Delayed facial paralysis after vestibular schwannoma surgery: role of herpes viruses reactivation--our experience in eight cases.

OBJECTIVES: The objectives of this study were to study the role of herpes virus reactivation in the onset of delayed facial paralysis (DFP) occurring more than 72 hours after vestibular schwannoma (VS) surgery and to advocate specific medical management. STUDY
DESIGN: We conducted a retrospective case review.
SETTING: University-based, tertiary care center. PATIENTS: Eight patients managed for DFP in a series of 348 patients operated for a VS.
INTERVENTIONS: Patients were evaluated and graded according to the House and Brackmann grading system and followed up for 1 year. A serologic search for specific antiherpes simplex viruses type 1 and 2 (HSV-2) and varicella zoster virus (VZV) antibodies at the onset of DFP and 2 weeks later was possible in three cases. Seven of the eight patients were given intravenous acyclovir (30 mg/kg/ for 5 days) and methylprednisolone (2 mg.kg/ for 7 days).
RESULTS: Mean delay of DFP onset was 8.75 days. All treated patients had a House and Brackmann Grade 1 recovery: mean time to recovery was 40.4 days. The last one had only a Grade 3 recovery because he could not be treated because of postoperative transient psychiatric problems. Serologic testing in those patients in whom it could be done revealed 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 an HSV or VZV reactivation.
CONCLUSION: HSV or VZV reactivation might be responsible for most cases of DFPs, thus suggesting the usefulness of immediate steroid and acyclovir administration to obtain total recovery. The viral reactivation mechanism is comparable to that already suspected in DFP occurring with the same delay in middle ear surgical procedures.