Facial Nerve Paralysis

1
Facial Nerve Paralysis

• Vanessa S. Rothholtz, M.D., M.Sc.
• UCI Department of Otolaryngology - Head and Neck
  Surgery
• May 24, 2007

2
Chief Complaint

• My Starbucks caramel macchiatto dribbled down my
  chin this morning, and it ruined my white coat.
  Now my face isnt working. Do I need a face lift?

3
History

• Unilateral left-sided otalgia (TMJ)
• Fever, chills
• Headache
• Generalized fatigue
• Conjunctivitis two weeks ago (resolved with
  antibiotics)
• My eczema acted up again last week, but it
  looked a little different.
• Travel Sonoma County for a friends wedding a
  last month

4
Physical

• Eyes Left eye with injected conjunctiva, pupils
  equal and reactive
• Ears EAC patent, TM c/m/i
• Nares Patent, clear
• OC/OP Dentition intact, tongue midline / mobile,
  No tonsillar hypertrophy
• Face
• Normal tone and symmetry at rest
• Obvious facial asymmetry with effort
• No perceptible forehead movement
• Incomplete eye closure
• Asymmetrical motion of mouth with maximal effort

5
What grade of paralysis is this based on the
House-Brackmann facial nerve grading scale?

• IV

6
House-Brackmann Facial Nerve Grading Scale

• I Normal
• II Normal tone and symmetry at rest
• Slight weakness on close inspection
• Good to moderate movement of forehead
• Complete eye closure with minimum effort
• Slight asymmetry of mouth with movement
• III Normal tone and symmetry at rest
• Obvious but not disfiguring facial asymmetry
• Synkinesis may be noticeable but not severe
• /- hemifacial spasm or contracture
• Slight to moderate movement of forehead
• Complete eye closure with effort
• Slight weakness of mouth with maximum effort

• IV Normal tone and symmetry at rest
• Asymmetry is disfiguring or results in obvious
  facial weakness
• No perceptible forehead movement
• Incomplete eye closure
• Asymmetrical motion of mouth with maximum effort
• V Asymmetrical facial appearance at rest
• Slight, barely noticeable movement
• No forehead movement
• Incomplete eye closure
• Asymmetrical motion of mouth with maximum effort

7
Differential Diagnosis

• V Anomalous sigmoid sinus, benign intracranial
  hypertension, intratemporal aneurysm of internal
  carotid artery, embolization for epistaxis
  (external carotid artery branches)
• I Malignant otitis externa, otitis media,
  cholesteatoma, mastoiditis, meningitis,
  parotitis, chicken pox, Ramsay Hunt syndrome,
  encephalitis, poliomyelitis (type I), mumps,
  mononucleosis, leprosy, HIV/AIDS, influenza,
  Coxsackie virus, malaria, syphilis, scleroma, TB,
  botulism, mucormycosis, Lyme disease
• T Cortical injuries, basilar skull fractures,
  brainstem injuries, penetrating injury to middle
  ear, facial injuries, altitude paralysis
  (barotrauma), SCUBA diving (barotrauma)
• A Temporal arteritis, periarteritis nodosa,
  Multiple sclerosis, myasthenia gravis,
  sarcoidosis, Wegener granulomatosis, eosinophilic
  granloma

• M Paget disease, osteopetrosis, diabetes
  mellitus, hyperthyroidism, pregnancy, alcoholic
  neuropathy, bulbopontine paralysis,
  oculopharyngeal muscular dystrophy
• I Bell palsy, Melkersson-Rosenthal syndrome
  (recurrent facial palsy, furrowed tongue),
  hereditary hypertrophic neuropathy,
  (Charcot-Marietooth disease, Dejerine-Scottis
  disease), Landry-Guillain-Barre syndrome,
  Sarcoidosis, Kawasaki disease, surgery,
  embolization
• N Acoustic neuroma, glomus jugulare tumor,
  leukemia, meningioma, hemangioblastoma,
  hemangioma, pontine glioma, sarcoma, hydradenoma,
  gacial nerve neuroma, teratoma, fibrous
  dysplasia, von Recklinghausens disease,
  carcinomatous encephalitis, cholesterol
  granuloma, carcinoma (invasive or metastatic)
• C Molding, forceps delivery, myotoic dystrophy,
  Moebius syndrome
• D Vaccine for rabies, Antitetanus serum,
  mandibular block anesthesia

8
Course of the Facial Nerve

• Intracranial Arises at the pontomedullary
  junction and courses with CNVIII to the internal
  acoustic meatus - 12mm
• Meatal Anterior to the superior vestibular
  nerve and superior to the cochlear nerve 10mm
• Intratemporal
• Labyrinthe segment
• Passes through narrowest part of fallopian canal
  - 12mm
• Narrowest part of facial nerve. The most
  susceptible to compression secondary to edema.
• Tympanic segment
• From geniculate ganglion to pyramidal turn 11mm
• Mastoid segment
• Exits the stylomastoid foramen 13mm
• Extracranial From stylomastoid foramen to pes
  anserinus

9

• The longest segment of the facial nerve is
• A. Vertical of mastoid portion
• B. Cisternal portion
• C. Tympanic portion
• D. Portion in the IAC
• Captier G. Organization and microscopic anatomy
  of the adult human facial nerve Anatomical and
  histological basis for surgery

10
Blood supply to facial nerve clinical relevance

• Courses between the epineurium and periosteum
  making the blood supply at risk when mobilizing
  at the first genu
• Extrinsic
• Stylomastoid artery (branch of the postauricular
  artery of external carotid artery)
• Greater petrosal artery (branch of middle
  meningeal artery)
• Internal auditory artery (branch of the AICA)
• Labyrinthe segment - lacks anastomosing arterial
  cascades thereby making the area vulnerable to
  ischemia
• Parhizkar N, Hiltzik DH and Selesnick SH.
  Facial nerve rerouting in skull base surgery.
  Otol Clin N Am. 2005 38(4) 685-710

11
Work Up

• Basic labs, thyroid function panel, Lyme titers
  ELISA for antibodies
• Audiogram
• Stapedial reflex
• EKG
• MRI with gadolinium / CT
• Nerve Excitability Test, Maximal Stimulation
  Test, Electroneuronography (EnoG) - Useful 72
  hours post-injury

12
Topognostic Testing

• Schirmer test for lacrimation
• Stapedial reflex test (stapedial branch)
• Taste testing (chorda tympani nerve)
• Salivary flow rates and pH (chorda tympani)

13
Topognostic Testing

• Schirmer Test
• Greater superficial petrosal nerve
• Filter paper is placed in the lower conjunctival
  fornix bilaterally
• 3- 5 minutes
• Value of 25 or less on the involved side or
  total lacrimation less than 25 mm is considered
  abnormal.

14
Topognostic Testing

• Stapedial Reflex
• Stapedius branch of the facial nerve
• Most objective and reproducible
• A loud tone is presented to either the
  ipsilateral or contralateral ear ? evokes a
  reflex movement of the stapedius muscle ? changes
  the tension on the TM (which must be intact for a
  valid test) resulting in a change in the
  impedance of the ossicular chain
• If intact stapedial reflex, complete recovery can
  be expected to begin within six weeks
• Absence of the stapedial reflex during the first
  two weeks in Bells Palsy is common

15
Topognostic Testing

• Taste Testing
• Chorda tympani
• Extremely subjective
• Papillae generally disappear within 10 days post
  injury - middle 1/3 of the tongue is most
  indicative, because the anterior 1/3 may receive
  bilateral input.

16
Topognostic Testing

• Salivary flow rates
• Chorda tympani
• Cannulation of Wharton's ducts bilaterally
• 5 minute measurement of output
• Significant if 25 reduction in flow of the
  involved side as compared to the normal side
• Salivary pH ? Flow Rate

17
Nerve Excitability Test (NET)

• Most predictive prognostic factor for recovery of
  facial nerve function
• Hilger nerve stimulator over stylomastoid foramen
• Reflects elevated thresholds for neuromuscular
  stimulation due to degeneration / disruption of
  axons (comparison to contralateral side)
• Difference 2.5 milliamps - poor prognosis
• Ikeda M et. al. Clinical factors that influence
  the prognosis of facial nerve paralysis and the
  magnitudes of influence. Laryngoscope. 2005
  115855-860.

18
Nerve Excitability Test (NET)

• Benefits
• Easy to perform
• More comfortable for patient
• Drawbacks
• Subjectivity (relies on operators visual
  detection of response)
• May exclude smaller fibers (current thresholds
  are likely to selectively activate larger fibers
  with lower thresholds and not those smaller
  fivers closer to stimulating electrode)

19
Maximal Stimulation Test (MST)

• Electrical impulse administered to saturate the
  nerve with current and to compare it to
  contralateral side
• Test is repeated periodically until definitive
  response
• Response
• Equivalent to contralateral side
• Minimally diminished (50)
• Markedly diminished (
• Absent
• Symmetric response within first ten days
  complete recovery in 90
• No response within first ten days incomplete
  recovery with significant sequelae
• Superior to NET - test becomes abnormal sooner,
  but drawback is subjectivity

20
Evoked electromyography (EEMG) or
Electroneuronography (EnoG)

• Records compound muscle action potential (CMAP)
  with surface electrodes placed transcutaneously
  in the nasolabial fold (response) and
  stylomastoid foramen (stimulus)
• Waveform responses are analyzed to compare
  peak-to-peak amplitudes between normal and
  uninvolved sides where the peak amplitude is
  proportional to the number of intact axons

21
Evoked electromyography (EEMG) or
Electroneuronography (EnoG)

• Most reliable in first 2-3 weeks post event (as
  neuropraxic fibers recover or regenerate, they
  discharge asynchronously and the response is
  subsequently diminished)
• Response prognosis
• Response 90 of normal within 3 weeks of onset
  80-100 probability of recovery
• Testing every other day
• Advantages Reliable
• Disadvantages
• Uncomfortable
• Cost
• Test-retest variability due to position of
  electrodes

22
Electromyography (EMG)

• Measures post-synaptic membrane di/triphasic
  (polyphasic) potentials with voluntary muscle
  contraction that are present 6-12 weeks prior to
  visible return of function
• Assesses reinnervation potential of muscles two
  weeks after onset
• Limited value early in evaluation because
  fibrillation potentials indicating axonal
  degeneration do not appear until 10 14 days
  post onset
• Detection of motor units in 2 of 3 muscle groups
  87 satisfactory outcome
• Detection of motor units in 1 muscle group 11
  satisfactory

23
More Methods

• Antidromic (retrograde) Conduction F-waves
  represent activated motor neurons in facial
  muscles.
• Transcranial magnetic stimulation Enables
  central activation via a transcranial application
  of induce current via an electromagnetic coil
• Trigeminofacial Reflex Records action
  potentials reflexively generated in the
  orbicularis oculi muscle in response to an
  electrical stimulus applied to V1

24
Lyme Disease - Borrelia Burgdorferi

• Ten percent of patients have facial nerve
  paralysis after 1-4 weeks incubation period
• ELISA to search for IgG and IgM antibodies
• Facial paralysis resolves in 6 to 12 months
• Treatment
• Early antibiotics
• Reduce symptoms
• Event long-term sequelae
• Children - IV penicillin, ceftriaxone or
  cefotaxime
• Adults - tetracycline
• Muscular therapy

25
Bells Palsy

• 60-70 cases
• Pathophysiology Impaired axoplasmic flow from
  edema of facial nerve within fallopian canal
• Rapid onset and evolution
• May be associated with acute neuropathies of
  cranial nerves V- X
• Pain or numbness affecting ear, mid-face, tongue
  and taste disturbances
• Recurrences are more likely (2.5x) in patients
  with family history, immunodeficiency or diabetes

26
Bells Palsy

• Treatment
• Oral antivirals - Acyclovir - 10mg/kg (500mg)
  q8hrs x 7 days
• Corticosteroid taper 1mg / kg / day for 10 days
• Eye protection - lacrilube
• Follow progression with serial exams
• Facial nerve decompression
• Progression to 90 degeneration on ENOG
• Performed before irreversible injury to the
  endoneural tubules occurs (two weeks), will allow
  for axonal regeneration to occur

27
Treatment of Bells Palsy with Steroids A
controversial closer look

• Steroids may have the following effects
• Reduce risk of denervation
• Preventing / lessening synkinesis
• Preventing progression to complete paralysis
• Hastening recovery
• Controversy
• Lack of randomization, controls and definitive
  dosing in most studies
• Stankiewicz J. Steroids and idiopathic facial
  paralysis. Otlaryngol Head Neck Surg. 1983 91
  672.
• Wolf S. Wagner J. Davidson S. et.. al. Treatment
  of Bells palsy with prednisone a prospective
  randomized study. Neurology. 1978 28 158.

28

• Facial Nerve function recovers to HB grade I
  function in what percentage of patients with
  Bells Palsy?
• A. 50
• B. 70
• C. 85
• D. 95
• Ikeda M et. al. Clinical factors that influence
  the prognosis of facial nerve paralysis and the
  magnitudes of influence. Laryngoscope. 2005
  115855-860.

29

• Which of the following factors is a predictor of
  poor facial nerve outcome following Bells Palsy?
• A. Age over 50 years
• B. Male Gender
• C. Loss of lacrimation
• D. Hypothyroidism
• Ikeda M et. al. Clinical factors that influence
  the prognosis of facial nerve paralysis and the
  magnitudes of influence. Laryngoscope. 2005
  115855-860.

30
What is this Condition?
Ramsay Hunt Syndrome
31
Herpes Zoster Oticus (Ramsay Hunt syndrome)

• 10-15 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 segment

32

• The most common etiology of facial nerve
  paralysis in children is
• A. Infection
• B. Congenital
• C. Trauma
• D. Iatrogenic
• Evans AD et. al. Pediatric facial nerve
  paralysis Patients, management and outcomes.
  Int J Ped Otol. 2005 691521-1528.

33

• Which of the following infections is most likely
  to cause facial paralysis in a pediatric patient?
• A. Acute otitis media
• B. Mastoiditis
• C. Mycobacterium infection
• D. Disseminated herpes
• infection
• Evans AD et. al. Pediatric facial nerve
  paralysis Patients, management and outcomes.
  Int J Ped Otol. 2005 691521-1528.

34
Acute Otitis Media

• History and physical exam make the diagnosis
• Palsy is progressive over 2 to 3 day period
• Infectious agent Staphylococcus non-aureus,
  Propionobacterium
• CT temporal bone
• Treatment
• Myringotomy
• Otic antibiotic drops containing topical steroids
• IV antibiotics and steroids
• If not improved mastoidectomy

35
Möbius Syndrome

• Most frequently sporadic
• Congenital facial weakness with impairment of
  ocular abduction
• Dysfunction of other cranial nerves III, IV,
  IX, X, XII
• Skeletal abnormalities (orofacial, limb
  malformations)
• Pathogenesis Genetic cause vs. Ischemic cause

36
Melkersson-Roenthal syndrome

• Triad
• Recurrent orofacial edema
• Recurrent facial palsy (50-90)
• Lingua plicata (fissure tongue) 25
• Lips become chapped, fissured and red-brown in
  appearance
• Biopies identify granulomatous changes
• Facial nerve decompression may be indicated if
  facial paralysis is severe and recurrent

37
Neoplastic

• About 5 of cases of facial nerve paralysis are
  caused by tumors
• Characteristics of facial nerve palsy
• Slow developing
• Additional cranial nerve deficits
• Recurrent ipsilateral involvement
• Adenopathy
• Palpable neck or parotid mass
• Most common benign tumor - facial nerve
  schwanomma
• Most common malignant tumors - mucoepidermoid
  carcinoma and adenoid cystic carcinoma of the
  parotid gland.

38
Temporal Bone Fractures

• Longitudinal fractures
• 80 incidence but 10-20 with facial nerve injury
• Transverse fractures
• 20 incidence, but 50 with facial nerve injury
• Most common site of fracture
• Perigeniculate region

39
Temporal Bone Fractures

• Penetrating injury to extratemporal facial nerve
  branches
• Injuries medial to a line perpendicular to the
  lateral canthus do not need to be explored
  because they recover spontaneously (draw please)
• Immediate paralysis after injury lateral to this
  line needs to be explored and repaired with an
  end-to-end anastomosis 48-72 hours after the
  initial injury

40
Sunderland Nerve Injury Classification

• I Neuropraxia
• Conduction block from compression and loss of
  axonic flow
• Complete recovery
• II Axonotmesis
• Axon disrupted but endoneurium preserved
• Wallerian degeneration occurs distal to site of
  injury
• Complete recovery
• III Neurotmesis
• Complete disruption of axon including its
  surrounding myelin and endoneurium
• Wallerian degeneration
• Unpredictable outcome High risk for synkinesis
• IV Complete disruption of perineurium
• V Complete disruption of epineurium
• Risk of a neuroma from nerve sprouts outside of
  nerve sheath

41

• A patient with facial nerve injury following a
  gunshot wound to the temporal bone typically
  presents with which of the following symptoms?
• A. Midface branch paralysis
• B. Complete facial paralysis
• C. Forehead paralysis
• D. Partial weakness of the facial nerve
• Bento RF and de Brito RV. Gunshot wounds to
  the facial nerve. Otol Neurotol. 2004 25
  1009-1013.

42

• Following surgical repair of facial nerve injury
  due to a gunshot wound, the typical facial nerve
  function outcome is House Brackmann grade
• A. I or II
• B. III or IV
• C. V
• D. VI
• Bento RF and de Brito RV. Gunshot wounds to
  the facial nerve. Otol Neurotol. 2004 25
  1009-1013.

43
A patient presents to the trauma bay after a
closed head injury. He has a unilateral facial
nerve paralysis and a CT scan confirms a temporal
bone fracture. The family wants your expert
opinion on the prognosis and return of facial
nerve function.

• Immediate onset as above
• Delayed onset
• 94-100 complete recovery
• Patients with 90 degeneration of neural
  integrity poor recovery

44
What if the facial paralysis doesnt resolve?

• End-to-End Anastomosis
• Cable Nerve Graft
• Hypoglossa-Facial Nerve Anastomosis (Crossover or
  Jump Graft)
• Muscle transposition (Gracilis)
• Static Suspension (Gortex, Threads)

45
Complications

• Keratitis
• Emotional/Social Issues
• Synkinesis

46
THANK YOU