[Delayed facial palsy after vestibular schwannoma resection: the role of viral reactivation. Our experience in 8 cases].

OBJECTIVE: To study the role of herpes virus reactivation in the onset of more than three days-delayed facial paralysis (FP) following vestibular schwannoma (VS) surgery and advocate a specific medical management. MATERIAL AND METHODS: Retrospective study on 8 cases from a series of 348 patients operated on of a VS between 1996 and 2002. Seven of the eight patients were given intravenously acyclovir (30 mg x kg(-1) x d(-1) for 5 days) and methyl-prednisolone (2 mg x kg(-1) x d(-1) for 7 days). A serologic testing looking for specific anti-herpes simplex viruses type 1 and 2 (HSV-2) and varicella-zoster virus (VZV) antibodies at the onset of the FP and 2 weeks later could be done in only 3 cases. RESULTS: Mean delay of FP onset was 8.75 days. Mean time for recovery with intravenous treatment was 90 days. All treated patients had a House and Brackmann grade 1 recovery. The last one had only a grade 3 after 400 days of evolution: he could not be treated because of postoperative transient psychiatric problems. Serologic testing revealed in those patients in whom it could be done either a high level of anti-HSV or -VZV antibodies at the time of onset or a dramatic increase in anti-HSV or anti-VZV antibodies between the two samples, strongly suggesting a HSV or VZV reactivation. CONCLUSION: HSV or VZV reactivation can be evocated in most cases of delayed FPs arising in the postoperative course of VSs, suggesting usefulness of emergency-given steroid and acyclovir intravenous regimen to block virus replication and fight secondary oedema and inflammation causative of nerve lesions. Evoked reactivation mechanism is comparable to that already suspected in delayed FP arising with the same delay in middle ear surgical procedures.