Bell's Palsy - Medical Treatment and Influence of Prognostic Factors

Abstract: Bell’s palsy is an acute onset of peripheral facial nerve dysfunction. Despite extensive research the aetiology is unclear. The most prevailing theory is that reactivation of viruses such as Herpes simplex type-1 or Varicella zoster may cause Bell’s palsy. The natural course is favourable but at least 30% of patients will suffer sequelae such as residual paresis, synkinesis and/or contracture. The most commonly used medical treatment to reduce sequelae has been corticosteroids and/or antiviral agents, the usefulness of which has been debated since earlier studies have shown diverging results.
The aim of this thesis was to evaluate the effect of treatment with prednisolone and/or valaciclovir in a large number of Bell’s palsy patients and study how prognostic factors such as age, severity of palsy at baseline, and time to treatment start may influence outcome.
Data from the Scandinavian Bell’s Palsy Study (SBPS), a prospective, randomised, double-blind, placebo-controlled multicentre study with 12-month follow-up, were evaluated. In total, 829 patients, aged 18−75, were included in the intention to treat (ITT) analysis: 210 patients received prednisolone plus placebo, 207 valaciclovir plus placebo, 206 prednisolone plus valaciclovir and 206 placebo plus placebo. Outcome was measured using the Sunnybrook facial grading system (SFGS) and House-Brackmann scale (HBS) at baseline and each follow-up. Follow-ups were scheduled for day 11–17 and 1, 2, 3, 6 and 12 months after palsy onset.
Significantly better outcome was seen in patients treated with prednisolone (72%) compared with patients who did not receive prednisolone (57%) (P<0.0001). Time to complete recovery was also significantly shorter in patients treated with prednisolone compared with patients not treated with prednisolone (P<0.0001). Synkinesis at 12 months was less frequent in patients treated with prednisolone (14%) compared with patients not receiving prednisolone (29%) (P<0.0001). Where treatment started within 48 hours, patients in the prednisolone group had shorter time to complete recovery, higher complete recovery rates and less synkinesis compared with the group not treated with prednisolone. Patients aged ≥40 years had significantly higher complete recovery rates if treated with prednisolone. This was not seen in patients <40 years, but synkinesis was less prevalent in patients <40 years old given prednisolone. All patients, regardless of severity at baseline, showed significantly higher complete recovery rates if treated with prednisolone compared with no prednisolone. In patients with moderate and mild palsy at baseline, significantly fewer prednisolone-treated patients had synkinesis at 12 months. Valaciclovir alone showed no effect on recovery rates, time to recovery or synkinesis and did not show any additive effect to prednisolone.
In conclusion, prednisolone treatment in Bell’s palsy is recommended for use in adult patients regardless of severity of palsy and age, and should be started as early as possible, as long as no contraindications for steroid treatment is present.