Gentry Facial Nerve - 2017 ASHNR - Educational SymposiaLindell R. Gentry, M.D. Facial Paralysis: Objectives: • Discuss the anatomy of the facial nerve • Look at common patterns

Lindell R. Gentry, M.D.

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.

Facial Nerve Anatomy: Facial Nerve Anatomy:

Facial Nerve Anatomy: 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:

Muscles of Facial Expression

Greater Petrosal Nerve

Motor Root

Facial Nerve

Chorda Tympani

Sensory Root

Nerve to Stapedius

Facial Nerve Anatomy:

•  Loss of Function –  Central Facial Palsy –  Peripheral Facial Palsy

• Hyperactive Function –  Hemifacial Spasm

Facial Nerve: Symptoms Facial Nerve: Symptoms •  Facial Weakness (Muscles of Facial Expression)

•  Loss of Taste –  Anterior 2/3 of the tongue

• Hyperacusis

•  Loss of Lacrimation

Central Palsy 1. Suprabulbar - Supranuclear

–  Sparing of the upper face

2. Brainstem –  Other CN Palsies (CN 5-6) –  May or may not spare upper face

Peripheral Palsy 1.  Intratemporal

–  Loss of lacrimation –  Hyperacusis –  Loss of taste to anterior 2/3 of tongue

2.  Intraparotid –  Pure motor

Facial Nerve Palsy: Location

Optimal imaging workup: - depends on location of offending lesion - depends on pathology - depends on acuity

Facial Nerve Palsy: Location Central Facial Palsy Peripheral Facial Palsy

Left Facial Palsy with Sparing of the Upper Face

Facial Nerve Palsy: Location Central Palsy

1.  Suprabulbar - Supranuclear –  Sparing of the upper face

2.  Brainstem –  Other CN Palsies (CN 5-6) –  May or may not spare upper face










Lymphoma

6th and 7th CN Palsy

Meningoencephalitis

57 Y/O diabetic with HA, hearing loss, facial pain and lower facial palsy

Central Palsy 1.  Suprabulbar - Supranuclear

–  Sparing of the upper face











Facial Nerve Palsy: Location

Parotid Adeno Ca

CN 7 Schwannoma







•  Neoplasm -  Primary -  Metastasis - Meningeal -  Perineural Spread (H&N) -  Vascular

•  Infection-Inflammatory -  Herpetic (Bell’s) Palsy -  Herpes Zoster Oticus -  Mastoiditis - Cholesteatoma -  Other

•  Trauma •  Other

-  Normal Variants CN 7 Schwannoma

Peripheral Facial Nerve Palsy:




-  Normal Variants


CN 7 Schwannoma










Peripheral Facial Nerve Palsy: •  Neoplasm

-  Primary -  Metastasis - Meningeal -  Perineural Spread (H&N) -  Vascular










CN 7 Schwannoma






Courtesy of Michelle Michel CN 7 Schwannoma






Plexiform Neurofibroma






V1

V2 V3

V3

V2

V3

CN 7 CN 7

V2

Auriculotemporal Nerve

CPA Meningioma






Nasopharyngeal SCCA











Smoker






Renal Cell Met Smoker

“Dropped” Metastasis






SCCA of Cheek











Adenoid Cystic Ca











Adenoid Cystic Ca






Glomus Jugulare Smoker

Glomus Faciale





Peripheral Facial Nerve Palsy: Progressive facial paralysis secondary to a rare temporal bone tumor: Glomus faciale. Parker, NP & Huang, TC. Archives of Oto- HNS, 137:712-715. DOI: 10.1001/archoto.2011.96-a






Intraosseous Venous Malformation

Idiopathic -  Bell’s Palsy -  Other Viral

Specific -  Bacterial (strep, H Flu, staph, pseudomonas)

-  Spirochete (syphilis, Lyme) -  Fungal (blastomycosis, mucormycosis, aspergillosis)

-  Viral (herpes zoster) -  TB





Peripheral Facial Nerve Palsy: 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






Herpetic (Bell’s) Palsy





Peripheral Facial Nerve Palsy: Imaging

–  Herpetic (Bell’s) Palsy is a clinical diagnosis –  Imaging only required in atypical presentations –  MRI to exclude other causes (CVA, neoplasm, TB infection)

Treatment –  Observation –  Nerve regenerates at 1-2 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%


















Background –  J. Ramsay Hunt (1907)

Clinical Triad –  Otalgia (+/- before paralysis) –  Facial paralysis –  Herpetic eruptions

Etiology –  Varicella zoster (HV-3)

Features –  CN 8 dysfunction (> Bell’s) –  Vertigo, hearing loss, tinnitus –  Peri-auricular edema –  < 50% complete recovery





Peripheral Facial Nerve Palsy: Role of Imaging

– Limited – Exclude other lesions

CN 7 Enhancement – Geniculate ganglion – Labyrinthine segment facial nerve –  IAC meninges – Degree enhancement not prognostic – Peri-auricular soft tissue edema > Bell’s

Treatment –  IV acyclovir and steroids – No role for nerve decompression






Acute Pre-eruption Phase











Cholesteatoma











Cholesteatoma

Aggressive Otitis Externa











Blastomycosis






Wegener’s Granulomatosis






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
















Facial Nerve Prolapse





Peripheral Facial Nerve Palsy: 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:

Lindell R. Gentry, M.D.

Central Facial Palsy Peripheral Facial Palsy

Documents

Gentry Facial Nerve - 2017 ASHNR - Educational SymposiaLindell R. Gentry, M.D. Facial Paralysis: Objectives: • Discuss the anatomy of the facial nerve • Look at common patterns