged
- 2. Perseveration- when a response that was appropriate is repeated when it is no longer appropriate (usually stops after a while, if it perseveres, that is not a good prognostic indicator)
- 3. Impaired understanding single words- can't understand a word without context
- 4. Retention deficits- have to work on understanding each part of the utterance and may forget the beginning of it
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Later C-B Therapy: Attention Deficits
- 1. Use alerters (verbal or nonverbal)
- 2. Specify topic change (verbal or nonverbal)
- 3. Teach to alternate tasks (break long activities up by interjecting other activities in the middle, like watching a movie)
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Later C-B Therapy: Perseveration
- No agreement on how to treat
- a. Allow time to integrate and consolidate
- b. Treatment of Aphasic Perseveration (recommend communicating clearly to the client that the perseverating response is not appropriate)
- Change the activity (move to a nonverbal activity) or take a break
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Later C-B Therapy: Problem Understanding Single Words
- Behavioral Indicators:
- 1. More trouble identifying by name than by function
- 2. Repetition of word; perplexed
- When interference with communication occurs, SLP:
- a. Increases redundancy
- b. Increases contextual support
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Later C-B Therapy: Retention Deficits
- Can further restrict comprehension of contextual situations and isolated tasks
- Teach behavioral and compensatory strategies:
- Asking for repetition
- Rehearsal (doesn't usually help)
- Personal cuing (try to related a name to someone they know)
- Memory aid (external)- writing notes
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Later C-B Therapy: Improving Discourse Comprehension
- 1. Rest/Withdraw- let the clients know it's okay to rest after a conversation or visit with a friend
- 2. Pre-stimulation- give information before a situation so the person can start imagining and guessing what the conversation topics may contain
- 3. Supplementary input- closed captioning, reading a description of a movie
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Reading Comprehension Problems in Aphasia
- Slow rate (reduced mental resources)
- Misperceptions
- Word by word decoding (easy to lose meaning)
- Poor retention
- Loss of overall meaning (since it takes so long to get through, cohesion is decreased)
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Assess Reading at Sentence and Paragraph Levels
- Subtests: WAB-R, BDAE (matching word to picture, picture to word, letter to letter, etc.)
- Reading Comprehension Battery for Aphasia-2 (good for people who already have reading comprehension at sentence level)
- Gray Oral Reading Test-3 (requires person to read aloud, gives you grade-level equivalent, this may not really be testing comprehension because the person may just be able to express it)
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2 Types of Reading Comprehension Problems
- 1. Deep or Phonologic Alexia:
- Errors when "decode"
- Can recognize whole words
- Poor bottom-up approach
- Good with familiar, meaningful words
- 2. Surface or Semantic Alexia:
- Poor whole word reading
- Have to sound words out (at a deficit with unusual spellings)
- Depend on decode approach
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Alexia
Acquired reading comprehension deficit due to brain damage
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Deep/Phonological Alexia
- 1. Can read high frequency concrete nouns
- 2. Whole-word recognition intact
- 3. Problems with function words
- 4. Poor grapheme-to-phoneme (better off to teach them combinations of sounds- syllable approach)
- Some success: biograph-syllable /pa/ vs. /p/ + /a/
- Some success: phrase-formatted text and multiple oral rereadings
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Surface/Semantic Alexia
- 1. Impaired whole-word reading:
- Case studies suggest success with improving WWR
- Teach through memorization and repetition
- 2. Depend on grapheme-to-phoneme (word length effect is problem)
- 3. Irregularly spelled words are mispronounced (teach to use context)
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Impaired Processes for Reading
- Lost or impaired whole word reading
- Lost or impaired phonemic analysis
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Occular Causes of reading Impairment
- 1. Visual field loss
- 2. Eye movement problem
- 3. Poor central vision
- Check brain imaging report
- Question vision history
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Treating Neurogenic Reading Impairments
- 1. Obtain literacy history:
- Level of education
- Reading preferences prior to stroke
- How much they read prior to stroke
- How much reading was involved in their job
- 2. Determine current skills
- 3. Determine importance to client
- Best prognosis: sentence level comprehension of written material, intact vision, motivation to read/rich reading history, responsiveness to trial therapy, attending and memory skills
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Treating Severe Reading Comprehension Disorders
- Survival Reading Skills (client indicates list of reading materials- most wanted to wanted but can do without)
- Develop and teach core sight-reading vocabulary
- Depends on discharge plan and who the person will have around them
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Treating Mild to Moderate Reading Comprehension Disorders
- Teach clients to use context to establish topic and deduce word meaning
- Taps heuristic knowledge
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Treatment of Reading: Stimulus Manipulations
- Familiarity
- Length
- Redundancy
- Salience/Directness
- Vocabulary
- Syntactic Complexity
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Reading Programs Based on Grade Level and Specific Skills
- Identifying main ideas
- Locating details
- Homework assignments used in treatment sessions
- Make sure reading selection is not demeaning
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Agraphia vs. Dysgraphia
Agraphia is acquired
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Deep Agraphia/Sublexical Agraphia
- Presence of written semantic errors, effects of frequency, imagery, and class
- Word frequency is very important
- They can write something that they can picture better than something they can't picture (ex. jogging)
- Semantic paraphasia (ex. can visualize jogging, but may write down run)
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Surface Agraphia/Lexical Agraphia
- Over reliance on sound to letter conversion; regularization of irregularly spelled words
- Don't think about whole word units, think about decoding
- Frequency and imagery do not help
- Irregularly spelled words will be spelled the way they sound ("you" instead of "yacht")
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Global Agraphia
- Impaired lexical and sub lexical spelling processes (will not functionally write in future)
- Trace name over and over so they know the motor movements to sign their name
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Writing Deficits in Aphasia
- Most aphasic adults write less well than they speak
- Writing resembles speech in nature of errors:
- Fluent aphasia: Fluent cursive, neat, empty content, paraphasic errors
- Nonfluent aphasia: Distorted printing, uneven spaces and lines, confluent, agrammatic (often writing with left/non-dominant hand)
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Assessment of Single Word Writing
- Use controlled word list for evaluation of lexical features (frequency, imagery, class, spelling regularity, word length, morphological complexity)
- Johns Hopkins University Dysgraphia Battery (used for deficits with spelling)
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Writing Impairments: Damage to Processes?
- Semantic system
- Graphemic output lexicon
- Graphemic buffer than temporarily holds graphemic information for writing
- Conversation processes necessary to select and form (converting a word into writing)
- Graphic motor processes (referral to occupational therapist)
- Working memory
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Survival Writing Skills in Aphasia
- Elicit client and family input to generate list of what client would most like to write, extract core vocabulary and basic syntax
- Some clients are happy with writing phonemically (they write words the way they sound)
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Treating Mild Writing Deficits
- Recent returned focus on writing: email
- If informal, tolerance for telegraphic form
- Formal messages require more complex syntax than spoken messages with accurate vocabulary (academic, vocational, professional)
- Use spell check, style check, word prediction (word prediction requires good editing/self-correction skills)
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SLP Plus Neuroplasticity
- Functional reorganization of language in aphasia
- a. Recruitment of residual left hemisphere structures
- b. Recruitment of right hemisphere regions, typically homologous to left hemisphere language areas (right hemisphere contributions may reflect attention, executive function, memory)
- Cognitive reorganization
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What Do We Need to Express a Message?
- Mental Lexicon: Store of information
- Semantic Network: Connected representation of word meanings
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Mental Lexicon
- Semantic and syntactic knowledge
- Word forms knowledge (how spelled, what is sound pattern)
- Orthographic (vision based)
- Phonologic (sound based)
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Semantic Network
- Connection strength or distance determined by associative relations
- Model assumes that activation spreads from 1 conceptual node to others
- Nodes closer together will benefit more from spreading activation
- Activation spreads- where we store certain categories
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Message Formulation
- Conceptual message grammatically encoded
- Syntactic representation
- LEMMA
- Conceptual message activates encoding process, appropriate lemmas are
- retrieved: Lexical selection
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LEMMA
- Contains information about a word's syntactic properties and semantic specifications
- Abstract conceptual form that has been mentally selected for utterance, but before any sounds are attached to it
- Knowledge of a word
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Phonological encoding
- Selected lemma activates the lexeme (sound form of words)
- Move from intent to lemma to lexeme
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What Causes Word Retrieval Problems in Aphasia?
- Phonologic access impairment- can client recognize words and pictures but cannot assign phonologic rules?
- Semantic access impairment- mental lexicon; can client recognize words and pictures?
- Combination of both impairments
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