Background: The most common disorder of the facial nerve is acute idiopathic facial paralysis or Bell's palsy and there may be significant morbidity or incomplete recovery associated with severe cases.
Objectives: To assess the efficacy of aciclovir or similar agents for treating Bell's palsy.
Search strategy: We searched the Cochrane Neuromuscular Disease Group register (searched April 2003), MEDLINE (from January 1966 to April 2003), EMBASE (from January 1980 to April 2003) and LILACS (from January 1982 to April 2003). We also contacted authors of identified trials.
Selection criteria: Randomised or quasi-randomised trials of aciclovir or valaciclovir therapy, alone or in combination with any other drug, in patients with Bell's palsy.
Data collection and analysis: We identified six randomised trials.
Main results: Three studies met our inclusion criteria, including 246 patients. One study evaluated aciclovir with corticosteroid versus corticosteroid alone, another study evaluated aciclovir alone versus corticosteroid and a further study evaluated valaciclovir with corticosteroid versus corticosteroid alone or versus placebo alone. Incomplete recovery after one year: data were not available. An analysis was performed on data reported at the end of the study period in each trial. The results from one study four months after the start of treatment significantly favoured the treatment group, whilst the results of the study three months after the start of treatment significantly favoured the control group. The results from the second study at four months showed no statistically significant difference between the three groups. Adverse events: relevant data were not reported in any of the three trials. Complete facial paralysis six months after start of treatment: only one patient had complete paralysis upon entering one of the studies. This patient was assigned to the control group and the level of recovery attained was not reported. Motor synkinesis or crocodile tears one year after start of treatment: data were available up to a maximum of four months after onset of paralysis. One study reported a significant difference between the treatment groups in favour of the aciclovir plus corticosteroid group over corticosteroid alone, another demonstrated an inconclusive result with no difference between the aciclovir and corticosteroid. The third study did not comment upon these sequelae.
Reviewers' conclusions: More data are needed from a large multicentre randomised controlled and blinded study with at least 12 months' follow up before a definitive recommendation can be made regarding the effect of aciclovir or valaciclovir on Bell's palsy.