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Facial nerve palsy

Last updated: December 10, 2021

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Facial nerve palsy is the partial (paresis) and/or total (paralysis) loss of facial nerve (cranial nerve VII) function. The most common cause is idiopathic peripheral facial nerve palsy, also known as Bell palsy. Secondary causes include trauma, infections, brainstem stroke, tumors, and metabolic disorders. Clinical features include decreased or absent movement of the facial muscles, hyperacusis, alterations in taste, and dry eyes and mouth. Facial nerve palsy is a clinical diagnosis made after obtaining a thorough history and physical examination, which includes assessing for motor signs in central and peripheral facial palsy in order to differentiate between central upper motor neuron lesions (e.g., as a result of stroke) and peripheral lower motor neuron lesions (e.g., idiopathic, or caused by infection or trauma). If a secondary cause is suspected following assessment, diagnostic studies may be performed. Idiopathic peripheral facial nerve palsy is treated with oral glucocorticoids with or without antivirals and most cases resolve within three weeks. If secondary causes are identified, the underlying cause is treated. Complications include incomplete recovery of facial nerve function, facial synkinesis, and ocular complications related to incomplete eye closure.

References:[2][3][4][5]

References:[6]

Central vs. peripheral facial nerve palsy [6]

Motor signs in central and peripheral facial palsy
Clinical feature Central (signs are contralateral to the lesion) Peripheral (signs are ipsilateral to the lesion)
Ability to frown or lift eyebrows
  • Intact
  • Impaired
Ability to close the eyelids completely
  • Intact
  • Impaired
Mouth drooping
  • Present

Additional signs of peripheral facial palsy

  • Sensory disturbances
  • Dry mouth (as a result of decreased saliva production)
  • Ocular features
    • Bell's phenomenon: a physiologic, reflexive movement of the eye (upward and outward) that occurs when the eyelid is actively closed
    • Lagophthalmos: The patient cannot fully close the eyes (due to paralysis of the orbicular oculi muscle). [7]
    • Decreased lacrimation
    • Corneal ulceration and keratitis
    • Ectropion
  • Facial synkinesis; : involuntary movements of the facial muscles; (e.g., facial spasms while closing the eyes)

In central facial palsy, paralysis is contralateral to the lesion, and eyelid and forehead muscles are not affected!

Clinical evaluation [8][9][10]

Bell palsy is a clinical diagnosis of exclusion.

Typical features of Bell palsy include acute (< 72 hours), nonprogressive, unilateral peripheral facial nerve paralysis, with no identified cause after thorough clinical evaluation. [9]

When an acute central cause is suspected (e.g., other acute focal neurological symptoms are present), evaluate for ischemic stroke. Consider a tumor in patients with gradual onset, or slowly progressing neurological symptoms (e.g., change in mental status, involvement of select branches of the facial nerve and/or other cranial nerves, or other subacute focal neurological deficits). [4][9]

Severity assessment [9][11]

  • Determine the level of dysfunction of forehead movements, eye closure, and mouth closure.
  • Consider the use of a validated severity scale.

Diagnostic studies [8][9][10]

Diagnostic studies are not routinely needed for acute unilateral facial nerve palsy unless a secondary cause is suspected (see “Etiology”) based on atypical symptoms and/or abnormal physical examination findings (See “Clinical features” and “Clinical evaluation”). Specialist consultation is advised.

Up to 25% of acute facial nerve palsy cases may be attributed to Lyme disease in highly endemic areas. [9]

Recommendations in this section are consistent with the 2013 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) Bell palsy guidelines and the 2012 American Academy of Neurology (AAN) guideline update on steroids for Bell palsy (reaffirmed in January 2020). [8][9]

Begin initial management of ischemic stroke without delay if acute central facial nerve palsy is suspected.

Symptomatic therapy [8][9][10]

Provide symptom-based treatment for all patients (regardless of the cause).

  • Incomplete eye closure: Initiate eye care; (e.g., artificial tears; , eye ointment, and/or taping or patching of the eye). [9]
  • Incomplete mouth closure: Advise the patient on proper lip and mouth care.
  • Persistent facial nerve paresis (≥ 3 months): Consider physical therapy and facial reconstructive options. [9][10]

Consider early ophthalmology referral for patients with severe facial nerve palsy, severe, persistent lagophthalmos, or other ocular symptoms (e.g., pain, itching, irritation). [9]

Targeted treatment

Bell palsy [8][9][10]

Idiopathic peripheral facial nerve palsy is self-limited, but early treatment is recommended to improve recovery time and prevent incomplete recovery. [9]

  • Oral glucocorticoids: Consider for all patients (regardless of severity). [9]
  • Antivirals
  • Surgical decompression [9][10]
    • Not routinely recommended because of severe risks and unclear benefits
    • Consider urgent surgical (e.g., plastic surgery, ENT) referral for patients with severe facial nerve involvement (confirmed on nerve conduction studies). [9]
  • Follow up with specialist consult and/or advanced studies if the patient has any of the following: [9][12]
    • No signs of improvement in 2–3 weeks [10]
    • Persistent (≥ 3 months), progressive, and/or recurrent symptoms

Initiate therapy (i.e., oral glucocorticoids with or without antivirals) within 48–72 hours of symptom onset. [8][9][10]

Secondary facial nerve palsy

Consider the following depending on the suspected etiology.

  • Idiopathic facial palsy: complete recovery in ∼ 85% of cases (within 3 weeks)
  • Misdirected regrowth of nerve fibers can lead to persistent disorders (e.g., synkinesias)

References:[15][16]

  1. Gronseth GS, Paduga R. Evidence-based guideline update: Steroids and antivirals for Bell palsy: Report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology. 2012; 79 (22): p.2209-2213. doi: 10.1212/wnl.0b013e318275978c . | Open in Read by QxMD
  2. Baugh RF, Basura GJ, Ishii LE, et al. Clinical Practice Guideline: Bell’s Palsy. Otolaryngol Head Neck Surg. 2013; 149 (3_suppl): p.S1-S27. doi: 10.1177/0194599813505967 . | Open in Read by QxMD
  3. De Almeida JR, Guyatt GH, Sud S, et al. Management of Bell palsy: clinical practice guideline. Can Med Assoc J. 2014; 186 (12): p.917-922. doi: 10.1503/cmaj.131801 . | Open in Read by QxMD
  4. Zhang W, Xu L, Luo T, Wu F, Zhao B, Li X. The etiology of Bell’s palsy: a review. J Neurol. 2019; 267 (7): p.1896-1905. doi: 10.1007/s00415-019-09282-4 . | Open in Read by QxMD
  5. Turel KE, Sharma NK, Verghese J, Desai S. Post Traumatic Facial Paralysis Treatment Options and Strategies. Indian Journal of Neurotrauma . 2005; 2 (1): p.33-34. doi: 10.1016/S0973-0508(05)80008-5 . | Open in Read by QxMD
  6. Ronthal M. Bell's palsy: Pathogenesis, clinical features, and diagnosis in adults. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/bells-palsy-pathogenesis-clinical-features-and-diagnosis-in-adults.Last updated: December 1, 2016. Accessed: December 4, 2017.
  7. Tiemstra JD, Khatkhate N. Bell's palsy: diagnosis and management.. Am Fam Physician. 2007; 76 (7): p.997-1002.
  8. Gaudin RA, Jowett N, Banks CA, Knox CJ, Hadlock TA. Bilateral Facial Paralysis. Plast Reconstr Surg. 2016; 138 (4): p.879-887. doi: 10.1097/prs.0000000000002599 . | Open in Read by QxMD
  9. Blumenfeld H. Neuroanatomy Through Clinical Cases. Wiley-Blackwell ; 2010
  10. Correia Pereira MV, Firmato Glória AL. Lagophthalmos. Semin Ophthalmol. 2010; 25 (3): p.72-78. doi: 10.3109/08820538.2010.488578 . | Open in Read by QxMD
  11. Fattah AY, Gurusinghe ADR, Gavilan J, et al. Facial Nerve Grading Instruments. Plast Reconstr Surg. 2015; 135 (2): p.569-579. doi: 10.1097/prs.0000000000000905 . | Open in Read by QxMD
  12. Policeni B et al.. ACR Appropriateness Criteria ® Cranial Neuropathy. J Am Coll Radiol. 2017; 14 (11): p.S406-S420. doi: 10.1016/j.jacr.2017.08.035 . | Open in Read by QxMD
  13. Sweeney CJ. NOSOLOGICAL ENTITIES?: Ramsay Hunt syndrome. J Neurol Neurosurg Psychiatry. 2001; 71 (2): p.149-154. doi: 10.1136/jnnp.71.2.149 . | Open in Read by QxMD
  14. Wormser GP, Dattwyler RJ, Shapiro ED et al. The Clinical Assessment, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006; 43 (9): p.1089-1134. doi: 10.1086/50866710.1086/508667 . | Open in Read by QxMD
  15. Ronthal M. Bell's palsy: Treatment and prognosis in adults. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/bells-palsy-treatment-and-prognosis-in-adults?source=see_link#H2641362362.Last updated: August 27, 2016. Accessed: February 14, 2017.
  16. Facial Nerve Palsy. http://www.msdmanuals.com/professional/neurologic-disorders/neuro-ophthalmologic-and-cranial-nerve-disorders/facial-nerve-palsy. Updated: February 1, 2016. Accessed: March 1, 2017.