Spastic Dysarthria Flashcards
Spastic dysarthria is caused by:
Damage to the direct and indirect activation pathways of the CNS
Rarely is there only direct activation or indirect activation pathway damage because these tracts intermingle.
T or F
Typically, if the DAP is damaged, the IAP is also damaged
T
Spastic dysarthria involves the UMN or LMN?
UMN lesions are involved
We do not see as much CP anymore because?
Better pre and perinatal care
We no longer use forceps during birth
Is spasticity common with CP?
Yes
Why does spasticity cause weakness?
Because it is hard to move muscles that have so much tension and spasticity.
Spasticity is reflected in weakness and muscles that are hard to move – flaccid muscles are not hard to move.
Does unilateral damage to UMN usually cause severe symptoms?
No.
Unilateral lesions don’t have as severe affect because something is getting through on the side not affected – (there is usually bilateral innervation).
Does bilateral damage to UMN usually cause severe symptoms?
Yes.
Bilateral lesions are usually required to have significant dysarthria.
Reduced ROM results in:
imprecise consonants, inability to move tongue to articulators
Spastic dysarthria may also be referred to as:
pseudobulbar palsy
Which subsystems does spastic dysarthria effect?
All subsystems:
- repiratory
- phonatory
- resonatory
- articulatory
Damage to DAP results in:
reduction of skilled movement
Effects of Spasticity:
- Muscle weakness
- Slows movement and decreases ROM and force
- Too much muscle tone meaning contracted muscles
- Spasticity itself is a result of the hyperactivity of the stretch reflex
Primary Characteristic of Spastic Dysarthria:
Spasticity
All defining characteristics of Spastic Dysarthria (4):
- Spasticity
- Weakness
- Slow movements
- Reduced ROM
*There is slow movement because of the increased resistance to movement
Lesions of UMN system cause (6):
- Weakness
- Loss of skilled movements - With damage to the direct pathway you find the ability to produce fine, skilled movements, like those in speech, is affected or completely lost.
- Decreased tone - at first, the signs are of reduced muscle tone and weakness but as it progresses the signs change to increased muscle tone and spasticity.
- Hypertonia – see above
- Babinksi reflex - A positive Babinski reflex is a sign of UMN/direct pathway damage. To elicit this you stroke the bottom of the foot and the toes fan out with the large toe extending. This is an abnormal response in adults, but is normal in babies.
- Reflexes at first may be reduced but then become hyper.
Other abnormal reflexes seen with UMN damage are (3):
- Sucking
- Snout
- Jaw jerk reflex
What is the sucking reflex?
*An abnormal reflex seen with UMN damage
- Stroke the tongue blade across the upper lip starting at the side and move to the middle – do on both sides.
- Abnormal reflex is when there is pursing of lips. Normally nothing happens. In very exaggerated reflexes, the mouth may turn toward the tongue blade to result in a rooting reflex
What is the snout reflex?
*An abnormal reflex seen with UMN damage
– if you use tongue blade or finger to tap or push backward on tip of nose or philtrum (part between nose and upper lip) you see the bottom lip pull up
What is the jaw jerk reflex?
*An abnormal reflex seen with UMN damage
– have lips open and parted. Place a tongue blade or finger on the chin and tap with the other finger. Abnormal response is quick closing of the jaw
DAP damage (4):
Loss of fine, skilled movement
Hypotonia
Weakness (distal> proximal)
Absent adbominal reflexes
Direct pathway:
- Is also known as the pyramidal system because it passed through the pyramidal structures
- Part of the UMN system
- It sends messages to the LMN or FCP to tell them what to do.
2 Parts of the DAP:
Corticobulbar and corticospinal tracts
- Corticobulbar goes to the cranial
- Corticospinal goes to spinal nerves.
What would you commonly see with a brain-stem stroke? (2)
Problems with respiration
Problems with speech (flaccid dysarthria more likely, but can get spastic dysarthria)
The DAP is unilateral or bilateral?
Bilateral.
It has one nerve originating in each cerebral hemisphere, left and right
Why is the DAP called ‘direct’?
Because it leads directly to the cranial nerve nuclei in the brainstem and spinal nerve nuclei in the spinal cord
Why do most CNs have bilateral innervation?
Cranial nerves innervating speech muscles have bilateral input meaning that innervation comes from both sides.
This helps to protect the function of those muscles so that even if there is damage in one side you have bilateral innervation which reduces the impact of damage
If you have only unilateral/contralateral innervation and there is damage to the left side…
…the right side would show strong affect
If you have innervation from both hemispheres, if left side is damaged…
…the right side can still send innervation
*The direct pathway mainly arises (60%) in motor cortex.
Why is the direct pathway is called facilitory?
Because it leads to movement
It is responsible for skilled, discrete, quick movements
The indirect pathway is also called:
Extrapyramidal
Why is the IAP called ‘indirect’?
Because it has many synapses along its path from the cerebrum to the brain stem and spinal cord
It also originates in the cortex of each cerebral hemisphere (like the DAP)
Where does the IAP make connections? (5)
In the basal ganglia cerebellum reticular formation vestibular nuclei and red nucleus
IAP is essential for:
regulating skilled movements
IAP helps maintain:
tone – which is important for sustained postures required to support movements of direct activation system
Damage to the indirect pathway primarily affects:
The inhibitory role of motor control
- So there is increased muscle tone and hyperactive reflexes
- It is demonstrated by a spasticity that causes the legs to resist bending and the arms to resist straightening
Do we understand spastic dysarthria as much as flaccid dysarthria?
No.
We don’t understand spastic dysarthria as well as flaccid due to the complexity of the CNS
Etiology of Spastic Dysarthria (6):
Anything that affects the direct or indirect pathway
Can include:
- degenerative
- inflammatory
- toxic
- metabolic
- traumatic
- and vascular diseases
Typically vascular diseases have more _____ dysarthrias than other kind of dysarthrias.
Spastic
Specific disorders that cause Spastic Dysarthria (6):
- Vascular disorders
- Lacunar Infarcts
- Lacunar State
- Binswanger’s Subcortical Encephalopathy
- Inflammatory Disease (e.g. Leukoencephalitis)
- Degenerative Disease (e.g. PLS and ALS)
Vascular disorders and Spastic Dysarthria:
Infarcts of interior carotid artery and middle and posterior cerebral arteries can cause spastic dysarthria – but usually you must have bilateral lesions – one in each hemisphere- to get spastic dysarthria.
However in the brain stem where the left and right pathways are closer together, you may get damage to both pathways by a single lesion or single brainstem stroke.
To be clearer – a single brainstem stroke can cause spastic dysarthria, but a single cerebral hemisphere stroke usually cannot
Lacunar infarcts and Spastic Dysarthria:
Caused by very tiny holes in the cortex from strokes
Can lead to dementia or damage to brain
The patient may not even know they are having a stroke – they are mini strokes
Lacunar state and Spastic Dysarthria:
Term for pts with many lacunar infarcts who have dementia, usually spastic dysarthria, dysphagia, & incontinence
Slow and regular AMRs occur with:
Spastic Dysarthria
Slow and irregular AMSs occur with:
Ataxic Dysarthria
Binswanger’s subcortical encephalopathy and Spastic Dysarthria:
Term given to patients with multiple infarct dementia occurring over years and months
They may have spastic dysarthria
Dysarthria is a differentiating characteristic and can help differentiate this dz from other dementias that don’t have dysarthria
Inflammatory disease and Spastic Dysarthai:
Leukoencephalitis – inflammation of white matter of brain
Can cause spastic dysarthria
Degenerative disease and Spastic Dysarthria:
Primary lateral sclerosis (PLS) – a type of motor neuron disease
ALS is a subcategory of PLS
But in PLS there are only signs of UMN damage, not LMN.
PLS has _____ dysarthria
spastic
ALS has ______ dysarthria
mixed flaccid-spastic
Patient Complaints with Spastic Dysarthria:
- Slow or effortful speech – they feel as if there some physical resistance to their speaking. In other dysarthrias, you don’t hear this complaint, except in some hyperkinetic dysarthrias.
- Fatigue – with accompanying speech deterioration. In flaccid dysarthria you don’t hear this except with myasthenia gravis and in MG the deterioration is more rapid.
- Patient feels their speech is nasal – this is more common in spastic than flaccid.
- Difficulty swallowing – you hear this more in spastic than in other dysarthrias.
- Drooling – you hear this more in spastic than in others.
- Difficulty controlling their emotions, especially laughing and crying. This is called a “pseudobulbar affect” and usually not seen in other dysarthrias, except spastic mixed. This is also referred to as emotional lability or pathological laughing and crying. It is due to decreased inhibition
If a patient complains of difficulty swallowing is it most likely _____ dysarthria
spastic
What is the “pseudobulbar affect”?
Difficulty controlling their emotions, especially laughing and crying.
Occurs with spastic dysarthria and spastic mixed (not common in other dysarthrias)
This is also referred to as emotional lability or pathological laughing and crying
It is due to decreased inhibition
Nonspeech Clinical Findings with Spastic Dysarthria (7):
- Dysphagia often seen along with nasal regurgitation.
- Drooling is seen due to poor control of secretions.
- Face may be held in a fixed posture, either smiling or pouting. May be excessive facial emotional expressions.
- Emotional lability seen – cry or laugh inappropriately or for no reason. May not be able to control it once started. May switch from laughing to crying. This may not match their inner emotional state.
- Jaw strength may be normal, face may be weak bilaterally, tongue may have reduced ROM and show weakness when doing strength testing. Palate is symmetric but slow to move.
- Gag reflex may be hyperactive. Cough may be weak.
- Pathological oral reflexes.
Speech findings & assessment with Spastic Dysarthria:
• All of speech movements are generally affected
- jaw movement
- tongue movement
- soft palate movement, etc
* Therefore spastic dysarthria has severe affect on intelligibility.
- Look for patterns of symptoms, not just one symptom.
How do you assess speech for spastic dysarthria:
- Assess with conversational speech, reading and AMRs and vowel prolongation.
- It doesn’t help here to assess individual cranial nerve effects because it is CNS damage and results in impaired movement patterns.
Prominent speech characteristics of spastic dysarthria (4):
Can all be traced to spasticity, slowness of movement, reduced ROM and to lesser degree, weakness):
1 strained-strangled voice quality, harshness, low pitch, reduced pitch and loudness variability
2 hypernasality – due to slowness of palate
3 imprecise articulation – movements are restricted
4 slow rate – slow but regular AMRs
What do we hear in voice samples of spastic dysarthria:
- strained voice
- (some breathiness, but not so much)
- hypernasality
- slow speech rate
- effortful speech
Strange reflexes are associated with ___ dysarthria
spastic
Drooling is associated with ____ dysarthria
spastic
