MOTOR SPEECH MOTOR SPEECH DISORDERSDISORDERS

By: Hina KhalidBy: Hina Khalid

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

Motor Speech DisordersMotor Speech DisordersSpeech 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 11

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

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)

Defining Characteristics of Defining Characteristics of Prevalent Types of Motor Speech Prevalent Types of Motor Speech

DisordersDisordersMotor 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 developmentaldevelopmentalMotor 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

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

DefinitionDefinitionDysarthria 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 22. .

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).

Four Subsystems of Speech ProductionFour Subsystems of Speech Production::

RespiratoryRespiratoryPhonatoryPhonatoryResonatoryResonatoryArticulatoryArticulatory

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

Respiratory SystemRespiratory SystemSpeech production requires airflowSpeech production requires airflowPulmonary 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 airflowIngressive – inhalationIngressive – inhalationEgressive – exhalationEgressive – exhalation

-1:6 inhalation:exhalation ratio during -1:6 inhalation:exhalation ratio during speech productionspeech productionExhalation 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)

.

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.

Resonatory SystemResonatory SystemRegulates 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

Articulatory SystemArticulatory SystemControl 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

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

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)

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 33

slow-labored rateslow-labored rate of speech of speech

strained or strangled strained or strangled voice qualityvoice qualitylimited vocal pitchlimited vocal pitch and and loudnessloudness range and range and controlcontrolIn-coordinated, shallow, forced, uncontrolled, and In-coordinated, shallow, forced, uncontrolled, and overall overall disruptivedisruptive speech speech breathing patternsbreathing patterns

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.

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 diseasesdamage to the developing nervous system damage to the developing nervous system during pre or peri natal periodduring pre or peri natal period

Acquired DysarthriaAcquired DysarthriaDisruption 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 movementSpeech 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 dysarthriadysarthriaThree concepts: Three concepts: spasticity, dyskinesia, ataxiaspasticity, dyskinesia, ataxiaTypically occurs because of a progressive Typically occurs because of a progressive disease or traumadisease or trauma

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

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

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.

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..

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.

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.

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.

..

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 imprecisionhypernasal voice, hypernasal voice, hoarse and breathy vocal quality, hoarse and breathy vocal quality, slow-labored speech rate.slow-labored speech rate.

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 ..

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.

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

BIBLIOGRAPHYBIBLIOGRAPHY1.1.

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,NewJersey07458Gale 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