耳鼻咽喉科学英文版课件 facial nerve palsy.ppt

1、Facial Nerve PalsyAnatomy Facial nerve is a mixed nerve, having a motor root and a sensory root Motor root supplies all the mimetic muscles of the face which develop from the 2nd brachial arch Sensory root “nerve of Wrisberg” carries taste fibers from the anterior 2/3 of the tongue and general sensa

2、tion from the concha and retroauricular skin Also it carries secretomotor fibers to the lacrimal, submandibular and sublingual glands as well as those in the nose and palateAnatomyAnatomy: Parts Intracranial part Intratemporal part Extracranial partCourse of the Facial Nerve Intracranial Arises at t

3、he pontomedullary junction and courses with CNVIII to the internal acoustic meatus 12mm Intratemporal Meatal Labyrinthe segment Tympanic segment Mastoid segmentCourse of the Facial Nerve Extracranial From stylomastoid foramen to pesanserinusCourse of the Facial NerveAnatomy: Branches Greater superfi

4、cial petrosal nerve Nerve to stapedius Chorda tympani Comunicating branch Posterior auricular nerve Muscular branches Peripheral branches: “Pes anserinus”Presentation Functional and cosmetic problems Upper lid fails to drop down and close Lower lid loses tone and sags downward May evert leading to e

5、ctropion Produces lagophthalmos and consequent corneal exposure.Presentation Interruption of the tear film Leads to drying of cornea Ocular discomfort Corneal ulcers Infection Perforation Upper motor neurone (UMN) can wrinkle their forehead (unless bilateral lesion) Lower motor neurone (LMN) cant wr

6、inkle their foreheadPresentationHouse-Brackmann Facial NerveGrading Scaleo I. Normalo II. Mild dysfunction (slight weakness noticeable on close inspection)o III. Moderate dysfunction (obvious weakness, but not distinguishing differences between the two sides of the face)o IV. Moderately severe dysfu

7、nction (obvious weakness and disfigurement)o V. Only barely perceptive motor functiono VI. Complete paralysisDiagnosis History Presentation Hearing test Vestibular function MRI / CT Topognostic - Where is the lesion? Qualitative -Degree of the lesion Schirmers tear test Stapedius reflex Taste test S

8、ubmandibular salivary flow testTopodiagnostic DiagnosisTopodiagnostic DiagnosisQualitative Diagnosis Nerve Excitability Test: NET Maximum stimulation Test: MST Electroneurography: ENoG Electromyography: EMGBells Palsy 60-70% cases Pathophysiology Impaired “axoplasmic” flow from edema of facial nerve

9、 within fallopian canal Rapid onset and evolution 90% degeneration on ENOGnPerformed before irreversible injury to the endoneurial tubules occurs (two weeks), will allow for axonal regeneration to occurTreatmentHerpes Zoster Oticus(Ramsay Hunt syndrome)Herpes Zoster Oticus(Ramsay Hunt syndrome) 10-1

10、5% of acute facial palsy cases Lesions may involve the external ear, the skin of EAC or soft palate Associated symptoms hearing loss, dysacusis and vertigo Additional involvement of CN V, IX and X and cervical branches 2, 3 and 4 Pathogenesis Neural injury due to edema at point between the meatal foramen and the geniculate fossa in the labyrinthe segmentThanks！