Facial Nerve Monitoring in Patients Under The Low Level Of Neuromuscular Blockade During Resection Of acoustic Neurinomas / 中国神经精神疾病杂志

ABSTRACT

Objective To perform facial nerve monitoring in patients under the low level of neuromuscular blockade during resection of acoustic neurinomas.Methods Twenty-eight patients with large,or medium acoustic neuroma underwent the surgery of acoustic neurinomas resection. During the operation,TOF and EEG monitoring were performed in order to detect the degree of muscle relaxation and the depth of anesthesia. Neuromuscular relaxation was maintained at T_4/T_1=25%～50% by adjusting doses of muscle relaxant and aneasthetic. Free-run EMG and Triggered EMG of orbicularis oris, orbicularis oculi, masseter and trapezius were recordered to monitor the function of the facial, trigeminal and accessory nerves, respectively. The function of the facial nerve was evaluated at first week and half year postoperatively according to House-brackmann classification.Results The facial never was successfully identified and mapped by neurominitoring in all 28 patients. successfully, tThe electrical stimulation was 0.1 mA-0.3 mA and no any involuntary body movement was observed in all patients ne of patients have moved during operation. The preservation of the facial nerve function following surgery was good. Five patients had a HB grade I, 13 a HB grade II, 8 a grade III and 2 a HB grade IV The facial nerve function was HB Grade Ⅰin 5 of 28 patients, HB GradeⅡ in 13, HB Grade Ⅲ in 8 and HB Grade Ⅳ in 2 immediately after operation. Six months after surgery, 10 casespatents showed demonstrated a HB GradeⅠof facial never function, 12 cases exhibited a slight palsy (HB Grade II) , and 5 cases exhibited a HB Grade III palsy and . Another 1 cases a exhibited severe palsy (HB Grade IV).Conclusions Facial nerve monitoring in patients under the low level of neuromuscular blockade can ensure the surgical safety and preserve the facial never function.