An Unusual Abnormal Muscular Response During Microvascular Decompression Under Endoscope Assistance

Abstract Abnormal muscular response (AMR) has been widely used in the intraoperative monitoring of microvascular decompression due to its advantages for the identification of responsible arteries and the evaluation of adequate decompression. Here the authors report a 48-year-old man with an unusual AMR during microvascular decompression under endoscope assistance. The morphology and number of AMRs were influenced by different stimulation and recording sites. Abnormal muscular response disappeared and hemifacial spasm was completely relieved without facial paralysis postoperatively.