Electrophysiological Monitoring Research Articles

P06.05 The Sitting Position in the Very Young Pediatric Population: Pearls and Pitfalls of a 10-Years’ Experience

Abstract BACKGROUND To investigate pearls and pitfalls of the sitting positioning in the pediatric population with special focus on related morbidity and surgical practicability. MATERIAL AND METHODS A retrospective analysis of a prospectively maintained internal database was performed. All pediatric patients younger than 18 years at date of surgery, who underwent procedures in sitting position between 01/2010 and 10/2020 were included into this analysis. RESULTS A total of 42 of posterior fossa surgeries were performed in 38 children between 01/2010 and 10/2020. Mean age at surgery was 8.9 years (13 months - 18 years). Mean height and weight were 134.4 (± 30.2) cm and 36.6 (± 21.7) kg respectively. Three children (7.9%) were diagnosed with persistent foramen ovale. Electrophysiologic monitoring was unremarkable during positioning in all cases. Mean time needed for anesthesiologic preparation and positioning was 84.5 (± 20.6) minutes. Perioperative blood transfusion was needed in 5 cases (11.9%). Incidence of VAE was 11.9%. There was no VAE related severe complication. One child (2.4%) showed postoperative skull fracture and epidural bleeding due to skull clamp application. Clinical status immediately after surgery was favorable or stable in 33 of the cases (78.6%). CONCLUSION Attentive performance and an experienced surgical team provided; the sitting position remains a safe variant for posterior fossa surgery in the pediatric population. Precautious skull clamp application and appropriate monitoring is highly recommended. Considering eloquent aspects, the sitting position offers excellent anatomical exposure and is ideal for combination with endoscopic techniques.

Comparative analysis of functional assessment for contusion and transection models of spinal cord injury.

Descriptive secondary analysis of two spinal cord injury (SCI) animal models. To compare the somatosensory evoked potential (SSEP) and motor behavioral (BBB) assessments of the two most used rodent SCI models (contusion and transection), to elucidate their functional similarity and differences over the acute phase of 3 weeks. Neuro-electrophysiology SSEP and motor behavioral BBB assessments are used to provide a comparative analysis of the functional changes among various severities of contusion and transection SCI. Adult male and female rats randomly grouped (n = 5) as following: mild (6.25 mm), moderate (12.5 mm), severe (25 mm), and very severe (50 mm) contusion as well as right T10 hemi-transection (RxI), left T8 and right T10 double hemi-transection (DxI), and T8 complete transection (CxI) injuries, plus the control group (laminectomy with no injury). Animal weight, body temperature, anesthesia, surgical procedures, electrophysiological SSEP monitoring, locomotion BBB scoring, and statistical analysis were identical among all animal groups. Statistical analysis of the SSEP and BBB data from both contusion and transection injury models indicate significant differences (P < 0.05). The results also show remarkable similarity for the severe and very severe contusion injuries to the complete transection, the moderate contusion injury to the double hemi-transection, and the mild contusion injury to the T10 hemi-transection injury. Although contusion and transection spinal cord injuries have two completely different pathophysiologies, their injury progress during acute phase follow a similar trend.

The usefulness of the averaging rule in consumer studies: A partial replication with an eye at neuroeconomics

IntroductionInformation Integration Theory models how different pieces of information are combined by people into unified judgments. Its contribution to decision-making and to consumer studies distinctly relies on a set of empirically established algebraic models for reflecting the cognitive structure of judgments and decisions (cognitive algebra). Among these, the averaging model has particular properties, allowing for operationally distinguishing between the elusive notions of psychological value and importance. ObjectivesThe main goal of the paper is to support the applicability and robustness of the averaging model in consumer studies, by partially replicating a published study that documented averaging. Additionally, it tentatively explores potential contributions of the averaging model to neuroeconomics, by simultaneously recording ratings and electroencephalographic (EEG) responses. MethodsTwenty-five participants rated on a satisfaction scale (format 0-20) a set of experimental conditions arising from the full factorial combination of three levels of sneakers’ branded models and three levels of purchase prices, expanded with conditions in which brands were presented in isolation (sub-design). Simultaneous electrophysiological monitoring was performed with an EEG mask (international system 10-20, referenced to the mastoid apophyses). Segmentation and processing of evoked response potentials were done in Matlab. Both ratings and magnitudes of event-related potentials (ERP) components were analyzed through inspection of the factorial plots with the support of repeated-measures ANOVAs. ResultsThe rating responses revealed an averaging model, with equal weighting in a cluster of subjects and differential weighting in another, but more overall importance of the branded model variable in both cases. The only tentative suggestions of relevant neural correlates involved the LPP and P300 components of the ERP and a reduced number of EEG channels (P4, P3, Fz and T3). ConclusionsThe averaging model is robustly applicable and useful in consumer studies, both for measurement (value and importance) and consumer segmentation (cognitively based clusterization) purposes. While calling attention to the later components of the ERP at specific topographies, the paucity of EEG results suggests that ERP peak amplitude may not be a useful measure for the purpose. Apart from that, a functional measurement approach to neuroeconomics seems feasible in principle and an explorable path in the future.

Environmental noise at library learning commons affects student performance and electrophysiological functioning

Environmental noise (EN) refers to unpleasant harmful sounds that deteriorates living conditions. Therefore, this study aims to investigate how EN affects students at learning commons, where EN increases between 70 and 90 dBA, and which levels disturb psycho-physiologically. For this purpose, 16 students of Tecnologico de Monterrey were recruited: nine men and seven women. They were divided into four groups, and were involved in two activities: to solve a puzzle of 300 pieces without and with EN at 75 dBA. In both activities, a summative evaluation based on the level of puzzle completeness, and the electrophysiological monitoring of heart and blink rate, and neural electrical activity were conducted. Results showed that student performance was 4% higher in a quiet room than in learning commons. EN increased heart rate in 3.48%, and blink rate in 22.91%, and neural electrical activity was reduced at least in 3%, regardless of task demands. The findings of the present study suggest that academic work is difficult to undertake in learning commons when EN is above the permissible limit, and what diminishes the performance of students and alters their electrophysiological functioning.

Prognostication of the neurological outcome of tethered cord based on intraoperative neuromonitoring findings: how close can we get?

Purpose To evaluate the correlation of intraoperative neuromonitoring (IONM) data in surgery for tethered cord syndrome (TCS) in children to the neurological outcome at 1-year follow-up. Methods 208 consecutive patients operated on for TCS, between January 2011 to February 2020, under electrophysiological monitoring in the Division of Paediatric Neurosurgery, AIMS, Kochi, India, were included. Their preoperative neurological, urological and orthopaedic status were compared with the postoperative status at 1 year follow-up. Results Our study prospectively collected the IONM data and retrospectively correlated it to the children's neurological outcome on follow-up. Out of 208 children, 28% (n = 59/208) had motor, 35% (n = 73/208) had bladder and 26% (n = 54/208) had bowel disturbances. Postsurgery, at one-year follow-up, 91% (n = 52/57) of the patients who had motor deficits had improvement, 82.3% (n = 51/62) of patients who had bladder deficits showed an improvement, and 88.8% (n = 48/54) with bowel deficits showed improvement. The monitorability for motor and sphincter potentials were 99.4% and 89.3%, respectively. Except for four patients (3 with bladder and 1 with motor worsening), all the patients who were monitorable with no deficits remained intact except for four patients, all the patients who had deficits and were monitorable improved after detethering (at 1 year). Clinical worsening corresponded to those who had a drop in amplitude of baseline TcMEP (n = 4). 18 events showed an increase in amplitude compared to the baseline TcMEP. These patients improved clinically on follow-up (at 1 year). Conclusions IONM complements the preoperative clinical details in predicting immediate and long-term outcomes.

Clinical study of modified one stage posterior approach total en block spondylectomy and spinal reconstruction in the treatment of invasive thoracic vascular tumor

To explore the surgical method and safety of modified one stage posterior approach total en block spondylectomy combined with pedicle screw fixation and titanium mesh reconstruction for the treatment of invasive thoracic vascular tumor. The clinical data of 12 patients with invasive thoracic vasculay tumor from December 2012 to May 2015 was retrospectively analyzed. There were 8 males and 4 females, aged from 40 to 62 years with an average of 51.2 years, the course of disease was 2 months to 8 years with an average of 3.4 years. The lesions involved vertebral bodies:1 case of T2, 4 cases of T4, 1 case of T5, 2 cases of T6, 2 cases of T8, and 2 cases of T10. According to Tomita classification, there were 3 cases of typeⅠ, 3 cases of typeⅡ, 1 case of type Ⅲ, and 5 cases of type Ⅳ. The Japanese Orthopaedic Association (JOA) score was 8.0±2.7 before operation. One patient with T10 lesions had sensory dyskinesia below the umbilicus, and the muscle strength of both lower limbs was grade Ⅰ-Ⅱ, and the others 11 patients were grade Ⅲ-Ⅳ. All 12 patients underwent one stage posterior approach total en block spondylectomy and the pedicle screw fixation combined with titanium mesh reconstruction under general anesthesia and continuous motor evoked potential (MEP) spinal cord electrophysiological monitoring throughout the operation. The operation time, intraoperative blood loss and transfusion, postoperative pain and recovery of spinal cord function, bone graft fusion, tumor recurrence and other complications were followed up. All the operations were successful. The average operation time, intraoperative blood loss and blood transfusion were 5.5 h (4.5 to 6.0 h), 1 850 ml (1 650 to 2 500 ml), 1 050 ml (600 to 1 500 ml), respectively. All 12 patients were followed up for 5 months to 2.5 years with an average of 21 months. Local pain and lower limb muscle strength were improved to varying, and the nerve compression symptoms disappeared. The JOA score at 6 months after operation was 12.0±3.4, which was statistically significant difference compared with the preoperative 8.0±2.7 (t=3.20, P<0.05). Titanium mesh bone grafts were all fused in phaseⅠ, with an average fusion time of 4.5 months (3 to 7 months). During the follow-up period, there was no tumor recurrence, loosening or breaking of nails, sinking and displacement of titanium mesh. Modified one stage posterior approach total en block spondylectomy is an ideal surgical method for the treatment of invasive thoracic vascular tumors, which has a safe, reliable and long lasting efficacy.

Self-adhesive, biodegradable silk-based dry electrodes for epidermal electrophysiological monitoring

Epidermal flexible devices can continuously and real-time record the electrical potential changes from human skin, which is essential for chronic disease diagnosis and smart health monitoring. However, it remains challenging to fabricate high-performance epidermal dry electrodes with excellent self-adhesive while maintaining excellent biodegradability as well as high mechanical performance and low contact impedance. Herein, we fabricate an epidermal dry electrode with high mechanical performance, low contact impedance and excellent self-adhesive by coating polypyrrole (Ppy) conductive layer and calcium (Ca)-modified SF adhesive layer on acid-modified silk (AM-SF)/cellulose nanocrystals (CNC) films. The AM-SF could effectively promote the absorption and intercalation of Ppy into the SF network, endowing the tight integration between the Ppy conductive layer and the AM-SF/CNC films and improving the conductivity of Ppy@AM-SF/CNC films. On the other side, the Ca ions in the Ca-modified SF adhesive layer capture water molecules from the atmosphere and result in a much higher flowability to allow conformal contact between Ca-modified SF and the human skin, leading to significantly low skin-electrode impedance. As a proof-of-concept, the Ppy@AM-SF/CNC electrodes are employed for both electrocardiography (ECG) and electromyography (EMG) recording. Interestingly, this electrode allows detaching from the skin by simple water rinsing to reduce skin-damage for people. Moreover, the Ppy@AM-SF/CNC electrodes possess excellent enzymatic degradability without leaving hazardous substances. This work offers a unique prospective for developing next-generation wearable healthcare devices in the era of personalized healthcare.

Optimization of electromyographic endotracheal tube electrode position by UEScope for monitored thyroidectomy.

ObjectiveProper position of an electromyographic (EMG) endotracheal tube within the larynx plays a key role in functional electrophysiologic intraoperative neural monitoring (IONM) in thyroid surgery. The purpose of this study was to determine the feasibility of a portable video‐assisted intubation device (UEScope) to verify the optimal placement of an EMG tube.MethodsA retrospective study enrolled 40 consecutive patients who underwent monitored thyroidectomies. After positioning the patient for surgery, an anesthesiologist performed tracheal intubation with UEScope and checked the position of the tube at the proper depth without rotation to the vocal cords. The main outcome measured was the proper EMG tube position, free from further adjustment. The secondary outcomes assessed were the percentage of available initial vagal stimulation (V1) signals.ResultsAll tracheal intubations were successful at first attempt. Proper EMG tube placement without position adjustment was found in 97.5% of the patients. Tube withdrawal was required in a male patient. All patients obtained detectable V1 signals; the lowest and median V1 amplitude was 485 and 767 μV as a reference value, respectively.ConclusionThe UEScope is a valuable and reliable tool for placing an EMG tube and confirming its position during monitored thyroidectomy. In addition, further tube adjustment might be waived in most cases when the anesthesiologist placed the EMG tube after patient positioning for surgery. Routine use of video‐assisted intubation devices is highly recommended.Level of Evidence4.

Neural Mass Model-Based Different EEG Signal Generation and Analysis in Simulink

The electroencephalogram (EEG) is an electrophysiological monitoring strategy that records the spontaneous electrical movement of the brain coming about from ionic current inside the neurons of the brain. The importance of the EEG signal is mainly the diagnosis of different mental and brain neurodegenerative diseases and different abnormalities like seizure disorder, encephalopathy, dementia, memory problem, sleep disorder, stroke, etc. The EEG signal is very useful for someone in case of a coma to determine the level of brain activity. So, it is very important to study EEG generation and analysis. To reduce the complexity of understanding the pathophysiological mechanism of EEG signal generation and their changes, different simulation-based EEG modeling has been developed which are based on anatomical equivalent data. In this paper, Instead of a detailed model a neural mass model has been used to implement different simulation-based EEG models for EEG signal generation which refers to the simplified and straightforward method. This paper aims to introduce obtained EEG signals of own implementation of the Lopes da Silva model, Jansen-Rit model, and Wendling model in Simulink and to compare characteristic features with real EEG signals and better understanding the EEG abnormalities especially the seizure-like signal pattern.

Neural Mass Model-Based Different EEG Signal Generation and Analysis in Simulink

The electroencephalogram (EEG) is an electrophysiological monitoring strategy that records the spontaneous electrical movement of the brain coming about from ionic current inside the neurons of the brain. The importance of the EEG signal is mainly the diagnosis of different mental and brain neurodegenerative diseases and different abnormalities like seizure disorder, encephalopathy, dementia, memory problem, sleep disorder, stroke, etc. The EEG signal is very useful for someone in case of a coma to determine the level of brain activity. So, it is very important to study EEG generation and analysis. To reduce the complexity of understanding the pathophysiological mechanism of EEG signal generation and their changes, different simulation-based EEG modeling has been developed which are based on anatomical equivalent data. In this paper, Instead of a detailed model a neural mass model has been used to implement different simulation-based EEG models for EEG signal generation which refers to the simplified and straightforward method. This paper aims to introduce obtained EEG signals of own implementation of the Lopes da Silva model, Jansen-Rit model, and Wendling model in Simulink and to compare characteristic features with real EEG signals and better understanding the EEG abnormalities especially the seizure-like signal pattern.

ROC Curve Analysis of Electrophysiological Monitoring and Early Warning During Intracranial Aneurysm Clipping

To explore the safe duration of temporary clipping of the parent artery under intraoperative electrophysiological monitoring. The clinical data of 97 patients who underwent intracranial aneurysm clipping under electrophysiological monitoring in the Department of Neurology, Affiliated Hospital of Qingdao University from June 2019 to June 2020 were retrospectively analyzed. The safety duration of temporary clipping was analyzed using receiver operating characteristic (ROC) curves, and the results were validated in clinical data. Temporary clipping during operation (P < 0.05) and electrophysiological warning during operation (P < 0.05) were related risk factors of a cerebral ischemia event after operation. The ROC curve was drawn for the duration of temporary clipping and the occurrence of intraoperative electrophysiological warning, and the area under the curve was 0.78 (P < 0.05). The optimal cutoff value was 372.5 seconds, the sensitivity was 0.818, and the specificity was 0.762. After reviewing the clinical data, P < 0.05 was statistically significant after a χ2 test with 372.5 seconds equal to approximately 6 minutes. The ROC curve was drawn for the duration of temporary clipping and the time of postoperative ischemia, and the area under the curve was 0.667 (P < 0.05). The optimal cutoff value was 430.5 seconds, the sensitivity was 0.592, and the specificity was 0.842. Temporary intraoperative block is the risk factor for cerebral ischemia after operation. In this study, the temporary clipping time of the parent artery should not be longer than 6 minutes, and there is approximately 1 minute to adjust the current procedure after the electrophysiological warning to restore the baseline of intraoperative electrophysiological monitoring.

Surgery of the Brainstem

The book “Surgery of the brainstem” is a richly illustrated book, covering almost every aspect of surgery in and around the brainstem. The first two sections (Chapters 1–4) of the book cover the history of brainstem surgery and the complex anatomy. Section III (Chapters 5–7) deals with the neurologic examination of patients with brainstem pathology, imaging, and intraoperative electrophysiologic monitoring. Surgical approaches to the brainstem, thalamus, and pineal region are explained in great detail in Section IV (Chapters 8–12). Section V (Chapters 13–22) deals with the management of tumors, whereas Section VI (Chapters 23–32) deals with the management of vascular pathologies in and around the brainstem. In the last section with the heading “Implants and cranial nerve repair,” the role of auditory brainstem implants in treating hearing loss is discussed.

Follow the Venous Path to the Hidden Lesion: A Technical Trick in Brainstem Cavernous Malformation Surgery

Deep-seated brainstem cavernous malformations (BSCMs) pose a particular challenge for brainstem entry intraoperatively and their treatment can require comprehensive application of neuronavigation, electrophysiological brainstem mapping and monitoring, and full knowledge of safe brainstem entry zones. In the present report, we have introduced a supplementary technical trick for localizing a hidden tiny lesion inside the brainstem when a developmental venous anomaly (DVA) is present on the brainstem surface. A retrospective analysis of a 74-case cohort treated surgically from January 2011 to December 2019 was conducted. We identified 11 patients (14.9%) whose deep-seated BSCMs were exposed and removed following a brainstem surface DVA path as a supplementary technical trick. We have presented 2 typical cases to illustrate the operative nuances. Of the 11 patients, 5 were male and 6 were female. Their average age was 38.0 ± 14.0 years (range, 15-62 years). Most BSCMs were located in the pons (n= 5; 45.5%), followed by the pontomesencephalic area (n= 3; 27.3%), midbrain (n= 2; 18.2%), and medulla oblongata (n= 1; 9.1%). All BSCMs were successfully located and completely removed. In 5 cases, the DVA was impaired after lesion removal (45.5%). However, no aggravated postoperative brainstem edema occurred in any of the 11 patients. After 3.6 ± 2.0 years of follow-up (2 patients were lost to follow-up; follow-up rate, 81.8%), no rebleeding was found, and the modified Rankin scale score of the patients had improved from 2.7 ± 1.1 preoperatively to 1.7 ± 0.9 at follow-up (P= 0.031). The presented method could help surgeons trace deep-seated BSCMs with minimal brainstem parenchyma impairment, avoiding unnecessary aggressive exploration.

Simple and cost-effective microfabrication of flexible and stretchable electronics for wearable multi-functional electrophysiological monitoring

The fabrication of flexible and stretchable electronics is a critical requirement for the successful application of wearable healthcare devices. Although such flexible electronics have been commonly fabricated by microelectromechanical system (MEMS) technologies, they require a specialised equipment for vacuum deposition, photolithography, and wet and dry etching. A photolithography-free simple patterning method using a desktop plotter cutter has been proposed; however, the metal formation and electrode opening still rely on the MEMS technology. To address this issue, we demonstrate a simple, rapid, cost-effective, and a complete microfabrication process for flexible and stretchable sensor platforms encompassing conductor formation and patterning to encapsulate and open sensing windows, which only require an economic plotter cutter and readily available supplies. Despite its simplicity, the proposed process could stably create microscale features of 200 μm wide conductor lines and 1 mm window openings, which are in the useful range for various wearable applications. The feasibility of the simple fabrication of multi-functional sensors for various physiological monitoring applications was successfully demonstrated in electrochemical (glucose), electrical (electrocardiogram), mechanical (strain), and thermal (body temperature) modalities.

Microsurgery for Vestibular Schwannoma via Retrosigmoid Transmeatal Approach with Intraoperative Monitoring Techniques.

Background: Functional preservation of cranial nerves remains an issue in surgical treatment of vestibular schwannoma.Aims: To explore the functional outcomes of vestibular schwannoma removed by microsurgery via a retrosigmoid transmeatal approach with intraoperative monitoring techniques.Study Design: A retrospective cross-sectional study was conducted on a group of patients with vestibular schwannoma operated by microsurgery.Methods: The outcomes, including the extent of tumor removal, the anatomic positions of the facial nerve, and postoperative Karnofsky performance status score, facial nerve function, and hearing function were reviewed and were statistically compared among tumor sizes (small, medium, and giant) and intraoperative monitoring types [electrophysiological monitoring only (E), electrophysiological monitoring + intraoperative imaging examination (E+I), and electrophysiological monitoring + neuronavigation (E+N)].Results: A total of 436 patients with VS received microsurgery. The position of the facial nerve was anterior in 85.5% of cases with small vestibular schwannoma. Other position patterns, especially anterior–superior and anterior–inferior, increased in tumors > 2.0 cm. Total resections were performed in all patients with small vestibular schwannoma. A total of 98.1% and 84.8% of patients with medium and giant vestibular schwannoma, respectively, had total resections. More than 90% of patients in all of the 3 monitoring groups had total resections. More than 80% of patients had excellent Karnofsky performance status score regardless of tumor size and monitoring type. After surgery, 100%, 84.4%, and 59.8% of patients with small-, medium-, and giant-sized vestibular schwannoma, respectively, had good facial nerve function. More than 70% of patients in all of the 3 monitoring groups had good facial nerve function postoperatively. The hearing preservation rate was 26.7% and 7.7% in small- and medium-sized vestibular schwannoma, respectively, and was 21.6% and 27.3% in the E group and the E+N group, respectively. The statistical analyses showed that tumor size was significantly associated with the extent of tumor resection, facial nerve localization, complications, postoperative Karnofsky performance status score, facial nerve function, and hearing function (all P ≤ .001). Monitoring type was significantly associated with the extent of resection (P ≤ .001). Additionally, patients in the E+N group had higher total resection rates than those in the E group (P ≤ .001). No cerebrospinal fluid leakage and surgery-related death occurred.Conclusion: In vestibular schwannoma microsurgery, tumor size is an important parameter that affects the localization of the facial nerve, the extent of resection, postoperative outcomes and complications. Intraoperative electrophysiological techniques combined with neuronavigation may be helpful to improve the extent of resection.

Stretchable and Transparent Metal Nanowire Microelectrodes for Simultaneous Electrophysiology and Optogenetics Applications

Recently developed optically transparent microelectrode technology provides a promising approach for simultaneous high-resolution electrical and optical biointerfacing with tissues in vivo and in vitro. A critically unmet need is designing high-performance stretchable platforms for conformal biointerfacing with mechanically active organs. Here, we report silver nanowire (Ag NW) stretchable transparent microelectrodes and interconnects that exhibit excellent electrical and electrochemical performance, high optical transparency, superior mechanical robustness and durability by a simple selective-patterning process. The fabrication method allows the direct integration of Ag NW networks on elastomeric substrates. The resulting Ag NW interface exhibits a low sheet resistance (Rsh) of 1.52–4.35 Ω sq−1, an advantageous normalized electrochemical impedance of 3.78–6.04 Ω cm2, a high optical transparency of 61.3–80.5% at 550 nm and a stretchability of 40%. The microelectrode arrays (MEAs) fabricated with this approach exhibit uniform electrochemical performance across all channels. Studies on mice demonstrate that both pristine and stretched Ag NW microelectrodes can achieve high-fidelity electrophysiological monitoring of cardiac activity with/without co-localized optogenetic pacing. Together, these results pave the way for developing stretchable and transparent metal nanowire networks for high-resolution opto-electric biointerfacing with mechanically active organs, such as the heart.

A rare case of carotid body tumor associated with near complete cerebral sinus thrombosis and idiopathic intracranial hypertension. Management strategy and review of the literature

Background: Carotid body tumors (CBTs) are rare hypervascular lesions with critical location which makes them very challenging to treat. In rare occasions, compression of the jugular vein from the tumor mass could predispose to progressive thrombosis of intracranial venous sinuses. The latter consequently leads to intracranial hypertension (pseudotumor cerebri) with the accompanying danger to the vision. Herewith, we present our management strategy for this rare presentation of CBTs.Case Description: A 38-year-old woman, with no medical history, was admitted in the emergency unit with acute onset of headache, dizziness, and vomiting. On the diagnostic imaging studies (CT venography and MRI) a near total occlusion of all cerebral venous sinuses and a large CBT (Shambin Type II) were diagnosed. Initially, the patient was treated with anticoagulants for the thrombosis and with lumbo-peritoneal (LP) shunt for the management of pseudotumor cerebri. At a second stage, after resolution of the cerebral sinus thrombosis, the CBT was completely resected under electrophysiological monitoring, without preoperative embolization. At 1-year follow-up, the patient is neurologically intact with functioning LP shunt, patent cerebral venous sinuses, without tumor recurrence.Conclusion: We present a rare case of CBT with intracranial complications, which was managed successfully by staged treatment. Careful study of the preoperative radiological and laboratory data, thorough preoperative planning of the tridimensional lesion anatomy, as well as meticulous microsurgical technique under intraoperative electrophysiological monitoring was essential for the successful outcome of the case.

Silk E‐Tattoos: Multifunctional and Ultrathin Electronic Tattoo for On‐Skin Diagnostic and Therapeutic Applications (Adv. Mater. 24/2021)

A multifunctional electronic skin tattoo system is developed by drawing carbon nanotube patterns on electrospun silk nanofiber mats, as described by Sunghwan Kim and co-workers in article number 2008308. The tattoo system offers ultrathin, ultralight, biocompatible, deformable, and skin adhesion. Heat-stimulated drug delivery with controlled temperature and electrophysiological signal monitoring are possible using this electronic tattoo system in a noninvasive manner.

Flexible, Air Dryable, and Fiber Modified Aerogel-Based Wet Electrode for Electrophysiological Monitoring

This study presents a novel type of wet electrode material for electrophysiological monitoring based on a conductive aerogel film. The electrode material incorporates cellulose nanocrystal and fiber as a biocompatible polymer and multi-walled carbon nanotube as a conductive filler. The fabricated electrode is fully characterized to explore the chemical, mechanical, electrical, and water absorption properties. The wet aerogel film presents suitable mechanical flexibility owing to the use of fiber enabling it to be conformal to curved surfaces like human body. The water absorption percentage of the fabricated aerogel film is extremely high (∼500%) due to the porosity of the film and hydrophilicity of the base polymer allowing it for effective wet electrode applications. The film is air dryable with a fast (∼10 min) and facile wetting process granting the electrode application for long-term, multiple use, and remote monitoring of patients. The electrical impedance range of the fabricated aerogel electrodes is relatively low (20 Ω/cm2-370 Ω/cm2) which is within the range of use for various electrophysiological monitoring purposes such as electrocardiography (ECG) and electroencephalography (EEG). Overall, the presented study introduces a novel wet electrode based on porous and electrically conductive aerogel film to be used for various biomedical applications.

Glioma Surgery and Surgical Supporting Technology

Maximum safe resection is the principal goal of glioma surgery to improve patient prognosis, and various skills and techniques are available to achieve this. First, detailed preoperative image assessment of the tumor, arteries, veins, and white matter is helpful in developing the surgical plan. Second, surgical supporting technology, such as a navigation system, electrophysiological monitoring, awake craniotomy, and fluorescence-guided surgery, are vital for glioma surgery. Third, and most importantly, neurosurgeons should develop surgical techniques. In this review, we will focus on the following points: how to determine and dissect the tumor boundary, how to preserve passing arteries and veins, how to identify and preserve the eloquent cortex and fibers, and how to treat bleeding during tumor removal. Dissection of the tumor margin includes sharp dissection and subpial dissection. Subpial dissection using a suction tube or Cavitron Ultrasonic Surgical Aspirator(CUSA)is often effective in glioma surgery, not only for achieving better resection, but also for the preservation of passing vessels. Using these techniques, excessively small vessels, such as perforating arteries, can be finely exposed and preserved during tumor resection. In this way, we should achieve an ideal balance between maximum tumor resection and patient quality of life.