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Goals of small vestibular schwannoma (VS) microneurosurgery are as follows: radical resection, facial nerve (FN) preservation, and hearing preservation (HP). Microsurgical advances make HP possible in many patients with preoperative socially useful hearing (SUH). We evaluated postoperative HP in VS with maximum diameter 2 cm monitored with two different auditory brainstem response (ABR) techniques.Twenty-eight consecutive non-randomized patients with SUH suffering from small VS underwent keyhole microneurosurgery by retrosigmoid (RS) approach. Selection criteria are as follows: speech discrimination 50%, pure tone audiogram 50 dB loss (50/50 criterion; AAO-HNS classes A-B), maximum diameter 2 cm. HP was attempted with intraoperative ABR, evoked by classical Click (16 cases, group 1) and LS-CE-ChirpMean age was 47.5 years (16-75); average maximum diameter was 1.35 cm (0.5-1.9 mm). Total and nearly total resection ( 95%) was obtained in all, as confirmed by 24-48-h postoperative enhanced MRI. Mortality and major morbidity were 0. In all cases, FN was preserved; in 3, incomplete deficit recovered within few weeks. Socially useful HP (pre- and postoperatively) was 64.3% (18 of 28): 56.25% group 1 and 75% group 2 (p = NS). Postoperative ipsilateral deafness was observed in 5 cases of group 1 (p 0.0001). Preoperative tinnitus had negative impact on HP (p 0.05).Microsurgery can cure small growing VS with SUH. Our limited experience confirms that keyhole RS removal assisted by intraoperative ABR monitoring leads to valuable rates of SUH. LS-CE-Chirp-evoked ABRs allow a safe, effective, and clear neurophysiological feedback and are faster and, thus, more useful than the Click-ABR.

To describe the surgical management and postoperative course of two patients presenting with facial nerve (FN) paralysis as one of the presenting symptoms of small intracanalicular vestibular schwannomas (VS). Among 153 patients operated for VS since September 2010 to August 2017, two adult female patients presented with rapidly progressive hearing decrease, vestibular symptoms, and FN paralysis (House-Brackmann grades III and IV, respectively). In both cases, c.e. T1-weighted magnetic resonance imaging revealed an enhancing tumor within the internal auditory canal without lateral extension beyond the fundus. Retrosigmoid approach and excision of tumor showed that the origin of tumor was from the superior vestibular nerve, extrinsic to FN. Gross total tumor resection was obtained, with FN preservation. In the first case, a millimetric fragment of capsule was left because of tight adhesion on FN itself. Histopathology confirmed schwannoma. After surgery, both patients improved FN motor function. Although very rarely, VS may start clinically with FN palsy, mimicking FN schwannomas and other less common pathologies. This presentation is exceptional in patients with small intracanalicular VS. Early surgical resection is the only reliable treatment for decompression of nerve, avoiding a complete and not-reversible damage, with possible postoperative FN function improvement or complete recovery.