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Bell's palsy is characterised by an acute, unilateral, partial or complete paralysis of the face, which may occur with mild pain, numbness, increased sensitivity to sound, and altered taste. Bell's palsy remains idiopathic, but a proportion may be caused by reactivation of herpes viruses from cranial nerve ganglia. Bell's palsy is most common in people aged 15-40 years, affecting 1 in 60 in their lifetime. Most make a spontaneous recovery within 1 month, but up to 30% have delayed or incomplete recovery.
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments in adults and children? We searched: Medline, Embase, The Cochrane Library and other important databases up to February 2006 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
We found eight systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: antiviral treatment, corticosteroids (alone or plus antiviral treatment), facial nerve decompression surgery, and mime therapy.
Bell's palsy is characterised by unilateral, acute paresis or acute paralysis of the face, which may occur with mild pain, numbness, increased sensitivity to noise, and altered taste.
We don't know whether facial nerve decompression surgery is beneficial in Bell's palsy, as no studies of adequate quality have been found.
Mime therapy may improve facial stiffness and lip mobility in Bell's palsy, but the evidence is too weak to draw conclusions.
Bell's palsy is an idiopathic, acute, unilateral paresis or paralysis of the face in a pattern consistent with peripheral facial nerve dysfunction, and may be partial or complete, occurring with equal frequency on the right and left sides of the face. While other possible causes need to be excluded, there is increasing evidence that Bell's palsy is caused by herpes viruses. Additional symptoms of Bell's palsy may include mild pain in or behind the ear, oropharyngeal or facial numbness, impaired tolerance to ordinary levels of noise, and disturbed taste on the anterior part of the tongue. Severe pain is more suggestive of herpes zoster virus infection (shingles) and possible progression to a Ramsay Hunt syndrome, but another cause should be carefully excluded. Up to 30% of people with an acute peripheral facial palsy will not have Bell's palsy; other causes may include stroke, tumour, trauma, middle ear disease, and Lyme disease. Features such as sparing of movement in the upper face (central pattern), or weakness of a specific branch of the facial nerve (segmental pattern), suggest an alternative cause. Bell's palsy is less commonly the cause of facial palsy in children under 10 (under 40%), so an alternative cause should be carefully excluded. The assessment should identify acute suppurative ear disease (including mastoiditis), a parotid mass or Lyme disease in endemic areas.
The incidence is about 20/100,000 people a year, or about 1/60 people in a lifetime. Bell's palsy has a peak incidence between the ages of 15 and 40 years. Men and women are equally affected, although the incidence may be increased in pregnant women.
The cause of Bell's palsy is unknown, but it is thought that reactivated herpes viruses from the cranial nerve ganglia have a key role in the development of this condition. Herpes simplex virus-1 has been detected in in up to 50% of cases by some researchers and herpes zoster virus in approximately 13% of cases. Herpes zoster associated facial palsy more frequently presents as zoster sine herpete (without vesicles), although 6% of people will subsequently develop vesicles (Ramsay Hunt syndrome). Thus, treatment plans for the management of Bell's palsy should recognise the high incidence of herpes zoster virus, which is associated with worse outcomes. Inflammation of the facial nerve initially results in reversible neuropraxia, but ultimately Wallerian degeneration ensues.
Overall, Bell's palsy has a fair prognosis without treatment. Clinically important improvement occurs within 3 weeks in 85% of people and within 3-5 months in the remaining 15%. People failing to show signs of improvement by 3 weeks may have suffered severe degeneration of the facial nerve, or have an alternative diagnosis that requires identification by specialist examination or investigations, such as computed tomography or magnetic resonance imaging. Overall, 71% of people will fully recover facial muscle function (61% of people with complete palsy, 94% of people with partial palsy). The remaining 29% are left with mild to severe residual facial muscle weakness, 17% with contracture and 16% with hemifacial spasm or synkinesis. Incomplete recovery of facial expression may have a long-term impact on quality of life. The prognosis for children with Bell's palsy is generally good, with a high rate (more than 90%) of spontaneous recovery, in part because of the high frequency of partial paralysis. However, children with complete palsies may suffer poor outcomes as frequently as adults.
To prevent progression from partial to complete facial palsies; to maximise the speed of recovery; to increase the proportion of people making a full recovery; to reduce the incidence of motor synkinesis and contracture; to avoid morbidity to the eye, with minimum adverse effects.
Grade of recovery of motor function of the face; presence of sequelae (motor synkinesis, autonomic dysfunction, hemifacial spasm); time to full recovery.
BMJ Clinical Evidence search and appraisal February 2007. We performed a broad search for RCTs of any type of corticosteroid, antiviral agent, corticosteroid plus antiviral agent, or physical treatments other than electrical or magnetic stimulation for facial retraining in adults and children with Bell′s palsy, and included any RCT of sufficient quality. Trials used different scoring systems for reporting outcomes. The following databases were used to identify studies for this review: Medline 1966 to February 2007, Embase 1980 to February 2007, and The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials 2007, Issue 1. Additional searches were carried out using these websites: NHS Centre for Reviews and Dissemination (CRD) — for Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA), Turning Research into Practice (TRIP), and National Institute for Health and Clinical Excellence (NICE). Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the author for additional assessment, using predetermined criteria to evaluate relevant studies. Study design criteria for inclusion in this review were: published systematic reviews and RCTs in any language, at least single blinded, and containing more than 20 individuals of whom more than 80% were followed up. There was no minimum length of follow-up required to include studies. We excluded all studies described as "open", "open label", or not blinded unless blinding was impossible. In addition we use a regular surveillance protocol to capture harms alerts from organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA), which are added to the reviews as required. We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table ).
The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients.To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.
RECOVERY OF MOTOR FUNCTION Compared with placebo or no specific treatment: Corticosteroids (cortisone acetate, prednisolone, methylprednisolone) may be no more effective at 6–12 months at recovering facial motor function than placebo or no specific treatment ( very low-quality evidence ). Compared with antivirals: Prednisolone is more effective at 12 weeks at producing full recovery of facial function compared with aciclovir ( moderate-quality evidence ). PRESENCE OF SEQUELAE Compared with placebo or no specific treatment: Corticosteroids are no more effective at 6–12 months at reducing cosmetically disabling sequelae, motor synkinesis and autonomic dysfunction than placebo or no specific treatment (moderate-quality evidence). Compared with antivirals: Prednisolone may be no more effective at 12 weeks at reducing motor synkinesis than aciclovir ( low-quality evidence ). TIME TO RECOVERY Compared with placebo or no specific treatment: Prednisolone is more effective at reducing the time to recovery of facial nerve function compared with placebo or no specific treatment (moderate-quality evidence). For corticosteroids in combination with antivirals, see separate option .
We found one systematic review (search date 2003, 4 RCTs, 179 people). The first RCT identified by the review (26 people, aged 12–76 years) compared cortisone acetate versus placebo; the second RCT (51 people, ages not specified) compared prednisolone plus vitamins versus vitamins alone; the third RCT (42 children, aged 24–74 months) compared methylprednisolone versus no treatment; and the fourth RCT (62 people, aged 15–84 years) compared prednisolone plus vitamins versus saline solution plus vitamins. The review found no significant difference between corticosteroids (cortisone acetate, prednisolone, methylprednisolone) and control in the proportion of people with incomplete recovery of facial motor function after 6 months (3 RCTs: 13/59 [22%] of people with corticosteroid v 15/58 [26%] of people with control; RR 0.86, 95% CI 0.47 to 1.59). When data from two quasi-randomised trials found by the review were added to the pooled estimate, the result remained non-significant (RR 0.69, 95% CI 0.42 to 1.16; absolute numbers not reported; see comment below). The review also found no significant difference between corticosteroid and control in the proportion of people with cosmetically disabling sequelae after 6 months (3 RCTs, 117 people: 8/59 [14%] of people with corticosteroid v 9/58 [16%] of people with control; RR 0.86, 95% CI 0.38 to 1.98). When data from two quasi-randomised trials found by the review were added to the pooled estimate, the result remained non significant (RR 0.82, 95% CI 0.39 to 1.73; absolute numbers not reported). The fourth RCT identified by the review but not included in the meta-analysis, found that prednisolone significantly reduced the time to recover facial nerve function compared with placebo (18.8 days with prednisolone v 35.6 days with control; P = 0.005). It also found that prednisolone increased full recovery compared with placebo at 12 months, although the significance of this difference was not reported (83% with prednisolone v 75% with control). The review found no significant difference between treatments in motor synkinesis and autonomic dysfunction at 12 months (5/32 [16%] with prednisolone v 7/30 [24%] with control; RR 0.67, 95% CI 0.24 to 1.88).
See benefits of antiviral treatment.
See benefits of corticosteroids plus antiviral treatment.
One RCT identified by the review reported temporary sleep disturbances with prednisolone (3/32 [9%] with prednisolone; results for placebo group not reported). The side-effects of steroid treatment are well documented, including diabetes, hypertension, glaucoma, psychosis, fluid and electrolyte disturbances, gastrointestinal tract haemorrhage, and aseptic necrosis of the hip. The high incidence of abnormal glucose tolerance in people with Bell's palsy warrants special caution.
Of the two quasi-randomised trials identified by the review, one compared corticosteroids (preparation not stated) versus supportive therapy only, and used alternation in matched participants as the method of allocation. The other compared dexamethasone versus placebo, and used allocation according to the day of admission.
No new evidence
RECOVERY OF MOTOR FUNCTION Compared with corticosteroids: Aciclovir is less effective at 12 weeks at producing full recovery of facial function than prednisolone (moderate-quality evidence). PRESENCE OF SEQUELAE Compared with corticosteroids: Aciclovir may be no more effective at 12 weeks at reducing motor synkinesis compared with prednisolone ( low-quality evidence ). NOTE Aciclovir requires five times daily dosing and demonstrates poorer bioavailability than valaciclovir, which has shown greater effectiveness in the management of shingles. We found no direct information assessing the effects of antiviral agents other than aciclovir in people with Bell's Palsy. For antivirals in combination with corticosteroids, see separate option .
We found one systematic review (search date 2003, 1 RCT, 101 people), which identified one RCT comparing aciclovir (2400 mg per day for 10 days) versus prednisolone (1 mg/kg for 10 days then tapered to zero over the next 6 days). The RCT found that prednisolone produced full recovery significantly more often compared with aciclovir alone at 12 weeks (people with incomplete recovery: 12/54 [22%] with aciclovir v 3/47 [6%] with prednisolone; RR 3.48, 95% CI 1.05 to 11.1). However, it found no significant difference in motor synkinesis between treatment groups (motor synkinesis: 13/54 [24%] with aciclovir v 11/47 [23%] with prednisolone; RR 1.03, 95% CI 0.51 to 2.07).We found no RCTs comparing antivirals other than aciclovir versus corticosteroids.
See benefits of corticosteroids plus antiviral treatment.
The systematic review identified three further studies of aciclovir, which were not of sufficient quality for inclusion. In the RCT identified by the review, the 10-day duration of administration of aciclovir was shorter than the 16 days of prednisolone, which may have biased the study against aciclovir.In pregnant women, antiviral treatments such as aciclovir should only be prescribed under the guidance of an obstetrician. Aciclovir requires five times daily dosing and demonstrates poorer bioavailability than valaciclovir (a prodrug of aciclovir), which has shown greater effectiveness in the management of shingles.
No new evidence
RECOVERY OF MOTOR FUNCTION Compared with no treatment: Prednisolone plus valaciclovir may be more effective at increasing complete recovery of full facial function compared with no medical treatment ( very low-quality evidence ). Compared with corticosteroids: Prednisolone plus aciclovir is more effective at four months at recovering full facial function compared with prednisolone alone ( moderate-quality evidence ).
We found no systematic review or RCTs. One observational study (56 people) comparing valaciclovir plus prednisolone versus no medical treatment found that valaciclovir plus prednisolone increased complete recovery compared with no medical treatment in people over 60 years (complete recovery: AR 10/10 [100%] with valaciclovir plus prednisolone v 5/12 [42%] with no medical treatment, P less than 0.01).
We found one systematic review (search date 2003), which identified one RCT (119 people) comparing aciclovir (400 mg 5 times daily for 10 days) plus prednisolone versus prednisolone alone (see comment below). It found that after 4 months, aciclovir plus prednisolone produced full recovery of facial function significantly more often compared with prednisolone alone (moderate or moderately severe dysfunction measured using a facial function scoring system: 4/53 [8%] of people with aciclovir plus prednisolone v 11/46 [24%] with prednisolone alone; RR 0.32, 95% CI 0.11 to 0.92; see comment below). In the RCT, 20/119 (17%) of people enrolled in the trial were lost to follow-up. It is not clear to which treatment group these belonged. Results were calculated from the 99/119 (83%) people who completed the trial. We found no RCTs assessing the effects of corticosteroids in combination with antiviral agents other than aciclovir compared with either treatment alone, and no RCTs comparing combined treatment versus antiviral treatment alone.
The RCT identified by the review reported mild to moderate gastrointestinal complaints, which did not require treatment. No numbers were reported.We found no RCTs assessing the effects of corticosteroids in combination with antiviral agents other than aciclovir compared with either treatment alone, and no RCTs comparing combined treatment versus antiviral treatment alone.
In pregnant women, antiviral treatments such as aciclovir should only be prescribed under the guidance of an obstetrician. Aciclovir requires five times daily dosing and demonstrates poorer bioavailability than valaciclovir (a prodrug of aciclovir), which has shown greater effectiveness in the management of shingles.
Treatment decisions involve balancing the current evidence for benefit against the potential risk. Treatment is likely to be more effective if started within 72 hours and less effective after 7 days. People with "mild" and "moderate" (people who can close their eye) Bell’s palsy have high rates of spontaneous recovery and many clinicians feel that an informed discussion assessing the need for treatment is appropriate. People with "severe" palsies who are unable to close their eye or who have features suggestive of herpes zoster virus involvement (vesicles or pain), should be considered for combined corticosteroid plus antiviral treatment (aciclovir or valaciclovir), close follow-up, and specialist assessment. Clinicians would recommend that children with facial palsies be referred for acute specialist assessment to rule out an alternative cause. Those with moderate to severe palsies can be considered for combined treatment.
No new evidence
RECOVERY OF MOTOR FUNCTION Compared with no surgery: Facial nerve decompression surgery may be more effective at producing complete recovery of full facial function compared with no surgery ( very low-quality evidence ). ADVERSE EFFECTS Surgery is associated with hearing loss.
The systematic review found reports of permanent unilateral deafness in four non-randomised prospective studies of facial nerve decompression in people with Bell's palsy. One study of people with complete facial palsy undergoing facial nerve decompression found that 4/41 (10%) people had conductive deafness and 2/41 (5%) people had sensory-neural deafness after 1 year.
We found one multicentre, prospective, non-randomised, observational study, which compared total facial nerve decompression surgery versus no surgery. All participants were treated with prednisolone and were offered surgery if serial electrophysiological testing showed severe nerve degeneration within 2 weeks of the onset of their palsy. The study found that there were significantly more complete recoveries with surgery plus prednisolone compared with prednisolone alone (31/34 [91%] with surgery plus prednisolone v 15/33 [42%] with prednisolone alone; P = 0.0002). Two people who had decompression surgery reported adverse effects; one person reported conductive hearing loss, and one person experienced a cerebrospinal fluid leak. No other adverse effects for either group were reported. The study had significant recruitment problems and the numbers are clearly small; surgery was only performed in specialised centres.
No new evidence
RECOVERY OF MOTOR FUNCTION Compared with waiting list control: Mime therapy is more effective at three months at improving facial symmetry, stiffness and lip mobility than waiting list control ( moderate-quality evidence ). NOTE We found no other direct information assessing other physical therapies for facial retraining in the treatment of people with Bell’s palsy.
We found one small RCT comparing mime therapy versus waiting list control. Improvement in social and physical aspects of facial disability were measured using the Facial Disability Index (FDI) questionnaire. The FDI uses a 100-point scale, with a higher score indicating less handicap and less impairment. The RCT (48 people with peripheral facial paralysis for at least 9 months) found that mime therapy significantly improved physical and social aspects of facial paralysis compared with waiting list control at 3 months (mean change in physical FDI scores: from 56.8 to 73.5 with mime therapy v from 63.2 to 59.6 with control; P less than 0.02 for difference between treatments at 3 months: mean change in social FDI scores; from 68.6 to 80.7 with mime therapy v from 72.6 to 66.2 with control; P less than 0.01 for difference between treatments at 3 months). The RCT also found significant improvements in facial stiffness and lip mobility (change in pout and lip-length indices) in the mime therapy group compared with the control group (mean change in stiffness scores: from 3.72 to 2.37 with mime therapy v from 3.68 to 3.54 with control; P less than 0.001 at 3 months: mean change in pout score: from 14.7 to 21 with mime therapy v 16.3 to 15.7 with control; P less than 0.001 at 3 months: mean change in lip-length score; from 17.6 to 23.7 with mime therapy v from 21.6 to 19.6 with control; P less than 0.03 at 3 months). Facial stiffness was patient assessed on a 5-point scale (1 = no stiffness and 5 = very stiff). Lip mobility was physician assessed by measuring the pout and lip-length indices. At 12 months' follow-up, the RCT found a trend towards improved social FDI score and pout index at 3 and 12 months after treatment (mean social FDI score: 81.6 immediately after treatment; 83.6 at 3 months; 85.3 at 12 months: mean pout index: 22.2 immediately after treatment; 23.5 at 3 months; 24.2 at 12 months).
We found no systematic review or RCTs.
We found no RCTs.
There is limited evidence that physical facial retraining, such as mime therapy, can improve both the function and quality of life of people with long-standing facial nerve palsies. Optimal outcomes are likely to be achieved in a multidisciplinary clinic setting, which would facilitate coordination of medical, surgical, physical, and psychological services.