Improved preservation of function during acoustic neuroma surgery

Abstract

OBJect Restoration of cranial nerve functions during acoustic neuroma (AN) surgery is crucial for good outcome. The effects of minimizing the injury period and maximizing the recuperation period were investigated in 89 patients who consecutively underwent retrosigmoid unilateral AN surgery. MetHODS Cochlear nerve and facial nerve functions were evaluated during AN surgery by use of continuous auditory evoked dorsal cochlear nucleus action potential monitoring and facial nerve root exit zone-elicited compound muscle action potential monitoring, respectively. Factors affecting preservation of function at the same (preoperative) grade were analyzed. reSUltS A total of 23 patients underwent standard treatment and investigation of the monitoring threshold for preservation of function; another 66 patients underwent extended recuperation treatment and assessment of its effect on recovery of nerve function. Both types of final action potential monitoring response and extended recuperation treatment were associated with preservation of function at the same grade. cOnclUSiOnS Preservation of function was significantly better for patients who received extended recuperation treatment.http://thejns.org/doi/abs/10.3171/2014.8.JNS132525KeY WOrDS acoustic neuroma surgery; continuous direct brainstem auditory evoked potential monitoring; oncology aBBreViatiOnS AEDNAP = auditory evoked dorsal cochlear nucleus action potential; AN = acoustic neuroma; APR = amplitude preservation ratio; AUC = area under the curve; BAEP = brainstem auditory-evoked potential; FREMAP = facial nerve root exit zone-elicited compound muscle action potential; GR = Gardner-Robertson; HB = House-Brackmann; M-max = maximum peak-to-peak amplitude; ROC = receiver operating characteristic.

Preoperative electrophysiological analysis predicts preservation of hearing and facial nerve function following vestibular schwannoma surgery with continuous intraoperative neural monitoring: Clinical outcomes of 22 cases

“…In the 2010s, a novel form of intraoperative monitoring for hearing function was developed, that is dorsal cochlear nucleus action potential (DNAP) monitoring. 5 In DNAP monitoring, the detection prove is set on the dorsal cochlear nucleus of the brainstem. The action potential of the dorsal cochlear nucleus will be detected by this prove.…”

Combined use of diffusion tensor tractography and multifused contrast-enhanced FIESTA for predicting facial and cochlear nerve positions in relation to vestibular schwannoma

“…Regarding identification methods for nerves, the facial nerve was identified by the presence of facial muscle action potentials elicited by direct facial nerve fascicle stimulation at 0.1-0.2 mA. With regard to the cochlear nerve, we used our unique invention, electric stimuli elicited dorsal cochlear nucleus action potential (ESE-DNAP) monitor-ing, 16 to identify the specific direct connection of the specific nerve fascicle with the dorsal cochlear nucleus by intraoperative electrical stimulation at 0.2-0.4 mA (Video 1). Multifused CE-FIESTA, however, suggests that one low-intensity area is an artery (arrowheads).…”

Single-Cell Information Analysis Reveals That Skeletal Muscles Incorporate Cell-to-Cell Variability as Information Not Noise

“…We measured human facial muscle contraction by electromyography in response to 10 repetitive EPS of facial nerves at 20 different currents in three human patients during intraoperative neurophysiological monitoring (Figures 6A and S6A). We calculated the peak-to-peak amplitude of the electromyogram (Figure S6B), a measure of muscle contraction (Amano et al, 2011;Nakatomi et al, 2015;Figures 6B-6D and S6C-S6F).…”