CHAPTER 06: FACIAL PALSY, SCALP RECON & VASCULAR ANOMALIES Flashcards
What is the anatomy of the facial nerve?
brainstem, temporal bone, internal auditory meatus, facial canal, parotid gland
Within facial canal, it gives off
- Greater petrosal nerve → secretomotor → lacrimal gland and palatal glands
- Tympanic nerve → sensory
- Nerve to stapedius
- Chorda tympani → taste to the ant 2/3 of the tongue, travels with the lingual nerve.
It then emerges from the stylomastoid foramen:
- Posterior auricular nerve → occipital muscles and sensation to post earlobe.
- Nerve to posterior belly of digastric and stylohyoid
What happens to the facial nerve as it emerges from the stylomastoid foramen?
Temporozygomatic branch & lower cervicofacial branch
- Temporal (frontal) branch - runs along Pitanguy’s line, at temple it lies just deep to sup temporal fascia. Supplies frontalis
- Zygomatic branch - orbicularis oculi
- Buccal branch - buccinator, upper lip muscles
- Marginal mandibular - just below mandible, deep to platysma, superficial to facial vein
supplies lower lip muscles, depressors - Cervical - platysma
What are the congenital causes of facial nerve palsy?
Obstetric - forceps
Möbius syndrome
Goldenhar’s syndrome
What is Möbius syndrome?
Defect in development of facial nerve VI & VII nuclei Bilateral facial paralysis May also involve III, V, IX, XII CLUFT abnormalities C ranial nerves L ower limb U pper limb F acial T horacic (15%)
Rx - LD direct coaptation to CN IX, V, XI
What is Moebius syndrome?
1888 Moebius
‘Congenital facial diplegia and bilateral abducens nerve palsies’
Incidence - 1: 50,000 live births
Aetiology - multifactorial
- 2% genetic
- hypoxic / ischaemic injury (basilar / subclavian artery)
- intrauterine toxin exposure - ergotamine, misoprostol, cocaine
Pathogenesis
underlying problem is an inherited congenital hypoplasia or agenesis of the CN nuclei
facial nerves (CN VII) 100% abducens nerves (CN VI) 75% hypoglossal nerves (CN XII) (CN VI - XII can be affected, with VIII spared)
What is noted in history and examination of Moebius syndrome?
HISTORY inability to suck drooling incomplete eye & mouth closure lack of eye mvmt lack of facial expression speech problems normal intelligence usually (autism 30-40%)
EXAMINATION
- Bilateral incomplete facial nerve palsy (VII) → mask-like facies
- External ocular palsies (VI) → internal strabismus
- Dysphagia (IX & X)
- Inability to protrude tongue (XII)
Upper limb abnormalities
- radial club hand
- syndactyly, brachydactyly
- Poland’s
- Arthrogryposis
Lower limb
- club foot (Talipes equinovarus)
Who is involved in the MDT?
Pediatricians Plastic surgeons Hand surgeons General surgeons Pediatric dentists Orthopedic surgeons Ophthalmologists Pediatric otolaryngologists Psychologists Occupational and physical therapists Audiologists Speech therapists Dieticians
What are the immediate and early treatments that need to be considered in Moebius syndrome?
Immediate
- eye protection
- NG feeding
- infections (prone to aspiration, otitis media)
Early surgical
- tracheostomy
- PEG
- strabismus correction (can delay, as may improve with time)
- gold weight upper lid insertion
- club foot, radial club hand correction
What procedures may be be considered in reanimating the face in Moebius syndrome?
Ideally before 7yrs
Donor - unaffected accessory nerve or the masseteric branch of CN V
Gracilis muscle transfer with masseteric nerve innervation (or Pec minor, LD)
Nerve grafting, cross-face grafting, and cranial nerve (CN) substitution techniques have had poor success due to lack of functional neuromuscular system
What is Goldenhar’s syndrome?
Oculo-auriculo-vertebral syndrome 1st & 2nd branchial arch abnormality Hemifacial microsomia Epibulbar dermoids \+/- facial nerve abnormality
Clinical 10% bilateral Incomplete development of ear, nose, soft palate, lip, mandible (deafness, blindness) hypoplasia of heart, kidney, lungs scoliosis
What are the acquired causes of facial palsy?
SYSTEMIC
hypo/hyperthyroid, DM, lead, tetanus, diphtheria COHb
CENTRAL
Intracranial
CNS tumours, acoustic neuroma, MS, Polio, Mobius
Intratemporal Bell's palsy trauma (incl iatrogenic) otitis media infection (HZV - Ramsay Hunt Syndrome) cholesteatoma middle ear tumours
Extratemporal
trauma, tumours, parotid tumours (esp acinic cell - perineural invasion), iatrogenic
What is Bell’s palsy?
described by Charles Bell 1811
idiopathic facial palsy
e.g. viral infection, swelling of nerve within tight intratemporal course
1/60 lifetime risk, 20/100,000
90% recover fully, good sign = incomplete paralysis, recovery 4wks
How is facial palsy assessed?
House and Brackman
Grade 1 → some mimetic (spontaneous) movement
Grade 2 → no mimetic
Grade 3 → only mass action of facial muscles
Grade 4 → unable to completely close eyelids
Grade 5 → symmetry despite complete paralysis
Grade 6 → an asymmetrical face with no movement
Others
Nottingham score
MRC grade
Facial grading scale (Ross)
Clinical evaluation of facial palsy
History - insidious vs rapid
Trauma - blunt / sharp
Total / partial, uni / bilat symmetry - rest & dynamic
Synkinesis? Over innervation?
Forehead - wrinkles
Brow - lift
Eyes - ptosis, ectropion, snap test, Bell’s phenomenon
Nose - nasal tilt, nasal valving
NL fold, malar prominence
Mouth - position, occulsive cant (tongue dep)
clench teeth - test temporalis
Investigations for facial nerve palsy
Electroneuronography
Schirmer’s test 1 (2 = with LA)
Stapedius reflex test
Taste and 2/3 of tongue - chorda tympani
What are the principles of VII palsy treatment?
No op vs op
Static vs dynamic
Functional vs free muscle
Goals of treatment
- rest symmetry
- facial function
- voluntary function
- spontaneous mvmt
- absence of synkinesis
What conservative treatment is there for facial palsy?
Protect eyes - drops, taping at night
Botox normal side to improve symmetry
Bells palsy - high dose steroids, antivirals
What static procedures are there for facial nerve palsy?
Tarsorrhaphy - perm/temp, lateral / Frost
Kuhnt-Symanowski procedure - over orbic
Gold weight / springs
Brow lifts / suspensions - endo / open
Forehead skin excision - melon slice
Unilateral facelift type procedures
Fascial slings - fascia lata - corner of mouth, nose to temporalis
What dynamic procedures are there for facial nerve palsy
- Nerve repair / graft
- Cross-facial nerve graft
- Nerve transfers / substitution
- glossopharyngeal, hypoglossal, accessory, phrenic: coarse mvmts, donor defect - Muscle shortening / local muscle flaps
- masseter (3 slips above, on below commissure)
- temporalis - Cross face nerve grafting & free muscle transfer
- 1 stage - donor muscle with long nerve pedicle - but long denervation time
- 2 stage - reversed sural nerve graft, wait for Tinels sign, then harvest free muscle and insert onto zygomatic arch to mimic zygomaticus major (gracilis, LD, pec minor)
What procedures are you familiar with for dynamic correction of facial nerve palsy?
Royal Free - Pec minor to upper, lower lip & alar base. 2 stage
EG - Nduka - Labbe temporalis lengthening myoplasty & lip reanimation
Chester - temporalis turndown?