Steroids vs Steroids & Antivirals for Bell ’s Palsy

by Dr Tom Waterfield

Bell’s palsy is an idiopathic facial nerve palsy first described by Sir Charles Bell in 1830. It typically presents with a sudden onset of unilateral facial palsy. It presents as a unilateral lower motor neurone weakness ie. the forehead is also involved (if the forehead is not involved, this is an upper motor neurone weakness with a different aetiology and needs prompt referral for further investigation). The prognosis in true Bell’s is typically good with up to 90% of children recovering by 3 months of age¹. The mainstay of management in children is supportive (artificial tears/patching). The convention – at least in adults – is for the early (within 72 hours of onset) use of oral prednisolone at a dose of 2mg/kg (max 60-80mg) for 5 days followed by a 5 day tapering dose². The evidence base for this comes from large randomised controlled studies in adults^3,4.

Evidence for the use of steroids alone

Two large double blind randomised control studies looking at over 1300 patients demonstrated that early use of Prednisolone orally significantly improved symptoms at 3 months (p<0.001) with a NNT of around 5^3,4. There are no similar studies in children and it is worth considering that children typically have a better prognosis than adults. Whilst prednisolone orally would be appropriate and safe for most children there may be instances where the risks of oral steroids could be considered too great to justify their use i.e. in a poorly controlled diabetic patient (which is a group in whom Bell’s palsy is more prevalent).

Evidence for the use of combined steroids and antivirals

In the last decade there has been an ongoing debate around the use of oral antiviral agents such as Aciclovir in the management of Bell’s Palsy. It is widely believed that Bell’s Palsy is due to an underlying Herpes Simplex infection and PCR studies have demonstrated concurrent HSV infection at the facial nerve in adult patients with Bell’s Palsy⁵. Despite this, good quality, large scale studies looking at the efficacy of oral antiviral agents have failed to demonstrate a benefit^3,4.

Summary

The current evidence base for the medical management of Bell’s palsy comes predominantly from adult data^3,4. Children typically have a milder illness with a quicker recovery than adults irrespective of the treatment chosen¹. UpToDate would have us believe that the mainstay of medical management is the use of oral steroids at a dose of 2mg/kg(max 60-80mg) for 5 days followed by a 5 day taper. Additional antiviral treatment appears to be unnecessary with large-scale, high quality studies not showing a benefit. Smaller, lower quality studies have suggested additional antivirals may be useful and these could be considered on a case by case basis^6,7. For example in a severe case (complete paralysis) with clinical evidence of concurrent Herpes Simplex infection it may be worth considering additional antiviral medication such as oral Aciclovir.

References:

1. Peitersen E. Bell’s palsy: the spontaneous course of 2,500 peripheral facial nerve palsies of different etiologies. ActaOtolaryngol Suppl. 2002.
2. https://www.aan.com/Guidelines/Home/GetGuidelineContent/574 (Last accessed 19/08/2014 at 12:03)
3. Sullivan FM, Swan IR, Donnan PT et al. Early treatment with prednisolone or acyclovir in Bell’s palsy. N Engl J Med. 2007;357(16):1598.
4. Yeo SG, Lee YC, Park DC, Cha CI. Acyclovir and steroid versus steroid alone in the treatment of Bell’s palsy. Am J. Otolaryngol 2008;29:163–168.
5. Schirm J, Mulkens PS. Bell’s palsy and herpes simplex virus. APMIS. 1997;105(11):815.
6. Minnerop M, Herbst M, Fimmers R, Kaabar P et al. Bell’s palsy: combined treatment of famciclovir and prednisone is superior to prednisone alone. Neurol. 2008 Nov;255(11):1726-30.
7. 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 Apr;126(4):336-41.