Speech Disorders Unit 3

The Process of Speech Production

Intent → Cognitive-Linguistic Processes → Speech Motor Programming → Speech Motor Execution

Motor Speech Disorder Definition

A disorder of speech resulting from neurological impairment affecting the motor programming or neuromuscular execution of speech

Motor Speech Disorders Types/Impairments

Includes dysarthria and apraxia of speech

Other oral movements may be impaired, including chewing and smiling

May co-occur with language impairments

Dysarthria Definition

Speech disorder resulting from weakness, paralysis, or incoordination of the muscles of the speech mechanism

Apraxia Definition

Speech disorder which results from an impairment in (sensori)motor programming for volitional speech

• No problems with the muscles themselves, just the programming

• Volitional: voluntary

• Highly learned (repetitive) things are typically spared as well as nonvoluntary speech

Motor Speech Disorders Causes

Acquired: stroke, TBI, degenerative diseases

Developmental: cerebral palsy, developmental disabilities

Muscular Control Issues

Paralysis

Paresis/Weakness

Spasticity

Flaccidity

Incoordination

Paralysis

Muscle can’t move at all

Paresis/Weakness

Muscles can’t move well

Spasticity

Muscle is too tight

Flaccidity

Muscle is too loose

Incoordination

Muscle is uncoordinated

Describing Motor Speech Disorders

Acquired

Congenital/Developmental

Acute

Recovering

Stable

Degenerative

Exacerbating-Remitting

Nervous System for Speech: Upper and Lower Motor Neurons

Upper: motor areas of cerebral cortex & some subcortical structures

• Initiate voluntary movement

Lower: connect brain & spinal cord to muscle fibers

• “Final common pathway”: nerve impulses = contraction of muscle fibers

Types of Dysarthria

Flaccid

Spastic

Ataxic

Hypokinetic

Hyperkinetic

Mixed (1/3 of patients)

Flaccid Lesion Site and Primary Defect

Lesion Site: Lower Motor Neuron

Primary Defect: Weakness

Spastic Lesion Site and Primary Defect

Lesion Site: Upper Motor Neuron

Primary Defect: Spasticity

Ataxic Lesion Site and Primary Defect

Lesion Site: Cerebellum

Primary Defect: Incoordination

Hypokinetic Lesion Site and Primary Defect

Lesion Site: Basal Ganglia Circuit

Primary Defect: Rigidity, Reduced ROM

Hyperkinetic Lesion Site and Primary Defect

Lesion Site: Basal Ganglia Circuit

Primary Defect: Involuntary Movement

Mixed (1/3 of patients) Lesion Site and Primary Defect

Lesion Site: More than one of above

Primary Defect: Multiple

Flaccid Dysarthria Causes

Uni/bilateral LMN stroke (brainstem stroke)

Myasthenia gravis

Muscular dystrophy

Flaccid Dysarthria Signs

Muscle weakness

Reduction of muscle reflexes

Loss of muscle tone

Atrophy of muscles

Fasciculations

Cranial Nerves Important for Speech

V Trigeminal: jaw movements

VII Facial: control facial expression and lip movement for speech

X Vagus (larynx/pharynx/velopharynx): controls phonation, resonance, and swallowing

XII Hypoglossal: tongue movement for articulation

Moebius Syndrome

Damage to nerves VI and VII

Clear speech with very little facial movement

Myasthenia Gravis

Problem at neuromuscular junction: fluctuating muscle weakness and fatigue

ACh is attacked by antibodies so muscle can’t contract

Speech Sample: Slurred/imprecise speech, resonance problems, difficultly chewing & swallowing

Muscular Dystrophy

Genetic

Degenerative & progressive

Diffuse, chronic effects

• Main symptom is muscle weakness

Over 30 types by 9 major forms

• Duchenne

• Becker

• Myotonic

Spastic Dysarthria Signs

Spastic paralysis (stiff, contracted muscles)

Hyperactive and pathological muscle reflexes

Strained/harsh voice, slow & labored speech

Ataxic Dysarthria Causes

Cerebellar lesions

Coordinates and sequences speech movements

Integrates sensory feedback into revised production

Ataxic Dysarthria Signs

Inaccurate/irregular movements

Impaired prosody

Can sound “drunk”

Cerebellar Damage

Errors: Force, Speed, Timing, Range, Direction

Speech Problems: usually bilateral or generalized lesion

“Scanning speech”: words are broken up into separate syllables often separated by a noticeable pause, and spoken with varying force

Hypokinetic Dysarthria Cause

Basal ganglia damage

• Reduces movement or leads to failure to inhibit involuntary movement

Depletion/insufficiency of dopamine = reduced movement

Prototypical example: Parkinson’s disease

Hypokinetic Dysarthria Signs

Most evident in voice, articulation, and prosody

Reduced loudness

Short rushes of speech

Reduced respiratory movement

Medical Management

Levadopa (L-DOPA): precursor to dopamine, can cross blood-brain barrier whereas DA cannot

Given with another drug to prevent the peripheral synthesis of dopamine from L-DOPA

Side Effects of L-DOPA

Akinesia/dyskinesia

Rigidity/stiffness

“On-Off Response”: Phases of immobility and incapacity associated with depression alternating with jubilant “thaws”

Extreme emotional state (anxiety, hypersexuality), confusion, hallucinations

Hyperkinetic Dysarthria

Basal Ganglia Damage

Huntington’s Disease

Types of Involuntary Movements

• Tardive Dyskinesia

Basal ganglia damage

BG circuit connects to motor areas of cortex to inhibit motor output

Damps or modulates cortical output that required to accomplish movement goals

Types of Involuntary Movements:

Chorea

Athetosis

Myoclonus: myoclonic jerk

Dystonia

Torticollis (twisted neck)

Blepharospasm (eyelid spasm)

Tardive Dyskinesia

Repetitive, involuntary, jerky, purposeless movements

Often a side effect of medication

Mixed Dysarthria

Amyotrophic Lateral Sclerosis (ALS): mixed flaccid/spastic

Cerebral Palsy: several types

CP Overview

Non-progressive (symptoms may change with age)

Muscles are weak, stiff, and/or uncoordinated

Most common childhood movement disability in US

1/3 of people DO NOT have cognitive impairment

Causes of CP

Brain injury in the prenatal, perinatal, or early postnatal periods

• Prenatal: genetic, agenesis (failure of organs to develop), viruses, anoxia

• Perinatal: anoxia due to cord compression, blockage of the airways, aspiration pneumonia, hypoxia due to use of narcotics during birth

• Postnatal: brain injury, high fevers, meningitis, encephalitis

85-90% of cases are congenital (at or before birth)

Low birth weight, preterm delivery, multiple births put children at a higher risk of CP

Initial Signs of CP

Maintenance of primitive reflexes

• Asymmetric tonic neck reflex

• Positive supporting reaction: leg muscles contract in a straight standing position when balls of feet make contact with solid surface

• Moro reflex: reaction to loss of support/feel of falling

• Sucking, rooting, and biting reflexes

Delayed developmental milestones

Classifications of CP

Spastic

Dyskinetic (athetoid)

Ataxtic (dystonic)

Mixed

Mild Case

Associated Problems with CP

Limitations:

• Intellectual/cognitive functioning

• Behavioral problems

• Depression

• Ocular abnormalities

• Deafness/hearing loss

• Seizures

• Impaired bowel/bladder control

• Orthopedic complications

• Additional dental needs

Acquired Apraxia of Speech

Result of brain injury

Impaired motor planning/programming

Difficulties only with voluntary movement for speech. Non-speech tasks remain unaffected

Prosody and articulation are disrupted

Areas associated with motor planning

Left hemisphere (dominant for language) - frontal lobe

Also parietal lobe, thalamus, basal ganglia, insula

Articulation in Apraxia Patients

Slow/effortful

Initiation difficulty

Inconsistent errors (close to target)

Errors increase with complexity

Movement in Apraxia Patients

Groping Articulators

Silent Posturing

Prosody in Apraxia Patients

Due to compensation

Impaired stress, slow/effortful rate, prolonged phonemes, odd pauses

Apraxia of Speech: Fluency

Restarts and repeated attempts at producing a word or sound, and syllable repetitions

Articulatory groping, sometimes with facial grimacing

Initiation of utterances especially problematic

Not the same as stuttering!

Concomitant Apraxia

Oral apraxia

Limb apraxia

Oral Apaxia

Problems with voluntary oral nonspeech movements

e.g., blowing a kiss, smiling, etc.

Movements are okay when they are reflexive

Limb Apraxia

Problems with voluntary arm movements

Dysarthria vs Apraxia of Speech

Dysarthria

• Motor speech execution disorder

• Muscles have reduced range, strength

• Consistent errors

• No island of clear speech

• Consonants imprecise

AOS

• Motor speech programming disorder

• No muscle weakness or paralysis

• Inconsistent errors

• Islands of clear speech

• Errors increase with complexity

Evaluation Components

History

Oral Motor Examination

Perceptual Assessment

Intelligibility Assessment

Acoustic & Physiological Measures

Oral Mechanism Exam

Lips

• Close, pucker

• Puff cheeks

• Alternate “eee-ooo”

Jaw

• Open

• Close

• Alternate

Tongue

• Protrude

• Up/Down

• Left/Right

• Alternate

Velopharyx

• “a” with mouth open

• Nasal Emission

Larynx

• Cough

• Glottal Coup

• Inspiratory Stridor

Respiration

• Posture

• Shortness of Breath

• Breathing Rate

Dysdiadochokinesis

Measure how quickly and accurately a person can produce alternating and sequential articulatory movements

AMR: alternating motion rate

• Say “pa-pa-pa-pa…” as fast as you can

SMR: sequential motion rate

• Say “pa-ta-ka-pa-ta-ka…” as fast as you can

Some General, Useful Tasks

Neuro tests

AMR

SMR

Contextual Speech

Stress Testing for Fatigue

Motor Speech Programming Tasks

Speech Intelligibility Measure

Measure in connected speech, not single words most of the time

Two primary approaches to measuring intelligibility

• Word-identification approaches

• Scaled ratings

Word-Identification Approaches

Involve having an unfamiliar listener orthographically transcribe what they think the child said

Optimal for tracking progress in therapy, but are relatively time-consuming

Scaled Ratings

Involve making global judgments about a child’s intelligibility

Adequate in cases where the goal is to obtain an overall measure of severity or for children who are unable to participate in structured testing

Standardized Tests Advantages and Disadvantages

Advantages

• Empirical (validity & reliability)

• Allows for comparison

Disadvantages

• Methods used

• Biases

• Availability'/expense

Perceptual Eval: Respiration

Tasks and Trial Shaping

Tasks

• Listen to volume during conversation, reading

• Count 1-20 on one breath

• Produce /a/ from soft to loud

Trial Shaping

• Take a big breath and start talking at the beginning of exhalation

If muscle weakness is wrong, what will you hear?

Reduced overall loudness, monoloudness, short phrases

If abnormal tone is wrong, what will you hear?

Reduced overall loudness, monoloudness, impaired loudness control

If incoordination of respiratory muscles is wrong, what will you hear?

Sudden forced inspiration or expiration, speaking on low air

Perceptual Eval: Phonation

Tasks and Trial Shaping

Tasks

• Listen to reading or conversation

• Cough/throat clear/grunt

• Hold /a/ for as long as possible

• Glide up/down scale

Trial Shaping

• Speak louder or softer

• Match pitch

If weakness of laryngeal muscles is wrong, what will you hear?

Breathiness, hoarseness, monopitch, decreased loudness, short phrases, audible inspiration

If reduced tone is wrong, what will you hear?

Breathiness, hoarseness, monotone, decreased loudness, low pitch

If increased tone is wrong, what will you hear?

Strained-strangled dysphonia, harshness, low/high pitch, pitch breaks

If incoordination of laryngeal muscles is wrong, what will you hear?

Inappropriate pitch changes, inconsistent hoarseness, voicing errors, tremors, excessive loudness variation, audible inspiration

Perceptual Eval: Resonance

Tasks and Trial Shaping

Tasks

• Prolong /i/ and occlude nose and release

• Repeat nasal vs. non-nasal sentence

• Place mirror under nose if nasal emission is suspected

• Observe movement of soft palate

Trial Shaping

• Open mouth wide during speech

• Contract nasal and non-nasal word pairs

If weakness of velopharyngeal muscles is wrong, what will you hear?

Hypernasality or nasal emission

If increased tone is wrong, what will you hear?

Hypernasality

Perceptual Eval: Articulation

Tasks and Trial Shaping

Tasks

• Oral-motor exam

• Diadochokinetic rates

  • Alternate motion rates

  • Sequential motion rate

• Word/phrase reading, repetition

• Listen to reading, conversation

Trial Shaping

• Imitate production, overarticulation

If decreased strength is wrong, what will you hear?

Imprecise consonant production

If decreased coordination is wrong, what will you hear?

Irregular articulatory breakdowns, distorted vowels

If decreased ROM is wrong, what will you hear?

Imprecise consonant production, distorted vowels

If increased tone is wrong, what will you hear?

Imprecise consonant production

If unpredictable movements is wrong, what will you hear?

Irregular articulatory breakdowns, distorted vowels

Evaluating Prosody

Contrastive stress drills

Multisyllable word stress drills

Declarative and interrogative sentence drills

Conservation/reading words per minute WPM

Trial Shaping

• Slow speaking rate

• Use pauses for emphasis

• Repeat contrastive stress/intonation patterns

If increased or decreased strength is wrong, what will you hear?

Reduced stress, monotone

If decreased coordination is wrong, what will you hear?

Slow rate, poor pitch control

If decreased ROM is wrong, what will you hear?

Poor pitch control, intonation

If decreased respiratory strength is wrong, what will you hear?

Short phrases, rushes of speech

If unpredictable movements is wrong, what will you hear?

Prolonged intervals, phonemes

Differential Dx: Dysarthria

Spastic

Strained-strangled phonation, hypernasality, imprecise consonants, impaired stress

Differential Dx: Dysarthria

Flaccid

Breathy, imprecise consonants, hypernasal

Differential Dx: Dysarthria

Hypokinetic

Decreased loudness, poor vocal quality, imprecise consonants

Differential Dx: Dysarthria

Hyperkinetic

Involuntary movements, variable rate, strained phonation, hypernasality, imprecise consonants

Differential Dx: Dysarthria

Ataxia

Irregular articulatory breakdowns, impaired prosody

Differential Dx: Apraxia of Speech

Phonetic Complexity

Test along a hierarchy of phonetic complexity

• rain → train → strain

• come → compute → computer → computation → computational

Differential Dx: Apraxia of Speech

Cueing for Response

Test along a hierarchy of cues (no feedback → visual → tactile)

Test along a hierarchy of timing between cue and response (simultaneous → immediate → with delay)

Differential Dx: Apraxia of Speech

Length of utterance

Test along a hierarchy of lengths

• I → I eat → I eat lunch and so on

Differential Dx: Apraxia of Speech

Linguistic complexity

Test along a hierarchy of linguistic load

• Repetition → Conversation → Picture Description → Narrative

Management Approaches for Dysarthria

1. Medical Management

   1. Surgical management

   2. Pharmacologic management

   3. Prosthetic management

2. Behavioral Management (speech therapy)

SLP responsibilities

Assess the need for surgery, the benefits, how speech will change, the need for post-surgery therapy, and communicate those things to the patient

Surgical Management

Deep Brain Stimulation

Thyroplasty

Pharyngeal Flap Surgery

Pharmacologic Management

Usually directed at relieving symptoms of the larger disease/disorder

Improvement in general function may not be accompanied by commensurate change in speech function

Know the drug the client is taking and for what

Begin other therapy when the effects are stable