09f09fCLINICAL APPLICATIONS OF CLINICAL APPLICATIONS OF YOUR KNOWLEDGE OF THE YOUR KNOWLEDGE OF THE

MOTOR SYSTEMSMOTOR SYSTEMS

Think: Unilateral damage to upper motor neuron… and reasons for associated spastic

hemiplegia • At first:At first:– Flaccidity of Flaccidity of

distal musclesdistal muscles– Loss of precise Loss of precise

controlcontrol– Positive Positive

BabinskiBabinski

• 1 to 4 weeks later1 to 4 weeks later– Spasticity of Spasticity of

distal muscles, distal muscles, esp. for cortico-esp. for cortico-spinal systemspinal system

– HyperreflexiaHyperreflexia– Clasp-knife Clasp-knife

rigidityrigidity

Signs present

____________ to site of

lesionSee pp. 352-357 in book

Spastic Spastic hemiplegia, hemiplegia, spastic spastic monoplegiamonoplegia

Which UMNs have been affected?

Think: Bilateral damage to upper motor neuron… and reasons for associated

pseudobulbar palsy• SignsSigns– FlaccidityFlaccidity of facial of facial

musclesmuscles– Loss of precise Loss of precise

control of facial control of facial musclesmuscles

– hyperreflexiahyperreflexia– Strain-strangled Strain-strangled

spasticityspasticity of voice of voice– Voluntary mvmnt Voluntary mvmnt

of face poor, but of face poor, but emotional mvmnt emotional mvmnt of face (via limbic of face (via limbic system) presentsystem) present

Little spasticity in face, but voice

strained (spastic)See p. 353-357 in book

Pseudobulbar Pseudobulbar palsypalsy

• Examples of hyper-reflexia, as well Examples of hyper-reflexia, as well as preservations of normal reflexes, as preservations of normal reflexes, in cases of severe TBI with in cases of severe TBI with associated pseudobulbar palsyassociated pseudobulbar palsy

• Strained-hoarse voice, slow rate, Strained-hoarse voice, slow rate, imprecision of articulation and imprecision of articulation and hypernasality in Case 13 hypernasality in Case 13 (pseudobulbar palsy)(pseudobulbar palsy)

Think: Brainstem stroke, and how it may result in alternating or “crossed” hemiplegia

• Simultaneous lesion of Simultaneous lesion of – Cranial nerve motor Cranial nerve motor

nuclei and/or nerves, nuclei and/or nerves, LMN (motor unit)LMN (motor unit)

– UMNUMN

• LMN signs ipsilateral to LMN signs ipsilateral to lesionlesion

• UMN signs contralateral UMN signs contralateral to lesionto lesion

See p. 353-354 in book

Think: Damage to LMN and its clinical presentation. Why this association?

• Includes bulbar Includes bulbar palsy, damage to palsy, damage to nerves, or poor nerves, or poor neuro-muscular neuro-muscular communicationcommunication

• SignsSigns– Absent reflexesAbsent reflexes– Flaccid toneFlaccid tone– Muscle Muscle

wasting/atrophywasting/atrophy– Fasciculations Fasciculations

and fibrilations and fibrilations (activity of (activity of denervated denervated muscle)muscle)

See p. 353-357 in book

Example of fasciculations Example of fasciculations and atrophy and atrophy with LMN with LMN involvementinvolvement• Case 14—Fasciculations of tongueCase 14—Fasciculations of tongue

• Case 15---Flaccidity of face and soft Case 15---Flaccidity of face and soft palatepalate

Speech motor system complex Speech motor system complex and neurologically sensitiveand neurologically sensitive

• Over 100 muscles must be controlled and Over 100 muscles must be controlled and coordinatedcoordinated

• Approximately 14 recognizable speech sounds Approximately 14 recognizable speech sounds are uttered per secondare uttered per second

““Normal speech production requires the finest Normal speech production requires the finest motor control in the body” (W&A, p. 125)motor control in the body” (W&A, p. 125)

Speech motor system highly sensitive to even Speech motor system highly sensitive to even small neurological changes/damage, small neurological changes/damage, at any at any point in the motor neural pathwayspoint in the motor neural pathways

SLP / A----Our role in SLP / A----Our role in diagnosisdiagnosis

“ “Motor speech disorders (and other Motor speech disorders (and other communication disorders) often can communication disorders) often can be linked to disease location and be linked to disease location and sometimes to specific diseases, even sometimes to specific diseases, even when localization and diagnosis have when localization and diagnosis have not yet otherwise been established.” not yet otherwise been established.”

(Joseph Duffy, Mayo Clinic, (Joseph Duffy, Mayo Clinic, The ASHA The ASHA Leader Leader , November 25, 2008), November 25, 2008)

Dysarthrias (speech motor disorders)Dysarthrias (speech motor disorders)

• Dysarthria associated with bilateral upper Dysarthria associated with bilateral upper motor neuron damage: motor neuron damage: Spastic dysarthriaSpastic dysarthria (muscles are overly tight, because inhibition of (muscles are overly tight, because inhibition of LMN which would normally be supplied from LMN which would normally be supplied from cortex through UMN cannot reach the LMN; cortex through UMN cannot reach the LMN; hyper-reflexia makes muscles extra tight)hyper-reflexia makes muscles extra tight)

• Dysarthria associated with lower motor neuron Dysarthria associated with lower motor neuron damage: damage: Flaccid dysarthriaFlaccid dysarthria (muscles are (muscles are floppy because they are not receiving floppy because they are not receiving activation through LMN) activation through LMN)

Dysarthrias (speech motor Dysarthrias (speech motor disorders), cont.disorders), cont.• Dysarthrias associated with basal ganglia Dysarthrias associated with basal ganglia

involvement involvement – Hypokinetic dysarthria Hypokinetic dysarthria (prob. w/ movement inititation)(prob. w/ movement inititation)

•Dysarthria associated with Parkinson’s disease (not enough Dysarthria associated with Parkinson’s disease (not enough dopamine in substantia nigra)dopamine in substantia nigra)

– Hyperkinetic dysarthria Hyperkinetic dysarthria (prob. w/ movement (prob. w/ movement inhibition)inhibition)•E.g. Huntington’s choreaE.g. Huntington’s chorea

•E.g. myoclonusE.g. myoclonus

• Dysarthria associated with cerebellar Dysarthria associated with cerebellar involvement: involvement: Ataxic dysarthriaAtaxic dysarthria

IF DAMAGE/LESION IS IF DAMAGE/LESION IS IN….IN….

……THE SPEECH/VOICE/ THE SPEECH/VOICE/ RESPIRATORY RESPIRATORY MUSCLES…MUSCLES…

……AND THIS IS CALLEDAND THIS IS CALLED

lower motor neuronlower motor neuron are weak and lacking in are weak and lacking in muscle tonemuscle tone

flaccid dysarthriaflaccid dysarthria

upper motor neuron upper motor neuron (bilaterally)(bilaterally)

have too much muscle have too much muscle tone (a “tight feeling”) tone (a “tight feeling”) and move slowly and and move slowly and with difficultywith difficulty

spastic dysarthriaspastic dysarthria

cerebellum or cerebellum or cerebellar pathwayscerebellar pathways

are uncoordinated in are uncoordinated in their movementstheir movements

ataxic dysarthriaataxic dysarthria

basal ganglia circuits, basal ganglia circuits, for:for:--movement initiation--movement initiation

--movement inhibition--movement inhibition

--display excessive, --display excessive, small small movements, not fully movements, not fully initiatedinitiated--display extraneous, --display extraneous, involuntary movementinvoluntary movement

dyskinetic dysarthriadyskinetic dysarthria--hypokinetic --hypokinetic dysarthriadysarthria

--hyperkinetic --hyperkinetic dysarthriadysarthria

language dominant language dominant hemisphere, especially hemisphere, especially frontal lobe motor frontal lobe motor planning areasplanning areas

……are NOT weak, tight, are NOT weak, tight, uncoordinated, or uncoordinated, or dyskinetic, BUT the dyskinetic, BUT the planningplanning for the for the correctcorrect movements is poormovements is poor

apraxia of speechapraxia of speechNote: Mixed

dysarthria also possible

Additional examples of Additional examples of dysarthriadysarthria

• Case 16—Cerebellar degenerative Case 16—Cerebellar degenerative diseasedisease– _______________ articulatory breakdown_______________ articulatory breakdown

• Case 17—Hypokinetic dysarthria of Case 17—Hypokinetic dysarthria of Parkinson’s diseaseParkinson’s disease

• Cases 18, 19, 20—Focal hyperkinetic Cases 18, 19, 20—Focal hyperkinetic dyskinesias affecting speech (facial dyskinesias affecting speech (facial and fasciaolingual dyskinesias)and fasciaolingual dyskinesias)