Preoperative prediction of vestibular schwannoma's nerve of origin with posturography and electronystagmography.

CONCLUSION

Chances of hearing preservation are better in patients with vestibular schwannoma (VS) from the superior vestibular nerve (SVN) than from the inferior vestibular nerve (IVN). Pathologic posturography and electronystagmography (ENG) findings are more common in schwannomas from the SVN compared with tumors from the IVN. In this way, computerized dynamic platform posturography (CDPP) and ENG contribute to predict the nerve of origin of VS and can be used indirectly as a prognostic factor for hearing preservation.

OBJECTIVES

To test whether preoperative CDPP or ENG results contribute to predict the nerve of origin in VS and also to evaluate the influence of the nerve of origin on hearing preservation.

METHODS

Eighty-nine patients with VS originating from the IVN and 22 patients with VS from the SVN were included. Hearing loss due to surgery was calculated on postoperative and preoperative audiograms. Caloric response was measured by ENG and condition 5 and 6 score were recorded by CDPP before surgery.

RESULTS

Hearing loss due to surgery was significantly lower in patients with tumors from the SVN than from the IVN (p = 0.011). Pathologic results in preoperative ENG (p < 0.0001) and CDPP (p = 0.025) were significantly more frequent in subjects with SVN than with IVN schwannomas.