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Facial Nerve Bastaninejad Shahin, MD, Otolaryngologist VIIth nerve Anatomy 4mm 11mm 8-10 IAC 15-17 CPA Porus 13mm Fundus G.G. Selected Clinical Scenarios Bell’s Palsy • Spontaneous idiopathic facial paralysis – paralysis or paresis of all muscle groups of one side of the face – sudden onset – absence of signs of CNS disease – absence of signs of ear or cerebellopontine angle disease • Incidence 20-30/100000, it’s greater in more than 65yrs • M/F ratio is equal, but in less than 20yrs it’s more common in F; but in more than 40yrs, it’s more common in M. • 30% have incomplete paralysis • 70% have complete paralysis Bell’s Etiology • Microcirculatory failure of vasa nervorum • Viral infection most accepted concept • Ischemic neuropathy • A.I. reaction HSV Reactivation • Other caranial nerve involvment in Bell’s palsy (in more than 50% of the pts): 5,7,9,10 + C2 • Site of involvement: proximal Labyrinthine and meatal portion • Prognosis is excellent: 80-90% complete recovery (95-100% in partial paralysis) • Poor outcome measures: – Hyperacusis (brain stem reactivation) – Decreased tearing – Age more than 60 – DM and HTN – Severe aural and facial radicular pain Bell’s Palsy (cont’) • Bell’s in Children – Female preponderance – 97% full recovery – Impact of corticosteroid is uncertain! • Familial Bell’s8% • Recurrent9.3% – More common in females, and DM sufferers – No prognostic difference with primary Bell’s Bell’s in pregnancy • More frequent in pregnant women (*3.3) • Most common in third trimester immediate postpartum • Pre-eclampsia is a RF • Treatment is with prednisolone or • Management: – Corticosteroids (mainstay) : 1mg/kg/day in seven days, then taper it down – Antiviral agents – Surgery: within 2wks if ENOG showed more than 90% axonal degeneration (Gantz et al.) Ramsay Hunt Syndrome (RHS) • Skin vesicles (aural, facial ,...) + faicial nerve paralysis • Relates to VZV ( while Bell’s was HSV ) • It’s 2nd most common cause of the facial paralysis Poor outcome • Complete recovery: – In complete paralysis 10%! – In incomplete paralysis 66% • Treatment is with Corticosteroid and Acyclovir • The main benefit of the corticostroid is reduction of postherpetic neuralgia, vertigo and acute pain ( it’s usefulness on recovery of the nerve is controvercial) Congenital facial paralysis • Birth trauma 78% • Syndromic (Mobius syn., CHARGE,...) – Surgical exploration and decompression of the nerve is rarely useful – Main option is muscle transfer. 6th and Mastoid segment of the 7th nerve Bilateral Facial Paralysis • • • • • • • • Guillain barre syndrome (9, 10, 7) Bell’s palsy 0.3 to 2% of pts Idiopathic cranial neuropathies Brain stem encephalitis BIH Syphilis Leukemia Sarcoidosis, Lyme disease &... Traumatic Facial Paralysis • Most susceptible region: distal Labyrinthine and Geniculate ganglion • Surgical timing depends on the onset after injury (late, immediate) Blunt head truma (sharp nerve cut repair in 3 days) • Surgical time planing: – Immediate paralysis: 3 wks after onset – Delayed paralysis: Expectant management and corticosteroids will be Okay!, but surgery indicates when you see gross disruption of fallopian canal in the CT-scan. • Fisch advocates surgical intervention on the basis of ENOG, rather than time of onset of the paralysis (...>90% degeneration within 6 days of onset) Otitis Media • AOM, COM, Cholesteatoma • Most susceptible segment is Tympanic part • AOM IV Abx + Myringotomy • Cholesteatoma Removal of the choles. + nerve decompression without opening the perineurium • COM decide regarding to the degree of inflammation