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Facial nerve palsy

Last updated: September 25, 2020

Summary

Facial (nerve) palsy is a neurological condition in which function of the facial nerve (cranial nerve VII) is partially or completely lost. It is often idiopathic but in some cases, specific causes such as trauma, infections, or metabolic disorders can be identified. Two major types are distinguished: central facial palsy (lesion occurs between cortex and nuclei in the brainstem) and peripheral facial palsy (lesion occurs between nuclei in the brainstem and peripheral organs). Central facial palsy manifests with impairment of the lower contralateral mimic musculature. In contrast, peripheral facial palsy leads to impairment of the ipsilateral mimic muscles and also affects the eyelids and forehead. Additionally, peripheral facial palsy can cause various sensory and autonomic disorders (depending on the exact location of the lesion). Diagnosis can usually be made clinically while patient history often helps in evaluating the underlying etiology. Idiopathic facial nerve palsy is treated with oral glucocorticoids and, in severe cases, antivirals. Treatment of the other types depends on the underlying cause. Most cases of idiopathic facial palsy heal completely within 3 weeks.

Etiology

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

Pathophysiology

References:[6]

Clinical features

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)
Inability to frown
  • No
  • Yes
Inability to close the eyelids completely
  • No
  • Yes
Mouth drooping
  • Yes

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
  • Synkinetic 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!

Diagnostics

  • Ask about symptom onset and duration, recent infections, and outdoor trips
  • Ask patient to perform facial movements ; (e.g., frown, whistle, inflate cheeks, smile, show teeth/grimace, close eyes tightly, blink) and observe inabilities and asymmetries of the face.
  • Additional studies to investigate for potential causes (e.g., serology for Lyme disease)
  • Nerve conduction studies: can be performed to assess recovery prognosis [8]

References:[6][9]

Treatment

References:[9][11]

Prognosis

  • 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:[12][13]

References

  1. 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
  2. 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
  3. 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.
  4. Tiemstra JD, Khatkhate N. Bell's palsy: diagnosis and management.. Am Fam Physician. 2007; 76 (7): p.997-1002.
  5. 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
  6. Blumenfeld H. Neuroanatomy Through Clinical Cases. Wiley-Blackwell ; 2010
  7. 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
  8. M. Fieux, V. Franco-Vidal, P. Devic, F. Bricaire, A. Charpiot, V. Darrouzet, L. Denoix, P. Gatignol, N. Guevara, M. Montava, J.A. Roch, F. Tankéré, S. Tronche, F. Veillon, S. Vergez, C. Vincent, G. Lamas, S. Tringali. French Society of ENT (SFORL) guidelines. Management of acute Bell's palsy. European Annals of Otorhinolaryngology, Head and Neck Diseases. 2020 . doi: 10.1016/j.anorl.2020.06.004 . | Open in Read by QxMD
  9. Baugh RF, Basura GJ, Ishii LE, et al. Clinical Practice Guideline. Otolaryngology–Head and Neck Surgery. 2013; 149 (3_suppl): p.S1-S27. doi: 10.1177/0194599813505967 . | Open in Read by QxMD
  10. 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
  11. Alsuhaibani AH. Facial nerve palsy: providing eye comfort and cosmesis. Middle East Afr J Ophthalmol. 2010; 17 (2): p.142-147. doi: 10.4103/0974-9233.63078 . | Open in Read by QxMD
  12. 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.
  13. 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.