Corticosteroids for Bell's palsy (idiopathic facial paralysis).

BACKGROUND: Inflammation and oedema of the facial nerve are implicated in causing Bell's palsy. Corticosteroids have a potent anti-inflammatory action which should minimise nerve damage and thereby improve the outcome of patients suffering from this condition.

OBJECTIVES: The objective of this review was to assess the effect of steroid therapy in the recovery of patients with Bell's palsy.

SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group register (searched December 2003) for randomised trials, as well as MEDLINE (January 1966 to April 2003), EMBASE (January 1980 to April 2003) and LILACS (January 1982 to April 2003). We contacted known experts in the field to identify additional published or unpublished trials.

SELECTION CRITERIA: Randomised trials comparing different routes of administration and dosage schemes of corticosteroid or adrenocorticotrophic hormone therapy versus a control group where no therapy considered effective for this condition was administered, unless it was also given in a similar way to the experimental group.

DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed eligibility, trial quality, and extracted the data.

MAIN RESULTS: Four trials with a total of 179 patients were included. One trial compared cortisone acetate with placebo; one compared prednisone plus vitamins, with vitamins alone; one compared high-dose prednisone administered intravenously against saline solution, and one, not-placebo controlled, tested the efficacy of methylprednisolone. Allocation concealment was appropriate in two trials, and the data reported allowed an intention-to-treat analysis. The data included in the meta-analyses were collected from three trials with a total of 117 patients. Overall 13/59 (22%) of the patients allocated to steroid therapy had incomplete recovery of facial motor function six months after randomisation, compared with 15/58 (26%) in the control group. This reduction was not significant (relative risk 0.86, 95% confidence interval 0.47 to 1.59). The reduction in the proportion of patients with cosmetically disabling sequelae six months after randomisation was also not significant (relative risk 0.86, 95% confidence interval 0.38 to 1.98). The trial not included in the meta-analysis showed a non-significant difference in outcomes between the arms.

REVIEWERS' CONCLUSIONS: The available evidence from randomised controlled trials does not show significant benefit from treating Bell's palsy with corticosteroids. More randomised controlled trials with a greater number of patients are needed to determine reliably whether there is real benefit (or harm) from the use of corticosteroid therapy in patients with Bell's palsy.