Background: Bell's palsy is an acute paralysis of one side of the face of unknown aetiology. Bell's palsy should only be used as a diagnosis in the absence of all other pathology. As the proposed pathophysiology is swelling and entrapment of the nerve, some surgeons suggest surgical decompression of the nerve as a possible management option.
Objectives: The objective of this review was to assess the effectiveness of surgery in the management of Bell's palsy and to compare this to outcomes of medical management.
Search strategy: We searched the Cochrane Neuromuscular Disease Group Specialized Register (23 November 2010). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) (23 November in The Cochrane Library, Issue 4 2010). We adapted this strategy to search MEDLINE (January 1966 to November 2010) and EMBASE (January 1980 to November 2010).
Selection criteria: We included all randomised or quasi-randomised controlled trials involving any surgical intervention for Bell's palsy.
Data collection and analysis: Two review authors independently assessed whether trials identified from the search strategy were eligible for inclusion. Two review authors assessed trial quality and extracted data independently.
Main results: Two trials with a total of 69 participants met the inclusion criteria. The first study considered the treatment of 403 patients but only included 44 in their surgical study. These were randomised into a surgical and non surgical group. The second study had 25 participants which they randomly allocated into surgical or control groups.The nerves of all the surgical group participants in both studies were decompressed using a retroauricular approach. The primary outcome was recovery of facial palsy at 12 months. The first study showed that both the operated and non operated groups had comparable facial nerve recovery at nine months. This study did not statistically compare the groups but the scores and size of the groups suggested that statistically significant differences are unlikely. The second study reported no statistically significant differences between their operated and control groups. One operated patient in the first study had 20 dB sensorineural hearing loss and persistent vertigo.
Authors' conclusions: There is only very low quality evidence from randomised controlled trials and this is insufficient to decide whether surgical intervention is beneficial or harmful in the management of Bell's palsy.Further research into the role of surgical intervention is unlikely to be performed because spontaneous recovery occurs in most cases.