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Foundations of Treatment and Management of Motor Speech Disorders

Dysarthria

  • A group of neurological speech disorders that affect speech production.

    • Dysarthria can affect:

      • Strength

      • Speed

      • Range

      • Steadiness

      • Tone

      • Accuracy of movements

      • Respiration

      • Phonation

      • Resonance

      • Articulation

      • Prosody

    • It is neurologic

    • It is a disorder of movement
       

A summative reference guide

  • Types of Dysarthria

    • Flaccid

      • Localization: Lower motor neuron (final common pathway)

        • Cranial nerves and spinal nerves

      • Neuromotor Basis: Execution

      • Neurologic: Weakness

      • Key Distinguishing Characteristics:

        • Hypernasality

        • Continuous breathiness

        • Diplophonia

        • Nasal emission

        • Audible inspiration

        • Speaking on inhalation

        • (for Myasthenia Gravis- short phrases, rapid deterioration and recovery after rest)

        • Abnormal findings on oral peripheral examination

          • Atrophy

          • Fasciculations

          • Nasal regurgitation

          • Synkinesis (eye blink using lower face)

          • Unilateral palatal weakness

      • Other Characteristics:

        • Imprecise AMRs

        • Hypoactive gag reflex

        • Facial myokymia

      • Subtypes:

        • Unilateral or bilateral

        • Cranial or spinal nerve or combination
           

    • Spastic

      • Localization: Bilateral upper motor neuron (direct and indirect activation pathways)

        • Extrapyramidal damage: overactivity of muscle movement

        • Pyramidal damage: weakness

      • Neuromotor Basis: Execution

      • Neurologic: Spasticity

      • Key Distinguishing Characteristics:

        • Abnormal movements affects all speech systems, especially phonation

        • Strained, strangled, harsh voice quality

        • Monopitch

        • Monoloud

        • Slow rate

        • AMRs are slow but regular/steady

      • Other Characteristics:

        • Pitch breaks

        • Pathological reflexes

        • Lability of affect

        • Hypertonia

        • Hyperactive gag reflex

      • Common etiologies: bilateral strokes, multiple lacunar strokes, binswanger’s disease (subcortical vascular dementia), primary lateral sclerosis, pseudobulbar palsy.

      • Common pathological reflexes: Babinski sign, oral reflexes (suck snout, jaw jerk)
         

    • Ataxic

      • Localization: Cerebellum (cerebellar control circuit)

      • Neuromotor Basis: Control

      • Neurologic: Incoordination

      • Key Distinguishing Characteristics:

        • Irregular articulatory breakdowns

        • Irregular AMRs

        • Dysprosody

      • Other Characteristics:

        • Imprecise consonants

        • Reduced stress

        • Monoloud

        • Monopitch

        • Distorted vowels

        • Head tremor

        • Normal oral peripheral exam

          • No facial or lingual weakness

          • No unusual positioned jaw, face, or tongue movements

        • Patient may complain about biting tongue or cheeks during speaking or swallowing, difficulty coordinating breathing and speaking, slurred/”drunken” quality
           

    • Hypokinetic

      • Localization: Basal ganglia control circuit (extrapyramidal)

        • Imbalance of dopamine

          • Substantia nigra neurons die

          • There is more acetylcholine than dopamine

      • Neuromotor Basis: Control

        • The impaired system reduced movement

      • Neurologic: Rigidity, reduced range of movement, scaling problems

      • Key Distinguishing Characteristics:

        • Monopitch

        • Monoloud

        • Rushed of speech

        • Breathy phonation

        • Masked facial expression

      • Other Characteristics:

        • Inappropriate silences

        • Rapidly repeated phonemes

        • Palilalia (repeated words, phrases, or sentences)

        • Rapid, burred AMRs

        • Reduced range of motion on AMR tasks

        • Resting tremor

        • Rigidity

        • Bradykinesia (slow initiation and speed of movements)

        • Akinesia

          • Lack of natural movemnets

          • Abnormal gait with rushes

          • Reduced arm movements

          • Micrography

          • Swallowing abnormalities

          • Masked face

        • Loss of postural reflexes, such as trunk flexion

      • Non-sensorimotor features: cognitive decline, depression, apathy, anxiety, sleep disturbances, and autonomic failure

      • Common etiologies: Parkinson’s disease, Progressive Supranuclear Palsy, thalamic strokes, chronic metal exposure, HIV, West Nile
         

    • Hyperkinetic

      • Localization: Basal ganglia control circuit (extrapyramidal)

        • More dopamine than acetylcholine

      • Neuromotor Basis: Control

        • The impaired system fails to inhibit unwanted movements (hyperkinesia)

          • So there are a lots of extra movements

      • Neurologic: Involuntary movements

      • Key Distinguishing Characteristics:

        • Extra movements

        • Abnormal involuntary movements present when awake, but not when asleep

        • Types of involuntary movements vary

      • Other Characteristics:

        • Voluntary movements are generally slow

        • Irregular and unpredictable speech movements

        • Sudden forced inspiration/expiration

        • Transient breathiness

        • Voice stoppages/arrests

        • Voice tremor

        • Intermittent hypernasality

        • Deterioration with increased rate

        • Inappropriate vocal noises

        • Distorted vowels

        • Excessive loudness variation

        • Slow and irregular AMRs

        • Motor tics

        • Myoclonus

        • Jaw, lip, tongue, pharyngeal or palatal tremor

        • Facial grimacing during speech

        • Chorea

        • Dystonias

      • Common etiologies: unknown origins (presumed to be psychogenic not neurogenic) lesions of basal ganglia, degenerative disease (Huntington’s disease), infections (Sydenham’s chorea), inherited disorders
         

    • Unilateral Upper Motor Neuron

      • Localization: Unilateral upper motor neuron

      • Neuromotor Basis: execution/ control (weakness/incoordination)

      • Neurologic: More than one

      • Key Distinguishing Characteristics:

        • Imprecise consonants

          • Lingual weakness

        • Slow rate

        • Irregular articulatory breakdowns

      • Other Characteristics:

        • Reduced loudness

        • AMRs can be regular

        • Unilateral lower face weakness

        • Unilateral lingual weakness

          • Without atrophy or fasciculations

        • Nonverbal oral apraxia

      • Other considerations:

        • Most often found following a stroke

        • Rarely accompanied by resonance or voice abnormalities

        • Never associated with atrophy or fasciculations
           

    • Mixed

      • Localization: More than one

        • Distributed across two or more divisions of the nervous system

      • Neuromotor Basis: execution and/or control

      • Neurologic: More than one

      • Key Distinguishing Characteristics:

        • A combination of characteristics from two or more of the other types of dysarthria

      • Flaccid-spastic dysarthria is the most common combination, especially in patients with ALS

        • Characteristics:

          • Slow single and repetitive articulatory movements

          • Slow rate

          • Slow AMRs

          • Imprecise articulation

          • Increased vowel duration within syllables

          • Reduced strength of tongue, lips, and jaw

          • Reduced utterance length

      • Common etiologies: degenerative diseases (ALS), vascular diseases, trauma
         

​

  • A neurologic speech disorder that impairs motor planning or programming that results in abnormal speech.

    • Inability to perform intended acts

    • The same intended acts can occur reflexively

    • Can exist in an absence of comprehension deficit, motor weakness, or incoordination

    • It can occur in isolation, but most often co-occurs with aphasia and/or dysarthria

    • Key Distinguishing Characteristics:

      • Sound substitutions and sound disorders

      • An increase in distortions with increase rate or complexity

      • Articulatory inaccuracy related to place and manner

      • Disproportionate number of words per minute relative to vowel duration

    • Other Characteristics:

      • Phonetic errors

        • Error often differs from target by one phonetic dimension (place, manner, voicing)

      • Aware of errors

      • Abnormal prosody

      • Possible normal oral mechanism exam

      • Visible and audible groping

      • Verbal fillers

      • More errors on polysyllabic words than monosyllabic

      • AMRs better than SMRs

      • Highly learned tasks (like counting forward or singing happy birthday) often are within normal limits

      • Difficulty initiating articulation sequences

      • Sound and syllable repetitions

      • False starts and restarts

      • Slow rate

    • Neurophysiology of Acquired Apraxia of Speech: left frontal lesion

      • Severity depends on the nature, extend, and site of brain injury

  • Common etiologies: stroke, neurodegenerative conditions, tumors, trauma.

Apraxia of Speech (AOS)

Principles of Motor Learning

  • A set of practice and feedback conditions
     

    • Structure of Practice

      • Distribution

        • Distributed: rest is greater than or more than practice

          • Promotes learning and long term retention

        • Massed: rest is less than practice

      • Order

        • Blocked: one target, uninterrupted by another target

          • Better for acquisition

        • Random: targets interspersed with each other

          • Better for retention and transfer

      • Variability

        • Varied: variety of movements in various contexts

        • Constant: one movement in a single context

      • Coordination

        • Part: isolated each component separately (like individual sounds)

          • May not transfer to whole task

        • Whole: practicing entire target (like whole words)

      • (high vs low trials- multiple practice opportunities needed for learning)
         

    • Structure of Feedback

      • Content

        • Knowledge of Results (KR): result of movement, information about the outcome

          • Results in better long-term retention of a learned skill

          • Ex. “You are really close to the target”

        • Knowledge of Performance (KP): specific movement information, about the quality of movement

          • Most beneficial during initial stages of acquiring a skill or when task is unclear

          • Ex. “Your tongue tip was back too far”

      • Timing

        • Immediate: right after target action

        • Delayed: following target action

          • May lead to improvements in retention and transfer

      • Modality

        • Verbal: spoken

        • Nonverbal: unspoken, visual, biofeedback, tactile

      • (high frequency vs low frequency- high frequency enhances practice performance and low frequency enhances performance in retention)
         

    • Rationale for its use in treatment of MSDs:

      • There are commonalities between principles of neuroplasticity and motor learning

        • Use it or lose it

        • Saliency

        • Repetition matters

      • Several studies show manipulating the principles of motor learning within existing treatment protocols can be effective

      • Helps facilitate acquisition of motor skills

      • Leads to long term retention and transfer

Treatment Approaches for Dysarthria

  • Respiration (speech breathing)

    • Possible candidate: A person with Hypokinetic Dysarthria due to Parkinson’s Disease

    • Example: SpeechVine

      • Device worn in the ear that presents background noise to improve vocal intensity and subglottal pressure with laryngeal and respiratory strategies

      • Affects the respiratory and phonatory systems

      • Provides instant results

  • Phonation

    • Possible candidate: A person with hypokinetic dysarthria associated with Parkinson’s Disease

    • Example: Lee Silverman Voice Treatment (LSVT)

      • Massed practice

      • Increase sensory awareness of loudness and effort using visual feedback and assessment

      • Affects the respiratory and phonatory systems

  •  Resonance

    • Possible candidate: A person with significant velopharyngeal weakness associated with flaccid dysarthria

    • Example: Palatal lift prosthesis

      • Attached to the teeth and extends to lift the palate

      • May eventually lead to improved palatal function without the prosthesis

  •  Articulation

    • Possible candidate: Nonprogressive dysarthria secondary to a stroke

    • Example: Clear Speech

      • Modifies or exaggerates aspects of speech to improve intelligibility

      • Affects articulation, rate, loudness, and prosody

  • Rate Control

    • Possible candidate: A person with mixed spastic-ataxic dysarthria from a traumatic brain injury

    • Example: Pacing Board

      • Finger or hand taps the numbers on the board for each syllable or word

  •  Prosody

    • Possible candidate: A person with hypokinetic dysarthria associated with Parkinson’s Disease

    • Example: SPEAK OUT! And LOUD Crowd

      • Improves self-awareness of vocal intensity and pitch

      • Focuses on speaking with intent

  • Compensatory Strategies

    • Possible candidate: A person with severe dysarthria that impacts communication to the point where there is a decrease in independence and a reliance on others to communicate

    • Example: AAC

      • A variety of options exist ranging from low technology to high technology

      • Helps maintain independence, sustain quality of life, and support natural communication

Treatment Approaches for Apraxia of Speech

  • Categories of behavior approaches

    • Articulatory kinematic (AK)

      • Example: Sound Production Treatment (SPT)

        • Adapted from 8-Step Continuum (traditional framework)

        • Focuses on spatial targeting and timing of articulation at segmental and syllable level

        • Includes repetition, integral stimulation, modeling, orthographic cueing, phonetic placement cues, feedback, and minimal contrasts

        • Treatment stimuli chosen based on patient’s errors

        • Minimal assistance is given during the first steps and increases when errors occur

        • All productions are following a model

        • Outcome measure are also following a model

    • Rate and/or rhythm

      • Example: Metronomic Pacing

        • To re-establish the temporal programming

        • Can have positive effects on articulatory accuracy

        • Tones provided corresponding to syllables in an utterance

        • Target phrases are frequently used phrases

        • Involves a cueing hierarchy

        • Can be combined with hand tapping

    • Alternative Augmentative Communication

      • Example: Amerind sign language

        • To supplement natural speech for communication

        • Beneficial to use for practice outside of therapy

        • May have carryover for spoken communication

    • Intersystemic facilitation reorganization

      • Example: Intersystemic reorganization

        • Uses gestures to facilitate and promote speech production

          • Examples: tapping head, tapping foot, pacing, gestures

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