Prednisolone is effective
In an effort to shorten recovery time and increase the number of patients who regain nerve function, a number of therapeutic options have been investigated. Antiviral agents have been tried – based on the theory that the herpes simplex virus is the cause of the palsy – while several studies have administered cortisone to reduce the presumed inflammatory reaction and thus limit nerve damage. Up until the early 2000s, numerous small studies were carried out with both types of drugs, in the absence of any evidence that either had an effect (5, 6).
Clinical practice has varied as a consequence with some countries giving no treatment and others using cortisone and/or antiviral agents.
In the 2000s, however, several large randomised studies were conducted to examine the efficacy of cortisone and antiviral agents in adults with Bell's palsy. There is now grade A evidence that treatment with prednisolone shortens recovery time and increases the proportion of patients who recover completely. Several meta-analyses have been published, from the Cochrane Group among others, which recommend prednisolone within 72 hours for adult patients (7, 8). There is currently insufficient evidence available, however, regarding the treatment of paediatric populations. The last few years have also seen the publication of review articles with guidelines on diagnosis and treatment, which again recommend early prednisolone (9) – (11).
These meta-analyses and reviews are based largely on one Scottish and one Scandinavian study. The Scottish study is a randomised, placebo-controlled, double-blind trial that compared the efficacy of prednisolone, aciclovir and combined prednisolone and aciclovir versus placebo in 551 patients (12). Prednisolone was administered at 50 mg per day and aciclovir at 2 000 mg per day for ten days. The results were published in 2007 and showed recovery in a significantly greater number of patients in the prednisolone group after three and nine months. Aciclovir had no effect, either as monotherapy or in combination with prednisolone (12).
In parallel with the Scottish study, a similar trial was conducted in Sweden and Finland (13). A total of 839 patients were randomised to receive placebo, prednisolone, valaciclovir or combination therapy with prednisolone and valaciclovir. Prednisolone was given at 60 mg per day for five days and then tapered by 10 mg per day for a further five days. Valaciclovir was given at a dose of 1 gram three times daily for seven days. The results were published in 2008 and showed a significantly shorter recovery time and greater proportion of patients with normal nerve function after 12 months in the prednisolone group. Antiviral treatment with valaciclovir had no significant effect on recovery compared to placebo (13).
In both studies, treatment was initiated within 72 hours of the onset of the facial nerve palsy. Subgroup analyses from the Scandinavian study suggest that prednisolone is effective irrespective of palsy severity and in all age groups over 18 years. The results also suggest that prednisolone is more effective if given within 48 hours (14, 15).