ADULT LANGUAGE DISORDERS

Week 3Jan 27, 2011

Review

Word finding difficulty is one of the striking feature of aphasia (T/F)

Aphasia is a language impairment affecting all four modalities of language (T/F)

Writing is typically least impaired area in an individual with aphasia (T/F)

Aphasic individuals are good at using ________ forms of speech

Aphasia is an impairment of intellectual functioning such as reasoning, problem solving, etc. (T/F)

Objectives

Understand the explanations for Aphasia Learn about the etiology of Aphasia Understand the Aphasia classification

systems Discuss the symptomatology of different

forms of fluent Aphasias Wernicke’s Aphasia Conduction Aphasia Anomic Aphasia Transcortical sensory aphasia

Explanations for Aphasia

Two orientations: Neurological and cognitive 1. Neural processes

(i.e., neurons, cerebral areas)

2. Psychological or

mental processes (i.e., ideas or memories, comprehension)

• Relationship between ideas and words

Neurological Explanation for Aphasia

Features and severity of neurogenic communication disorders depend on location and magnitude of the damage… (Brookshire, 1997)

Neurological Explanation for Aphasia

• Luria (1970) – three functional divisions

• 1. Brainstem: general awareness and distribution of sensory input

• 2. Posterior cortex: perceives, recognizes, and integrates sensory information

• 3. Anterior cortex: generates volitional response

Luria

Neurological Explanation for Aphasia

Focal lesions (e.g., stroke) multifocal lesions (e.g., little strokes

through the year) diffuse lesions (spread evenly

throughout the brain)

Neurological Explanation for Aphasia

Left and Right hemispheres have different functional specialties (i.e., Left- language and Right – nonverbal)

Within the left: anterior – nonfluent, posterior – fluent form of aphasia

Cognitive Explanation for Aphasia

Encoding and decoding messages – relationship between ideas and words stored in our memory

Two features of cognition Knowledge (stable storage) – about the world and

language we speak Process – transient activity of mind, a response to

stimulus

Memory is the key to carryout all cognitive functions

Memory

Long-term memory (LTM) Different types of knowledge

Episodic memory Semantic memory- common knowledge Procedural memory Lexical memory- words and knowledge

about words

Memory

Working memory (WM) – work space of any cognitive activity

Short-term memory is one component of WM

Aphasia

Cognitive processing including language processing Constrained by the capacity of WM Draws knowledge from LT storage Operates at automatic and controlled levels

In aphasia language storage system is relatively intact Impairment of processing

Aphasia- Take Home

Aphasia is a selective impairment of the cognitive system specialized for comprehending and formulating language, leaving other cognitive capacities relatively intact. (Davis, 2007, p.15)

Etiology of Aphasia Deprivation of Blood Supply Cerebrovascular Accident

or CVA 1) Thrombosis

▪ Buildup of fatty tissues and other deposits on wall of artery

▪ Over time, artery hole is totally blocked, leading to thrombosis

2) Embolism: substance originating from another part of body, usually heart, lodging itself in brain blocking blood flow – CVA is instantaneous

http://homepage.psy.utexas.edu/homepage/class/Psy332/Salinas/Disorders%20/stroke1.gif

Etiology of Aphasia

Spilling of Blood – blood spills on neurons causing damage to them

Hemorrhage 1. bursting of aneurysm: walls of artery

become weak causing swelling or bulging of artery wall (pressure of blood causes bursting)

2. trauma: rupturing of blood arteries causing hemorrhage

Subarachnoid hemorrhage (SAH) is bleeding into the cerebrospinal fluid (CSF) of the subarachnoid space surrounding the brain.

http://www.humanillnesses.com/original/images/hdc_0001_0001_0_img0020.jpg

Aphasia Classification

A. Receptive versus expressive aphasia▪ 1. based on predominance of one set of

abilities over another▪ 2. major difficulties related to language

reception or expression

Aphasia Classification

B. Anterior versus posterior aphasia : anatomically-based

C. Fluent versus nonfluent aphasia▪ 1. divides patients based on verbal output▪ 2. using this dichotomy, patients can be

additionally classified

Aphasia Classification

Fluent a. patients who

produce longer phrases

b. five or more connected words

c. speak more than 75 words per minute

Nonfluent a. those who

produce only single word utterances or short phrases

b. four or fewer connected words

c. speak 50 or fewer words per minute

Fluent Aphasias

• Posterior lesions

• Discharged early – may not be referred to speech-pathologist

• They are not controllable (stimulus-response model) – agitated, suspicious

• They are fewer than fluent aphasics

• Mixed up with confused patients (misdiagnosed)

• Older than most aphasic patients (mean age -63 Vs 52 in Broca’s)

Fluent Aphasias

• Three syndromes based on speech features: • Wernicke’s, conduction, anomic • (dysproportionality features, it is not all or nothing) –

Long-standing classification

▪ Melodic line – intonational pattern encompasses entire sentence

▪ Phrase length- length of uninterrupted word groups

▪ Articulatory agility – ease with which patient articulates phonemic sequence

▪ Grammatical forms – variety of grammatical construction

Wernicke’s aphasia

• Set of behaviors associated with a generally similar lesion.

• Wernicke postulated that traces of words would be stored at or near the Sylvian fissure (first temporal gyrus)

• Defective auditory comprehension

Wernicke’s aphasia

• Poor self-monitoring

• Fluent but paraphasic speech (due to loss of the internal correction of the motor process)

• Paraphasic speech pattern is unnoticed by the speaker (due to impaired auditory monitoring)

• Defective repetition skills (due to impaired auditory comprehension)

• Both reading and writing usually disrupted including reading comprehension

• Verbal expression consists of • a) word finding problems• b) verbal paraphasias (semantic and unrelated)• c) some phonemic paraphasias• d) neologisms• e) jargon• g) paragrammatism

▪ Press for speech: irrepressible intention of the speaker to continue in his monologue (possible due to lack of correction over output)

▪ increase in awareness of errors usually demonstrates an improvement in comprehension

Wernicke’s aphasia

▪ Because posterior lesion, usually show no paralysis (hemiplegia) or weakness (hemiparesis) in extremities

▪ http://www.youtube.com/watch?v=B-LD5jzXpLE&feature=related

▪ Lesion site:▪ Posterior portion of STG▪ The auditory association area or Wernicke’s area▪ Kertesz et al. (1993) found that persisting Wernicke’s

aphasia usually involves the supramarginal and angular gyri in addition to the superior temporal area

Wernicke’s aphasia

• Functional reorganization of language after stroke

• Recovery of function in Wernicke’s aphasia may be accompanied by a redistribution of activity within both cerebral hemispheres.

• fMRI data suggests that clinical recovery is associated with a redistribution of function to the right hemisphere (Thurlborn et al., 1999; Cherney & Robey, 2001)

Wernicke’s aphasia

Comprehension deficit

Fluent but paraphasic speech

Reading comprehension deficits: Aphasic Alexia Oral reading versus reading

comprehension

Writing deficits

Wernicke’s aphasia:Differentiating features

Ancillary behaviors: Depression: 37% (cumulative)

▪ Major post stroke depression▪ Reactive post stroke depression

▪ Sadness, dependency and indecisiveness

Lesion causing Wernicke’s symptomatology may go unnoticed.

Wernicke’s Aphasia

1. Locus of lesion is parietal operculum or arcuate fasciculus although controversy exists over lesion site• Left hemisphere supramarginal gyrus and arcuate

fasciculus• The insula, and underlying white matter of left

hemisphere• Small lesions of Wernicke’s area• More anterior and inferior lesions (anterior

supramarginal gyrus, underlying white matter, angular gyrus, and insular cortex) are deemed responsible for phonologic output problems

Conduction Aphasia

▪ 2. breakdown in transmission of information from posterior to anterior regions

▪ 3. relatively good auditory comprehension

▪ 4. verbal expression consists of ▪ Fluent, preserved melody, variety and complexity of syntactic structures▪ word finding problems, ▪ paraphasias with much higher incidence of phonemic than verbal paraphasias; ▪ hallmark feature of disorder is severe repetition deficit, especially for functions

and numbers

▪ 5. much more aware of errors and more interested in correcting errors than Wernicke’s patients probably due to better comprehension

▪ 6. visual comprehension is relatively intact and writing skills mirror verbal output

Conduction Aphasia

Disconnection Model Conduction aphasia

as disconnection between the auditory “comprehension” region and the speech “production” region.

Repetition, which requires interaction between two centers is imapired

Many have challenged the rigid disconnection model of conduction aphasia

Conduction Aphasia

The Bimodal distribution model: damage along the continuum extending from Wernicke’s area to Broca’s area.

Researchers have reported variability in the degree of fluency with the less fluent patients exhibiting more anterior lesions; those with higher fluency scores had more posterior lesions (Kertesz et al., 1977)

Conduction Aphasia

The “Two” Conduction Aphasias Two disorders with distinct pathophysiologic

mechanism (Nadeau, 2001)▪ Repetition conduction aphasia: deficit in auditory

short-term memory, disturbance only of verbal repetition tasks

▪ Reproduction conduction aphasia: more general language impairment affecting phonologic output process▪ Deficits in word production across verbal tasks including

conversation, naming, and oral reading as well as repetition.

▪ These two types of difficulties arise from lesions in functionally distinct but anatomically adjacent areas in temporoparietal region

Conduction Aphasia

Primary criteria for diagnosis Fluent, paraphasic conversational speech

No significant difficulty in comprehension of normal conversation

Significant verbal repetition disturbance

A preponderance of phonemic paraphasias

Conduction Aphasia

Differentiating features (text book, pg 156)

Conduction Aphasia

Broca’s Aphasia/ AOS Conduction Aphasia

Nonfluent Fluent (100-200 WPM)

Dysprosody Intact prosody

Agrammatic Preserved grammer or paragrammatic

Comprehension relatively good

Comprehension relatively good

Repetition impaired proportionate to other verbal tasks

Repetition disproportionally impaired

Error recognition Error recognition

Probably anomic Probably anomic

More description of salient features:• Fluency

▪ Fluent but not as fluent as Wernicke’s aphasics

• Word finding (content words): Some variability • Paraphasias: phonemic paraphasias

▪ produce more errors on a forced choice of specific target words

• Error recognition• Repetition

▪ Difficulties appear more on phrases, short sentences, poly syllabic words

• Auditory comprehension• Reading

Conduction apahsia

Favorable spontaneous recovery pattern

Conduction aphasics show significant or even complete recovery

Sometimes they “evolve” from classifications such as “jargon or Wernicke’s aphasia

They perform well in situations that do not require single-word accuracy or specific responses.

Conduction Aphasia

▪ Poorly localized: angular gyrus lesion and/or posterior middle gyrus

▪ Many Wernicke’s evolve into Anomic

▪ 1. Empty speech: lot of words like, thing, it, you know what I mean.. Frustrated

▪ 2. relatively good auditory comprehension

Anomic aphasia

▪ 3. verbal expression consists of predominance of word finding problems with the more salient the word, the more difficulty finding it and an absence of paraphasic errors (emptiness of substantive words in speech)

▪ 4. reading and writing skills vary from patient

to patient due to how extensive the lesion posteriorly – the more posterior the lesion, the more involved are reading and graphic impairments

Anomic aphasia

▪ 1. like severe Wernicke’s aphasia in verbal output with verbal paraphasias (both unrelated and semantic), phonemic paraphasias, neologisms, word retrieval deficits – more jargon

▪ 2. very poor auditory comprehension

Transcortical sensory aphasia

▪ 3. unlike Wernicke’s aphasia, repetition is intact as well as a preservation of memorized material

▪ 4. lesion is in posterior part of parietal lobe with sparing of Wernicke’s area and arcuate fasciculus fibers (referred to as watershed lesion)

▪ 5. written language is impaired for both reading and writing

Transcortical sensory aphasia

Fluent Aphasias

Wernicke’s Conduction Transcortical sensory

Auditory comprehension Severely impaired Slightly impaired Severely impairedReception Impaired Impaired IntactSpeech Fluent, paraphasic Paraphasic Fluent, ParaphasicReading Impaired Intact ImpairedWriting Impaired Impaired Impaired

Behavioral Patterns of Types of Aphasia