Assessment of Corticosteroid Effect in the Prevention of Facial Palsy After Cerebella-pontine Angle Surgery

Facial palsy after surgical removal of cranial base tumors adherent to the nerve can partly be explained by inflammation.

The purpose of this study was to assess the efficiency of corticosteroids to prevent facial palsy after such surgery and to identify the patients that will have the highest benefit from an anti-inflammatory treatment.

This study will include patients undergoing surgery for a benign tumor of the cranial base (vestibular schwannoma). The efficiency of high dosage corticosteroids administered intravenously during and after surgery will be evaluated on the facial nerve function in comparison to a placebo. Pre operative and intra operative data will be collected and analysed in order to investigate possible predictive factors of response to the treatment.

Introduction: After the surgical removal of a cerebella-pontine angle tumor (mainly vestibular schwannoma), and despite the anatomical integrity of the facial nerve, an immediate or delayed facial palsy may occur. This palsy may be explained by ischemia, edema, inflammation, or a neurotmesis (ruptured axons in an intact nerve sheet). This phenomenon is highly dependent on the size of the tumor. In our preliminary studies, we observed an immediate facial palsy in 16% and a palsy occurring at postoperative day 8 in 23% of the patients operated on for a vestibular schwannoma. Corticosteroids may decrease the inflammation and the edema around the nerve and reduce the incidence of the postoperative facial palsy. Their efficiency has already been demonstrated in idiopathic facial palsy. In a previously published study , a single dose of dexamethasone during surgery did not influence the facial function outcome. But the short period of the treatment do not allow definitive conclusions.

Objectives: The aim of this study is to analyze the effect of a corticosteroid (methyl prednisolone) administered intra- and postoperatively on the incidence of facial palsy after surgery of cerebella-pontine angle tumors and to determine intra operative prognostic factors for the facial function outcome.