04
Motor ncleus – pons<br>
05
Intracranial
Intratemporal
Extracranial<br>
06
INTRACRANIAL Intracranial part –From pons to Internal Acostic meatus
15-17 mm<br>
07
Intratemporal Frm IAM to stylomastoid foramen Meatal segment – 8-10 mm ,within IAM
Labyrinthine segment 4 mm – fundus of meatus to geniclate ganglion
shortest segment
Narrowest – 0.61- 0.68 mm
Tympanic segment 11mm –frm GG to just above pyramidal eminence
Mastoid / vertical segment – 13 mm
Frm pyramid to Stylomastoid foramen<br>
08
Extracranial Frm stylomastoid foramen to peripheral branches<br>
09
BRANCHES Greater superficial petrosal nerve –frm GG & carries secretomotor fibres to lacrimal gland & glands of nasal mucosa and palate
Nerve to stapedius – Arises at level of 2nd genu & supplies stapedius muscle
Chorda tympani – middle of vertical segment , passes btw incus & neck of malleus & leaves thru petrotympanic fissure.
it carries secretomotor fibres to submandibular ,sublingual glands ,brings taste from ant 2/3rds of tonge<br>
10
Muscular branches – stylohyoid & post belly of digastric
Peripheral branches
Upper- temperofacial
Lower-cervicofacial
Temporal
Zygomatic
Buccal
Marginal mandiblar
cervical<br>
11
BLOOD SUPPLY Anteroinf cerebellar artery - CP angle
Labyrinthine artery –IAC
Superficial petrosal artery –GG
Stylomastoid artery – mastoid & tympanic segment<br>
12
Cartilaginous pointer – nerve lies 1 cm deep & slightly anterior & inf to pointer.
Tympanomastoid suture – Nerve lies 6-8 mm deep to suture.
Styloid process – nerve crosses lateral to styloid process.
Posterior belly of digastric – nerve lies between it & styloid process.<br>
13
Electrodiagnostic tests Minimal nerve excitabilty tests – diff btw 2 sides exceeds 3.5 amp ,test + for degeneration
48- 72 hr .
Maximal stimulation test – equal , decreased ,absent
Decreased /absent – degeneration
Electroneuronography –degeneration of 90% occuring in 1st 14 days –poorer prognosis
Electromyography –motor activity of facial muscles.
Fibrillation potentials –spont invol action potentials in a denervated muscle.(14-21 after denervation )
Polyphasic reinnervation -6-12 wks prior to clinical evidence<br>
14
Central
brain abscess
pontine gliomas
polio
multiple sclerosis
Intracranial part (CP angle)
Acoustic neuroma
meningioma
cong cholesteastoma
metastatic carcinoma
meningitis<br>
15
Intratemporal part
idiopathic-bells palsy
- melkersson syndrome
Infectious-asom,csom,herpes zoster otics,MOE
Trauma – surgical :mastoidectomy & stapedectomy
Accidental: fractures of temporal bone
Neoplasms- malignancies of ext & middle ear,glomus tmr,facial nerve neuroma,mets to temporal bone<br>
16
Extracranial –malignancy of parotid,surgery of parotid ,accidental injury in parotid,neonatal facial injury (obstetrical forceps )
Systemic diseases –DM , hypothyroidis,uraemia,polyarteritis nodosa,wegeners granulomatosis ,sarcoidosis,leprosy,lekemia,demyelinating disease<br>
17
BELLS PALSY 60-75% of facial paralysis
Idiopathic , peripheral facial paralysis or paresis of acute onset.
Equal sexes affected
Any age grp maybe affected
Postive family history -6-8 %
Risk is more in DM ,pregnant women<br>
18
AETIOLOGY Viral infections – HSV ,HZ,EBV
Vascular ischemia –pri –cold,emotional stress
sec – result of pri ischaemia
Hereditary
Autoimmune disorder<br>
19
Diagnosis By exclusion
History
Ent examination
X ray studies
Blood sugar
Serology
Nerve excitabilty tests
Topodiagnostic tests<br>
20
general Reassurance
Analgesics
Eye care
physiotherapy<br>
21
medical Steroids – prednisolone 1mg/kg
Surgical - nerve decompression – vertical & tympanic segmnent
Prognosis – 85-90% recover fully<br>
22
Melkersson syndrome Idiopathic
Triad - facial paralysis, lip swelling ,fissured tonge
recurrent<br>
23
Recurrent facial palsy Bilateral facial palsy Bells palsy
Melkersson syndrome
Diabetes
Sarcoidosis
Tumours
Recurrent palsy on same side – tmrs in 30 % Gillain barre syndrome
Sarcoidosis
Sickle cell disease
Acute leukemia
Bulbar palsy
Leprosy
Systemic diseases<br>
24
Ramsay hunt syndrome/Herpes zoster oticus Facial palsy
Vesicular rash eac & pinna
Anaesthesia of face , giddiness<br>
25
Temporal lobe fractures<br>
26
UMN- opp side lower half,wrinkling +,invol emotional movements,tone of facial muscles +
Nucleus – 6th cn palsy
CP angle –vestibular+ auditory defects,V,IX,X,XI CN
Bony canal – frm IAM to SMF –topodiagnostic tests<br>
27
SCHIRMER TEST Lesion – proximal to GG - secretomotor fibres to lacrimal gland at the GG via GSPN
Filter paper – no.41 whatman – 5mm wide 35 mm length
< 10 mm after 5 mins - abnl<br>
28
Stapedial reflex Lost in lesions above n. to stapedius<br>
29
Taste test Lesion above chorda tympani<br>
30
Submandibular salivary flow test decreased saivation – Lesion above chorda tymapani<br>
31
complications Incomplete recovery
Exposure keratitis
Synkinesis ( mass movements ) –cross innervation
Contractures
Psychological & social problems<br>
32
Freys syndrome /gustatory sweating Sweating & flushing of skin over parotid area during mastication
Parotid surgery<br>
33
Facial nerve surgery Decompression
End to end anastomosis
Nerve /graft cable- greater auricular ,sural nerve,lateral cutaneous nerve of thigh
Hypoglossal –facial anastomsis
Plastic procedures – facial slings , face lift operation,slings of masseter & temporalis muscle<br>