Dysarthia

Motor speech disorder: dysarthria

1. MOTOR SPEECH MOTOR 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 from Speech production deficit that results from
impairment of the neuromuscular and/or impairment of the neuromuscular and/or
motor control system motor control system
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May co-occur with other language May co-occur with other language
impairmentsimpairments
Other oral movements (besides speech) may Other 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 acquired Among adults with acquired
communication disorders, 41% have communication disorders, 41% have
motor speech disorders (36% dysarthria, motor speech disorders (36% dysarthria,
5% apraxia of speech)5% apraxia of speech)

5. Defining Characteristics of Defining Characteristics of
Prevalent Types of Motor Speech Prevalent Types of Motor Speech
DisordersDisorders
Motor Planning/Programming DisordersMotor Planning/Programming Disorders : :
Inability to group and sequence the relevant Inability 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 that Dysarthria is a speech diagnostic term that
can be used to classify various types of can be used to classify various types of
neuromuscular speech disturbances.neuromuscular speech disturbances.
Dysarthria results from notable degrees of Dysarthria results from notable degrees of
one or more abnormalities involving speech one or more abnormalities involving speech
musculature, including weakness, paralysis, musculature, including weakness, paralysis,
in-coordination, sensory deprivation, in-coordination, sensory deprivation,
exaggerated reflex patterns, uncontrollable exaggerated reflex patterns, uncontrollable
movement activities, and excess or reduced movement activities, and excess or reduced
tone tone
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. .

8. Definition Cont……Definition Cont……
The name of each dysarthria subtype is partially The name of each dysarthria subtype is partially
derived from the basic characteristics of the derived from the basic characteristics of the
overlying movement disturbances. Notably, overlying movement disturbances. Notably,
normal speech production involves the normal speech production involves the
integration and coordination of five primary integration and coordination of five primary
physiological subsystems: respiration (breath physiological subsystems: respiration (breath
support); phonation (voice production); support); phonation (voice production);
articulation (pronunciation of words); resonation articulation (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 these The muscles and muscle groups in these
subsystems must be coordinated in time subsystems must be coordinated in time
and spaceand space

10. Respiratory SystemRespiratory System
Speech production requires airflowSpeech production requires airflow
Pulmonary airstream mechanism: pushes air Pulmonary airstream mechanism: pushes air
out of lungs through trachea (windpipe) to out 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 in Exhalation cycle needs to be extended in
time (for completion of utterance) and time (for completion of utterance) and
modulation (to reflect stress)modulation (to reflect stress)
.

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

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

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

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

15. Planning, Programming, and Planning, Programming, and
ExecutionExecution
Motor planningMotor planning: processes that define and : processes that define and
sequence articulatory goals (prior to initiation sequence 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 across and prepare the flow of motor info across
muscle, as well as control timing and force of muscle, 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 of relevant muscles (during and after initiation of
movement)movement)

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

17. SYMPTOMS……SYMPTOMS……
In general, people with dysarthria struggle with In general, people with dysarthria struggle with
these speech difficulties because of widespread these 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 as Problems with emotional breakdowns, such as
unprovoked crying and laughing, also occur in unprovoked crying and laughing, also occur in
many cases, due to uncontrolled releases of many cases, due to uncontrolled releases of
primitive reflexes. primitive reflexes.
Finally, swallowing difficulties, known as Finally, swallowing difficulties, known as
dysphagia, are not uncommon in this population, dysphagia, are not uncommon in this population,
because of underlying weakness and paralysis because of underlying weakness and paralysis
of the tongue and throat wall muscles.of the tongue and throat wall muscles.

18. Classification of Motor Speech Classification of Motor Speech
DisorderDisorder
AcquiredAcquired: damage to a previously intact : damage to a previously intact
nervous system caused by:nervous system caused by:
cerebrovascular accidents cerebrovascular accidents
degenerative diseases, degenerative diseases,
brain tumors orbrain tumors or
traumatic brain injurytraumatic brain injury
Developmental:Developmental: abnormal development of abnormal development of
nervous system caused bynervous system caused by
congenital diseasescongenital diseases
damage to the developing nervous system damage 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 speech Disruption in the execution of speech
movements resulting from neuromuscular movements resulting from neuromuscular
disturbances to muscle tone, reflexes, and disturbances 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 of or uneven depending on the type of
dysarthriadysarthria
Three concepts: Three concepts: spasticity, dyskinesia, ataxiaspasticity, dyskinesia, ataxia
Typically occurs because of a progressive Typically 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 affecting A type of motor speech disorder affecting
speech articulation, caused by lesions of the speech articulation, caused by lesions of the
corticobulbar tractscorticobulbar tracts.. It affects It affects
StrengthStrength
speedspeed
PrecisionPrecision
range of motion andrange of motion and
coordination of speech coordination 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 the or its connections to the cerebral cerebral
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 common The most common causescauses of ataxia include of ataxia include
cerebral palsy,cerebral palsy,
multiple sclerosis, and multiple sclerosis, and
closed head injuries.closed head injuries.

25. Hypo kinetic DysarthriaHypo kinetic Dysarthria
Hypokinetic dysarthria is caused by damage to the Hypokinetic dysarthria is caused by damage to the
upper brainstemupper brainstem region. When various speech region. When various speech
muscles are involved, mask-like facial expressions muscles are involved, mask-like facial expressions
numerous communication deficits occur, including numerous communication deficits occur, including
imprecise articulation of sounds,imprecise articulation of sounds,
harsh-hoarse voice quality, and harsh-hoarse voice quality, and
abnormal bursts of speech that sound like the abnormal 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 in hypokinetic dysarthria is most common in
Parkinson's Parkinson's diseasedisease
SwallowingSwallowing difficulties may co-occur difficulties 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 brain and 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 during The 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 two Damage 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 and and very slow movementvery slow movement, known , known
as rigidity, as seen in patients with as rigidity, as seen in patients with Parkinson's diseaseParkinson's disease. .
Another type involves Another type involves involuntary, excessive, and involuntary, excessive, and
uncontrollableuncontrollable quick-jerky, slow-twisting, or quick-jerky, slow-twisting, or
tremblingtrembling limb and speech musculature behaviors. Patients with limb and speech musculature behaviors. Patients with
Huntington's diseaseHuntington's disease and tic disorders frequently exhibit the and 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 or characterized by strained strangled or
abnormally breathy vocal quality and abnormally breathy vocal quality and
episodes of periodic arrests of voice, is a episodes of periodic arrests of voice, is a
form of hyperkinetic dysarthria.form of hyperkinetic dysarthria.
Swallowing difficulties can be a significant Swallowing 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 that Flaccid dysarthria is caused by damage to nerves that
emerge from the brainstem (cranial) or spinal cord and emerge from the brainstem (cranial) or spinal cord and
travel directly to muscles that are involved in speech travel directly to muscles that are involved in speech
production.production.
These nerves are generically referred to as These nerves are generically referred to as lower lower
motor neurons. Cranial nerves V, VII, X, motor neurons. Cranial nerves V, VII, X,
and XIIand XII are of great importance because they supply are of great importance because they supply
the chief muscles of speech production, namely, the the 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 a Patterns or twitch-like behaviors known as fasciculation. In a
structure like the tongue, which is not covered with thick overlying structure like the tongue, which is not covered with thick overlying
skin, fasciculation can sometimes be evident by shining a flashlight skin, 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 specific Additionally, the actual nerves that are damaged dictate the specific
types of speech difficulties that may occur. For example, if a focal types of speech difficulties that may occur. For example, if a focal
lesion involves only the cranial nerve VII, as in lesion 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 usually the 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 flaccid The most common speech signs observed in patients with flaccid
dysarthria, regardless of the cause or severity, include dysarthria, 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 simultaneous Mixed dysarthria is caused by simultaneous
damage todamage to two or more primary motor two or more primary motor
components of the nervous system, components of the nervous system,
It is not uncommon for severe head injuries to It is not uncommon for severe head injuries to
cause multi-focal nervous system lesions and cause 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 neuron Unilateral upper motor neuron
(UMN) dysarthria(UMN) dysarthria
Unilateral UMN dysarthria is caused by damage to Unilateral UMN dysarthria is caused by damage to
either the left or right either 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 the mild to moderate weakness and paralysis of the
lower face, tongue, arm, and leg on the side of the lower 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 known Usually occurs along with known
disturbance to neuromotor functioningdisturbance to neuromotor functioning
Can be caused by pre-, peri-, or post-natal Can 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
1.1.
Justice Communication Sciences and Disorders: An Justice Communication Sciences and Disorders: An
Introduction-Copyright ©2006 by Pearson Education, Introduction-Copyright ©2006 by Pearson Education,
Inc.Inc.
2.2. UpperSaddleRiver,NewJersey07458UpperSaddleRiver,NewJersey07458
Gale Encyclopedia of Neurological Disorders | 2005|Gale Encyclopedia of Neurological Disorders | 2005|
Dworkin,James speechtherapy.ygoy.com/symptoms-of-Dworkin,James speechtherapy.ygoy.com/symptoms-of-
dysarthriadysarthria