Flaccid Dysarthria Flashcards
A Lesion in ______ can cause flaccid dysarthria
LMN system
UMN involves all of pathway above or below the level of the synapse?
above
LMN involves the pathway above or below the synapse to the muscle fiber?
below
In the UMN system, do fibers leave the brain stem?
No, fibers never leave the brain stem
*except for the cortico-spinal tract
T or F
Deficits are the similar when they occur in the LMN or UMN systems
False.
Deficits are very different if they occur in the LMN or UMN system
What results in because it all comes together in the LMN system.severe damage in the UMN system?
need 2 lesions that take out both bilateral tracts to have severe damage
Is there severe damage if there is 1 lesion in the UMN system?
No.
If just one lesion, something can get through to the LMN system
With the LMN system, it takes ____ lesion(s) to wipe out the function?
1
* because it all comes together in the LMN system
Where do lesions that result in flaccidity occur?
Anywhere along the motor unit
Do symptoms vary according to where the lesion/damage is?
Yes.
Symptoms vary according to where damage occurs
Primary unique deficit in flaccidity is..
Weakness to muscles.
Can happen to any muscle.
Weakness refers to…
…reduced strength/force of muscle contraction
Most things can be explained on basis of weakness
If the palate too weak to close, the patient will have…
hypernasality
UMN system damage results in what kind of dysarthria?
Spastic dysarthria.
Primary unique deficit is spasticity.
Can also have some weakness but weakness is not defining character.
What is the primary unique deficit of spastic dysarthria?
Spasticity
What is the only dysarthria with PNS involvement?
Flaccid dysarthria
2 other names for PNS
LMN and FCP – refer to same as PNS
When motor units are damaged…
…muscle looses its ability to contract
If all of the LMN input (nerve impulse) is lost to a muscle what occurs?
paralysis
It there is only partial loss of LMN input what occurs?
paresis
What is paresis?
There’s still some input to muscle, but contraction is weakened, therefore weaker muscle movement
Other defining characteristics of Flaccid Dysarthria (4):
- Hypotonia & weak reflexes
- Atrophy
- Fasiculations & fibrillations. Fasiculations don’t occur immediately after insult – takes a while to see them (1-3 weeks after nerve supply is gone). They’re quick, jerky movements in resting muscles. Difference between fasiculations & fibrillations - fasiculations are visible, fibrillations aren’t.
- Progressive muscle weakness – in all flaccid dyarthria fatigue is a factor. But in some disorders, there is a quick weakening with use. The muscle fatigues quickly when used. This occurs in neuromuscular junction dz, such as Myasthenia Gravis.
Where the damage occurs on the motor unit determines…
the type of characteristics
ATROPY & FASICULATIONS ARE ONLY SEEN IN LMN or UMN INVOLVEMENT?
LMN INVOLVEMENT