Download Swallowing Disorders

Motor Speech
Disorders
Samantha Shune, PhD, CCC-SLP
[email protected]
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
Brief introduction to motor speech disorders

Brief neuroanatomy primer

Video samples
INTRODUCTION
Neurogenic Communication
Disorders


Neurogenic communication disorders can be
defined as impairments in speaking, listening,
reading, and writing skills that result from
damage in different parts of the nervous system.
These impairments include:
Aphasia
 Cognitive-Communication Disorders
 Motor Speech Disorders

Dysarthria
 Apraxia of Speech

Cognitive-Communication
Disorder
Aphasia
Apraxia of
Speech
Dysarthria
Motor Speech Disorders

Motor speech disorders can be defined as
disorders of speech resulting from neurologic
impairments affecting the:
Motor planning,
 Motor programming, or
 Neuromuscular execution of speech


Dysarthria and apraxia of speech
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Motor speech disorders are a significant
proportion of acquired communication
disorders
Motor speech disorders
8%
8%
41%
8%
4%
Other cognitive-language
disorders
Psychogenic
11%
19%
Other neurologic speech
disorders
Aphasia
1%
Etiologies of Motor Speech
Disorders
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VITAMIN D (Dworkin, 1991)
V
 I
 T
 A
 M
 I
 N
 D
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vascular accidents
infectious processes
traumatic insults
allergic or anoxic
metabolic disorders
idiopathic
neoplasms
degenerative demyelinating
Major types of MSDs
Type
Localization
Neuromotor basis
Flaccid Dysarthria
Lower motor neuron
Weakness
Spastic Dysarthria
Bilateral upper motor neuron
Spasticity
Ataxic Dysarthria
Cerebellum
Incoordination
Hypokinetic Dysarthria
Basal ganglia control circuit
Rigidity/reduced range
of movement
Hyperkinetic Dysarthria
Basal ganglia control circuit
Involuntary movements
Unilateral Upper Motor
Neurons (UUMN)
Dysarthria
Unilateral upper motor neurons
Weakness,
incoordination, or
spasticity
Mixed
More than one
More than one
Apraxia of Speech
Left (dominant) hemisphere
Motor planning
Distribution of MSDs
Type
Percentage
Flaccid Dysarthria
8%
Spastic Dysarthria
7%
Ataxic Dysarthria
9%
Hypokinetic Dysarthria
9%
Hyperkinetic Dysarthria
19%
Unilateral Upper Motor Neurons
Dysarthria
8%
Mixed
28%
Apraxia of Speech
7%
Dysarthria, type undetermined
4%
From Duffy, 2012
Methods for Studying &
Categorizing MSDs

Perceptual
Eyes, ears, and hands
 Examples

Prolonged /a/
 Diodokinetic task /pataka/
 Read grandfather passage
 Oral motor examination
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Methods for Studying &
Categorizing MSDs

Instrumental

Acoustic methods
Same data as perceptual = speech signal
 Provides quantification, description, and confirmation of
human (clinical) perception

Methods for Studying &
Categorizing MSDs

Instrumental
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Physiologic methods
Study of movements of speech structures, air flow and air
pressure, muscle contraction, nervous system, CNS and
PNS activities in relationship to biomechanical activity
and and CNS activity during speech planning and
execution.
 Ex.
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
Electromyography and aerodynamic measures
Methods for Studying &
Categorizing MSDs

Instrumental

Visual imaging methods
Allows visualization of upper aerodigestive tract during
speech
 Ex.
 Videofluoroscopy
 Nasoendoscopy
 Videostroboscopy
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(RE)VISITING
NEUROANATOMY
Speech Motor System
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The final common pathway
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Lower motor neurons
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The direct activation pathway
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Upper motor neurons (pyramidal system)
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Corticobulbar and corticospinal tracts
The indirect activation pathway
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Cranial and spinal nerves
Upper motor neurons (extrapyramidal system)
The control circuits
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Basal ganglia and cerebellar
Final Common Pathway
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Lower motor neuron system
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
Brainstem and spinal cord  muscles
Includes: cranial nerves supplying muscles for
phonation, resonance, articulation, and prosody;
spinal nerves for respiration and prosody

CN V (trigeminal), VII (facial), IX (glossopharyngeal), X
(vagus), XI (accessory), XII (hypoglossal)
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Damage to lower motor neuron system
Weakness
 Paralysis
 Diminished reflexes
 Decreased muscle tone
 Atrophy
 Fasciculations


Flaccid dysarthria
Direct Activation Pathway
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
Upper motor neurons with direct, fast
connection and influence on lower motor
neurons
Includes: corticobulbar tract (cortex to
brainstem/cranial nerves); corticospinal tract
(cortex to spine/spinal nerves)

Damage to direct activation pathway
Loss or reduction of skilled movement
 Unilateral upper motor neuron lesion = contralateral
weakness


Particularly of tongue, lower face
Bilateral upper motor neuron lesion = bilateral
weakness and alterations in muscle tone (spasticity)
 Normal reflexes


UUMN, spastic dysarthria
Indirect Activation Pathway


Upper motor neurons with indirect influence on
lower motor neurons
Effects of damage:
Increased muscle tone (spasticity)
 Hyperreflexia

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UUMN, spastic dysarthria
Control Circuits
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Basal ganglia and cerebellum
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Coordinate, integrate, control movement activites
Effects of damage

Cerebellar control
Ataxia, incoordination
 Intention tremor
 Dysdiodokinesia
 Ataxic dysarthria

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Basal ganglia control
Hypokinesia (too little movement)
 Hyperkinesia (too much movement)
 Hypokinetic, hyperkinetic dysarthria

What does this damage look like
in speech?

Flaccid (‘weakness’)
Articulation: imprecise consonant production
 Phonation: breathy/hoarse voice quality,
diplophonia, short phrases, weak cough or glottal
coup, vocal flutter, audible inhalations (stridor)
 Prosody: monopitch, monoloudness
 Resonance: hypernasality, nasal emissions, weak
pressure consonants
 Respiration: reduced loudness, short phrases,
strained vocal quality


Spastic (‘spasticity’)
Articulation: imprecise consonant production,
labored and slow production
 Phonation: harsh and/or strained-strangled vocal
quality, low pitch, short phrases, pitch breaks
 Prosody: monopitch, monoloudness, slow rate
 Resonance: hypernasality
 Respiration: [shallow, slow inhalation]


Ataxic (‘incoordination’)
Articulation: imprecise consonant production,
distorted vowels (slurred), irregular breakdowns
 Phonation: harsh vocal quality, voice tremor
 Prosody: equal and excess stress, prolonged
phonemes and intervals between phonemes,
monopitch, monoloudness, slow rate
 Resonance: [intermittent hyponasality]
 Respiration: exaggerated and/or paradoximal mvmt


Hypokinetic (‘diminished movement’)
Articulation: imprecise consonants, repeated
phonemes, palilalia
 Phonation: harsh or breathy voice, low pitch
 Prosody: monopitch, monoloudness (low), reduced
stress, inappropriate pauses, short rushes of speech
 Resonance: [mild hypernasality]
 Respiration: faster breathing rates, incoordination of
muscles, shallow breath support, poor control of
exhalation for speech


Hyperkinetic (‘extraneous movement’)
Articulation: imprecise consonants, distorted vowels,
prolonged phonemes
 Phonation: harsh, strain-strangled, or breathy voice,
excess loudness variation, voice stoppage
 Prosody: prolonged intervals between syllables/
words, variable rate of speech, monopitch,
inappropriate silences, monoloudness
 Resonance: hypernasality and hyponasality
 Respiration: unexpected inhalations and exhalations
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Motor System Actions
Motor Planning
Motor Programming
Motor Execution
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Higher level
Goal-oriented
What to do
Plans are inflexible
Sets the plan for place
& manner of
articulation
• Premotor cortex
• Insular cortex
Apraxia of Speech
Lower level
Procedure-oriented
How to do it
Modifiable via sensory
feedback
• Detailed program of
motor acts across 5
speech systems
• Basal ganglia
• Cerebellum
Lowest level
Muscle oriented
Do it
Modifiable via sensory
feedback
• Executes muscle
movements
• Upper motor neurons
• Lower motor neurons
Dysarthrias
VIDEO/AUDIO SAMPLES
Questions/comments?