1 / 92

Facial Nerve

Facial Nerve. Dr. Badi ALDOSARI Assistant Professor Facial Plastic Surgery Consultant ENT Consultant King Abdulaziz University Hospital. Facia l Nerve. Embryology Anatomy Physiology Pathology Pathophysiology Evaluation Causes Treatment. Embryology.

leaman
Download Presentation

Facial Nerve

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. FacialNerve Dr. Badi ALDOSARI Assistant Professor Facial Plastic Surgery Consultant ENT Consultant King Abdulaziz University Hospital

  2. FacialNerve • Embryology • Anatomy • Physiology • Pathology • Pathophysiology • Evaluation • Causes • Treatment

  3. Embryology • The facial nerve is developmentally derived from the hyoid arch , which is the secondbranchialarch • It arises as 2 main divisions- motor and sensory • The motor division of facial nerve is derived from the basal plate of the embryonic pons • The sensory division originates from the cranial neural crest.

  4. FacialNerve • Embryology • Anatomy • Physiology • Pathology • Pathophysiology • Evaluation • Causes • Treatment

  5. FacialNerve • 10,000neurons • 7,000myelinatedfacialexpression. • SuperiorlyalongtheroofoftheIAC(7UP) • Thecourse7segments

  6. FacialNerveAnatomy Facialnervesegments: Pons Cerebulo-pontineangle(CPA) InternalAuditoryCanal(IAC) Labyrinthine Tympanic Mastoid External Fallopiancanal(FC)

  7. Pons 4SsNuclei Solitarius(Taste) Superiorsalivatorynucleus Spinalnucleusofthetrigeminalnerve Seventhmotor

  8. Solitarius

  9. Superiorsalivatorynucleus

  10. Motorpart • Precentralgyrus(frontallobe) • Upperfacecorticobulbarcross • Contralateralpredominance • Motorfiberbendaroundtheabducens(CNVIth)nucleus

  11. Fallopiancanal • Thelabyrinthinesegment • shortest&narrowestpartsusceptibletocompression • Onlysegmentthatlacksarterialanastomosis • embolicphenomena • vascularcompression • Geniculateganglion • 1stgenu(bendorknee) • Commontrunk(nervusintermediusandVIInerve) • Greatersuperficialpetrosalnervelacrimalgland • Tympanicsegment • 50%dehiscent –1st2nd genu

  12. Fallopiancanal • Mastoidsegment –2nd genuverticallystylomastoidforamen • longestpartoftheintratemporalcourse • Branchs • Stapediusmuscle • Chordatympaninerve • submaxillaryandsublingual • Tasteanterior2/3tongue • pain,temperature,andtouchEAC. • Auricularnerve

  13. Extracranial • Postauricularmuscles • Stylohyoidmuscle • Posteriorbellyofthedigastricmuscle • Pesanserinus(goose'sfoot)separatesparotiddeepandsuperficiallobes • 5majorbranchesT,Z,B,M,C • HighestriskduringsurgicalT&M

  14. Pesanserinus(goose'sfoot)

  15. FacialNerve • Embryology • Anatomy • Physiology • Pathology • Pathophysiology • Evaluation • Causes • Treatment

  16. Physiology • Lacrimation • Expression • Mastication • Salivation • Speech • Hearing

  17. FacialNerve • Embryology • Anatomy • Physiology • Pathology • –Pathophysiology • Evaluation • Causes • Treatment

  18. FacialNervePalsy • Degeneration • Metabolicsource(cellbody) • Walleriandegeneration • Beginswithin24hours • Degenerationdistalaxon&myelinsheath • Distaltothesiteofaninjury • WithoutlocalInflammation • Macrophagesdegrademyelinandaxons

  19. FacialNervePalsy • Regeneration • Axonalstumpsswellandproliferatingneurofilaments • Misdirectedregrowthofnervefibers • FacialmusclecontracturesSynkinesia • Salivationcrocodiletears

  20. Pathophysiology • Neuropraxia–noaxonaldiscontinuity • Axonotmesis • Walleriandegeneration(distaltolesion) • Endoneuralsheathsintact • Neurotmesis • Walleriandegeneration(distaltolesion) • Axondisrupted,lossoftubules,supportcellsdestroyed

  21. House-Brackmann • Grade1 • –=Neurapraxia • Spontaneousrecovery • Grade2-3 • –=Axonotmesis • Flowinterruption • Walleriananterogradedegeneration. • Incompletedegeneration

  22. House-Brackmann • Grade4 • –=Neurotmesis(permanentlossofaxons) • Demyelinization • Moderate-to-severefacialmusculaturedysfunction • Regenerativesynkineticmovements • Grade5and6 • Partialorcompletetransectionofthenerve • Minimal/completelossoffunction

  23. FacialNerve • Embryology • Anatomy • Physiology • Pathology • Pathophysiology • –Evaluation • Causes • Treatment

  24. Evaluation • Carefulhistory • Physicalexam • Audiometry • CT/MRI/other • Topographic • Electrophysiology

  25. History • Timing • Associatedsymptoms • SNHL • Vesicles • Severe pain • Trauma • OM acuteor chronic • Pastmedicalhistory

  26. Physicalexam • Complete head and neck exam • Widesmile • Whistling • Blowing • LMNL • Forehead wrinkling • Eyeclosure • Bell’sphenomenon

  27. TopognosticTests • Schirmer’sTest • Stapedialreflex • Taste • SalivaryFlow • Imaging

  28. EvaluationFacialNervePalsy • Electro-Physiology • Electroneurography(ENoG) • Electromyography(EMG) • Nerveexcitabilitytest(NET) • Maximumstimulationtest(MST) ACUTE=Acute+Complete+Unilateral+ThreedaysEvaluate

  29. FacialNerve • Embryology • Anatomy • Physiology • Pathology • Pathophysiology • Evaluation • –Causes • Treatment

  30. FacialNervePalsy • Causes: • Congenital • Trauma • Iatrogenic • Idiopathic • Infection • Toxic • Neurologic • Neoplastic

  31. FacialNervePalsy • Trauma • Forcepsdelivery • Basalskull/temporalbonefractures • Facialinjury • Penetratingtomiddleear • Barotrauma • Lightning

  32. Racooneyessign

  33. Battle’ssign

  34. Fractures • Longitudinal • 80%ofTemporalBoneFractures • 15-20%FacialNerveinvolvement • Transverse • 20%ofTemporalBoneFractures • 50%FacialNerveInvolvement

  35. R

  36. FacialNervePalsy • Iatrogenic • Parotidsurgery • Mastoidsurgery • localanesthesia • Acousticneuroma

More Related