TY - JOUR AU - Thirumala, Parthasarathy D.; Mohanraj, Santhosh Kumar; Habeych, Miguel; Wichman, Kelley; Chang, Yue-fang; Gardner, Paul; Snyderman, Carl; Crammond, Donald J.; Balzer, Jeffrey TI - Value of Free-Run Electromyographic Monitoring of Extraocular Cranial Nerves during Expanded Endonasal Surgery (EES) of the Skull Base SN - 2193-6358 SN - 2193-6366 PY - 2013 JO - J Neurol Surg Rep JF - Journal of Neurological Surgery Reports LA - EN VL - 74 IS - 01 SP - 043 EP - 050 ET - 2013/06/13 DA - 2013/07/16 KW - electromyography KW - lower cranial nerves KW - expanded endonasal surgery AB - Objective To evaluate the value of free-run electromyography (f-EMG) monitoring of extraocular cranial nerves (EOCN) III, IV, and VI during expanded endonasal surgery (EES) of the skull base in reducing iatrogenic cranial nerve (CN) deficits.Design We retrospectively identified 200 patients out of 990 who had at least one EOCN monitored during EES. We further separated patients into groups according to the specific CN monitored. In each CN group, we classified patients who had significant (SG) f-EMG activity as Group I and those who did not as Group II.Results A total of 696 EOCNs were monitored. The number of muscles supplied by EOCNs that had SG f-EMG activity was 88, including CN III = 46, CN IV = 21, and CN VI = 21. There were two deficits involving CN VI in patients who had SG f-EMG activity during surgery. There were 14 deficits observed, including CN III = 3, CN IV = 2, and CN VI = 9 in patients who did not have SG f-EMG activity during surgery.Conclusions f-EMG monitoring of EOCN during EES can be useful in identifying the location of the nerve. It seems to have limited value in predicting postoperative neurological deficits. Future studies to evaluate the EMG of EOCN during EES need to be done with both f-EMG and triggered EMG. PB - Georg Thieme Verlag KG DO - 10.1055/s-0033-1346975 UR - http://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0033-1346975 ER -