[Neuroprotective medication in vestibular schwannoma surgery]

Abstract

Background: Except for glucocorticoids there is a lack of neuroprotective medication in neurosurgical interventions.

Objective: An overview of clinical trials investigating administration of the calcium antagonist nimodipine and hydroxyethyl starch (HES) in vestibular schwannoma (VS) surgery is given. Basic research is addressed and potential neuroprotective effect mechanisms are discussed, as are perspectives for application of the concept to other types of surgery with a risk postoperative impairment of nerve function.

Materials and methods: A selective PubMed search was performed and all 10 clinical trials corresponding to the search criteria were included.

Results: Four trials with an intraoperative start of the medication showed a positive effect for the preservation of facial nerve function and hearing preservation. A pilot study showed superiority of prophylactic treatment over intraoperative application. There were no significant results in a prospective multicenter phase III trial. After 1 year, postoperative facial nerve preservation rates were excellent in both groups. However, the risk of hearing loss was twice as high in the control group. A combined analysis of the phase III trial with its pilot study showed significant results for better hearing preservation rates in the treatment group (probably by increasing the case load).

Conclusion: Prophylactic nimodipine can be recommended in VS surgery in patients with good preoperative hearing. The effect mechanisms of nimodipine and modifications to prophylaxis should be clarified in basic research.

Keywords: Acoustic neuroma; Facial nerve; Hearing; Neuroprotection; Nimodipine.