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Surgical interventions for the early management of Bell's palsy

  1. Kerrie McAllister1,
  2. David Walker1,
  3. Peter T Donnan2,
  4. Iain Swan3,*

Editorial Group: Cochrane Neuromuscular Disease Group

Published Online: 16 OCT 2013

Assessed as up-to-date: 29 OCT 2012

DOI: 10.1002/14651858.CD007468.pub3


How to Cite

McAllister K, Walker D, Donnan PT, Swan I. Surgical interventions for the early management of Bell's palsy. Cochrane Database of Systematic Reviews 2013, Issue 10. Art. No.: CD007468. DOI: 10.1002/14651858.CD007468.pub3.

Author Information

  1. 1

    North Glasgow University NHS Trust, Department of Otolaryngology, Glasgow, UK

  2. 2

    University of Dundee, Tayside Centre for General Practice, Dundee, UK

  3. 3

    Glasgow Royal Infirmary, Glasgow, UK

*Iain Swan, Glasgow Royal Infirmary, Department of Otolaryngology, Royal Infirmary, Glasgow, G31 2ER, UK. Iain@ihr.gla.ac.uk.

Publication History

  1. Publication Status: Edited (no change to conclusions)
  2. Published Online: 16 OCT 2013

SEARCH

 

Summary of findings    [Explanations]

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

 
Summary of findings for the main comparison. Surgery for Bell's palsy versus medical treatment (oral prednisolone) or no treatment

Surgery for Bell's palsy

Patient or population: Bell's palsy
Settings: hospital attendance with idiopathic facial paralysis
Intervention: surgery

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

ControlSurgery

Recovery of facial nerve function at 12 months
Follow-up: 12 months
See commentSee commentNot estimable69
(2 studies)
⊕⊝⊝⊝
very low1,2
One study did not perform statistical analysis, one did not state the method used. Different outcome measures in each study made combining results impractical.

Side effects and complications of treatment
clinical assessment
Follow-up: 12 months
See commentSee commentNot estimable69
(2 studies)
⊕⊝⊝⊝
very low1
The numbers involved in the included studies were small and statistical analysis was not possible.

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1 Limitations in study design: in one study the method of randomisation was not described. There were small numbers in both studies and large numbers were not followed up in one study. One study followed participants up to 9 months not 12 months. In both studies there was unclear allocation concealment and outcome assessors were not blinded.
2 No evidence of publication bias for this outcome.

 

Background

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

Bell's palsy is an acute paralysis of one side of the face due to a lesion of the facial nerve. The condition is named after Sir Charles Bell, a Scottish surgeon (1774 to 1842). The cause is not known and Bell's palsy should only be used as a diagnosis in the absence of any other pathology. It was proposed in 1919 (Antoni 1919) that the underlying pathology was that of a viral neuropathy. Herpes simplex virus has been suggested as the likely pathogen (McCormick 1972) and animal studies have suggested that reactivation of the virus may lead to demyelination of the nerve leading to reduced function (Adour 1975; Stjernquist 2006).

The condition affects 25 to 35 people per 100,000 of the population per year and is most common in the 30 to 45 year age group. It is also more common in pregnant women, people with diabetes or people with a respiratory tract infection (Theil 2001). Recovery in most people can be expected to be good. It has been shown in a large review (Peitersen 2002) that over 70% of people with Bell's palsy will have normal function restored and of the remainder 25% will have slight or mild sequelae and only 4% will have severe sequelae. Contractures, facial disfigurement, with associated psychological difficulties, and facial pain (Morgenlander 1990) remain the most common long-term problems.

A number of studies have looked into identifying which population might benefit most from surgery. In addition to simple clinical assessment of disease using the House-Brackmann scale or similar, many studies have tried to assess the electrical function of the facial nerve. Electroneurography (ENOG) has been the most popular technique employed (Esslen 1977; Fisch 1984). In this the degree of muscle response to an electrically evoked stimulus is assessed. It was shown (Esslen 1977; Fisch 1984) that when 95% of the nerve had degenerated the patient had a 50% chance of a poor outcome (less than 50% chance of recovery to House-Brackmann grade 1 or 2) and would potentially benefit from surgical intervention (Sillman 1992).

Although Bell's palsy is a common condition, in the absence of an established aetiology, treatment continues to be based upon the presumed pathophysiology of swelling and entrapment of the nerve. Recent double-blind randomised controlled studies have shown that early treatment with prednisolone but not aciclovir significantly improves the chances of complete recovery, to 94% at nine months (Sullivan 2007; Engstrom 2008). Recent Cochrane reviews on the use of corticosteroids (Salinas 2010) and antivirals (Lockhart 2009) in Bell's palsy are consistent with these findings.

As the proposed pathophysiology involves entrapment of the nerve, this has led some surgeons to suggest that surgical decompression of the nerve is a suitable management option. The first recorded attempt at surgical decompression of the facial nerve for Bell's palsy was in 1932 (Ballance 1932). Ballance 1932 recommended slitting the sheath in the distal descending segment of the nerve. This was consistent with theories of the site of the lesion at that time. Over the next few decades, the proposed site for operation migrated from the distal 1 cm at the stylomastoid foramen (Ballance 1932) to the entrance of the Fallopian canal medially (Fisch 1972). The timing of surgery also varied from three months to immediately on onset (May 1972). In the early 1970s it was proposed that the most likely site of compression was at the entrance to the Fallopian canal (Fisch 1972). Intraoperative evoked electromyography (EMG) and an oedematous swelling at this point proximal to the geniculate ganglion was noted in up to 94% of their participants. In this study transmastoid/middle cranial fossa approaches were used to allow decompression of the nerve and geniculate ganglion. Other studies (May 1984) suggested that a transmastoid approach to decompression of the labyrinthine segment was of benefit. Two further studies published around the same time gave evidence both for (Giancarlo 1970) and against (McNeill 1974) operation. Because of the good outcome of the condition without treatment and with medical management and also the potential for damage to the facial nerve and other ear structures during surgery, there has been a continued debate as to whether surgery has a role in the management of Bell's palsy (Adour 2002; Friedman 2000).

Despite the debate on different surgical approaches there is a paucity of high quality evidence regarding facial nerve decompression surgery for acute Bell's palsy. Few large studies have been carried out. Of these one study (May 1985) convinced many surgeons that surgery did not have a place in the management of Bell's palsy. More recently, (Gantz 1999) found that when selected using ENOG, those patients who would have had a bad outcome as predicted by ENOG had a better outcome if surgically managed compared with those who were not. Currently most patients are managed medically with corticosteroids with or without aciclovir as discussed above. Surgery, certainly in the UK, is rarely undertaken (Sullivan 2007).

This is an update of a review first published in 2011.

 

Objectives

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

To assess the effects of surgery in the management of Bell's palsy.

 

Methods

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms
 

Criteria for considering studies for this review

 

Types of studies

We assessed randomised controlled trials (RCTs) and quasi-RCTs in the main review. Quasi-RCTs are trials in which allocation of participants is partly systematic (for example by medical record number or by alternation). Other studies, including observational studies are included in the Discussion.

 

Types of participants

We included any participant (adult or child) who presented with an idiopathic facial palsy which was diagnosed as Bell's palsy. Those who were diagnosed as having herpes zoster, who had a traumatic aetiology or other identified aetiology were excluded from the review. This included any cases of recurrent and familial Bell's palsy or Melkerson-Rosenthal syndrome.

 

Types of interventions

We included any surgical intervention carried out for Bell's palsy. We compared these interventions to no treatment, sham treatment, other surgical treatments or medical treatment. Where concomitant treatment was given this was the same in both treatment and comparator groups.

 

Types of outcome measures

 

Primary outcomes

The primary outcome measure was the degree of recovery of facial nerve function and resolution of symptoms at 12 months as measured using the House-Brackmann scale, the Sunnybrook scale, the Yanigahara scale or other similar scale.

 

Secondary outcomes

1. Complete recovery at three and six months.
2. Synkinesis and contracture at 12 months.
3. Psychosocial outcomes at 12 months.
4. Side effects and complications of treatment.

We selected recovery of facial nerve function at 12 months, and side effects and complications of treatment for inclusion in a 'Summary of findings' table.

 

Search methods for identification of studies

 

Electronic searches

On 29 October 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register (29 October 2012), CENTRAL (2012, Issue 10 in The Cochrane Library), MEDLINE (January 1966 to October 2012) and EMBASE (January 1980 to October 2012).

We used the following phrases, adapted to each database as appropriate:
#1 (Bell's palsy) OR (Bell palsy) OR (idiopathic facial paralysis) OR (facial paralysis) OR (facial palsy) OR (facial nerve)
AND
#2 (surgery) OR (surg*) OR (operative) OR (operat*) OR (decompression) OR (decompres*).

For this update we also searched clinical trials registries for ongoing studies:

The detailed search strategies are in the appendices: Appendix 1 (CENTRAL), Appendix 2 (MEDLINE), Appendix 3 (EMBASE), Appendix 4 (ClinicalTrials.gov) and Appendix 5 (ICTRP).

 

Searching other resources

  1. We reviewed the bibliographies of all trials identified.
  2. We performed a handsearch of the following conference abstracts:

  • American Academy of Otolaryngology - Head and Neck Surgery Annual Meeting 2006 and 2007; and
  • British Academic Conference in Otolaryngology and ENT Expo Birmingham, UK, both 2006.

 

Data collection and analysis

 

Selection of studies

Two review authors (DW, KA) reviewed titles and abstracts identified by the search strategy. The review authors obtained the full text of all relevant studies and assessed them independently. Two review authors (DW, KA) assessed whether each trial met the inclusion criteria. They resolved any disagreement by discussion with the lead author (IS) where required.

 

Data extraction and management

The extracted data included study participants, methods, interventions used and outcomes, along with results and 95% confidence intervals (CIs). Two review authors extracted the data independently and entered them onto a specifically designed form.

 

Risk of bias

Two review authors independently assessed the risk of bias in the included studies using the Cochrane Collaboration's 'Risk of bias' tool described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2008, current version Higgins 2011). We addressed six 'Risk of bias' domains: sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting and 'other sources of bias'. We judged each study in relation to each domain, as at a high, low or unclear risk of bias. We resolved any disagreement by discussion with the lead author (IS) where required.

 

Measures of treatment effect

There were insufficient studies to enable any statistical analysis. If in future updates, statistical analysis is possible we will enter data into the Review Manager (RevMan 2011) software and analyse the data using the standard statistical methods. For continuously measured outcomes we will use means to obtain mean differences (MDs) with 95% CI. For dichotomous outcome data we will estimate the pooled risk ratio (RR) with 95 % CI within the RevMan statistical package. We will calculate the number needed to treat for an additional beneficial effect (NNTB) or for an additional harmful effect (NNTH) if possible. We will combine observational RR if little trial evidence is found.

 

Assessment of heterogeneity

There were insufficient studies to enable any statistical analysis. Had there been sufficient studies, we would have performed a Chi2 test for homogeneity. If significant heterogeneity had been found, we would have tried to find the cause based on the characteristics of the studies included.

 

Assessment of reporting biases

There were insufficient studies to enable any statistical analysis. Had trials been available we would have assessed publication bias using a funnel plot.

 

Data synthesis

There were insufficient studies to enable any statistical analysis. If studies become available, initially, we will use a fixed-effect model and carry out the test for heterogeneity. Random-effects models such as DerSimonian and Laird account for more uncertainty and we will also utilise these, especially if there is unexplained heterogeneity (DerSimonian 1986).

 

Subgroup analysis and investigation of heterogeneity

There were insufficient studies and data sets were too small to enable statistical analysis. If statistical analysis becomes possible in the future, we will perform a sensitivity analysis omitting studies of high risk of bias. In addition, quality could be incorporated into mixed models simultaneously allowing for differences in quality using Bayesian methods, utilised in WinBUGS (Spiegelhalter 2000).

 

Economic issues

There was insufficient information in the included studies to discuss economic issues in the Discussion.

This review has a published protocol (McAllister 2008). We have documented changes from the protocol in Differences between protocol and review.

 

Results

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms
 

Description of studies

The numbers of papers found by the current strategies were MEDLINE 469 (59 new), EMBASE 271 (33 new), Cochrane Neuromuscular Disease Group Specialized Register 12 (0 new) , CENTRAL 56. We found no relevant trials on searching trials registries (ClinicalTrials.gov and ICTRP).

After two authors had screened the results, we declared 67 papers potentially eligible. We then shortlisted 11 papers but subsequently excluded nine. Two trials met the inclusion criteria (Adour 1971; Mechelse 1971).

Adour 1971 considered the treatment of 403 patients but only included 44 participants in their surgical study. These participants were randomised into a surgical and non-surgical group. However, the non-surgical control group also contained those who refused surgery. Adour 1971 based inclusion in the study upon an extensive clinical examination, which the trial authors report took around two hours for the initial assessment. Clinically this involved a neurological examination, an ear, nose and throat (ENT) examination, X-rays of the mastoid and chest, audiogram and a group of blood tests including full blood count, erythrocyte sedimentation rate (ESR) and glucose. More specifically for the facial nerve function, they carried out serial four-point nerve excitability tests, electromyography and nerve conduction studies. The investigators included participants in the study if they met all of the following criteria: a clinically complete facial nerve palsy, no contraindication to general anaesthesia and an increasing nerve excitability shown by a difference between the affected and unaffected sides. The investigators excluded any participant that did not fit all three inclusion criteria. In addition, the study excluded participants with facial paralysis thought to be of any cause other than Bell's palsy. The report did not state the mechanism of randomisation. Three groups were selected: no surgery, surgery within 48 hours of onset of denervation, surgery 8 to 12 weeks after onset of denervation.  Some participants declined surgery and were added to the non-surgical group. Other than the numbers, the study stated no differences between the groups.

Mechelse 1971, randomly allocated 25 participants into surgical or control groups. Mechelse 1971 used similar initial assessments when compared to Adour 1971. Investigators selected participants on the basis of a complete facial palsy and electromyography showing no voluntary control of motor unit or a minimal applied current to evoke a motor response on the affected side 2.5 times that required on the unaffected side. These responses needed to be confirmed on two occasions a few days apart. The trial authors excluded participants with signs or symptoms suggestive of a cause for their facial paralysis other than Bell's palsy, those with incomplete facial paralysis, and those with an abnormality on ENT examination, skull X-ray or in blood and urine tests. One participant declined surgery and was removed from the study. This study reports the age and sex of the participants, and the side of the face affected but did not report if there were statistically significant differences between the two groups at baseline (see Characteristics of included studies).

 

Outcome criteria

Adour 1971 used the Facial Paralysis Recovery Profile (FPRP) and the Facial Paralysis Recovery Index (FPRI) to measure outcomes. The trial authors developed these measures for this study and used them for subsequent studies. The FPRP score ranges from +2 for no recovery +10 for complete recovery. The FPRI score ranges from -12 to +10 (FPRI is the FPRP score minus points for complications, +10 represents complete recovery without any complications). This study did not stipulate what score on the clinical scale constituted a satisfactory recovery.

Mechelse 1971 used a scale of 0 to 5 to assess outcome (0 = no function, 5 = complete function). The authors did not stipulate what value on the clinical scale represented a satisfactory recovery.

Both studies predate the development of the House-Brackmann scale.

 

Operative procedure

The participants in the surgical groups of both studies underwent facial nerve decompression using a retroauricular approach.

 

Excluded studies

Several studies were excluded on the basis of non-random selection of the control groups. Giancarlo 1970; Fisch 1981; Brown 1982; May 1984; Aoyagi 1988; Gantz 1999; McNeill 1974 and Yanagihara 2001 all had control groups that were self selected, in that participants who refused surgery became the control group. We did not feel therefore that comparisons made between the operated groups of participants and the control groups were valid, as the reasons the participants refused surgery may have been relevant to their outcomes. For example, in Yanagihara 2001, younger participants opted for surgery whereas older participants declined (see Characteristics of excluded studies).

 

Risk of bias in included studies

 

Allocation

Adour 1971 does not describe the method of randomisation that was used. Some participants who declined surgery were added to the non-surgical group. The report states, "the attempt at randomisation into equal groups was made. Completely random distribution could not be effected because some patients and some patients' physicians, refused surgical intervention."

Mechelse 1971 randomly allocated 25 participants into surgical or control groups. The report states that "in both hospitals these patients were entered on a list, previously prepared by the statistical department, University of Leiden (head, Mr H. De Jonge), which randomly allocated them to surgical treatment or to a control group". One participant declined surgery and was removed from the study.

 

Allocation concealment

Neither report mentioned any attempted method of allocation concealment.

 

Blinding

It was not possible in either study to blind participants to the surgical or non-surgical intervention. Also, neither study report commented on blinding of the investigator or outcome assessor and this would have been difficult to perform because of the surgical intervention involved.

 

Incomplete outcome data

In Adour 1971, 6/21 control participants and 1/23 participants in the operated group were lost to follow-up before the end of the nine-month study. The trial authors made no comment on reasons for loss to follow-up.

Mechelse 1971 claim to have followed all their participants for one year with no losses ("All patients were followed clinically and electromyographically for a least a year").

 

Selective reporting

Adour 1971 reported no statistical analysis of their data but reported on all pre-specified outcomes.

Mechelse 1971 did report statistical comparison between the groups but did not report the statistical methods used. All prespecified outcomes were reported in this study.

 

Other potential sources of bias

Both studies appear to be free of other sources of bias.

Review authors' judgements about each 'Risk of bias' item for each included study are summarised in Figure 1.

 FigureFigure 1. Risk of bias summary: review authors' judgements about each risk of bias item for each included study. Red = high risk of bias, yellow = unclear risk of bias, green = low risk of bias.

 

Effects of interventions

See:  Summary of findings for the main comparison Surgery for Bell's palsy versus medical treatment (oral prednisolone) or no treatment

 

Primary outcome measure

Adour 1971 concluded that early or late surgical decompression of the facial nerve was not of benefit to people with Bell's palsy who have evidence of impending or actual denervation. Adour 1971 used the FPRP and FPRI scores to assess the degree of recovery of facial nerve function and resolution of symptoms at nine months. The study authors reported that the 21 participants who did not undergo surgery (who received oral prednisolone) had average outcome scores of +6 FPRP and +4 FPRI at nine months. The 10 participants who underwent surgery within 48 hours had average scores of +5 FPRP and +3 FPRI and the 13 participants who underwent surgery more than eight weeks post onset of denervation had average scores of +5 FPRP and +2 FPRI. The study authors do not statistically compare the groups but the scores given and size of the groups suggest that statistically significant differences are unlikely. 

Mechelse 1971 concluded that facial nerve decompression in the second or third week after the onset of paralysis did not increase the degree of recovery in participants with Bell's palsy. They reported that 11 participants were randomised to the operated group and 13 to the control group. They used a scale of 0 to 5 to assess outcome (0 = no function, 5 = complete function). Participants ranged in recovery from 2 to 5 on their scale and they reported no statistically significant differences between the surgical and non-surgical groups (P = 0.9).

 

Secondary outcome measures

 

Complete recovery at three and six months

Adour 1971 documents levels of recovery at three and six months but no statistical comparison was made.

In the Mechelse 1971 study, EMG follow-up showed that onset of recovery did not occur before the third month in both the surgical and non-surgical group. Facial nerve outcome scores were not documented for three and six months.

 

Synkinesis and contracture at 12 months

Adour 1971 listed individually synkinesis and other clinical features but did not compare the different study groups. The investigators found that almost all participants with evidence of denervation on nerve excitability testing had contracture and synkinesis by nine months.

In the Mechelse 1971 study, synkinesis and contractures were seen equally in the control and operated groups.

 

Psychosocial outcomes at 12 months

There was no mention of psychosocial outcomes in either study.

 

Side effects and complications of treatment

One participant in the Adour 1971 study had 20 dB sensorineural hearing loss and persistent vertigo. Tympanotomy showed injury to footplate and fibrous overgrowth. Removal of the overgrowth resulted in normal hearing and no further vertigo.

In the Mechelse 1971 study, no complications of surgery, such as wound dehiscence, infection, bleeding and numbness were reported.

 

Discussion

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

The evidence from the RCTs included in our study does not support surgical intervention for Bell’s palsy. The two trials included had relatively small numbers: 44 in the Adour 1971 and 25 in the Mechelse 1971 trial. Considered individually, the trials have too few participants for sufficient statistical power to detect the magnitude of effect that might plausibly be expected. Both trials stated that the participants were randomised into surgical and non-surgical (control) groups. However, the methods of randomisation were not clearly stated in either. Therefore, we cannot exclude the possibility of bias. In both studies there was unclear allocation concealment and outcome assessors were not blinded. Each study had similar inclusion criteria and only included patients with complete facial paralysis. The systems used in both studies to assess facial nerve function are less widely used in the assessment of Bell’s palsy than the House-Brackmann facial nerve grading system. There were different assessment systems used in each trial with no stipulated score that constituted recovery. These factors made combining the results for statistical analysis impractical (see  Summary of findings for the main comparison).

The results from Mechelse 1971 did not show any statistically significant difference between the surgical intervention and control groups. No statistical analysis was conducted in Adour 1971 but the scores given and size of the groups suggest statistically significant differences were unlikely. Observational studies have shown contrasting results after surgical decompression of the facial nerve for Bell's palsy. Some studies showed statistically significant improvement in facial nerve function in the surgical groups compared to control groups (Giancarlo 1970; Fisch 1981; Gantz 1999). The studies mentioned all involved surgery on patients with complete facial paralysis and indicators of poor prognostic outcome but the numbers involved in each study were low. In contrast, other studies were unable to show any statistically significant differences between surgical and control groups (McNeill 1974; May 1984; Aoyagi 1988).

With regard to complications of surgery, one of the included studies reported that one participant developed 20 dB sensorineural hearing loss and persistent vertigo. The included studies did not report any other complications of surgery. Only a few observational studies have commented on postoperative complications after decompression of the facial nerve. In one study, one of 13 people who underwent surgery developed a 40 dB hearing loss at 8 KHz (Fisch 1981). In another, six out of 19 participants who had surgical decompression had significant hearing losses postoperatively (McNeill 1974).

The natural history of Bell’s palsy is spontaneous recovery in the majority of people and this review did not find any evidence to support surgical intervention in this condition.

 

Authors' conclusions

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

 

Implications for practice

There is only very low quality evidence from RCTs and this is insufficient to decide whether surgical intervention is beneficial or harmful in the management of Bell's palsy.

 
Implications for research

Further research into the role of surgical intervention is unlikely to be performed because spontaneous recovery occurs in most cases.

 

Acknowledgements

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

Angela Gunn, the Trials Search Co-ordinator of the Cochrane Neuromuscular Disease Group performed the searches.

The editorial base of the Cochrane Neuromuscular Disease Group is supported by the MRC Centre for Neuromuscular Diseases.

 

Data and analyses

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

This review has no analyses.

 

Appendices

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms
 

Appendix 1. CENTRAL search strategy

#1 MeSH descriptor Bell Palsy, this term only with qualifier: SU
#2 MeSH descriptor Facial Paralysis, this term only with qualifier: SU
#3 MeSH descriptor Hemifacial Spasm, this term only with qualifier: SU
#4 (bell NEAR/2 palsy or facial NEAR/2 palsy or facial NEAR/2 paralysis or facial NEAR/2 paresis)
#5 hemifacial NEAR/2 palsy OR hemifacial NEAR/2 paralysis OR hemifacial NEAR/2 paresis
#6 facial NEAR/2 palsy or facial NEAR/2 paralysis or facial NEAR/2 paresis
#7 (#4 OR #5 OR #6)
#8 surg* or operati* or decompressi*
#9 (#7 AND #8)
#10 (#1 OR #2 OR #3 OR #9)

 

Appendix 2. MEDLINE (OvidSP) search strategy

Database: Ovid MEDLINE(R) <1946 to October Week 3 2012>
Search Strategy:
--------------------------------------------------------------------------------
1 randomized controlled trial.pt. (339605)
2 controlled clinical trial.pt. (85425)
3 randomized.ab. (242346)
4 placebo.ab. (135629)
5 drug therapy.fs. (1578525)
6 randomly.ab. (173863)
7 trial.ab. (251056)
8 groups.ab. (1136962)
9 or/1-8 (2939707)
10 exp animals/ not humans.sh. (3797751)
11 9 not 10 (2497281)
12 bell palsy/ or facial paralysis/ or hemifacial spasm/ (11053)
13 ((bell$ or facial or hemifacial$) adj3 (pals$ or paralys$ or paresi$ or spasm$)).mp. (14834)
14 12 or 13 (14834)
15 surgery/ or (surg$ or operat$ or decompres$).mp. (1755416)
16 14 and 15 (4721)
17 bell palsy/su or facial paralysis/su or hemifacial spasm/su (2137)
18 16 or 17 (5313)
19 11 and 18 (473)
20 remove duplicates from 19 (469)
21 20 and 20101101:20121029.(ed). (59)

 

Appendix 3. EMBASE (OvidSP) search strategy

Database: Embase <1980 to 2012 Week 43>
Search Strategy:
--------------------------------------------------------------------------------
1 crossover-procedure.sh. (35377)
2 double-blind procedure.sh. (111601)
3 single-blind procedure.sh. (16569)
4 randomized controlled trial.sh. (331618)
5 (random$ or crossover$ or cross over$ or placebo$ or (doubl$ adj blind$) or allocat$).tw,ot. (908624)
6 trial.ti. (136873)
7 clinical trial/ (873297)
8 or/1-7 (1509541)
9 (animal/ or nonhuman/ or animal experiment/) and human/ (1217670)
10 animal/ or nonanimal/ or animal experiment/ (3327400)
11 10 not 9 (2754501)
12 8 not 11 (1420397)
13 limit 12 to embase (1101523)
14 Bell Palsy/ (2044)
15 Facial Nerve Paralysis/ (14433)
16 HEMIFACIAL SPASM/ (1760)
17 ((bell$ or facial or hemifacial$) adj3 (pals$ or paralys$ or paresi$ or spasm$)).mp. (20209)
18 or/14-17 (20209)
19 surgery/ or (surg$ or operat$ or decompres$).mp. (2485479)
20 18 and 19 (6726)
21 Bell Palsy/su or Facial Nerve Paralysis/su or HEMIFACIAL SPASM/su (2180)
22 20 or 21 (7173)
23 13 and 22 (271)

 

Appendix 4. ClinicalTrials.gov

In conditions section: "Bell's palsy" OR "Bell palsy" OR "idiopathic facial paralysis" OR "facial paralysis" OR "facial palsy" OR "facial nerve"

AND

In interventions section: "surgery" OR "surg*" OR "operative" OR "operat*" OR "decompression" OR "decompres"

 

Appendix 5. World Health Organization International Clinical Trials Registry Platform (ICTRP)

In title section: Bell's palsy OR Bell palsy OR idiopathic facial paralysis OR facial paralysis OR facial palsy OR facial nerve

 

What's new

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

Last assessed as up-to-date: 29 October 2012.


DateEventDescription

9 October 2014AmendedCorrection to Background: removed statement that the condition was first described by Sir Charles Bell.



 

History

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

Protocol first published: Issue 4, 2008
Review first published: Issue 2, 2011


DateEventDescription

17 October 2013AmendedCorrected date of search in abstract

13 February 2013New citation required but conclusions have not changedNew search to 29 October 2012. Published notes included

29 October 2012New search has been performedThis review has been updated with a new search but no new relevant studies were identified. The text has been edited.



 

Contributions of authors

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

Miss K McAllister devised the search strategy, designed the protocol, assessed study quality, undertook data collection and analysis and wrote the review.

Mr D Walker devised the search strategy, designed the protocol, assessed study quality, undertook data collection and analysis and wrote the review.

Mr P Donnan provided statistical knowledge and expertise required for the protocol and review.

Mr I Swan suggested the review and supervised the writing of the protocol and the review.

 

Declarations of interest

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

None known.

 

Sources of support

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms
 

Internal sources

  • No sources of support supplied

 

External sources

  • None, Other.

 

Differences between protocol and review

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

We have updated the 'Risk of bias' methodology since the protocol was published, in order to conform to the 2008 Cochrane methodology. We also added a 'Summary of findings' table and specified outcomes for inclusion in the table, in the methods section. We have stated the comparisons that we would consider for inclusion and clarified this in the methods section.

We included searches of trials registries.

 

Notes

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. What's new
  13. History
  14. Contributions of authors
  15. Declarations of interest
  16. Sources of support
  17. Differences between protocol and review
  18. Notes
  19. Index terms

As new evidence on this topic is slow to emerge, the next update of this review will take place four years from the date of search rather than at the usual two years. If trials are conducted, the review authors will schedule an earlier update.

References

References to studies included in this review

  1. Top of page
  2. Abstract
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Notes
  20. Characteristics of studies
  21. References to studies included in this review
  22. References to studies excluded from this review
  23. Additional references
  24. References to other published versions of this review
Adour 1971 {published data only}
  • Adour KK, Swanson JPJ. Facial paralysis in 403 consecutive patients: emphasis on treatment response in patients with Bell's palsy. Transactions - American Academy of Ophthalmology and Otolaryngology 1971;75(6):1284-1301. [PUBMED: 5153092]
Mechelse 1971 {published data only}
  • Mechelse K, Goor G, Huizing EH. Van Bolhuis AH, Staal A, et al. Bell's palsy: prognostic criteria and evaluation of surgical decompression. Lancet 1971;2(7715):57-9. [PUBMED: 4103980]

References to studies excluded from this review

  1. Top of page
  2. Abstract
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Notes
  20. Characteristics of studies
  21. References to studies included in this review
  22. References to studies excluded from this review
  23. Additional references
  24. References to other published versions of this review
Aoyagi 1988 {published data only}
  • Aoyagi M, Koike Y, Ichige A. Results of facial nerve decompression. Acta Oto-Laryngologica Supplement 1988;446:101-5.
Brown 1982 {published data only}
Fisch 1981 {published data only}
  • Fisch U. Surgery for Bell's palsy. Archives of Otolaryngology 1981;107(1):1-11.
Gantz 1999 {published data only}
Giancarlo 1970 {published data only}
  • Giancarlo HR, Mattucci KF. Facial Palsy. Facial Nerve Decompression. Archives of Otolaryngology 1970;91:30-6.
May 1984 {published data only}
McNeill 1974 {published data only}
Yanagihara 2001 {published data only}

Additional references

  1. Top of page
  2. Abstract
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Notes
  20. Characteristics of studies
  21. References to studies included in this review
  22. References to studies excluded from this review
  23. Additional references
  24. References to other published versions of this review
Adour 1975
  • Adour KK, Bell DN, Hilsinger RL Jr. Herpes simplex virus in idiopathic facial paralysis (Bell palsy). Journal of the American Medical Association 1975;233(6):527-30.
Adour 2002
Antoni 1919
  • Antoni N. [Herpes zoster med forlamming (med sarskild hansyn ill f.k. polyneuritis cerebali Meniereformis)]. Hygeiea 1919;81:340-53.
Ballance 1932
  • Ballance C, Duel AB. The operative treatment of facial palsy: by the introduction of nerve grafts into the fallopian canal and by other intratemporal methods. Archives of Otolaryngology - Head and Neck Surgery 1932;15:1-70.
DerSimonian 1986
Engstrom 2008
  • Engstrom M, Berg T, Stjernquist-Desatnik A, Axelsson S, Pitkaranta A, Hultcrantz M, et al. Prednisolone and valaciclovir in Bell's palsy: a randomised, double-blind, placebo-controlled, multicentre trial. Lancet Neurology 2008;7(11):993-1000.
Esslen 1977
  • Esslen E. The acute facial palsies: investigations on the localization and pathogenesis of meato-labyrinthine facial palsies. Schriftenreihe Neurologie - Neurology Series. Springer Verlag Berlin, Heidelberg, New York, 1977; Vol. 18:1-164.
Fisch 1972
  • Fisch U, Esslen E. Total intratemporal exposure of the facial nerve. Pathologic findings in Bell's palsy. Archives of Otolaryngology - Head and Neck Surgery 1972;95(4):335-41.
Fisch 1984
Friedman 2000
Higgins 2008
  • Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions. The Cochrane Collaboration, 2009. Available from www.cochrane-handbook.org Vol. 5.0.2 [updated September 2009].
Higgins 2011
  • Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.
Lockhart 2009
May 1972
May 1985
McCormick 1972
  • McCormick DP. Herpes-simplex virus as a cause of Bell's palsy. Lancet 1972;1(7757):937-9.
Morgenlander 1990
Peitersen 2002
  • Peitersen E. Bell's palsy: the spontaneous course of 2,500 peripheral facial nerve palsies of different etiologies. Acta Oto-laryngologica Supplement 2002;549:4-30.
RevMan 2011
  • The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). 5.1. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2011.
Salinas 2010
Sillman 1992
  • Sillman JS, Niparko JK, Lee SS, Kileny PR. Prognostic value of evoked and standard electromyography in acute facial paralysis. Otolaryngology - Head and Neck Surgery. 1992;107(3):377-81.
Spiegelhalter 2000
  • Spiegelhalter DJ, Thomas A, Best NG. WinBUGS Version 1.2. User Manual. WinBUGS Version 1.2. User Manual. Cambridge, MRC Biostatistics Unit, 2000.
Stjernquist 2006
  • Stjernquist-Desatnik A, Skoog E, Aurelius E. Detection of herpes simplex and varicella-zoster viruses in patients with Bell's palsy by the polymerase chain reaction technique. Annals of Otology, Rhinology, and Laryngology 2006;115(4):306-11.
Sullivan 2007
  • Sullivan FM, Swan IRC, Donnan PT, Morrison JM, Smith BH, McKinstry B, et al. Early treatment with prednisolone or acyclovir in Bell's palsy. New England Journal of Medicine 2007;357(16):1598-607.
Theil 2001
  • Theil D, Arbusow V, Derfuss T, Strupp M, Pfeiffer M, Mascolo A, et al. Prevalence of HSV-1 LAT in human trigeminal, geniculate, and vestibular ganglia and its implication for cranial nerve syndromes. Brain Pathology 2001;11(4):408-13.

References to other published versions of this review

  1. Top of page
  2. Abstract
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. What's new
  14. History
  15. Contributions of authors
  16. Declarations of interest
  17. Sources of support
  18. Differences between protocol and review
  19. Notes
  20. Characteristics of studies
  21. References to studies included in this review
  22. References to studies excluded from this review
  23. Additional references
  24. References to other published versions of this review
McAllister 2008
  • Swan I, Donnan P, McAllister K, Walker D. Surgical interventions for the early management of Bell's palsy. Cochrane Database of Systematic Reviews 2008, Issue 4. [DOI: 10.1002/14651858.CD007468]
McAllister 2011