1. What is spastic dysarthria due to?
Due to bilateral damage of the upper motor neuron tracts of the pyramidal
and extra- pyramidal tracts (has an effect on both sets of lower motor
neurons)
2. Describe the speech and the reason why it sounds that way.
Speech is slow effortful and has a harsh vocal quality
Increased tone, but also has weakness, reduced range of motion and
decreased fine motor control in many of the same muscles.
3. Describe the role of upper motor neurons in spastic dysarthria.
Role of Upper motor neurons in Spastic Dysarthria:
Review of anatomy:
UMN are part of CNS.
They originate in the cortex and brainstem.
UMN are grouped into pyramidal and e-pyramidal tracts.
UMN (pyramidal-direct pathway from cortex and course down to
the LMN)- UMN are divided:
Cortex to cranial nerves (corticobulbar tract)
Cortex to spinal nerves (corticospinal tract)
Pyramidal tract is responsible
for transmitting neural impulses for discrete skilled
movements down to the lower motor neurons, which
sends them to the muscles. Speech is a discrete
skilled mvmt.
Damage to parts of the pyramidal system serving speech will
result in weakness and slowness in the musculature, i.e.,
weak slow movements of the tongue, lips, velum etc.
UMN (extrapramidal-indirect pathway from cortex to LMN)
Originate in the cortex and brainstem with numerous interconnections
including the reticular formation and the red nucleus.
UMN of extrapyramidal system eventually synapse w/ LMN of cranial
and spinal nerves.
Extrapayramidal system is responsible for
Maintaining posture, regulating reflexes and monitoring
muscle tone (done at the same time the pyramidal
is transmitting its neural impulses) Normally,
the pyramidal and e-pyramidal work together resulting
in allowing complex movements effortlessly.
Damaged to Extra and pyramidal systems
Weak and slow muscle mvmt (pyramidal )
Weakness, increased muscle tone (spasticity) and abnormal
reflexes (ex-pyramidal)
4. Describe the effects of the difference between bilateral damage
and unilateral damage to the UMN.
Spastic dysarthria: bilateral damage to both pyramidal and ex-pyramidal
systems that innervate speech. (affects tongue, lips, velum, larynx)
Significance of bilateral damage:
Speech production muscles will be weak, slow,(weak and slow mostly
in the tongue and lips) spastic (most noticeable in laryngeal muscles and
maybe velum – causing incomplete VP closure during the production of non-nasals)
and have abnormal reflexes.
(Unilateral damage causes unilateral upper motor neuron dysarthria. This is not as serious because most of the cranial n. serving speech (except lower face and tongue) receive bilateral innervation from the UMN of pyramidal and exPyramidal system)
5. Describe the different etiologies of spastic dysarthria.
Etiologies of Spastic Dysarthria
Stroke: Most common cause of spastic dysarthria.
Must have either 2 or more strokes (bilateral) in cerebral hemispheres
or one in the brainstem (right and left pyramidal and expyramidal tracts
are very close in the brain stem).
ALS
ALS results in progressive degeneration of LMN and UMN.
Some people begin with involvement in LMN and exhibit flaccid dysarthria
and weakness in the legs and muscle atrophy
Some begin with UMN involvement demonstrate spastic dysarthria, hyperactive
gag and jaw reflexes and swallowing disorders.
Eventually both UMN and LMn are affected and result in mixed dysarthria.
Head Injury:
HI can produce widespread damage (stretched and torn axons, lacerated
brain tissue and blood vessel hemorrhage)
Multiple Sclerosis
MS is a suspected immunological disorder that results in the
inflammation or complete destruction of the myelin sheath covering the
axons. MS can affect myelin anywhere w/in CNS (cerebral hemispheres, cerebellum,
brainstem, and spinal cord) so depending on where the damage is..this will
be the dysarthria exhibited i.e., ataxic dysarthria, mixed dysarthria).
Other:
Brainstem tumor, cerebral anoxia, viral or bacterial infections in
the cerebral tissue
6. Describe the speech characteristics of Spastic D
Speech Characteristics:
I.Articulation:
Imprecise Consonants (not helpful diagnostically—common characteristic
among dysarthrias)
1. Abnormally short voice onset time for voiceless consonants
2. Incomplete articulatory contact
3. incomplete consonants clusters
Vowel distortions
**II Phonation
Harsh vocal quality “friction of air” characteristic
Harshness occurs when air leaks through a partially open glottis.
Perhaps caused by purposeful partial abduction of vf to help prevent spastic
muscle tone in larynx from closing the glottis too tightly during speech.
They let some subglottic air leak through their tense, partly abducted
vf.
Strained-strangled Vocal quality (noticeable characteristic, but not
always present)
Sound created by subglottic air being forced through a narrow,
tightly constricted larynx due to spasticity of vf causing tight hyperadduction
of the vf
III Resonance
Hypernasality caused by spasticity in the velum which slows and reduces
its range of movement (not as severe as that seen in Flaccid d. and does
not include nasal emission as in Flaccid d.)
**IV. Prosody
Monopitch (one of the most obvious characteristics) caused by
overall tenseness of laryngeal muscles resulting in a reduced ability to
contract and relax (contracting and relaxing vf is what helps us vary our
pitch)
Monoloudness caused by overall tenseness in laryngeal muscles
(by increasing and decreasing vf tension, the larynx can precisely regulate
the amount of subglottic air that passes through the glottis.
Short phrases-probably due to speaking through a tight larynx.
The energy required to force air through the tightly adducted vf is great
so they shorten their utterances. Frequent inhalations interrupt the rhythm
of speech
Slow rate of speech caused by reduced speed and range of movement in
articulators. Weakness in articulators may contribute to slower speaking
rate. Slowed rate may be the result of speaking against tight adduction
of the vf
V. Respiration
Not really a problem, but there may be some abnormal respiratory movmts.
Deviant movemtns can cause reduced inhalation and exhalation, uncoordinated
breathing patterns and reduced VC.
7. Of the speech Characteristics what are the most definitive?
Phonation and Prosody are the most definitive in spastic D
8. What are some defining Non-speech characteristics of Spastic Dysarthria and how might they be treated?
Additional Defining NON-speech Characteristics:
1. Emotional liability known as the pseudobulbar effect may be
due to damage to areas that inhibit emotions
Crying is more common than laughing
Embarrassing to person. Distressing to family
Treatment limited. Drugs ineffective. Effect lessens with
recovery
2. Drooling: most prominent in Spastic D. probably due to impaired
oral control of saliva and possibly to swallowing.
Client often reports that the injury resulted in the production
of too much saliva. Embarrassing
Treatments: behavioral –cuing to swallow. Drugs. Surgery
Spastic dysarthia vs Flaccid D.
9. Define bulbar and pseudobulbar palsy
Definitions:
bulbar palsy: atrophy and weakness in muscles innervated through
the medulla. (tongue, velum, larynx and pharynx); a name for flaccid dysarthria
pseudobulbar palsy: (false bulbar palsy) means weakness and slowness
to the same muscles. (tongue, velum, larynx, and pharynx); a name
for spastic dysarthria
10. Describe the difference between Spastic and Flaccid dysarthria.
Difference betw. Spastic and flaccid dysarthria
The distinction between the two is their different etiologies. Bulbar palsy: lower motor neuron; pseudo bulbar palsy: UMN
1. Spastic D Bilateral damage to upper motor neurons of the pyramidal
and extrapyramidal systems.
Flaccid D. damage to lower motor neurons
CHECK MEDICAL REPORTS FOR SITE AND TYPE OF LESION.
2. Hypernasality is more severe in Flaccid D. and has nasal emissions. Hypernasality may appear more intermittent in Spastic D.
3. Spastic D may have a tight, strained strangled voice quality (but not always: it may more frequently have a harsh vocal quality instead)
4. Spastic D. : may have pseudobalbar effect (emotional liability) and drooling.
11. What are the key evaluation tasks and what are you looking
for?
Key evaluation tasks:
1. conversation/reading: hypernasality, imprecise consonants,
monopitch/loudness, reduced stress, short phrases,
2. AMR: slow
3. Vowel prolongation will evoke the phonatory deficits (harsh
voice quality, strained-strangled voice quality, low pitch
12. What are some possible areas of focus for treatment?
TX
Possible areas of focus:
1. decreasing hyperadduction of the vf
2. increasing articulatory precision (artic. Therapy)
3. prosody (more natural intonation
4. hypernasality (lifts etc.)
5. Respiration is usually not affected.
13. What is the treatment for the processes that may be affected
by Spastic D.
Phonation:
1. Hyperadduction: (Duffy says little success in reducing hyperadduction)
Forget any exercise that does not include speech
Easy onset of phonation to make softer glottal closures.
Yawn-sigh: (similar to the above)
Perhaps begin with yawn sigh to initiate easy onset of phonation.
Articulation: (weakness, reduced speed of movement, and reduced range
of movement)
Working on imprecise articulation.
What is the purpose of tongue/lip stretching and strengthening exercises?
To reduce hyper-tonicity and increase speed and ROM; watch out—may
be counterproductive and increase hyper-tonicity.
Increase intelligibility:
1. Client Reads words. Clinician (not looking) tries to
identify words. If unable to understand, tell the client what was
wrong with the production.
**2. Exaggerated consonants: overarticulation
**3. Minimal contrast drills (just like articulation)
Treatment of Prosody
**Contrastive stress drills
**Teaching appropriate phrasing
Pitch range exercise and intonation markings (on read passages) might
work if the client is able to demonstrate ability to reduce tenseness in
vf during conversation enough to make pitch changes.
Treatment of resonance (sluggish velum)
Pharyngeal flap
Gelfoam injections
Palatal lift (hyperactive gag reflex may make this difficult)
Exercises (only after surgical tx when closure can be achieved)
Biofeedback with nasal mirror for nasal emission; use of See Scape
Increased loudness (use visual feedback voice light and VU meter or
a sound level meter)
This may work simply because the person opens their mouth which
will increase intelligibility and encourages overarticulation.