Week 6- Acquired Language and Speech Disorders

Acquired Language Disorders

• Aphasia:
  • Acquired communication disorder from brain damage.
  • Impairs understanding, production, and use of language.
  • Affects phonology, semantics, syntax, morphology, pragmatics, reading, and writing.
  • Aetiologies:
    • Cerebrovascular accident (CVA/stroke).
    • Traumatic brain injury.
    • Brain surgery, tumors, neurodegenerative disorders.
• Neurogenic Basis:
  • Lesions to multimodal association regions of the cortex.
  • Left hemisphere: language centers.
  • Anterior regions: language output.
  • Posterior regions: language reception.
• Presentations:
  • Nonfluent: labored speech, short word groupings (expressive issues).
  • Fluent: effortless articulation with errors in word choice and sound substitutions (reception/comprehension issues).
    • Cognitive Communication Disorders:
    • Difficulty with communication affected by cognition disruption.
    • Related to attention, memory, problem-solving, executive function.
    • Aetiologies:
    • Traumatic brain injury.
    • Right hemisphere damage.
    • Dementia.
• Aphasia vs CCDs
  • Aphasia: language-level disorder from focal brain lesion, affects language use across modalities.
  • CCDs: difficulties relating language to context despite intact linguistic ability.

Assessment of Acquired Language Disorders

• Goals: cognitive, linguistic, and pragmatic analysis.
  1. Cognitive abilities
  2. Comprehension of language content and form
  3. Production of language content and form
  4. Pragmatic abilities
• Key Questions:
  • Fluent or nonfluent?
  • Severity level?
  • Linguistic characteristics?
  • Word-finding difficulties?
  • Articulation?
  • Comprehension?
  • Repetition?
    • Common assessment tools:
    • ASSBI Cognitive Communication Checklist
    • Western Aphasia Battery (Revised)
    • Comprehensive Aphasia Test
    • Brisbane Evidence Based Aphasia Test
    • In acute settings:
    • Inpatient Functional Communication Interview

Intervention for Acquired Language Disorders

• Approaches:
  • Impairment-based: remediating impairment, relearning lost function.
  • Social/functional-based: improving communication within context. Modifying the environment.

Acquired Speech Disorders

• Components of Speech
  • Motor planning: Translating linguistic code into speech units.
  • Motor execution: Coordination of CNS & PNS activity, innervation of speech subsystems.
• Apraxia of Speech (AOS)
  • Impaired capacity to plan or program sensorimotor commands for speech.
  • Aetiologies: Most commonly Stroke.
  • Neurogenic Basis: Most commonly associated with lesions (damage) in the speech motor area of the frontal lobe.
  • Characteristics: Affects articulation and prosody.
    • Sound distortions/substitutions.
    • Greater difficulty as linguistic complexity increases.
    • Difficulties initiating speech movements.
    • Inappropriate pausing.
    • Equal stress in speech; monotone.
    • Client likely to be aware of difficulties and errors
• Dysarthria
  • Motor speech difficulty due to neuromuscular changes.
  • Muscles of mouth, face, pharyngeal, laryngeal and respiratory system may become weak, move slowly, be incoordinated or not move at all.
  • Aetiologies: varied and numerous – due to neuromuscular involvement.
  • Neurogenic Basis: As a diagrammatic representation of possible areas of damage
• Classifications of Dysarthria
  • Seven main classifications of dysarthria – see following slides
    • These are defined according to:
      • Localisation of lesion (i.e. damage) – eg cerebellum
      • General presenting characteristics – eg coordination
  • Types:
    • Flaccid: Weakness (lower motor neurons).
    • Spastic: Spasticity and weakness (bilateral upper motor neurons).
    • Ataxic: Incoordination (cerebellum).
    • Hypokinetic: Rigidity (basal ganglia).
    • Hyperkinetic: Involuntary movement (basal ganglia).
    • Unilateral Upper Motor Neuron: weakness, incoordination, or spasticity (unilateral upper motor neurons).
    • Mixed: More than one undetermined cause.
• Characteristics of Dysarthria
  • Ways speech may be affected
    • Respiration
      • Lack of breath support for speech
    • Phonation
      • Poor control of airflow through larynx
    • Resonance
      • Impaired velum function
    • Articulation
      • Impaired function of articulators
    • Prosody
      • Impairment to 'naturalness' of speech
      • May arise due to impairment in other systems

Assessment of Motor Speech Disorders

• Thorough assessment will identify
  • Impaired structure and function
  • Intact structure and function
• Assessment will inform
  • Differential diagnosis
  • Speech pathology management
  • Intervention planning
• Assessment Methods:
  • Perceptual, Acoustic, and Physiologic.
• Thorough assessment should include:
  • Case history
  • Oro-motor assessment
  • Perceptual assessment of speech (including intelligibility)
• Description and Diagnosis
  • Overall, assessment will aim to describe and inform
    • Type of motor speech disorder
    • Severity of motor speech disorder
    • Prognosis
    • Whether intervention is likely to benefit the client
      • Common Assessments:
      • Frenchay Dysarthria Assessment (2nd ed)
      • Apraxia Battery for Adults (2nd ed)

Intervention for Motor Speech Disorders

• Broad approaches to intervention include:
  • Medical interventions
  • Prosthetic interventions
  • Behavioural interventions
    • Behavioural Approaches to Intervention
    • Speech-oriented treatments (impairment)
    • Tasks that aim to improve speech function
    • Communication-oriented treatments (activity)
    • Activities that aim to improve communication and communicative participation