Facial Paralysis: Objectives: Discuss the anatomy of the facial nerve. Look at common patterns of facial nerve palsy

Transcription

1 Facial Paralysis: Objectives: Discuss the anatomy of the facial nerve Look at common patterns of facial nerve palsy Discuss imaging appearance of lesions that lead to facial paralysis. Lindell R. Gentry, M.D. Facial Nerve Anatomy: Facial Nerve Anatomy: Facial Nerve Anatomy: Facial Nerve Anatomy:

2 Facial Nerve Anatomy: Branchial Motor (Main Facial Nerve) Muscles of facial expression Greater Superficial Petrosal Nerve Autonomic (parasympathetic) Chorda Tympani Nerve Taste to anterior 2/3 tongue Posterior Auricular Nerve Periauricular region Facial Nerve Anatomy: Motor Root Sensory Root Greater Petrosal Nerve Facial Nerve Nerve to Stapedius Chorda Tympani Muscles of Facial Expression Facial Nerve: Symptoms Loss of Function Central Facial Palsy Peripheral Facial Palsy Hyperactive Function Hemifacial Spasm Facial Nerve: Symptoms Facial Weakness (Muscles of Facial Expression) Loss of Taste Anterior 2/3 of the tongue Hyperacusis Loss of Lacrimation 1. Suprabulbar Supranuclear CN Palsies (CN 56) Optimal imaging workup: depends on location of offending lesion depends on pathology depends on acuity Central Facial Palsy Peripheral Facial Palsy

3 1. Suprabulbar Supranuclear CN Palsies (CN 56) 1. Suprabulbar Supranuclear CN Palsies (CN 56) Lymphoma Left Facial Palsy with Sparing of the Upper Face 6 th and 7 th CN Palsy 1. Suprabulbar Supranuclear CN Palsies (CN 56) 57 Y/O diabetic with HA, hearing loss, facial pain and lower facial palsy 1. Suprabulbar Supranuclear CN Palsies (CN 56) Meningoencephalitis Parotid Adeno Ca 1. Suprabulbar Supranuclear CN Palsies (CN 56)

4 Metastasis Meningeal Metastasis Meningeal Mastoiditis Cholesteatoma Mastoiditis Cholesteatoma Metastasis Meningeal Metastasis Meningeal Mastoiditis Cholesteatoma Mastoiditis Cholesteatoma Metastasis Meningeal Metastasis Meningeal Mastoiditis Cholesteatoma Mastoiditis Cholesteatoma

5 Courtesy of Michelle Michel Auriculotemporal Nerve V1 V2 V3 CN 7 V3 V3 V2 CN 7 V2 Plexiform Neurofibroma CPA Meningioma Nasopharyngeal SCCA Smoker Smoker Renal Cell Met

6 Dropped Metastasis SCCA of Cheek Adenoid Cystic Ca Adenoid Cystic Ca Smoker Glomus Jugulare

7 Progressive facial paralysis secondary to a rare temporal bone tumor: Glomus faciale. Parker, NP & Huang, TC. Archives of Oto HNS, 137: DOI: /archoto a Glomus Faciale Intraosseous Venous Malformation Idiopathic Bell s Palsy Viral Specific Bacterial (strep, H Flu, staph, pseudomonas) Spirochete (syphilis, Lyme) Fungal (blastomycosis, mucormycosis, aspergillosis) Viral (herpes zoster) TB Demographics Very common cause of facial paralysis Afflicting 1 in 65 individuals More common (elderly, DM, pregnancy, immunosuppressed) Etiology Viral prodrome (60%) Unknown, probably viral (HSV 1) Features Abrupt, isolated, unilateral, paralysis entire face Hyperacusis, decreased tearing, dysgeusia Symptoms peak within days No imaging required with these typical features Imaging is a clinical diagnosis Imaging only required in atypical presentations MRI to exclude other causes (CVA, neoplasm, TB infection) Treatment Observation Nerve regenerates at 12 millimeters per day Steroids, antivirals may slightly improve outcome Surgical decompression controversial Prognosis Recovery = 85% Full recovery = 10% Partial deficit = 5% Complete deficit Duration = 50% few months = 35% within a year Recurrence = 10 20%

8 Background J. Ramsay Hunt (1907) Clinical Triad Otalgia (+/ before paralysis) Facial paralysis Herpetic eruptions Etiology Varicella zoster (HV3) Features CN 8 dysfunction (> Bell s) Vertigo, hearing loss, tinnitus Periauricular edema < 50% complete recovery Role of Imaging Limited Exclude other lesions CN 7 Enhancement Geniculate ganglion Labyrinthine segment facial nerve IAC meninges Degree enhancement not prognostic Periauricular soft tissue edema > Bell s Treatment IV acyclovir and steroids No role for nerve decompression Acute Preeruption Phase

9 Cholesteatoma Cholesteatoma Aggressive Otitis Externa Blastomycosis Wegener s Granulomatosis

10 Incidence Intralabyrinthine Fxs 30 50% Extralabyrinthine Fxs 10 20% Location of Injury Perigeniculate 80% Proximal mastoid 12% Multiple sites 20% Etiology Bony spicules 46% Contusion / edema 36% Transection 9% Intraneural hematoma 9% Degree 1. Immediate Onset 2. Delayed Onset Management questions 1. Location Injury 2. Etiology Injury? 3. Surgical Guidance

11 Facial Nerve Prolapse Objectives: Reviewed the anatomy of the facial nerve Looked at common patterns of facial nerve palsy Discuss imaging appearance of common and uncommon lesions that lead to facial paralysis. Facial Paralysis: Central Facial Palsy Peripheral Facial Palsy Lindell R. Gentry, M.D.