Background: Bell's palsy (idiopathic facial paralysis) is commonly treated by physical therapy services with various therapeutic strategies and devices. There are many questions about their efficacy and effectiveness.
Objectives: To evaluate the efficacy of physical therapies on the outcome of Bell's palsy.
Search strategy: We searched the Cochrane Neuromuscular Disease Group Trials Register (February 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2007), MEDLINE (January 1966 to February 2008), EMBASE (January 1980 to February 2008), LILACS (January 1982 to February 2008), PEDro (from 1929 to February 2008), and CINAHL (January 1982 to February 2008).
Selection criteria: We selected randomised or quasi-randomised controlled trials involving any physical therapy. We included participants of any age with a diagnosis of Bell's palsy and all degrees of severity. The outcome measures were: incomplete recovery six months after randomisation, motor synkinesis, crocodile tears or facial spasm six months after onset, incomplete recovery after one year and adverse effects attributable to the intervention.
Data collection and analysis: Titles and abstracts identified from the register were scrutinized. The assessment of methodological quality took into account secure method of randomisation, allocation concealment, observer blinding, patient blinding, differences at baseline of the experimental groups, and completeness of follow-up. Data were extracted using a specially constructed data extraction form. Separate subgroup analyses of participants with more and less severe disability were undertaken.
Main results: The search identified 45 potentially relevant articles. Six studies met the inclusion criteria. Three trials studied the efficacy of electrostimulation (294 participants) and three exercises (253 participants). Neither treatment produced significantly more improvement than the control treatment or no treatment. There was limited evidence that improvement began earlier in the exercise group.
Authors' conclusions: There is no evidence of significant benefit or harm from any physical therapy for idiopathic facial paralysis. The possibility that facial exercise reduces time to recover and sequelae needs confirming with good quality randomised controlled trials.