Intraoperative neuromonitoring for removal of large vestibular schwannoma: Facial nerve outcome and predictive factors.

BACKGROUND: Preservation of facial nerve (FN) function is one of the major goals for resection of large vestibular schwannoma (VS) (≥ 30 mm). Little is known about the FN outcome and its predictive factors due to limited data. OBJECTIVE: To explore the predictive factors affecting FN outcome following resection of large VS. METHODS: 106 Large VS patients underwent surgical resection from 2010 to 2012 via intraoperative neuromonitoring for FN preservation approach. Postoperative FN function evaluation was conducted at the time points of 3-7th day, 3rd month and at the end of the 2nd year. Correlation between tumor size, intraoperative parameters and FN function were examined. RESULTS: The ratios of total and subtotal resection were 82.1% and 14.2%, respectively. Acceptable FN function was achieved in 78% patients. Patients with good FN function showed much smaller (P < 0.01) VS size than those of poor-FN function patients at 3-7th day, 3rd month and 2nd year. There was a significant correlation between facial motor evoked potential (FMEP) ratios and postoperative FN function at 3-7th day (r = -0.709, P < 0.001) 3rd month (r = -0.709, P< 0.001) and 2nd year (r = -0.750, P < 0.001). Maximal response amplitude (MRA) ratio was a supplementary indicator for train time in predicting both immediate and long-term FN function in patients with large VS. CONCLUSION: Indicative factors of both immediate and long-term postoperative FN function in large VSs include tumor size, intraoperative train time, start to final FMEP ratios and proximal to distal MRA ratios.

Microtransplantation of whole ganglionic eminence cells ameliorates motor deficit, enlarges the volume of grafts, and prolongs survival in a rat model of Huntington's disease.

Studies have demonstrated that embryonic cell therapy is a potential approach for the treatment of Huntington's disease (HD). However, because of the limited resource of embryos, greater attention is needed in developing more efficient surgical techniques that not only enhance the therapy outcome but also avoid inefficient therapeutics of transplantation. In this study, we explored the curative effects of two different transplantation methods using a rat model of HD. Whole ganglionic eminence (WGE) cells or phosphate-buffered saline were transplanted into unilateral striatum of quinolinic acid (QA)-lesioned rats using microtransplantation instruments (with an outer diameter of 50 µm) or traditional transplantation instruments (with an outer diameter of 470 µm). Apomorphine-induced rotation test and adjusting step test were assessed after QA-induced lesion and 2, 4, 6, 8, 10, and 12 weeks after transplantation. The expression of neuronal nuclei (NeuN), dopamine, cAMP-regulated phosphoprotein of molecular weight 32 kDa (DARPP-32), and glial fibrillary acidic protein (GFAP) was analyzed at 12 weeks after transplantation. We observed that microtransplanted rats performed better in the stepping test and had higher numbers of DARPP-32-positive cells compared with traditionally transplanted rats. Moreover, microtransplantation group showed lower GFAP expression surrounding the grafts in unilateral striatum and a higher survival rate posttransplantation compared with the traditional transplantation group. We conclude that microtransplantation is capable of enhancing therapeutic efficacy in the rat model of HD. This finding establishes the basis of an alternative transplantation strategy for treatment of HD.