Dysarthria

What is dysarthria?

group of speech disorders caused by damage to the central or peripheral nervous system that creates speech musculature that exhibits:
-Weakness
-Incoordination
-slowness
-abnormal muscle tone

What might some with dysarthria have abnormalities in?

-strength
-speed
-range
-steadiness
-tone
-accuracy

What are strength, speed, range, steadiness, tone, and accuracy required to control?

-respiratory
-phonatory
-resonatory
-articulatory
-prosodic
aspects of speech

Is dysarthria difficulty with speech, language, or cognition?

speech

With dysarthria where do errors occur?

on short, simple words and long, complex words

With apraxia where do errors occur?

on longer and more phonetically complex words

How are automatic and volitional speech tasks with dysarthria?

they present with similar errors

How are automatic and volitional speech tasks with apraxia?

Automatic speech tasks easier than volitional speech tasks

How is velopharyngeal strength with dysarthria?

Impaired Velopharyngeal (VP) strength

How is muscle tone with dysarthria?

abnormal muscle tone

How is range of motion with dysarthria?

limited range or motion

How is muscle strength with apraxia?

normal

How is muscle tone with apraxia?

normal

How is range of motion with apraxia?

normal

If someone has apraxia, where is the lesion?

the base of the motor strip

What is hyperreflexia?

exaggerated reflexes

What is hyporeflexia?

-diminished reflex response
-low tone

What is hyperkinetic?

excessive movement

What is hypokinetic?

-decreased movement
-decreased control

What is hypertonia?

increased muscle tone

What is hypotonia?

decreased muscle tone

What is paralysis?

no movement

What is paresis?

weakness

What does the central nervous system consist of?

brain and spinal cord

What does the peripheral nervous system consist of?

carinal nerves and spinal nerves

What are the types of dysarthria?

-spastic
-flaccid
-ataxia
-Unilateral upper motor neuron
-hypokinetic
-hyperkinetic

Where is the lesion for spastic dysarthria?

Damage to bilateral upper motor neurons

Where is the lesion for unilateral upper motor neuron dysarthria?

Damage to unilateral upper motor neuron

Where is the lesion for flaccid dysarthria?

Damage to lower motor neuron

Where is the lesion for ataxia dysarthria?

Damage to the cerebellum

Where is the lesion for hypokinetic dysarthria?

damage to the basal ganglia

Where is the lesion for hyperkinetic dysarthria?

damage to the basal ganglia

Are real cases of dysarthria always just one type?

no usually mixed

How does the LMN work?

plugs into UMN to tell the body what to do

What are some etiologies of dysarthria?

●CVA
●TBI
●Infection
●Degenerative diseases
●Surgical trauma
●Tumors
●Toxins
●Mass effect
●Down's Syndrome
●Cerebral Palsy

What do many diseases first present themselves as?

dysarthria

What do you have to be aware of with dysarthria?

-be aware of the signs and symptoms
-differential dx

Where is the UMN?

"Lives" in the CNS

What is an UMN?

Efferent (motor) pathways running within CNS

What will a lesion in the UMN affect?

ALL structures innervated below the structure

Where do most UMN pathways decussate?

level of the medulla

If the UMN lesion is above decussation or medulla, where will the damage be?

contralateral spastic damage

If the UMN lesion is below decussation or medulla, where will the damage be?

ipsilateral spastic damage

If there is a lesion in the UMN is there still a connection?

yes

Lesion in UMN means \________ and \_________ \________ are still connected to the CNS

cranial and spinal nerves

Remaining connection to CNS below the UMN lesion renders what SPASTIC?

innervated muscles and structures

What creates spasticity?

hypertonia + resistance to movement

What do UMNs divide into?

-pyramidal system
-extrapyramidal system

Where does the pyramidal system course?

courses directly to LMN

What is the pyramidal system also called?

direct activation pathway

What does the pyramidal system/ direct activation pathway do?

Transmits impulses of fine motor and volitional motor movement

How does the extrapyramidal system course?

courses to subcortical structures before LMN

What is the extrapyramidal system also called?

indirect activation pathway

What does the extrapyramidal system/ direct activation pathway do?

Transmits impulses associated with automatic functions below the level of awareness

Unilateral upper motor neuron
If there is damage to the UMN, what is affected?

both direct activation pathway and indirect activation pathways

Unilateral upper motor neuron
What does damage to the direct activation pathway result in?

decreased ability to create volitional fine motor plans (speech)

Unilateral upper motor neuron
What does damage to the indirect activation pathway results in?

-decreased muscle tone
-posture
-reflex inhibition (hypertonia/hyperreflexia)

What does unilateral upper motor neuron dysarthria result in?

-mild speech system deficits affecting articulation
-nasality
-prosody
-loudness
-pitch

What are the hallmark characteristics of spastic dysarthria?

○Imprecise articulation
○strained/strangled vocal quality
○Excess and equal stress
○Monopitch/monoloud
○Hypernasality
○Short phrases (because of the tightness)
○Distorted vowels

What might happen with spastic dysarthria? give example

-primitive reflexes re-emerge
-oral reflexes or babinski

How are spastic dysarthria and UUMN dysarthria similar?

-Can manifest in all speech systems
-characterized by weakness and spasticity
-slow movements
-Movement reduced in ROM and force

How is spastic dysarthria different from UUMN dysarthria?

-bilateral damage
-increased negative impact on speech

How is UUMN dysarthria different from spastic dysarthria?

-unilateral damage
-less negative impact on speech than spastic dysarthria

Where are LMNs?

"live" in peripheral nervous system

What are LMNs?

Efferent (motor) section of cranial nerves and spinal nerves

What does LMN do?

takes message and tells the muscle what to do

What do lesions at the LMN do?

cut off efferent signal completely

LMN lesion
Can motor commands be sent from the brain to the muscles?

NO

What does damage in the LMN result in?

-flaccidity
-hypotonia

LMN lesions
If the lesion is before decussation what type of damage is there?

contralateral

LMN lesions
If the lesion is after decussation what type of damage is there?

ipsilateral

How does the damage for UMN lesions differ from LMN lesions?

UMN:
-increased muscle tone
-hyperreflexia
-spasticity
LMN:
-decreased muscle tone
-Hyporeflexia
-flaccidity

When does flaccid dysarthria occur?

when motor cranial nerve important for speech is damaged

What does flaccid dysarthria result in?

Efferent info to muscles is removed/decreased/disordered changing muscle tone and decreasing strength of movement

With flaccid dysarthria what does a lack of efferent signals cause?

-ipsilateral flaccidity (after decussation)
-hypotonia and weakness

Flaccid dysarthria
single cranial nerves can be damaged \__________ or \_________

unilaterally or bilaterally

What are cranial nerves?

I. Olfactory
II. Optic
III. Oculomotor
IV. Trochlear
V. Trigeminal
VI. Abducens
VII. Facial
VIII. Vestibulocochlear (auditory)
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal

cranial nerves are \________

bilateral

What does CN I or Olfactory do?

smell

What does CN II or optic do?

vision

What does CN III or oculomotor do?

-eye movement
-eyelid opening

What does CN IV or trochlear do?

eye movement

What does CN V or trigeminal do?

-facial sensation
-mastication

What does CN VI or abducens do?

eye movement

What does CN VII or facial do?

-motor to face
-anterior ⅔ tongue taste
-eyelid closing

What does CN VIII or vestibular do?

-hearing
-balance

What does CN IX or glossopharyngeal do?

-posterior ⅓ tongue taste
-swallowing

What does CN X or vagus do?

-swallowing
-taste
-pharyngeal/laryngeal muscles

What does CN XI or accessory do?

neck/ shoulders muscles

What does CN XII or hypoglossal do?

motor to tongue

Sensory or motor?
olfactory or CN I

sensory

Sensory or motor?
optic or CN II

sensory

Sensory or motor?
Oculomotor or CN III

motor

Sensory or motor?
Trochlear or CN IV

motor

Sensory or motor?
trigeminal or CN V

both

Sensory or motor?
Abducens or VI

motor

Sensory or motor?
facial or VII

both

Sensory or motor?
vestibular or VIII

sensory

Sensory or motor?
glossopharyngeal or IX

both

Sensory or motor?
vagus or X

both