Motor speech disorder: dysarthria

1. MOTOR SPEECHMOTOR SPEECH
DISORDERSDISORDERS
By: Hina KhalidBy: Hina Khalid

2. Motor speech disorders (dysarthria and apraxia of speech)
result from neurological impairment in the areas of the brain
responsible for motor planning, motor programming,
neuromuscular control, and execution of speech; and they
account for 41% of all acquired communication disorders
(Yorkston, Beukelman, Strand, & Bell, 1999; Duffy, 2005).
INTRODUCTION

3. Motor Speech DisordersMotor Speech Disorders
Speech production deficit that results fromSpeech production deficit that results from
impairment of the neuromuscular and/orimpairment of the neuromuscular and/or
motor control systemmotor control system 11
May co-occur with other languageMay co-occur with other language
impairmentsimpairments
Other oral movements (besides speech) mayOther oral movements (besides speech) may
be impaired, including chewing and smilingbe impaired, including chewing and smiling

4. Prevalence and IncidencePrevalence and Incidence
Reliable estimates are rare, however…Reliable estimates are rare, however…

Among adults with acquiredAmong adults with acquired
communication disorders, 41% havecommunication disorders, 41% have
motor speech disorders (36% dysarthria,motor speech disorders (36% dysarthria,
5% apraxia of speech)5% apraxia of speech)

5. Defining Characteristics ofDefining Characteristics of
Prevalent Types of Motor SpeechPrevalent Types of Motor Speech
DisordersDisorders
Motor Planning/Programming DisordersMotor Planning/Programming Disorders::
Inability to group and sequence the relevantInability to group and sequence the relevant
muscle with respect to each othermuscle with respect to each other
--Apraxia of speechApraxia of speech (AOS) – acquired and(AOS) – acquired and
developmentaldevelopmental
Motor Execution DisordersMotor Execution Disorders: deficits in: deficits in
physiology and movement abilities of musclesphysiology and movement abilities of muscles
--Dysarthria –Dysarthria – acquired and developmentalacquired and developmental

6. Dysarthria can cause a reduction in speaking rate, abnormal
prosodic features, and significant intelligibility deficits
resulting in a reduced ability to communicate successfully
(Ansel & Kent, 1992; Kent, 1992; Duffy, 2005).
Definition OF Dysarthria

7. DefinitionDefinition
Dysarthria is a speech diagnostic term thatDysarthria is a speech diagnostic term that
can be used to classify various types ofcan be used to classify various types of
neuromuscular speech disturbances.neuromuscular speech disturbances.
Dysarthria results from notable degrees ofDysarthria results from notable degrees of
one or more abnormalities involving speechone or more abnormalities involving speech
musculature, including weakness, paralysis,musculature, including weakness, paralysis,
in-coordination, sensory deprivation,in-coordination, sensory deprivation,
exaggerated reflex patterns, uncontrollableexaggerated reflex patterns, uncontrollable
movement activities, and excess or reducedmovement activities, and excess or reduced
tonetone 22
..

8. Definition Cont……Definition Cont……
The name of each dysarthria subtype is partiallyThe name of each dysarthria subtype is partially
derived from the basic characteristics of thederived from the basic characteristics of the
overlying movement disturbances. Notably,overlying movement disturbances. Notably,
normal speech production involves thenormal speech production involves the
integration and coordination of five primaryintegration and coordination of five primary
physiological subsystems: respiration (breathphysiological subsystems: respiration (breath
support); phonation (voice production);support); phonation (voice production);
articulation (pronunciation of words); resonationarticulation (pronunciation of words); resonation
(nasal versus oral voice quality); and prosody(nasal versus oral voice quality); and prosody
(rate, rhythm, and inflection patterns of speech).(rate, rhythm, and inflection patterns of speech).

9. Four Subsystems of Speech ProductionFour Subsystems of Speech Production::
RespiratoryRespiratory
PhonatoryPhonatory
ResonatoryResonatory
ArticulatoryArticulatory
The muscles and muscle groups in theseThe muscles and muscle groups in these
subsystems must be coordinated in timesubsystems must be coordinated in time
and spaceand space

10. Respiratory SystemRespiratory System
Speech production requires airflowSpeech production requires airflow
Pulmonary airstream mechanism: pushes airPulmonary airstream mechanism: pushes air
out of lungs through trachea (windpipe) toout of lungs through trachea (windpipe) to
produce airflowproduce airflow
Ingressive – inhalationIngressive – inhalation
Egressive – exhalationEgressive – exhalation
-1:6 inhalation:exhalation ratio during-1:6 inhalation:exhalation ratio during
speech productionspeech production
Exhalation cycle needs to be extended inExhalation cycle needs to be extended in
time (for completion of utterance) andtime (for completion of utterance) and
modulation (to reflect stress)modulation (to reflect stress)
.

11. Phonatory SystemPhonatory System
Includes various muscles and structures inIncludes various muscles and structures in
the larynx, and regulates the production ofthe larynx, and regulates the production of
voice and the intonational aspects of speech.voice and the intonational aspects of speech.
Vocal folds are brought closely together, andVocal folds are brought closely together, and
the airflow builds up to set the vocal foldsthe airflow builds up to set the vocal folds
into vibration.into vibration.
Vocal folds are stretched lengthwise toVocal folds are stretched lengthwise to
manipulate the frequency or pitch of themanipulate the frequency or pitch of the
voice.voice.

12. Resonatory SystemResonatory System
Regulates the vibration of the airflow as itRegulates the vibration of the airflow as it
moves from the pharynx into the oral andmoves from the pharynx into the oral and
nasal cavity.nasal cavity.
Manipulates shape and size of vocal tractManipulates shape and size of vocal tract
for maintaining normal sound qualityfor maintaining normal sound quality
Manipulates theManipulates the velo-pharyngeal portvelo-pharyngeal port,,
(whether nasal cavity is used as a(whether nasal cavity is used as a
vibrating chamber) for determiningvibrating chamber) for determining
nasalitynasality of soundsof sounds

13. Articulatory SystemArticulatory System
Control of the articulators within the oralControl of the articulators within the oral
cavity to manipulate the outgoing airflowcavity to manipulate the outgoing airflow
Major structures: lower jaw, lips, tongueMajor structures: lower jaw, lips, tongue
(most important)(most important)
Tongue: intrinsic muscles (fine-tunedTongue: intrinsic muscles (fine-tuned
movements) and extrinsic muscles (coarsemovements) and extrinsic muscles (coarse
movements – protrusion, retraction,movements – protrusion, retraction,
elevation, depression)elevation, depression)
Muscles contract to create constrictions in theMuscles contract to create constrictions in the
oral cavity to produce varying soundsoral cavity to produce varying sounds

14. Motor ControlMotor Control
To maintain speed and fluency, theTo maintain speed and fluency, the
sequences of movements are programmedsequences of movements are programmed
together as a single movement unittogether as a single movement unit

Degrees of freedom: the number of elementsDegrees of freedom: the number of elements
that can be independently controlledthat can be independently controlled

The greater the degrees of freedom, the greaterThe greater the degrees of freedom, the greater
the challenge to the speakerthe challenge to the speaker
Speakers reduce the number of degrees ofSpeakers reduce the number of degrees of
freedom by organizing motor actions intofreedom by organizing motor actions into
motor unitsmotor units

15. Planning, Programming, andPlanning, Programming, and
ExecutionExecution
Motor planningMotor planning: processes that define and: processes that define and
sequence articulatory goals (prior to initiationsequence articulatory goals (prior to initiation
of movement)of movement)
Motor programmingMotor programming: processes that establish: processes that establish
and prepare the flow of motor info acrossand prepare the flow of motor info across
muscle, as well as control timing and force ofmuscle, as well as control timing and force of
movement (prior to initiation of movement)movement (prior to initiation of movement)
Motor ExecutionMotor Execution: processes that activate: processes that activate
relevant muscles (during and after initiation ofrelevant muscles (during and after initiation of
movement)movement)

16. SYMPTOMSSYMPTOMS
Virtually all individuals with spastic dysarthriaVirtually all individuals with spastic dysarthria
present with a broad spectrum of speechpresent with a broad spectrum of speech
disturbances, including:disturbances, including:
abnormally excessiveabnormally excessive nasal speechnasal speech qualityquality
imprecise articulationimprecise articulation , such as slurred sound, such as slurred sound
productions and periods of speech unintelligibilityproductions and periods of speech unintelligibility 33
slow-labored rateslow-labored rate of speechof speech
strained or strangledstrained or strangled voice qualityvoice quality
limited vocal pitchlimited vocal pitch andand loudnessloudness range andrange and
controlcontrol
In-coordinated, shallow, forced, uncontrolled, andIn-coordinated, shallow, forced, uncontrolled, and
overalloverall disruptivedisruptive speechspeech breathing patternsbreathing patterns

17. SYMPTOMS……SYMPTOMS……
In general, people with dysarthria struggle withIn general, people with dysarthria struggle with
these speech difficulties because of widespreadthese speech difficulties because of widespread
involvement of the tongue, lip, jaw, soft palate,involvement of the tongue, lip, jaw, soft palate,
voice box, and respiratory musculature.voice box, and respiratory musculature.
Problems with emotional breakdowns, such asProblems with emotional breakdowns, such as
unprovoked crying and laughing, also occur inunprovoked crying and laughing, also occur in
many cases, due to uncontrolled releases ofmany cases, due to uncontrolled releases of
primitive reflexes.primitive reflexes.
Finally, swallowing difficulties, known asFinally, swallowing difficulties, known as
dysphagia, are not uncommon in this population,dysphagia, are not uncommon in this population,
because of underlying weakness and paralysisbecause of underlying weakness and paralysis
of the tongue and throat wall muscles.of the tongue and throat wall muscles.

18. Classification of Motor SpeechClassification of Motor Speech
DisorderDisorder
AcquiredAcquired: damage to a previously intact: damage to a previously intact
nervous system caused by:nervous system caused by:
cerebrovascular accidentscerebrovascular accidents
degenerative diseases,degenerative diseases,
brain tumors orbrain tumors or
traumatic brain injurytraumatic brain injury
Developmental:Developmental: abnormal development ofabnormal development of
nervous system caused bynervous system caused by
congenital diseasescongenital diseases
damage to the developing nervous systemdamage to the developing nervous system
during pre or peri natal periodduring pre or peri natal period

19. Acquired DysarthriaAcquired Dysarthria
Disruption in the execution of speechDisruption in the execution of speech
movements resulting from neuromuscularmovements resulting from neuromuscular
disturbances to muscle tone, reflexes, anddisturbances to muscle tone, reflexes, and
kinetic aspects of movementkinetic aspects of movement
Speech sounds slow, slurred, harsh or quiet,Speech sounds slow, slurred, harsh or quiet,
or uneven depending on the type ofor uneven depending on the type of
dysarthriadysarthria
Three concepts:Three concepts: spasticity, dyskinesia, ataxiaspasticity, dyskinesia, ataxia
Typically occurs because of a progressiveTypically occurs because of a progressive
disease or traumadisease or trauma

20. Types of Acquired DysarthriaTypes of Acquired Dysarthria
SpasticSpastic
FlaccidFlaccid
HypokineticHypokinetic
HyperkineticHyperkinetic
AtaxicAtaxic
Unilateral Upper Motor Neuron (UUMN)Unilateral Upper Motor Neuron (UUMN)
Mixed DysarthriaMixed Dysarthria

21. Spastic DysarthriaSpastic Dysarthria
A type of motor speech disorder affectingA type of motor speech disorder affecting
speech articulation, caused by lesions of thespeech articulation, caused by lesions of the
corticobulbar tractscorticobulbar tracts.. It affectsIt affects
StrengthStrength
speedspeed
PrecisionPrecision
range of motion andrange of motion and
coordination of speechcoordination of speech
musculaturemusculature

23. Ataxic DysarthriaAtaxic Dysarthria
Ataxic dysarthria is caused by damage to theAtaxic dysarthria is caused by damage to the
cerebellumcerebellum or its connections to theor its connections to the cerebralcerebral
cortex or brain-stemcortex or brain-stem. When the cerebellum is damaged. When the cerebellum is damaged
the affected person may exhibit drunk-like motor patterns,the affected person may exhibit drunk-like motor patterns,
Slurred speechSlurred speech
intermittently explosive voiceintermittently explosive voice
pitch and loudness outbursts.pitch and loudness outbursts.
Swallowing is not usually disturbed.Swallowing is not usually disturbed.
The most commonThe most common causescauses of ataxia includeof ataxia include
cerebral palsy,cerebral palsy,
multiple sclerosis, andmultiple sclerosis, and
closed head injuries.closed head injuries.

25. Hypo kinetic DysarthriaHypo kinetic Dysarthria
Hypokinetic dysarthria is caused by damage to theHypokinetic dysarthria is caused by damage to the
upper brainstemupper brainstem region. When various speechregion. When various speech
muscles are involved, mask-like facial expressionsmuscles are involved, mask-like facial expressions
numerous communication deficits occur, includingnumerous communication deficits occur, including
imprecise articulation of sounds,imprecise articulation of sounds,
harsh-hoarse voice quality, andharsh-hoarse voice quality, and
abnormal bursts of speech that sound like theabnormal bursts of speech that sound like the
individual is tripping over his or her tongue.individual is tripping over his or her tongue.
hypokinetic dysarthria is most common inhypokinetic dysarthria is most common in
Parkinson'sParkinson's diseasedisease
SwallowingSwallowing difficulties may co-occurdifficulties may co-occur..

26. Hyperkinetic DysarthriaHyperkinetic Dysarthria
Hyperkinetic dysarthria is generally caused by damage toHyperkinetic dysarthria is generally caused by damage to
nerve pathwaysnerve pathways and centers within the depths of the brainand centers within the depths of the brain
(subcortex) known as the(subcortex) known as the basal ganglia.basal ganglia.
The basal ganglia are largely responsible for overall stability duringThe basal ganglia are largely responsible for overall stability during
gross voluntary movement patterns.gross voluntary movement patterns.
Damage to these structures and their circuitry generally produces twoDamage to these structures and their circuitry generally produces two
different types of symptoms, depending upon the site(s) of injury:different types of symptoms, depending upon the site(s) of injury:
increased muscle toneincreased muscle tone andand very slow movementvery slow movement, known, known
as rigidity, as seen in patients withas rigidity, as seen in patients with Parkinson's diseaseParkinson's disease..
Another type involvesAnother type involves involuntary, excessive, andinvoluntary, excessive, and
uncontrollableuncontrollable quick-jerky, slow-twisting, orquick-jerky, slow-twisting, or
tremblingtrembling limb and speech musculature behaviors. Patients withlimb and speech musculature behaviors. Patients with
Huntington's diseaseHuntington's disease and tic disorders frequently exhibit theand tic disorders frequently exhibit the
quick and jerky forms of movement abnormalities.quick and jerky forms of movement abnormalities.

27. Hyperkinetic Dysarthria ContHyperkinetic Dysarthria Cont
Infact,spasmodic dysphonia,Infact,spasmodic dysphonia,
characterized by strained strangled orcharacterized by strained strangled or
abnormally breathy vocal quality andabnormally breathy vocal quality and
episodes of periodic arrests of voice, is aepisodes of periodic arrests of voice, is a
form of hyperkinetic dysarthria.form of hyperkinetic dysarthria.
Swallowing difficulties can be a significantSwallowing difficulties can be a significant
problem for these types of patients.problem for these types of patients.

28. Flaccid DysarthriaFlaccid Dysarthria
Flaccid dysarthria is caused by damage to nerves thatFlaccid dysarthria is caused by damage to nerves that
emerge from the brainstem (cranial) or spinal cord andemerge from the brainstem (cranial) or spinal cord and
travel directly to muscles that are involved in speechtravel directly to muscles that are involved in speech
production.production.
These nerves are generically referred to asThese nerves are generically referred to as lowerlower
motor neurons. Cranial nerves V, VII, X,motor neurons. Cranial nerves V, VII, X,
and XIIand XII are of great importance because they supplyare of great importance because they supply
the chief muscles of speech production, namely, thethe chief muscles of speech production, namely, the
jaw, lips, voice box and palate, and tongue,jaw, lips, voice box and palate, and tongue,
respectively.respectively.
..

30. Flaccid DysarthriaFlaccid Dysarthria
Patterns or twitch-like behaviors known as fasciculation. In aPatterns or twitch-like behaviors known as fasciculation. In a
structure like the tongue, which is not covered with thick overlyingstructure like the tongue, which is not covered with thick overlying
skin, fasciculation can sometimes be evident by shining a flashlightskin, fasciculation can sometimes be evident by shining a flashlight
on the surface at rest.on the surface at rest.
Additionally, the actual nerves that are damaged dictate the specificAdditionally, the actual nerves that are damaged dictate the specific
types of speech difficulties that may occur. For example, if a focaltypes of speech difficulties that may occur. For example, if a focal
lesion involves only the cranial nerve VII, as inlesion involves only the cranial nerve VII, as in Bell's palsyBell's palsy , only, only
the lip musculature will be weakened. The result in this case usuallythe lip musculature will be weakened. The result in this case usually
produces minimal dysarthria.produces minimal dysarthria.
The most common speech signs observed in patients with flaccidThe most common speech signs observed in patients with flaccid
dysarthria, regardless of the cause or severity, includedysarthria, regardless of the cause or severity, include
articulation imprecisionarticulation imprecision
hypernasal voice,hypernasal voice,
hoarse and breathy vocal quality,hoarse and breathy vocal quality,
slow-labored speech rate.slow-labored speech rate.

31. Mixed dysarthriaMixed dysarthria
Mixed dysarthria is caused by simultaneousMixed dysarthria is caused by simultaneous
damage todamage to two or more primary motortwo or more primary motor
components of the nervous system,components of the nervous system,
It is not uncommon for severe head injuries toIt is not uncommon for severe head injuries to
cause multi-focal nervous system lesions andcause multi-focal nervous system lesions and
nonspecific mixed dysarthrias.nonspecific mixed dysarthrias.
Patients usually have swallowing, cognitive,Patients usually have swallowing, cognitive,
language, perceptual, and psychosocial deficitslanguage, perceptual, and psychosocial deficits..

32. Unilateral upper motor neuronUnilateral upper motor neuron
(UMN) dysarthria(UMN) dysarthria
Unilateral UMN dysarthria is caused by damage toUnilateral UMN dysarthria is caused by damage to
either the left or righteither the left or right UMN tractUMN tract, anywhere along, anywhere along
its course to the brainstem and spinal cord.its course to the brainstem and spinal cord.
GENERAL PRESENTATIONGENERAL PRESENTATION
mild to moderate weakness and paralysis of themild to moderate weakness and paralysis of the
lower face, tongue, arm, and leg on the side of thelower face, tongue, arm, and leg on the side of the
body opposite the damaged UMN tractbody opposite the damaged UMN tract
Most common causes of this dysarthria subtype areMost common causes of this dysarthria subtype are
cerebral vascular accidents (i.e., strokes)cerebral vascular accidents (i.e., strokes)
mild-to-moderate head injuries.mild-to-moderate head injuries.

33. Developmental DysarthriaDevelopmental Dysarthria
Present at birthPresent at birth
Usually occurs along with knownUsually occurs along with known
disturbance to neuromotor functioningdisturbance to neuromotor functioning
Can be caused by pre-, peri-, or post-natalCan be caused by pre-, peri-, or post-natal
damage to the nervous systemdamage to the nervous system
Most common types:Most common types:
spasticspastic
dyskineticdyskinetic

34. BIBLIOGRAPHYBIBLIOGRAPHY
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Justice Communication Sciences and Disorders: AnJustice Communication Sciences and Disorders: An
Introduction-Copyright ©2006 by Pearson Education,Introduction-Copyright ©2006 by Pearson Education,
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Dworkin,James speechtherapy.ygoy.com/symptoms-of-Dworkin,James speechtherapy.ygoy.com/symptoms-of-
dysarthriadysarthria