Facial Nerve Palsy

Objectives

To guide management of patients presenting with an isolated facial nerve (seventh cranial nerve, CN VII) palsy.

Scope

This guideline covers the initial management of a patient with an isolated facial nerve palsy in the deployed setting, it is focused on the identification and management of Bell's Palsy.

Critical differential diagnoses for isolated facial nerve palsy include:

• Stroke (CVA) or acute neurological cause such as Guillain Barre syndrome – check for other neurological symptoms and assess for forehead sparing (see below).
• Infection – assess for ENT symptoms and signs of ear canal discharge or polyp, rash. Consider Lyme disease (see separate CGO)
• Head trauma – ask about history of trauma, and look for signs of skull base or maxillofacial fracture.
• Masses in the parotid or neck - thorough examination is essential
• Ramsay Hunt (varicella zoster) - examine for vesicles around the pinna or palate, with significant pain

Note that the management of these differential diagnoses are not covered within this CGO but other guidance is available.

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a general role in forward medical locations or in an Emergency Department on deployed operations.

Initial Assessment & Management

Assessment

• A diagnosis of Bell's palsy can be made when no other medical condition is found to be causing facial weakness or paralysis. 
• Apart from rapid onset uniformly distributed one-sided lower motor neurone facial palsy, the physical examination should be unremarkable. 

• History:
  • Onset and progression
  • Any recent head / facial trauma or URTI
  • Any previous facial palsy, face/lip/parotid swelling, uveitis
  • Associated symptoms – malaise, fever, rash, headache, arthralgia, other CN issues (diplopia / hoarse voice), ear symptoms (tinnitus, hearing loss, vertigo)
  • Current pregnancy
  • Comorbidities / medications – immunosuppression, autoimmune disorder, neurotoxic medications, malignancy.
  • Recent travel, for example to a Lyme disease endemic area

• Examination:
  • Neurological examination and head and neck examination:
  • Cranial nerve.
    • The forehead receives bilateral upper motor neurone innervation, therefore, if there is forehead sparing in the facial palsy, it is likely to be an upper motor neurone cause (such as a stroke). A lower motor neurone cause results in weakness of the entire side of the face including the forehead.
  • Ears:
    • Otoscopy - Any evidence of acute / chronic otitis media or cholesteatoma.
    • Weber's and Rinne's tuning fork tests (see below). Ramsay Hunt syndrome causes sensorineural hearing loss. Conductive hearing loss may indicate otitis media or cholesteatoma. Bell’s palsy may be associated with hypersensitivity to loud sounds.
    • Ear canal - Malignant otitis externa can cause LMN facial nerve palsy. Vesicles may indicated Ramsay Hunt syndrome.
  • Parotid gland — palpate the parotid gland and visually examine the oropharynx to rule out a deep lobe parotid tumour, which may displace the tonsil medially.
  • Skin of the head, face, cheek, oral cavity, mastoid region — to check for a skin rash, nodules, or vesicles (Ramsay Hunt), ulcerative lesions, bruises (skull base fracture), swelling and tenderness (mastoiditis).
  • Eyes and periocular complex.
  • Peripheral nervous system exam – power, tone, coordination, reflexes, sensory examination
  • Other symptoms – “bullseye” lesions suggest Lyme disease

Treatments

Steroids - If presenting within 72 hrs of onset start oral prednisolone:

• 60mg once daily for 5 days then reduce by 10mg/day (total treatment 10 days)
• Ensure PPI cover (e.g. Omeprazole, Lansoprazole) for duration of steroid course

Eye Care:

• Tape the eye closed when sleeping if the patient is unable to fully close it.
• Use regular eye lubrication (artificial tears) if available.
• Use eye protection to prevent dust / debris / sunglasses when outside.

Antivirals:

• Add Valaciclovir 1g three times daily for 7 days if paralysis is complete or almost complete (House Brackman score 5 or 6), or if vesicles are seen in the ear and/or on the palate.

General management:

• Initiate facial nerve palsy exercises - see accordion content below.
• Advise patient to urgently seek further medical advice in the event of eye irritation / pain / itching / visual changes.
• If facial weakness affects eating – consider soft diet / use of straws if available.

Evacuate:

• Bell's Palsy typically takes weeks to resolved during which time the patient may be unable to close their eye leading to a high risk of ocular injury in the deployed environment.
• In all but exceptional situations the patient should therefore be evacuated to deployed hospital care following diagnosis.

Advanced Assessment & Management

• As per initial management.
• Consider FBC and U&E if an infective cause is suspected from clinical history and examination – fevers, systemically unwell, evidence of mastoiditis (pain and tenderness posterior to ear), vesicular lesions (Ramsay Hunt).
• Consider CT head if available in the case of diagnostic uncertainty and need to rule out upper motor neurone lesion, base of skull fracture, malignancy or mastoiditis.

Seek specialist advice if any evidence of:

• Upper motor neurone cause (limb paresis, facial paraesthesia, other cranial nerves involved, postural imbalance) – need urgent assessment as suspected stroke (see relevant CGO).
• Trauma
• Cancer (gradual onset over 6 months, pain in facial nerve distribution, lesions suggestive of cancer, ipsilateral hearing loss)
• Suspected infective cause

• Discuss with neurology / ENT if:
  • Atypical features
  • No improvement after 3 weeks treatment
  • Changes in neurological findings
  • Incomplete recover at 3 months or recurrent episodes
  • Diagnosis uncertain
• Discuss with ophthalmology if any eye symptoms: pain, irritation, itch, changes in acuity.

Prolonged Casualty Care

• If evacuation is not possible, continue facial nerve palsy exercises as below.
• Wean steroids gradually.
• Ensure eye protection is carefully managed, particularly in dry austere environments.

Paediatric Considerations

The incidence of Bell's palsy in children is lower than in adults, so an especially careful assessment is needed to exclude other, potentially serious, causes of facial palsy; otherwise the management is the same as in adults.

If steroids are indicated due to presenting within 72 hours then adjust dose as per formulary.