Pre‑ and intra‑operative prognostic factors of facial nerve function in cerebellopontine angle surgery

Altres ajuts: Acord transformatiu CRUE-CSICPurpose: The study assesses whether pre- and intraoperative factors linked to electromyography and direct electrical stimulation (DES) of facial nerve can predict facial nerve function in the short- (12 days) and long-term (1 year) after cerebellopontine angle (CPA) tumor resection. Methods: 157 patients who underwent surgical resection of CPA tumors with facial nerve monitoring. Pre-operative factors (age, tumor size, pure tone average), surgical time and intra-operative parameters regarding facial function, minimum stimulation threshold (MST), compound muscle action potential (CMAP) and the diference between proximal and distal CMAP (DPDC) were evaluated. Results: A correlation between tumor size, MST, CMAP and facial function in both short and long term was found. A higher grade of immediate facial paralysis corresponded to a higher risk of poor outcome after one year. A postoperative House-Brackmann (HB) score of V or VI was correlated with poor outcome in 88.8% and 93.8% of cases. A risk of HB 3 or more, in the long term, was correlated with a tumor size of 20.2 mm. Using an MST of 0.1 mA, for long-term predictions, sensitivity and specifcity were 0.62 (95% CI 0.46-0.75) and 0.73 (95% CI 0.61-0.82), respectively. With a CMAP cut-of