Efficacy of Intraoperative Neuromonitoring during Thyroidectomy with Transcutaneous Adhesive Skin Electrodes

Background and Objectives Variable types of electrodes for intraoperative neuromonitoring (IONM) during thyroid surgery have been introduced to make up for the shortcomings of conventional endotracheal electromyogram tube. In this study, we sought to evaluate the efficacy of transcutaneous adhesive skin electrodes for IONM of recurrent laryngeal nerve (RLN) during thyroidectomy.Subjects and Method A total 97 nerves at risk of 80 patients were enrolled in this study. Two disposable adhesive skin electrodes were attached at both upper margins of thyroid cartilage. Using NIM 3.0 system (Medtronic), we recorded the amplitude and latency of signals of vagus nerve and RLN following the standard procedure of IONM. Clinicopathologic factors as well as the preoperative and postoperative vocal cord functions of the patients were analyzed.Results IONM was successful in all nerves at risk without any false loss of signals. There were no complications nor any significant time delay due to adhesive skin electrodes. The mean amplitudes from the vagus nerve (V1) and RLN (R1) were 230.64 µV and 293.48 µV, respectively. Two nerves at risk showed loss of signal and the two patients showed postoperative temporary vocal cord paralysis. The amplitude of signals from the vagus nerve (V1, V2) was significantly higher in the lower body mass index (BMI) group compared to that of the higher BMI group.Conclusion IONM using transcutaneous skin electrodes may be considered as an alternative technique for IONM during thyroid surgery.

Electrophysiological Monitoring of Focal and Entire Retinal Function during Treatment with Intravitreal Methotrexate for Intraocular Lymphoma

We describe the electroretinographic findings of a case of primary intraocular lymphoma (PIOL) wherein the patient received intravitreal injections of methotrexate (ivMTX). A 62-year-old man developed blurred vision and complained of decreased visual acuity (VA) in his right eye. Fundus examination showed vitreous opacity and multiple subretinal yellowish lesions. Optical coherence tomography (OCT) revealed subretinal and intraretinal infiltrations. The full-field electroretinogram (ffERG) showed subnormal combined rod-cone response and multifocal electroretinogram (mfERG) recorded using skin electrodes showed severe attenuation of the response compared with the other eye. Pars prana vitrectomy, phacoemulsification, and lens implantation were performed to remove the opacity, and vitreous biopsy revealed a high ratio of interleukin 10–6 (76.0). There was no systemic malignant lesion, and the patient was diagnosed with PIOL. Treatment with ivMTX (400 μg/0.1 mL) was started. One month later, the intraretinal infiltration had disappeared, and mfERG revealed recovery of the response density from the central area. Two months later, OCT showed recovery of the foveal ellipsoid and interdigitation zones, and VA recovered to 20/17; mfERG showed maintenance of macular function. However, the amplitude of a- and b-waves in the ffERG gradually decreased. Macular function recovered, but there was also a decrease in total retinal function. mfERG and ffERG recorded using skin electrodes were useful in monitoring macular and entire retinal function with repeated examinations and showed recovery and maintenance of macular function in a case of PIOL treated with ivMTX.

Application of Skin Electrodes for Intraoperative Neuromonitoring of Recurrent Laryngeal Nerve

Efficiency of intraoperative neuromonitoring (IONM) for recurrent laryngeal nerve (RLN) during thyroid or parathyroid surgery has been well established. Electromyogram (EMG) tube has been utilized as a standard method of IONM for RLN. However, limitations of EMG tube including false positive signals due to malposition of the tube and relatively high cost have been issued. Recently, there have been several alternative methods using variable types of skin electrodes to overcome the limitations of conventional EMG tube. These recent methods using skin electrodes will be reviewed in this article.

Highly adhesive, washable and stretchable on-skin electrodes based on polydopamine and silk fibroin for ambulatory electrocardiography sensing

Highly skin-adhesive, washable and stretchable electrodes were fabricated by combining polydopamine, silk fibroin, and SEBS/Au films for ambulatory electrocardiography sensing.