The reasons for exclusion were as follows: implanted defibrillator, rejected taking part in the study and signing informed consent, intraoperative sacrifice of the facial nerve due to malignant involvement (each excluding two patients); fibrosis of the facial nerve trunk, pseudocholinesterase deficiency, revision operation, preoperative facial nerve palsy, and no identification of the facial nerve trunk (each excluding one patient). The gene discussed is BCHE; the disease is hyperinsulinemic hypoglycemia, familial, 4.