“EVALUATION & MANAGMENT OF FACIAL NERVE

PALSY”

07/10/2014

ByDr. Aditya Tiwari,

Resident, Dept. of ENT, JNMC.

“The human face is the organic seat of beauty. It is the register of value in

development, a record of Experience, whose legitimate office is to perfect the life, a legible language to those

who will study it, of the majestic mistress, the soul."

- Farnham, Eliza

QUOTE

CONTENTS Introduction Causes Evaluation of nerve function. Goals of management of FN palsy Factors governing T/t of FN palsy Assessment & planning Management of facial nerve palsy FN disorders in newborn &children

INTRODUCTION Facial function plays an integral part in

our everyday lives - Smile; nonverbal communication, etc. Facial paralysis is devastating on many

leveL Functional Cosmetic Fortunately, a plethora of techniques

are available to treat the paralyzed face.

CAUSES

In middle ear surgery, the most comman site of inury is the tympanic segment due to high incidence of fallopian canal

dehiscence in that region. During mastoid surgery, the facial nerve is most commanly inured at the secong genu

Skull base neoplasms & metastasis from breast and lung cancer are comman neoplasms causing facial paralysis in

adults.Leukemia, lymphoma are the most comman etiologies in

children.A facial palsy progressive beyond 3 weeks since onset & with

no returns of function by 6 months is considered to be caused by tumor until proven by otherwise

If greater than 90% neural degeneration occurs with in 2 weeks, the mastoid & tympanic segment are decompressed.

EVALUATIONS OF NERVE FUNCTION

HISTORY is of vital importance to establish the onset characteristics, duration and degree of recovery.

Previous trauma, surgery or infection may help in arriving at a diagnosis

Examination of the face at rest and movement.

Radiolologic evaluations Topodiagnostic & Nerve excitability

tests.

GOALS OF MANAGEMENT OF FACIAL NERVE PALSY

Normal appearnce at rest Symmetry at involuntry motion. Restoration of oral, ocular & nasal

sphincter No loss of other significant functions.

FACTORS GOVERNING T/t OF FACIAL NERVE PALSY

Age Medical history. Residual hearing. Prior h/o ear discharge. Segment of nerve injured. Patient’s expectations. Risk tolerance.

ASSESSMENT AND PLANNING

Cause of facial paralysis Functional deficit/extent of paralysis Time course/duration of paralysis Likelihood of recovery Other cranial nerve deficits Patient’s life expectancy Patient’s needs/expectations

PSYCHOLOGICAL IMPACT & COUNSELLING

Psychological Trauma :- The most significant complication is the social isolation & these patients often succumb to.

Depression :- Patient often become by the facial deformity.

The patient must be encouraged to to adopt positive outlook.

Group therapy has been effective in helping patients to deal with facial deformity.

Resultls are better when group members are selected of the same age group & same age.

Patient should be learned to adapt permenant deformity in a positive way.

MANAGEMENT OF FACIAL NERVE PALSY

MEDICAL TREATMENT : - a) Physical therapy b) Pharmacological therapy c) Psychophysical therapy Surgical treatment : - a) Nerve decompression - Internally or externally. b) Nerve anastomosis c) Nerve grafting Physiotherapy

Physical Therapy It includes application of heat, massage

& exercises performed twice a day. Patient is adviced to follow these steps – a) Wet cotton towel with hot water, wring it out, keep the hot towel on the face until the towel cools. b) Massage facial cream on skin around the eyes & mouth and mid face for few minutes. c) Stand infront of mirror Watch face while doing facing exercises Intact nerve fibres activated & muscle tone maintained

Pharmacotherapy In case of the Bell’s palsy :- a) Oral antivirals - Acyclovir is DOC. b) Corticosteroids c) Eye protection d) Follow progression with serial exams e) Physiotherapy. Prednisolon is steroidal drug of choice in

both Bell’s palsy & Ramsay Hunt syndrom.

If the patient is seen within 2 to 3 weeks of onset of symptoms-tab. Prednisolone in doses of 1mg/kg/d for 10 to 14 days has been recommended with a gradual tapering.

Vitamins B1, B6, B12 may be administered which helps in nerve conduction & regeneration.

If patient is seen after 3-4 weeks, then steroid therapy is of no use.

Non-narcotic analgesic is used to control pain in Bell’s Palsy & mainly Ramsay Hunt syndrom.

Medical management of Bell’s palsy

SURGICAL TREATMENT MODALITIES

Nerve decompression - Internally or externally

Nerve anastomosis

Nerve grafting

Due to “skip” regions & diffuse neuritis of the facial nerve, surgical decompression is not recommended

in Ramsay Hunt syndrome.

A. Acute (< 3 wks) 1) Nerve

exploration/decompression 2) Nerve repair

a) Primary anastomosis b) Cable grafting i) Great auricular nerve ii) Sural nerve

B. Intermediate (3 wks- 2 yrs)

1) Nerve transfer a. Hypoglossal-facial

b. Spinal accessory-facial c. Masseteric-facial 2) Cross face nerve grafting

using sural nerve

C. Chronic (>2 yrs) 1) Muscle transfers a. Temporalis b. Masseter c. Digastrics 2) Free muscle flaps/

microneurovascular transfer a. Gracilis b. Latissimus dorsi c. Serratus anterior d. Pectoralis minor

D. Static procedures/ancillary procedures (can be performed at any time period listed above)

1) Gold weight/spring implants 2) Slings 3) Lid procedures

NERVE DECOMPRESSION Timing : within 72 hrs Indication : a) < 10% or less muscle function on ENoG, b) with absent voluntary muscle action

potential on EMG Method : a) Done by removing the facial fallopian

canal all around with widening of the canal with diamond burrs.

b) Perineural and epineural sheaths are split open (to drain perineural or intraneural edema / haematoma)

Approaches Transmastoid/Retrosigmoid

approach Middle cranial fossa approach. Retrolabyrinthine approach. Translabyrinthine approach.

Transmastoid approachIndication :- Tumors limited to the tympanic and/or the mastoid

segment of the facial nerve regrdless of preoperative hearing loss

Longitudinal fractures of temporal bone (only mastoid segmental involvement)

AOM, COM involving only tympanic segment and genu

Isolated mastoid fracture Infections involving the mastoid segmentLimitations :- Limited access to geniculate ganglion No access to labrynthine segment

Procedure:-a) Mastoidectomy air cells removed from

antrum downward to mastoid tip & ridge of the diagastric groove is defined cells also removed from the antrum forward to the root zygoma, until the upper edge of the incus & prominance of bony horizantal canal identified.

b) Landmark for the vertical mastoid portion of FN is post tip of incus above & ant end of diagastric groove below drilled upto stylomastoid foramen bone between foramen & horizantal SSC thinned & FN nerve is approached as pink streak.

DECOMPRESSION:-a) When horizantal segment of FN

involved, decompression done via triangle bounded by FN med., chorda tympani nerve & tympanic annulus laterally & short process of incus sup.

b) When patient’s hearing is normal & entire horizantal seg. of FN must be decompressed, incus must also be disarticulated.

c) Disposable Beaver knife is used for the decompression of the FN by slitting the nerve sheath.

Middle Cranial Fossa approach Exposure from IAC to Tympanic segment (for

intracanalicular and labrynthine segments) INDICATIONS :- a) Bells palsy, b) Longitudinal temporal bone fractures Advantages :- a) No hearing impairment, even

geniculate ganglion and tympanicsegment can be decompressed, when

b) Combined with retrolabyrinthine, transmastoid entire facial nerve can be seen.

PROCEDURE :

6x8cm trap door incision above ear (with postaural incision) 4x4 cm temporalis fascia graft harvested Anterior based temporalis musculo perisosteal flap elevated A bone flap centered over zygoma elevated, taking care middle

meningeal artery on inner table Dura elevated from posterior to anterior till petrous ridge, arcuate

eminence, meatal plane, and GSPN Anteriorly. Blue lining of superior semicircular canal seen Anterior to it IAC opened with 7th nerve anterosuperiorly (BILLS BAR

FORMS LATERAL BOUNDARY OF MEATAL FORAMEN) Labrynthine segment followed laterally till geniculate ganglion. Tegmen tympani removed Tympanic segment blue lined and final layer of bone removed with

elevator and decompressed Bone flap replaced, with temporalis fascia over it to seal the defect.

Complications :-

CSF leak, CHL/SNHL, meningitis, Bleeding from AICA, brainstem and

cerebellar infarction Injury to AICA

Retrolabyrinthine approach For exposure from brainstem to IAC ADVANTAGES :- a) Access without inner ear sacrifice b) Minimal cerebellar compression as compared to suboccipital approach. Disadvantages :- a) 8th nerve hampers 7th visualisation and can

lead to hearing loss b) Reduced intracranial exposure so intracranial

vascular complications very diff to manage Complications :- CSF leak, Hearing impairment, cerebellar

compression, vascular intracranial complications

Translabyrinthine approach Indications : 7th and 8th nerve function already lost Advantages : a) Entire nerve is exposed using single approach b) If interposition graft is required,

enough working space is available even at the level of brainstem

Limitations : Hearing and balance function loss,

CSF leak, Infections

Micro-neurological Surgery Facial nerve repair is the most effective

procedure to restore facial function in patients who have suffered nerve damage from an accident or during surgery.

It involves microscopic repair of a nerve that has been cut

PRIMARY NERVE REPAIR End-to-end

anastomosis preferred Adv - No tension Extratemporal repair

performed < 72 hrs of injury

Most common method a) Group fascicular

repair b) Epineural repair

Group fascicular repair

Primary Nerve Repair Severed ends of nerve

exposed Devitalized tissue/debris

removed with fine scalpel Small bites of epineurium Epineural sheath

approximated with 9-0 nonabsorbable suture

Epineural repair recommended for injury proximal to pes anserinus and intratemporal

EPINEURAL REPAIR TECHNIQUE

INTERPOSITION GRAFTING Cable grafts

Used when defect > 17mm nerve cannot be re-approximated without tension

Most common nerves used are:- a) Greater Auricular Nerve b) Sural Nerve c)Medial & lateral antibrachial

cutaneous nerves c) Sensory nerves from superficial

cervical plexusMotor nerve grafts are better than sensory

nerve grafts.

INTERPOSITION GRAFTING GREATER AURICULAR NERVE

Harvesting :- Located on lateral surface

of SCM at the midpoint of a line drawn between mastoid tip and mandibular angle.

May extend postauricular incision or use separate neck incision.

Ideally used for graft upto 10 cm in length.

Advantages: a) Proximity to facial nerve b) Cross-sectional area c) Limited morbidity Limitations: a) Reconstruction of long defects b) Ideal for defects < 6cm in length

Recently, the idea of nerve repair using autogenous axially aligned freez-thrawed skeletal muscle has been

proposed.

SURAL NERVE Anatomy:- Formed by union of medial sural

cutaneous nerve and lateral sural cutaneous branch of peroneal nerve

Advantages :- Diameter equal to FN dia. Length : >10cm Accessibility Low morbidity associated with

sacrifice Disadvantages: Variable caliber Often too large Difficult to make graft

approximation Unsightly scar

NERVE TRANSPOSITION/ CROSSOVER

Donor nerves are XII CN, spinal accessory, masseteric branch of trigeminal nerve.

Restores movement to the side of the face that has been paralyzed.

With the stump of the 12th nerve hooked up to the end of the 7th nerve, the face will move when the tongue is moved.

Best outcomes from cross facial nerve grafting obtained if the period of denervation is less than 6

months.

CROSSOVER TECHNIQUES INDICATIONS:

Irreversible facial nerve injury Intact facial musculature/distal facial nerve Intact proximal donor nerve Prior to distal muscle/facial nerve atrophy

Ideal if performed within a year of facial paralysis

Advantages:- Time interval until movement

4-6 months Avoid multiple sites of anastomosis Mimetic-like function achievable with practice

Disadvantages:- Donor site morbidity Some degree of synkinesis

Hypoglossal-Facial Technique1) Parotidectomy incision

extended into cervical crease ~ 2-3 cm below inferior border of mandible

2) Facial nerve identified and dissected distal to pes anserinus

3) Identify hypoglossal nerve a) SCM retracted posteriorly b) Dissect superiorly until

posterior belly of digastic is identifiedc) Retract digastric superiorly and CN XII is found inferiorly.d) Hypoglossal is within 2-3 cm of main trunk of the facial nerve

1) Hypoglossal nerve is dissected anteriorly and medially into the tongueTransect distal to ansa hypoglossis

2) Facial nerve transected at the stylomastoid foramen

3) Anastomose nerves using 9-0 epineural suture

Hypoglossal Facial Nerve Transfer

Entire hypoglossal nerve transected

40% segment of nerve secured to

lower division

Hypoglossal nerve reflected superiorly

“Split” XII – VII cranial nerve transfer transfer

XII – VII cranial nerve jump graft

End to end neurorrhaphy between XII CN & donor cable nerve graft ( eg. greater auricular nerve) which serves as a jump graft to the main trunk of facial nerve

Jump graft modification

Mobilisation of mastoid segment of facial nerve Facial nerve can be

mobilised in its mastoid segment from 2nd genu distally & rotated inferiorly to allow direct coaptation to the hypoglossal nerve.

It typically requires removal of the mastoid tip. Reflection of the facial

nerve out of the mastoid bone.

CROSS-FACIAL NERVE GRAFTING

Contralateral Facial nerve used to reinnervate paralyzed side using a nerve graft

Sural nerve often employed ~25-30cm of graft needed Restitution of smile and eye blinking

obtained. Disadvantage:- a)2nd surgical site b)Violation of the normal facial nerve

FOUR techniques Sural nerve graft routed from

buccal branch of normal VII to stump of paralyzed VII

Zygomaticus and buccal branch of normal VII used to reinnervate zygomatic and marginal mandibular portions respectively

4 separate grafts from temporal, zygomatic, buccal and marginal mandibular divisions of normal CN VII to corresponding divisions on paralyzed side.

Entire lower division of normal side grafted to main trunk on paralyzed side.

MUSCLE TRANSPOSITION

(“DYNAMIC SLING”)INDICATION: Congenital facial paralysis Facial nerve interruption of at least 3

years Loss of motor endplates Crossover techniques not possible due

to donor nerve sacrifice

TEMPORALIS Often used for

reanimation of the oral commisure.

Middle 1/3 of muscle is best for transfer (Sherris, 2004)

Temporalis Transfer Incision in preauricular

crease extending to sup. temporal line

Obtain wide exposure of temporalis muscle by dissecting above the SMAS

Incise down on periosteum to elevate muscle fibers

Harvest middle 1/3 Large tunnel created over

zygomatic arch Orbicularis oris muscle

exposed via vermilion border incision at oral commissure

Large tunnel over zygomatic arch used to connect oral commisure to zygomatic arch/superior incision.

Temporalis flap detached and elevated from its origin and tunneled to the oral commissure.

3-0 prolene used to suture orbicularis to temporalis at oral commissure

Overcorrection of nasolabial fold and oral commissure

MASSETER Used when temporalis muscle is not

opted. May be preferred due to avoidance of

large facial incision Disadvantages:- a) Less available muscle compared

to temporalis b) Vector of pull on oral commisure

is more horizontal than superior/oblique like temporalis

Vertical incision made in inferior portion of muscle.

Anterior half of muscle is split into 2 divisions.

The 2 anterior slips of muscle are tunneled anteriorly to reach the oral commisure via external vermillion border incisions.

Muscle slips are attached to lips and oral commisure in the deep dermal layer using suture.

MICRONEUROVASCULAR TRANSFER

FREE MUSCLE FLAPS They have potential of achieving

individual segmental contractions› Reduction of synkinesis

Muscle flaps used are:› Gracilis› Latissimus dorsi› Inferior rectus abdominus

MICRONEUROVASCULAR TRANSFERFREE MUSCLE FLAPS

Requires viable muscle and nerve innervation

Traditionally done in 2 stages a) 1st:- Cross-face nerve graft ~ 1 yr

prior to muscle transfer. b) 2nd:- Muscle transfer performed

after neural ingrowth of graft.

GRACILIS1. “Workhorse” for free

muscle transfer2. Long, thin muscle in

medial thigh-Good neurovasular

pedicle1. Adductor artery

and vein2. Anterior

obturator nerve3. 2 stages involved:

1. Sural nerve employed for cross-face graft

2. Gracilis muscle transferred after 6-12 months

4. Vascular anastomosis to the facial artery and vein or to superficial temporal vessels.

5. Obturator nerve of gracilis connected to distal end of sural nerve graft.

Anterior Obturator nerveAdductor a. & v.

ADDRESSING PARALYTIC EYELIDS

Exposure keratitis Corneal ulceration Corneal breakdown Blindness

Goal of treatment is to maintain Cornea safe.

Complications of orbicularis oculi paresis-

a) Delayed blinking b) Impairment of nasolacrimal system c) Dry eye d) Risk of cornea.

MANAGEMENT OF THE EYE

Initial treatment a) Ophthalmic drops/ointments b) Protective taping, c) Occlusive moisture chambers, d) Soft contact lenses, scleral shields e) Tarsorrhaphy suture

Majority of patients require definitive surgical treatment to correct chronic impairment

Surgical options include: a) Palpebral springs (Levine, May) b) Tarsorrhaphy (McLaughlin) c) Lid loading & shortening tech(Gold

weight, spring implant) d) Combinations e) Temporalis muscle transfer (Gillies) f) Encircling the upper and lower eyelids

with silicone or fascia lata (Freeman)Surgical T/t considered when medical T/t fails & in case of

BAD syndrome (Scott-Brown’s 6th edition)B Bell’s phenomenon

A corneal Anaesthesia D Dry eye

Palpebral Spring Advantages a) Less visible Disadvantages a) Technically difficult b) Higher risk of extrusion

Tarsorrhaphy Horizontal mattress 5-0 nylon Begin 3mm medial to lateral

canthus, 6mm from lid margin Stitch travels through gray line

to 5mm below lower lid margin Bolster with 3mm, 4-french

rubber catheter. Cosmetically unappealing,

visual field affected

Lid loading Early technique – Incision in the supratarsal crease – Subcutaneous pocket – Insert weight – Close skin

Stainless steel Gold– High profile– Migratory– High rate of extrusion

– Higher density - more weight in same size -Malleable - conforms to the globe-lower profile– Lower reactivity, Reversible,Migratory– High rate of extrusion

GOLD WEIGHT IMPLANTATION

Small incision made several millimeters above the upper eyelid margin.

Tarsal plate exposed with sharp dissection

Gold weight secured to tarsus beneath levator aponeurosis using 8-0 nylon.

Wound closed in 2 layers

Advantages a) Technically straightforward b) Consistent Disadvantages a) less than with previous technique b) Less Visibility c) Less Extrusion d) Less Mobility

Lower lid shorteninga) Procedure:-Wedge excision lateral canthopexy

b)Used in combination With gold weightimplantation

Facial Nerve disorders in newborn & childrens

The two main d/d possibilities are developmental & traumatic.

The most common finding asso with congenital facial palsy is presence of two or more other anomalies.

Develop. b/l facial palsy is freq. incomplete with lower portion of face

less affected than the upper part. This distinguishes it from facial palsy due to trauma, which is rarely B/L &

equally involves upper and lower part of the face.

Management of developmental facial paralysis

At present, with the exception of free muscle neurovascular transplantation, there is no effective way to restore facial function in conginital facial paralysis.

Delay reanimation surgical procedures until patient reaches adolescent years.

Management directed towards preventing complications.

Main area of concern for reanimation is the eye.