a case of lower motor neuron facial nerve palsy

Case presentationDr. Samten Dorji

Chief complaint

• A 27 year old woman presented to the eye OPD clinic with weakness in left side of face for 2 weeks duration

She is a monk from Punakha dzongkhag

History of chief complaint

• 2 weeks back she had a sudden onset of left side facial weakness and pain in the left ear which lasted for first three days

• She had difficulty in closing her left eye and had on and off watery discharge. She complains of mild drooling.

• No previous episode• There was no history of trauma

History cont.

• Systemic review• Past ocular history/ocular

medications/systemic medications/ comorbidities/allergies/family history

Examination

• Asymmetry of the face• Absent wrinkling of left forehead• Inability to close left eye(lagophthalmus)• Mouth deviated to the right side• Unable to puff out left cheek

Right eye Left eyeVisual acuity 6/6 6/6

With pinhole

Color vision Normal Normal

Extraocular movements Normal Normal

Bell’s phenomenon Present

Lids and adnexa Normal Normal

Schirmer’s test 15mm 15mm

Conjunctiva and sclera normal normal

Cornea clear Clear( sensation intact)

Anterior chamber Normal depth and quiet Normal depth and quiet

Iris and lens Normal Normal

Pupil Round regular and reactive

Round regular and reactive

Dilated fundus Vessel sheathing and healed scars

Normal

Case summary

• A 27 year old female presented with weakness in left side of face for 2 weeks with difficulty in closing the left eye and left earache for initial 3 days.neurological examination showed left lower motor neuron seventh nerve palsy. Bell’s phenomenon and corneal sensation was intact. Dilated funduscopy showed vessel sheathing and healed scars in the left fundus.

Problems

• Left lower motor neuron seventh nerve palsy

• Healed right retinal vasculitis

Diagnosis

• House-Brackmann grade 3 left lower motor neuron facial nerve palsy with idiopathic cause.

Differential diagnosis

• Infection • Neoplasm• Congenital • Trauma

Investigation

Management

Corticosteroids

•Oral prednisolone 60mg daily for 7 days and tapered until 5mg daily•Anti acid medications•Early treatment is recommended especially within 3 days of symptoms of onset.•Significantly reduced mild and moderate sequelae.

Facial physiotherapy•To help in recovery of facial nerve function•Prevents muscle atrophy and aids in full recovery if prognosis is good

Eye lubricants•To prevent exposure keratopathy•Depending upon the severity of keratopathy the frequency of lubricants is prescribed

ENT review•Assessement was normal•To rule out any pathology causing facial nerve palsy

Lower motor neuron facial nerve palsy

Outline

• Introduction• Anatomy• Aetiology• Clinical evaluation• Management

Introduction

Function Psychology Emotion

Anatomy • Motor fibers that innervate the facial

muscles• Parasympathetic fibers innervating

lacrimal, submandibular, and sublingual salivary glands

• Afferent fibers from taste receptors from the anterior two thirds of the tongue

• Somatic afferents from the external auditory canal and pinna

• The nerve arises from two roots from the pontomedullary junction and enters the internal auditory meatus

•The facial (fallopian) canal= 33 mm •labyrinthine, tympanic, and mastoid•Narrowest in the labyrinthine segment (average 0.68 mm in diameter)

•Facial nerve emerge at the stylomastoid foramen and pass through the parotid gland•These fibers divide into five groups of nerves between the deep and superficial lobes of the gland

Aetiology

• Idiopathic (Bell’s palsy)• Trauma• Infection• Neoplasms • Congenital• Miscellaneous

Bell’s palsy• Acute peripheral facial nerve palsy of unknown cause• Diagnosis of exclusion

Epidemiology

•The annual incidence rate =13 and 34 cases per 100,000 population•Age=15-45 years age group•No race, geographic, or gender predilection•Risk is three times greater during pregnancy

Pathophysiology

• Herpes simplex virus activation is the likely cause of Bell's palsy in most cases

• Inflammatory and possibly infectious cause

• Nerve damage is maximal in the labyrinthine part of the facial canal

Trauma

• Second most common cause• Most common is temporal bone

fractures(blunt and penetrating)• Iatrogenic

Infection

• Varicella zoster virus• Lyme disease• Tuberculosis• Polio• Mumps• leprosy

Ramsay hunt syndrome

•Geniculate ganglionitis•Zoster vesicles in external auditory canal or tympanic membrane(classic sign)

Neoplasms

Congenital

Moebius syndrome

Digeorge syndrome

ColobomaHeart defectsAtresia ofchoanaeRetardation of growthGenital abnormalitiesEar abnormalities

Miscellaneous

• Diabetes mellitus• Hypertension• Amyloidosis• Sarcoidosis• Multiple sclerosis• Guillain-Barre syndrome• Myasthenia gravis• Stroke

Clinical evaluation

Laboratory investigation

• VDRL screening• Imaging studies

Management

• Medical • Surgical

Risk factors for exposure keratopathy

•Absence of corneal sensation•Severe lagophthalmus•Absent bell’s phenomenon•Dry eye

Medical

Avoid ocular irritants

Spectacle side shields

Botulinum injection into levator muscle

•Cyanoacrylate glue•High dose of oral corticosteroids

External eyelid weights

Surgical treatment

• Management of corneal exposure• Correction of lower eyelid ectropion• Management of brow ptosis• Management of chronic epiphora

Management of corneal exposure

Mullerectomy and levator aponeurosis

recession

Silicone punctal plugs Temporary suture tarsorrhaphy

Lateral tarsorrhaphy

Medial canthoplasty Gold weight implant

Correction of lower eyelid ectropion

Skin graft procedure

Mid face lift

Lateral tarsal strip procedure

Management of brow ptosis

blepharoplasty

•Impairment of superior visual field•Cosmetic deformity•Pseudo- blepharoptosis

Management of chronic epiphora

Dry eye

•eye lubricants

Paralytic ectropion

•Lateral eyelid tarsal strip procedure•Dacryocystorhinostomy and jones tube insertion

Hypersecretion/aberrant innervation

• Crocodile tear syndrome(bogoraud’s syndrome)

• Transconjunctival intraglandular Botulinum toxin A injections

Summary

• Introduction• Anatomy• Aetiology• Clinical evaluation• Management

Take home message

• Facial paralysis can be difficult to manage• Should exclude other causes before

labelling it as idiopathic• Multidisciplinary approach• Ophthalmologist role: eye protection and

aesthetic improvement

Thank you