Here's a short overview of Bulbar and Pseudobulbar palsy !
If there is a lesion is at the level of Medulla - affecting the motor neurons : The nuclei of the cranial nerves - you get LMN Palsy features - Flaccid paralysis of 9 10 11 12 Cranial nerves. This is called a 'Bulbar palsy' as the bulb (Medulla) is involved in isolation.
Now , essentially when the fibres supplying the motor neurons of the bulb (your Medulla) are affected themselves - that is any neurons above the nucleus of the nerve - it's a UMN lesion. So you get 9 10 11 12 UMN palsy - Spastic paralysis.
This would be Pseudo-bulbar as same CN involved but lesion is above the Medulla
So Pseudobulbar you'd have a hyper active gag reflex while it'll be absent in Bulbar.(Mediated by 9th cranial nerve).
You'd have a Hot potato like speech in Pseudobulbar as your vocal muscles of larynx and tongue are spastic. - (10th and Cranial 11th. )
While you'd see a nasal twang in Bulbar (also called Donald duck speech)
As your soft palate doesn't abut against the nasal cavity (due to LMN flaccid paralysis). Also causing nasal Regurgitation of food in Bulbar.
So they both essentially present with 9 10 features and some of the 11 12. Hence one is Pseudo and the other is true Bulbar.
Psuedobulbar would also have emotional problems. Called Pseudobulbar affect (as the higher fibres are involved - lesions are generally multiple infarcts in the cortex).
A few important causes :
Psuedobulbar palsy :
- Vascular = B/L Frontal lobe lesion , B/L Pontine stroke , Vascular dementia = Multi infarct dementia.
- Central Pontine Myelinolysis
- Degenerative = Multiple sclerosis , Motor neuron disease
- Cerebral Palsy
_________________________________
Bulbar palsy :
- Guillian Barre Syndrome
- Polio
- Motor neuron Disease
- B/L Medullary infarction
Hoping this helped !
Happy studying guys !
And stay awesome !!
~ A.P.Burkholderia.
How does bilateral medullary stroke cause UMN type and bilateral medullary infarction cause LAMB type?
ReplyDeleteI thought it would be same palsy for both.
Hey thanks for bringing this out! Have corrected it on the blog :) Was a typing error.
DeleteNice post.this was really helpful :)
ReplyDeleteThanks ! Glad you found it helpful :)
Delete