There is insufficient evidence to support surgical operation for the management of Bell’s palsy.
Bell’s palsy is a paralysis of the muscles of the face, usually on one side, that has no known cause. People generally recover but there is a small group who do not recover. It is thought to be caused by swelling and entrapment of the nerve. Some surgeons thought that an operation to release the nerve may improve recovery.
Two studies were included in our review. They compared surgery with non-surgical management of 69 participants with Bell's palsy in total. The first study did not state how the participants were randomly allocated into surgical and non-surgical groups. The second study allocated their participants randomly using statistical charts into surgical and control groups (no treatment). There was no attempt in either study to hide which groups patients were being allocated into and both patients and assessors were aware of the management plan proposed. The first study lost seven participants to follow-up and there were no losses to follow-up in the second study.
The most important outcome was recovery of facial palsy at 12 months. The first study showed that the operated and non operated groups both had comparable facial nerve recovery at nine months. The second study reported no differences in recovery of the facial palsy between their operated and control groups at one year. One patient operated on in the first study had mild hearing loss and vertigo after the surgery.
The review found that there was only very low quality evidence and that this was insufficient to decide whether an operation would be beneficial or harmful in the management of Bell's palsy.
Further research into the role of an operation is unlikely to be performed because spontaneous recovery occurs in most cases.