Prevention and rehabilitation of facial palsy in patients with vestibular schwannomas.

The close anatomic position of the facial nerve in proximity to a vestibular schwannoma leads to an inherent risk of damage when managing this tumor. The nerve is particularly at risk from microsurgical tumor resection. A clearly transected nerve can be repaired intraoperatively, with either a direct anastomosis or an interposition graft. An electrically silent but anatomically intact nerve is usually managed conservatively. After surgery, the severity of facial palsy and the time to recovery are both determined by the severity of pathophysiology. Patients can be broadly categorized into three groups: those who recover quickly (within 3 months) and completely, those who recover slowly (3-12months) and only partially with synkinesis, and those with minimal or no recovery. Any patient with facial palsy acutely requires eye care, but otherwise, a conservative approach is taken to await any recovery. Patients who recover early require no further intervention, but those with later recovery, who will inevitably develop synkinesis, should be managed by a multidisciplinary team with access to physical therapy, chemodenervation, and surgical selective neurectomy as appropriate. Patients with minimal or no recovery can be considered for reanimation procedures using nerve transfers from either the hypoglossal or masseteric nerves with the potential addition of a cross-facial graft for improved spontaneous movement. Patients with untreated compete facial palsy of 24 months or longer duration should be offered either static procedures or dynamic muscle transfers. Oculoplastic procedures may be required for any patient who lacks complete eye closure in the longer term.