CSD 2230
HUMAN COMMUNICATION
DISORDERS
Topic 7
Speech Disorders
Motor Speech Disorders
Motor or Neurogenic
Speech Disorders
Speech difficulties that are related to
problems of movement as a result of some
neurological disorder or injury
 Heterogeneous
 Affect the planning, coordination, timing,
and execution of speech movements
 May affect phonation, resonation, and
articulation
Major Types of
Neurogenic Impairment
1. Cerebral Palsy
2. Dysarthria of speech
3. Apraxia of speech
Cerebral Palsy
Heterogenous group of neurological
disorders that result in difficulty with
motor movements
 Acquired shortly before, during, or after
birth
 Developmental disorder
 Continuum of physical manifestations
Dysarthria
Group of related speech impairment that result
from disturbed muscular control caused by
damage to the mature nervous system
 Acquired disorder
 May affect respiration, phonation, resonation,
and/or articulation
 Speech characteristics include slow or rapid
motor function, decrease in the range or
strength of motor skills, poor directionality or
motor timing
Apraxia
Affects the phonological selection and
sequencing of speech sounds and
articulation
 Acquired disorder
 Affects the ability to organize, plan, and
execute the movement of speech
muscles
What Causes Motor
Speech Disorders?
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Stroke
Traumatic brain injury (TBI)
Anoxia
Neoplasms
Infections and toxins
Acquired diseases
Cerebral Palsy
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A group of nonprogressive neurological
difficulties resulting from brain injury very early in
life
Areas affected include motor movement,
communication, growth and development,
locomotion, learning, and sensation
Incidence is 1.5-3/1000 births
Primary characteristics
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A developmental neurogenic disorder that results from
abnormal brain function
It’s not a disease
Types of Cerebral Palsy
1. Spastic (hypertonia)
Characterized by too much muscle tone
2. Athetoid (dyskinesia)
Characterized by slow involuntary
movements
3. Ataxic
Characterized by uncoordinated movements
Spastic Cerebral Palsy
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60% of individuals with cerebral palsy
Motor movements are jerky, labored,
and slow
Infantile reflex patterns
Athetoid Cerebral Palsy
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30% of individuals with cerebral palsy
Slow involuntary writhing
Infantile reflex patterns
Ataxic Cerebral Palsy
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10% of individuals with cerebral palsy
Uncoordinated movements
Disturbed balance which is especially
noticeable in their gait
Damage is to the cerebellum
Motor and Motor
Speech Characteristics with
Cerebral Palsy
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Speech isn’t always affected and varies
somewhat with the type of CP
When speech is affected, all aspects of
speech production may be affected
including respiration, phonation,
resonation, articulation, and prosody
CD-ROM Ch.14.02 shows a speaker
with spastic CP talking about sports.
How much can you understand?
Motor and Motor
Speech Characteristics with
Cerebral Palsy
Other issues related to cerebral palsy:
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Breathing problems
Rigidity
Velopharyngeal incompetency
Uncoordinated articulator movements
Intellectual processing
Auditory processing
Language impairments
Intervention might include augmentative and alternative
communication systems
CD-ROM Ch14.03 illustrates conversation with such a
device
The Dysarthrias
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A group of impairments that may affect
the speed, range, direction, strength,
and timing of motor movements
Results from paralysis, weakness, or
discoordination of speech muscles
Not a language disorder but rather a
difficulty in motor speech control
Types and Associated
Etiologies
Flaccid dysarthria
 Characterized by hypotonia (weak muscle tone)
which results in weakness or paralysis of the
affected muscle
 Speech characteristics include shallow
breathing, breathy voice, aphonia (no voice),
reduced pitch and loudness, monotone,
hypernasality, and imprecise articulation
 Etiologies include Bell’s Palsy, myasthenia
gravis, and muscular dystrophy
 Audio examples of flaccid dysarthria
Types and Associated
Etiologies
Spastic dysarthria
 Characterized by hypertonia (stiff and rigid
muscles) commonly caused by stroke
 Speech movements are difficult and speech
is characterized as slow with jerky, imprecise
articulation and reduction in the rapidly
alternating movements of speech
 Audio examples of spastic dysarthria
Types and Associated
Etiologies
Ataxic dysarthria
 Characterized by a combination of
hypotonia (reduced tone) and ataxia
resulting in problems in the accuracy,
timing, and direction of movement
 Speech movements are jerky and
imprecise
 Audio examples of ataxic dysarthria
Types and Associated
Etiologies
Hypokinetic Dysarthria
 Characterized by hypokinesis (decreased
movement)
 Parkinson’s disease results in a good example of
this kind of dysarthria
Progressive disorder where the muscles become rigid,
resulting in reduced motor movements, involuntary
shaking or tremors, slowness of movement, and difficul
initiating voluntary movements
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Audio examples of hypokinetic dysarthria from
Parkinson’s
Types and Associated
Etiologies
Hyperkinetic dysarthria
 Characterized by hyperkinesia (increased
movements) in the form of involuntary
tremors and tics
 Major speech characteristic is imprecise
articulation
 Dystonia and chorea provide examples
 Audio examples of hyperkinetic dysarthria
from dystonia and chorea
Types and Associated
Etiologies
Mixed dysarthria
 Caused by diffuse brain damage
 ALS provides a good example of mixed
dysarthria
 Audio examples of mixed dysarthria
from ALS
Apraxia
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Disorder of motor placement and sequencing
that’s unrelated to muscle weakness,
slowness, or paralysis
When speech muscle groups are affected, it
is called apraxia of speech
Speech difficulties are not the result of
muscle weakness or slowness (dysarthria) or
of linguistic processing (aphasia)
Almost always due to damage to Broca’s area
in the cortex
Characteristics of
Apraxia of Speech
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Groping attempts to find the correct
articulatory position
Frequent articulation errors
Self-correcting behaviors
Variable in their abilities
Audio example apraxia of speech