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Bell's palsy: Prognosis and treatment in adults

Michael Ronthal, MD
Section Editor
Jeremy M Shefner, MD, PhD
Deputy Editor
John F Dashe, MD, PhD


Bell's palsy is the appellation commonly used to describe an acute peripheral facial palsy of unknown cause. However, the terms "Bell's palsy" and "idiopathic facial paralysis" may no longer be considered synonymous. A peripheral facial palsy is a clinical syndrome of many causes, and evaluation requires more than a superficial examination.

This review will discuss the treatment and prognosis of Bell's palsy (ie, idiopathic facial nerve palsy or facial nerve palsy of suspected viral etiology). Other clinical aspects of this disorder are reviewed separately. (See "Bell's palsy: Pathogenesis, clinical features, and diagnosis in adults".)

The treatment of facial nerve palsy related to Lyme disease is discussed elsewhere. (See "Treatment of Lyme disease", section on 'Facial nerve palsy'.)


The prognosis of Bell's palsy is related to the severity of the lesion [1]. A simple rule is that clinically incomplete lesions tend to recover. The House-Brackmann grading system (table 1) was devised both as a clinical indicator of severity and also an objective record of progress [2]. On this scale, grades I and II have good outcomes, grades III and IV characterize moderate dysfunction, and grades V and VI portend a poor result. Other grading systems (eg, the Sunnybrook facial grading system [3]) are similar and sometimes favored [4-7].

Statistically, the natural history without treatment was described in a study of 1011 patients in 1982 [8]. One-third had an incomplete paralysis, and two-thirds had complete paralysis. Overall, 85 percent showed signs of recovery within three weeks, 71 percent had complete recovery, 13 percent had slight sequelae, and 16 percent had residual weakness, synkinesis, and/or contracture. Patients with incomplete lesions had a 94 percent rate of return to normal function, while only 60 percent of those with clinically complete lesions returned to normal function. Herpes zoster is associated with more severe paresis and a worse prognosis compared with "idiopathic" Bell's palsy [9].


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Literature review current through: Aug 2016. | This topic last updated: Dec 1, 2015.
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  1. Sunderland S. Nerve and Nerve Injuries, 2nd ed, Churchill Livingstone, London 1978.
  2. House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985; 93:146.
  3. Ross BG, Fradet G, Nedzelski JM. Development of a sensitive clinical facial grading system. Otolaryngol Head Neck Surg 1996; 114:380.
  4. Chee GH, Nedzelski JM. Facial nerve grading systems. Facial Plast Surg 2000; 16:315.
  5. Berg T, Jonsson L, Engström M. Agreement between the Sunnybrook, House-Brackmann, and Yanagihara facial nerve grading systems in Bell's palsy. Otol Neurotol 2004; 25:1020.
  6. Coulson SE, Croxson GR, Adams RD, O'Dwyer NJ. Reliability of the "Sydney," "Sunnybrook," and "House Brackmann" facial grading systems to assess voluntary movement and synkinesis after facial nerve paralysis. Otolaryngol Head Neck Surg 2005; 132:543.
  7. Marsk E, Bylund N, Jonsson L, et al. Prediction of nonrecovery in Bell's palsy using Sunnybrook grading. Laryngoscope 2012; 122:901.
  8. Peitersen E. The natural history of Bell's palsy. Am J Otol 1982; 4:107.
  9. Peitersen E. Bell's palsy: the spontaneous course of 2,500 peripheral facial nerve palsies of different etiologies. Acta Otolaryngol Suppl 2002; :4.
  10. Jabor MA, Gianoli G. Management of Bell's palsy. J La State Med Soc 1996; 148:279.
  11. CAWTHORNE T, HAYNES DR. Facial palsy. Br Med J 1956; 2:1197.
  12. Boddie HG. Recurrent Bell's palsy. J Laryngol Otol 1972; 86:117.
  13. Hallmo P, Elverland HH, Mair IW. Recurrent facial palsy. Arch Otorhinolaryngol 1983; 237:97.
  14. Pitts DB, Adour KK, Hilsinger RL Jr. Recurrent Bell's palsy: analysis of 140 patients. Laryngoscope 1988; 98:535.
  15. McGregor JA, Guberman A, Amer J, Goodlin R. Idiopathic facial nerve paralysis (Bell's palsy) in late pregnancy and the early puerperium. Obstet Gynecol 1987; 69:435.
  16. Holland NJ, Weiner GM. Recent developments in Bell's palsy. BMJ 2004; 329:553.
  17. Adour KK, Ruboyianes JM, Von Doersten PG, et al. Bell's palsy treatment with acyclovir and prednisone compared with prednisone alone: a double-blind, randomized, controlled trial. Ann Otol Rhinol Laryngol 1996; 105:371.
  18. Antunes ML, Fukuda Y, Testa JR. [Clinical treatment of Bell's palsy: comparative study among valaciclovir plus deflazacort, deflazacort and placebo]. Acta AWHO 2000; 19:68.
  19. Kawaguchi K, Inamura H, Abe Y, et al. Reactivation of herpes simplex virus type 1 and varicella-zoster virus and therapeutic effects of combination therapy with prednisolone and valacyclovir in patients with Bell's palsy. Laryngoscope 2007; 117:147.
  20. Hato N, Yamada H, Kohno H, et al. Valacyclovir and prednisolone treatment for Bell's palsy: a multicenter, randomized, placebo-controlled study. Otol Neurotol 2007; 28:408.
  21. Sullivan FM, Swan IR, Donnan PT, et al. Early treatment with prednisolone or acyclovir in Bell's palsy. N Engl J Med 2007; 357:1598.
  22. Yeo SG, Lee YC, Park DC, Cha CI. Acyclovir plus steroid vs steroid alone in the treatment of Bell's palsy. Am J Otolaryngol 2008; 29:163.
  23. Engström M, Berg T, Stjernquist-Desatnik A, et al. Prednisolone and valaciclovir in Bell's palsy: a randomised, double-blind, placebo-controlled, multicentre trial. Lancet Neurol 2008; 7:993.
  24. de Almeida JR, Al Khabori M, Guyatt GH, et al. Combined corticosteroid and antiviral treatment for Bell palsy: a systematic review and meta-analysis. JAMA 2009; 302:985.
  25. Quant EC, Jeste SS, Muni RH, et al. The benefits of steroids versus steroids plus antivirals for treatment of Bell's palsy: a meta-analysis. BMJ 2009; 339:b3354.
  26. van der Veen EL, Rovers MM, de Ru JA, van der Heijden GJ. A small effect of adding antiviral agents in treating patients with severe Bell palsy. Otolaryngol Head Neck Surg 2012; 146:353.
  27. Salinas RA, Alvarez G, Daly F, Ferreira J. Corticosteroids for Bell's palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2010; :CD001942.
  28. Turgeon RD, Wilby KJ, Ensom MH. Antiviral treatment of Bell's palsy based on baseline severity: a systematic review and meta-analysis. Am J Med 2015; 128:617.
  29. Gagyor I, Madhok VB, Daly F, et al. Antiviral treatment for Bell's palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2015; :CD001869.
  30. Berg T, Bylund N, Marsk E, et al. The effect of prednisolone on sequelae in Bell's palsy. Arch Otolaryngol Head Neck Surg 2012; 138:445.
  31. Lee HY, Byun JY, Park MS, Yeo SG. Steroid-antiviral treatment improves the recovery rate in patients with severe Bell's palsy. Am J Med 2013; 126:336.
  32. Gilden DH, Tyler KL. Bell's palsy--is glucocorticoid treatment enough? N Engl J Med 2007; 357:1653.
  33. Gronseth GS, Paduga R, American Academy of Neurology. Evidence-based guideline update: steroids and antivirals for Bell palsy: report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology 2012; 79:2209.
  34. Baugh RF, Basura GJ, Ishii LE, et al. Clinical practice guideline: Bell's palsy. Otolaryngol Head Neck Surg 2013; 149:S1.
  35. Schwartz SR, Jones SL, Getchius TS, Gronseth GS. Reconciling the clinical practice guidelines on Bell's palsy from the AAO-HNSF and the AAN. Otolaryngol Head Neck Surg 2014; 150:709.
  36. de Almeida JR, Guyatt GH, Sud S, et al. Management of Bell palsy: clinical practice guideline. CMAJ 2014; 186:917.
  37. McAllister K, Walker D, Donnan PT, Swan I. Surgical interventions for the early management of Bell's palsy. Cochrane Database Syst Rev 2011; :CD007468.
  38. Grogan PM, Gronseth GS. Practice parameter: Steroids, acyclovir, and surgery for Bell's palsy (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2001; 56:830.
  39. Yanagihara N, Hato N, Murakami S, Honda N. Transmastoid decompression as a treatment of Bell palsy. Otolaryngol Head Neck Surg 2001; 124:282.
  40. Knox GW. Treatment controversies in Bell palsy. Arch Otolaryngol Head Neck Surg 1998; 124:821.
  41. Fisch U. Prognostic value of electrical tests in acute facial paralysis. Am J Otol 1984; 5:494.
  42. Shrode LW. Treatment of facial muscles affected by Bell's palsy with high-voltage electrical muscle stimulation. J Manipulative Physiol Ther 1993; 16:347.
  43. Gittins J, Martin K, Sheldrick J, et al. Electrical stimulation as a therapeutic option to improve eyelid function in chronic facial nerve disorders. Invest Ophthalmol Vis Sci 1999; 40:547.
  44. Targan RS, Alon G, Kay SL. Effect of long-term electrical stimulation on motor recovery and improvement of clinical residuals in patients with unresolved facial nerve palsy. Otolaryngol Head Neck Surg 2000; 122:246.
  45. Ito H, Ito H, Nakano S, Kusaka H. Low-dose subcutaneous injection of botulinum toxin type A for facial synkinesis and hyperlacrimation. Acta Neurol Scand 2007; 115:271.
  46. Nava-Castañeda A, Tovilla-Canales JL, Boullosa V, et al. Duration of botulinum toxin effect in the treatment of crocodile tears. Ophthal Plast Reconstr Surg 2006; 22:453.
  47. Gilden DH. Clinical practice. Bell's Palsy. N Engl J Med 2004; 351:1323.
  48. Douglas RS, Gausas RE. A systematic comprehensive approach to management of irreversible facial paralysis. Facial Plast Surg 2003; 19:107.