Apraxia of Speech Models and Theories

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Questions and Answers

Which area is NOT mentioned as part of the network involved in speech organization?

Cerebellum

Precentral gyrus

Occipital lobe (correct)

Broca’s area

What aspect of speech organization may change after a stroke or traumatic brain injury?

Neuroplasticity (correct)

Motor function

Speech fluency

Cognitive abilities

According to Moser (2016), what does the differing brain damage locations in AOS patients suggest?

Brain imaging is ineffective in diagnosing AOS.

There is a specific area for AOS.

Only the left hemisphere is involved in AOS.

AOS may not be localized to a single brain structure. (correct)

What is a challenge in studying AOS mentioned in the content?

Controversies in diagnostic criteria. Signup and view all the answers

What is AOS primarily considered to be?

A breakdown in motor planning. Signup and view all the answers

Which model describes motor planning in the context of AOS?

4-Stage Model Signup and view all the answers

What component is NOT included in a motor plan or program?

Persuasion Signup and view all the answers

What can impact the organization of speech in the brain following an injury?

Neuroplasticity. Signup and view all the answers

What does AOS stand for in the context of motor planning?

Apraxia of Speech Signup and view all the answers

Which of the following may result from incorrect motor programme selection in AOS?

Producing the sound "/d/" when the target is "/p/" Signup and view all the answers

What might happen if the brain can no longer access stored motor programmes?

Inability to produce the intended target sounds Signup and view all the answers

What is a potential issue concerning motor programmes mentioned in AOS?

Interference between competing motor programmes Signup and view all the answers

How might applying the correct programme to the wrong articulator affect speech?

It could produce a completely unintended sound Signup and view all the answers

What aspect of motor planning is specifically related to timing in speech?

Temporal specifications Signup and view all the answers

What is a significance of the 'speech sound map' mentioned in AOS?

It provides size constraints for various speech units. Signup and view all the answers

What role does 'muscle-specific programmes' play in motor programming?

They allow for the selection of spatial specifications. Signup and view all the answers

What method is commonly used by clinicians to assess the severity of Apraxia of Speech (AOS)?

Subjective judgment based on speech characteristics Signup and view all the answers

Which of the following assessments specifically aims to describe and quantify characteristics indicative of AOS?

Apraxia of Speech Rating Scale (ASRS) Signup and view all the answers

When scoring the Apraxia of Speech Rating Scale (ASRS), during what activities should it be scored?

Conversational speech and tasks including AMR and SMR Signup and view all the answers

What is apraxia of speech primarily characterized by?

Imprecise or unnatural sounding speech Signup and view all the answers

What is a significant limitation mentioned regarding the Apraxia Battery for Adults (ABA)?

It is based on outdated diagnostic criteria from the 1980s Signup and view all the answers

Which hemisphere lesions are usually associated with apraxia of speech?

Left hemisphere lesions Signup and view all the answers

Which of the following factors is NOT considered when assessing the severity of AOS?

Patient's age Signup and view all the answers

Which aspect is assessed through written language evaluation for individuals possibly needing AAC support?

Understanding of written words Signup and view all the answers

What is a common co-occurring condition with apraxia of speech?

Aphasia Signup and view all the answers

Which is true about the current application of the Apraxia of Speech Rating Scale (ASRS)?

It is only standardized on people with progressive AOS Signup and view all the answers

Which of the following is noted as best practice for assessment of apraxia of speech?

Perceptual identification of a cluster of features Signup and view all the answers

What does the assessment for apraxia of speech need to consider?

Both speech tasks performance and psychosocial impact Signup and view all the answers

What is a critical consideration in the assessment of written language when evaluating AOS?

Vision and limb function Signup and view all the answers

Which is considered a key reference text for understanding motor speech disorders?

Motor Speech Disorders: Substrates, Differential Diagnosis, and Management Signup and view all the answers

In what year did Miller and Wambaugh publish their work on acquired apraxia of speech?

2017 Signup and view all the answers

What type of disorder is apraxia of speech classified as?

An acquired neurogenic disorder Signup and view all the answers

Which assessment focuses specifically on intelligibility of dysarthric speech?

Assessment of Intelligibility of Dysarthric Speech (AIDS) Signup and view all the answers

What distinguishing feature is often seen in dysarthria compared to AOS?

More predictable errors with consistent patterns Signup and view all the answers

What type of assessment tool measures quality of life in individuals with AOS?

Visual Analogue Self-Esteem Scale (VASES) Signup and view all the answers

Which statement about AOS and aphasia is correct?

Core features of AOS include prosody issues. Signup and view all the answers

In AOS compared to dysarthria, errors tend to vary more significantly depending on the task being performed. Why is this the case?

Individuals with AOS show different error patterns across tasks. Signup and view all the answers

What is a common characteristic of dysarthria regarding oro-motor deficits?

Oro-motor deficits match to speech errors Signup and view all the answers

Which assessment tool is specifically used to measure activity and participation in individuals with speech disorders?

Dysarthria Impact Profile (DIP) Signup and view all the answers

What distinguishes the error patterns in dysarthria from those in AOS?

Errors are predictable in dysarthria Signup and view all the answers

Study Notes

Speech and Motor Planning

Speech is organized across a network of brain structures which may be affected by conditions like stroke or traumatic brain injury (TBI).
Brain plasticity and re-organization may occur after stroke/TBI, making it difficult to determine if certain structures have taken over specific roles.
There is no one specific area for Apraxia of Speech (AOS); research indicates that different individuals with AOS have different regions of brain damage.
Diagnostic criteria for AOS are inconsistent, making it challenging to compare research findings.

Models and Theories of AOS

Two dominant theories explain Apraxia of Speech: the Van der Merwe 4-Stage model & the DIVA/GODIVA model.

Van der Merwe Model

The Van der Merwe model suggests that speech production involves a four-stage process starting from a pre-motor intention to speak and progressing to the execution of the motor plan.
These stages include:
- Conceptual-Linguistic: Constructs the message, including syntax, semantics, and phonology.
- Motor planning: Develops the strategy of action, including spatial specifications (location and action) and temporal specifications (timing) for articulator movements.
- Motor Programming: Selects and sequences muscle-specific programs for the core motor plans based on spatial and temporal information.
- Execution: The speech production process is initiated.

What Happens to Motor Planning in AOS?

Research suggests that motor planning and programming may malfunction after a stroke or TBI. This can cause a range of speech errors:
- The brain might mis-select the incorrect motor program, choosing the program for one sound instead of the intended sound.
- The brain might have trouble accessing stored motor programs for the target sound, or the quality of those programs might be degraded.
- There might be interference between competing motor programs.
- The correct program might be chosen, but applied to the wrong articulator.

Assessing Severity

There is no standard method of assessing severity of AOS.
Clinicians generally rate severity subjectively based on their judgement of speech.
Factors to consider when assessing severity include:
- Intelligibility scores
- Frequency of speech errors
- Percentage of correct sounds in a sample
- Perceived effort in speaking

Apraxia of Speech Rating Scale (ASRS)

The ASRS was recently published for quantifying characteristics indicative of AOS.
It uses a 5-point scale to describe the presence and severity of speech characteristics.
There are 16 items in the scale, organized based on their potential occurrence in individuals with AOS as well as with Aphasia and Dysarthria.
The ASRS should be scored during conversation, picture description, and various speech tasks.
The scale is currently standardized for progressive AOS, but not stroke-related AOS.

Formal Assessments

The Apraxia Battery for Adults (ABA) was developed for identifying speech characteristics of AOS.
It uses a range of tasks to assess speech features, but it was developed using diagnostic criteria from the 1980s.
Updated diagnostic criteria have altered the reliability of the ABA as a diagnostic tool for AOS, but it can be useful for specific assessments and stimuli.
Other formal assessments from different fields can be adapted for specific needs.
For example, the Assessment of Intelligibility of Dysarthric Speech (AIDS) can be used to assess intelligibility.

Assessing Beyond Impairment

Focus on functional and psychosocial impact of AOS in addition to assessing impairment level:
- How does AOS affect the individual’s activities and participation?
- What is the impact on their quality of life?

Tools for Assessing Activity, Participation, and Quality of Life

Dysarthria Impact Profile (DIP)
Visual Analogue Self-Esteem Scale (VASES)
LaTrobe Communication Questionnaire
International Classification of Functioning, Disability and Health (ICF)

Differential Diagnosis

It is highly important to differentiate AOS from Aphasia and Dysarthria.

AOS vs Dysarthria

Errors in Dysarthria are often more predictable than errors in AOS.
Task variation affects error patterns in AOS (e.g., some tasks might elicit fewer or more errors).
Speech errors are consistent in Dysarthria across different tasks.
Dysarthria is more likely to involve oro-motor deficits that correspond to speech errors.

AOS vs Aphasia

AOS and Aphasia share many similarities, with substantial overlap.
Sound distortions are more frequent in AOS.
Prosodic abilities are typically unaffected in Aphasia but a core feature of AOS.

Recap

Apraxia of Speech (AOS) is a neurogenic disorder affecting the motor planning and programming of speech.
The severity of AOS can range from an inability to speak to mild speech imprecision.
AOS often co-occurs with Aphasia, and occasionally, dysarthria.
Assessment methods for AOS are in development, but identifying a cluster of features is currently the best practice.
Assessment should include a range of speech tasks and consideration of the functional and psychosocial impact of AOS.

Key Readings and Core Texts

Duffy, J.R. (2013). Examination of Motor Speech Disorders. In Motor Speech Disorders: Substrates, Differential Diagnosis, and Management, 61-93.
Duffy, J.R. (2013). Apraxia of Speech. In Motor Speech Disorders: Substrates, Differential Diagnosis, and Management, 269-292.
Haley, K.L., Shafer, J.N., Harmon, Tyson, G., & Jacks, A. (2016). Recovering with acquired aprasia of speech: the first two years. American Journal of Speech-Language Pathology, 25(November), 1–15.
McNeil, M.R., Ballard, K.J., Duffy, J.R., & Wambaugh, J. (2016). Apraxia of Speech Theory, Assessment, Differential Diagnosis, and Treatment: Past, Present, and Future.
Miller, N., & Wambaugh, J.L. (2017). Acquired Apraxia of Speech. In I.Papathanasiou & P.Coppens (Eds.), Aphasia and Related Neurogenic Communication Disorders (2nd ed., pp. 493–527).

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Description

Explore the intricate relationship between brain structures and speech production through the lens of Apraxia of Speech (AOS). This quiz delves into dominant theories such as the Van der Merwe 4-Stage model and the DIVA/GODIVA model, highlighting the role of brain plasticity and the challenges in diagnosis. Test your understanding of how speech organization can be affected by conditions like stroke and traumatic brain injury.