Bifacial weakness

           What he is doing now? smilling, thinking? Can we guest what he is doing? One day u may encounter with people who experess less facial expression. Even, u make a joke, their face just show bored or (ur joke not funny enough). Alrite, now let think of y? Either they hinding their emotion or they are showing their emotion or is there any illness ? poor this guy...can express his facial expression...

approach to bifacial weakness:

a) what nerve innervate facial experession? (origin, distributiona and muscle innervated)

• origin : pons  (near 6th cranial nerve) * if 6th cranial nerve palsy without 7th cranial nerve palsy so not likely due to the lesion at nucleus. - ( coz -tumour, stroke demylination)
  
• distribution: Cerebellopontine angle - 5th, 6th, 7th and 8th  CN palsy -(coz-  acautic neuroma, meningioma)
• patrous part of temporal bone ( geniculate ganglion) - greater petrosal nerve - parasympathetic Inn to lacrimal gland - ( can be fracture to petrous bone, otitis media, Ramsay-hunt syndrome) *check any vesicles.
• parotid - divide into 5 branches: (temporal, zygomatic, buccal, mandibular and cervical ) (coz- parotid tumour, trauma) check: http://emedicine.medscape.com/article/835286-overview

b) uni or bifacial involvement?

Bifical : (pls check eye contact and any tremor)

1. extrapyramidal (eg: parkinsonism)  - tremor, good eye contact
2. pyschogenic disorder (eg: depression ) - no tremor, poor eye contact
3. pyrimidal disorder ( bifacial weakness) - no tremor, good eye contact.

- usually common case  in 3:  Guillain-barre syndome, myasthenia gravis, dystrophia myotonica. 

(pls study the def, aetiology, clinical, ix,treatment)
 

c) UMN or LMN ?

clue:  UMN - lower half  LMN - whole (LL)

UMN (bi or unilateral ) - most common ( stroke)

LMN - 

 unilateral (remember anatomy)

• parotid tumour/trauma (check swelling, scar)
• ramsay hunt syndrome
• Cerebellopantine tumour (check 5,6, 8 th CN and cerebella synd)
• tumour/ms/stoke (6th CN involvemnet)
• bell's palsy ( ??) isolated 7th nerve palsy

bifacial weakness

• myasthenia gravis ( ptosis, fatiguability, squit, reduce eyemovement)
• dystrophia myotonica ( frontal balding, temporalis wasting, myotonia)
• guillain Barre syndrome ( weakness of lims , areflexia)
• facio-scapula-humeral dystrophy ( shoulder , arm weakness)

d) other cranial nerver involvement?

check especially 5, 6, 7, 8 CN involvement

e) other neurological deficit?

contralateral hemiparesis - stroke

cerebellar syndrome 

check taste of ant 2/3 of tongue and hyperacusis.