1 Chapter 24: Disorders of the facial nerve Mark May - Famona Site
Disorders of facial nerve
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Transcript of Disorders of facial nerve
Facial nerve
DISORDERS OF FACIAL NERVE
Facial nerve
Nerve of second branchial arch
Mixed nerve- Both sensory and motor
Motor- muscles of facial expression* -muscles of 2nd pharyngeal arch
Sensory- Taste from anterior 2/3 of tongue & palate -general somatic sensations - secretomotor fibres
Facial nerve-components
Special visceral efferent
General visceral efferent
Special visceral afferent
General somatic afferent
SVE
GVE
SVA
GSA
Facial nerve-NucleiMotor nucleus
Superior salivatory nucleus
Lacrimatory nucleus
Nucleus tractus solitarius
Facial nerve -course
Facial nerve-Course
Intracranial part
Intratemporal part
Extracranial part
Intratemporal part
Meatal segement
Labrynthine segment
Tympanic segment
Mastoid segment
Labrynthine segment
Shortest segmnet of nerve
Narrowest diameter
Bony canal in this segment – narrowest
Odema or inflammation
BRANCHES
Surgical landmarks
Processus cochleariformisOval window and horizontal canalShort process of incusPyramidTympanomastoid sutureDigastric ridge
Surgical landmarks
Cartilagenous pointer
Tympanomastoid suture
Styloid process
Posterior belly of digastric
Variation and anomalies
Bony dehiscenceProlapse of nerveHump Bifurcation and trifurcation Bifurcation enclosing stapesBetween oval and round window
Structure of nerve
Sunderland classification-nerve injuries
1°-Neurapraxia2°-Axonotmesis3°-Neurotmesis4°-partial transection5°-complete transection
Electrodiagnostic tests
Minimal nerve exitability test
Maximal stimulation test
Electroneuronography
Electromyography
Facial paralysis-causes
CentralIntracranial part(cerebellopontine angle)Intratemporal partExtracranial partSystemic diseases
Intratemporal part
Idiopathic
Infections
Trauma
Neoplasm
IIT-N
Bell’s palsy60-70% of facial paralysis
Both sexes-equal frequency
Any age group- incidence increase with age
Family history-6-8%
Angiopathy and fluid retention
Bell’s palsy- Aetiology
Viral infection
Vascular ischemia
Hereditary
Autoimmune disorder
Bells’s palsy-clinical features
• Onset-sudden
• ‘Bell phenomenon’-attempt to close eye, eyeball turn up & out
• Asymmetry of face,Dribbling of saliva,epiphoria,noise intolerance,
Loss of taste
• Recurrent-3-10%
Bell’s palsy-Diagnosis
Diagnosis by exclusion
History ,complete otological , head & neck examination
Imaging studies,blood test –cbc, ps,ESR,Blood sugar,serology
Bell’s palsy-Diagnosis
• Nerve excitability test
• Topodiagnosis
Bell’s palsy-treatment
general
surgicalmedical
• General-reassure analgesics, care of eye, physiotherapy• Medical-steroids
PREDNISOLONE 1mg/kg/day x 5 days review after 5 days
• If Recovering – taper dose during next 5 days
• If Complete paralysis – continue 10 days thereafter taper the dose
Combined with acyclovir
Other drugs- vitamins , vasodilators, antihistamines, mast cell inhibitors
• Surgical- Nerve decompressionPROGNOSIS85-90% -Recover fully
10-15%- incomplete
Good prognosis- incomplete & recovery within 3 weeks
Melkersson syndrome
Fissured tongue
Swelling lips
Facial paralysis
Infections- Ramsay-Hunt syndrome
Herpis zoster oticus
Facial paralysis along with vescicular rash
Anasthesia of face,giddiness,hearing impairment
Middle ear infections, maligant otitis externa
Trauma
Fractures of temporal bone***
Ear or mastoid surgery
Parotid surgery or trauma to face
Neoplasm
• Intratemporal
• Tumours of parotid
Localisation of facial lesion
• Central facial paralysis CVA, tumor, abcess
-paralysis only lower half of face on c/l side
-involuntary movements and muscle tone retained
• Peripheral facial paralysisLevel of nucleus-6th nerve involement
Cerebellopontine angle- other cranial nerve
Bony canal???
Lesion outside temporal bone- only motor functions affected
Topodiagnostic test- intratemporal part
1.Schirmer test
2.Stapedial reflex
3.Taste test
4.Submandibular salivary flow test
Complications following facial paralysis
Incomplete recovery
Exposure keratitis
Synkinesis
Tics and spasms
Contractures
Crocodile tears
Frey’s syndrome
Psychological & social problems
Hyperkinetic disorders
Hemifacial spasmi)Essentialii)secondary
Blepharospasm
surgery
1.Decompession 2.end-end anastomoses3.Nerve graft4.Hypoglossal facial anstomoses5.Plastic procedures
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