THE FACIAL NERVE DR. SAMI ALHARETHY ASSIS. PROF. CONSULTANT-KSU بسم الله الرحمن الرحيم THE FACIAL NERVE DR. SAMI ALHARETHY ASSIS. PROF. CONSULTANT-KSU

Complications of Facial Paralysis Facial paralysis severely affect: Normal facial expressions Mastication Speech production Eye protection.

Psychological Trauma The most significant complication is the social isolation these patients.

Outline Anatomy Pathophysiology Diagnostics Treatment Reanimation

Facial Nerve Anatomy 10,000 neurons 7,000 myelinated facial expression. Parasympathetic secretomotor

Nuclei(PONS) 4 Ss 1. Solitarius (Taste) 2. Superior salivatory nucleus 3. Spinal nucleus of the trigeminal nerve 4. Seventh motor

Solitarius

Superior salivatory nucleus

FACIAL NERVE FIBERS Motor Secreto-motor Taste Sensory to the stapedius and facial muscles Secreto-motor to the submandibular, sublingual salivary glands and to the lacrimal glands Taste from the anterior two thirds of tongue and palate Sensory pain, temperature, and touch from the external auditory canal

Facial Nerve Segments Intracranial Meatal Labyrinthine Tympanic Mastoid Extratemporal intracranial (cisternal) segment meatal segment (internal auditory canal) - 8 mm - zero branches labyrinthine segment (IAC to geniculate ganglion) - 3 - 4mm - 3 branches (from geniculate ganglion) tympanic segment (from geniculate ganglion to pyramidal eminence) - 8 - 11mm - zero branches mastoid segment (from pyramidal eminence to stylomastoid foramen) - 8 - 14mm - 3 branches extratemporal segment (from stylomastoid foramen to division into major branches) 15 - 20mm - 9 branches (info.med.yale.edu)

Facial Nerve Segments Intracranial Meatal Labyrinthine Tympanic Mastoid Extratemporal intracranial (cisternal) segment meatal segment (internal auditory canal) - 8 mm - zero branches labyrinthine segment (IAC to geniculate ganglion) - 3 - 4mm - 3 branches (from geniculate ganglion) tympanic segment (from geniculate ganglion to pyramidal eminence) - 8 - 11mm - zero branches mastoid segment (from pyramidal eminence to stylomastoid foramen) - 8 - 14mm - 3 branches extratemporal segment (from stylomastoid foramen to division into major branches) 15 - 20mm - 9 branches (Lalwani AK, ed. Current Diagnosis and Treatment: Otolaryngology Head and Neck Surgery, 2nd Ed.) Internal auditory canal (IAC) 7 UP Zero branches

Facial Nerve Segments Intracranial Meatal Labyrinthine Tympanic Mastoid Extratemporal intracranial (cisternal) segment meatal segment (internal auditory canal) - 8 mm - zero branches labyrinthine segment (IAC to geniculate ganglion) - 3 - 4mm - 3 branches (from geniculate ganglion) tympanic segment (from geniculate ganglion to pyramidal eminence) - 8 - 11mm - zero branches mastoid segment (from pyramidal eminence to stylomastoid foramen) - 8 - 14mm - 3 branches extratemporal segment (from stylomastoid foramen to division into major branches) 15 - 20mm - 9 branches IAC to geniculate ganglion 3-4mm Only segment that lacks arterial anastomosis

Facial Nerve Segments Intracranial Meatal Labyrinthine Tympanic Mastoid Extratemporal intracranial (cisternal) segment meatal segment (internal auditory canal) - 8 mm - zero branches labyrinthine segment (IAC to geniculate ganglion) - 3 - 4mm - 3 branches (from geniculate ganglion) tympanic segment (from geniculate ganglion to pyramidal eminence) - 8 - 11mm - zero branches mastoid segment (from pyramidal eminence to stylomastoid foramen) - 8 - 14mm - 3 branches extratemporal segment (from stylomastoid foramen to division into major branches) 15 - 20mm - 9 branches Geniculate ganglion to pyramidal eminence 50% dehiscent Zero branches

Facial Nerve Segments Intracranial Meatal Labyrinthine Tympanic Mastoid Extratemporal intracranial (cisternal) segment meatal segment (internal auditory canal) - 8 mm - zero branches labyrinthine segment (IAC to geniculate ganglion) - 3 - 4mm - 3 branches (from geniculate ganglion) tympanic segment (from geniculate ganglion to pyramidal eminence) - 8 - 11mm - zero branches mastoid segment (from pyramidal eminence to stylomastoid foramen) - 8 - 14mm - 3 branches extratemporal segment (from stylomastoid foramen to division into major branches) 15 - 20mm - 9 branches Pyramidal eminence to stylomastoid foramen 8-14mm

Facial Nerve Segments Intracranial Meatal Labyrinthine Tympanic Mastoid Extratemporal intracranial (cisternal) segment meatal segment (internal auditory canal) - 8 mm - zero branches labyrinthine segment (IAC to geniculate ganglion) - 3 - 4mm - 3 branches (from geniculate ganglion) tympanic segment (from geniculate ganglion to pyramidal eminence) - 8 - 11mm - zero branches mastoid segment (from pyramidal eminence to stylomastoid foramen) - 8 - 14mm - 3 branches extratemporal segment (from stylomastoid foramen to division into major branches) 15 - 20mm - 9 branches Stylomastoid foramen to major branches 15-20mm (www.facialparalysisinstitute.com)

Anatomy of Facial Nerve The pathway of the facial nerve is long and relatively convoluted. So there are a number of causes that may result in facial nerve paralysis

CLINICAL MANIFESTATIONS Paralysis of facial muscles Asymmetry of the face Inability to close the eye Accumulation of food in the cheek Phonophobia Dryness of the eyes Loss of taste

Diagnostics History and Physical Examination Hearing loss or vertigo Timing Sudden onset Evolution over 2-3 weeks Presence of ear disease Vesicular eruption Bilateral Recurrence Symmetric audiological function Absent ipsilateral acoustic reflex

Diagnostics History and Physical Examination Hearing loss or vertigo Timing Presence of ear disease Vesicular eruption Bilateral Recurrence

Diagnostics History and Physical Examination Hearing loss or vertigo Timing Sudden onset Evolution over 2-3 weeks Presence of ear disease Vesicular eruption Bilateral Recurrence Chronic otitis media Cholesteatoma

Diagnostics History and Physical Examination Hearing loss or vertigo Timing Sudden onset Evolution over 2-3 weeks Presence of ear disease Vesicular eruption Bilateral Recurrence Ramsay-Hunt syndrome

Diagnostics History and Physical Examination Hearing loss or vertigo Timing Sudden onset Evolution over 2-3 weeks Presence of ear disease Vesicular eruption Bilateral Recurrence (ent.uci.edu) Guillain-Barre syndrome Lyme disease Intracranial neoplasm

Diagnostics History and Physical Examination Hearing loss or vertigo Timing Sudden onset Evolution over 2-3 weeks Presence of ear disease Vesicular eruption Bilateral Recurrence (Rev Bras Otorrinolaringol 2002; 68(5):755-760) Melkersson-Rosenthal syndrome

House-Brackmann Scale Grade Appearance Forehead Eye Mouth I normal II slight weakness normal resting tone moderate to good movement complete closure minimal effort slight asymmetry III non-disfiguring weakness slight to moderate movement maximal effort IV disfiguring weakness none incomplete closure asymmetric with maximal effort V minimal movement asymmetric resting tone slight movement VI asymmetric

Diagnostics Radiology Localize lesion Computed tomography Trauma Mastoiditis Cholesteatoma Magnetic resonance imaging (MRI) Nerve enhancement Exclude neoplasm Usually MRI enhancement in labyrinthine segment

Diagnostics Topography Schirmer test → greater superficial petrosal Stapedial reflex → stapedial branch Electrogustometry → chorda tympani Salivary flow → chorda tympani

Diagnostics Audiology Evaluate for pathology of eighth cranial nerve Bell’s palsy Symmetric audiological function Absent ipsilateral acoustic reflex Retrocochlear pathology Asymmetrical thresholds Evaluate for retrocochlear pathology (e.g. neoplasm) with either ABR or MRI.

Diagnostics Electrophysiology Provides prognostic information Not used for paresis only Tests Nerve excitability test (NET) Maximum stimulation test (MST) Electroneuronography (ENoG) Electromyography (EMG)

Upper motor lesions spare the upper facial muscles and affect the contralateral lower face Lower motor lesions affect all the ipsilateral facial muscles

BELL’S PALSY Most common diagnosis of acute facial paralysis Diagnosis is by exclusion

PATHOLOGY Edema of the facial nerve sheath along its entire intratemporal course (Fallopian canal)

ETIOLOGY Vascular vs. viral

CLINICAL FEATURES Sudden onset unilateral FP Partial or complete No other manifestations apart from occasional mild pain May recur in 6 – 12%

PROGNOSIS 80% complete recovery 10% satisfactory recovery 10% no recovery

TREATMENT Reassurance Eye protection Physiotherapy Medications ( steroids, antivirals vasodilators) Surgical decompression in selected cases

SURGICAL MANAGEMENT Debate over years Patients with 90% degeneration Within 14 days of onset

INFLAMMATORY CAUSES OF FACIAL PARALYSIS

Facial Paralysis in AOM Mostly due to pressure on a dehiscent nerve by inflammatory products Usually is partial and sudden in onset Treatment is by antibiotics and myringotomy

Facial Paralysis in CSOM Usually is due to pressure by cholesteatoma or granulation tissue Insidious in onset May be partial or complete Treatment is by immediate surgical exploration and “proceed”

HERPES ZOSTER OTICUS (RAMSAY HUNT SYNDROME) Herpes zoster affection of cranial nerves VII, VIII, and cervical nerves Facial palsy, pain, skin rash, SNHL and vertigo

HERPES ZOSTER OTICUS (RAMSAY HUNT SYNDROME) Herpes zoster affection of cranial nerves VII, VIII, and other nerves Facial palsy, pain, skin rash, SNHL and vertigo Vertigo improves due to compensation SNHL is usually irreversible Facial nerve recovers in about 60% Treatment by: Acyclovir, steroid and symptomatic

Traumatic Facial Injury Birth trauma Iatrogenic Temporal bone fracture

Congenital Facial Palsy 80-90% are associated with birth trauma 10 -20 % are associated with developmental lesions

Iatrogenic Facial Nerve Injury Operations at the CP angle, ear and the parotid glands

Temporal Bone Fracture Longitudinal - 80% of Temporal Bone Fractures - 15-20% Facial Nerve involvement   Transverse - 20% of Temporal Bone Fractures - 50% Facial Nerve Involvement

Transverse Fracture

Racoon eyes sign

Battle's sign

Pathology Edema Transection of the nerve

Management of Traumatic Facial Nerve Injury If it is delayed in onset, it is usually incomplete and is due to edema Conservative If of immediate onset, it is usually complete and due to transection of the nerve Surgical repair

Facial Reanimation Facial reanimation is a family of different surgical techniques to make one's paralyzed face move more normally.

Reanimation Techniques Are based on: The cause of the facial paralysis Type of injury and its location The duration of deficit.

Facial Reanimation Techniques Broadly classified into: NEURAL METHODS: Micro-neurological surgery to re-suture the damaged nerve. Nerve graft. Nerve substitution

Facial Reanimation Techniques MUSCULOFASCIAL TRANSPOSITIONS: Move new muscles and nerves into the face to take the place of the injured facial nerve. FACIAL PLASTIC PROCEDURES. PROSTHETICS.

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. A nerve graft replaces one that has been removed.

Nerve Substitution Is indicated when the nerve cannot be repaired in the conventional manner. In this procedure, another cranial nerve involved in facial movement is connected to the damaged nerve and takes over its function.

Nerve Transposition Nerve transposition is also known as facial-hypoglossal transfer. 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.

Hypoglossal Facial Nerve Transfer Entire hypoglossal nerve transected 40% segment of nerve secured to lower division. Hypoglossal nerve reflected superiorly

Hypoglossal Facial Nerve Transfer Jump graft modification Reflection of the facial nerve out of the mastoid bone.

Temporalis Transfer Involves taking a 1-2 cm band of the temporalis muscle. Rotating it from the temple region, over the cheek bone and down, to attach to the corner of the mouth. When it is appropriately secured, the act of biting down will result in elevation of the corner of the mouth toward the cheekbone, just as in smiling.

Temporalis Muscle Transfer

Temporalis Transfer

Digastric Muscle Transposition

Gracilis Graft For Facial Paralysis

Combination Muscle And Nerve Graft In a combination muscle and nerve graft, two procedures are performed several months apart. Free muscle tissue is grafted from the leg to the face following a cross-facial nerve graft. The nerve graft becomes the nerve supply for the healthy, transplanted muscle.

Rehabilitation of the Paralyzed Eye The eyebrow can be repositioned by performing a unilateral brow lift, and matching the brow height with the other side. The eyelids can be addressed using implantable eyelid springs so that gravity assists with eye closure. Using lid gold weights Canthoplasty

Lid Gold Weights.

Nasal wall Suspension

Static Facial Suspension Static Facial Suspension is used to lift the corner of the mouth so that balance is restored to the face and drooling out of the mouth is helped.

Cosmetic Surgeries Cosmetic surgeries such as: Brow-lifts Face-lifts Muscle shortening Removal of excess upper eyelid skin Static slings Improve appearance, but will not improve muscle function.

What do you think? What is the most likely diagnosis? Mention 2 common causes?

36 years old man with RTA: What is your diagnosis? Mention 2 clinical findings?

34 yrs old with LMN facial paralysis. A- what is your diagnosis? B- what is your management?

24 yrs old man involved in RTA. A- what is your diagnosis? B- mention 2 other clinical findings?

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