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The use of electrode implantation technology to explore the electrical activity of population neurons is crucial for brain and cognitive science, brain-like research and brain-computer interface technology research. This article introduces the nursing points and significance of electrode implantation in rhesus monkey cerebral cortex before, during and after operation. Preoperative care includes preoperative preparation, preoperative medication, cranial fixation, skin preparation, etc. Intraoperative care includes physiological index monitoring and cerebral cortex implantation surgery care, while postoperative care includes observation and monitoring, debridement and nutritional care. Doing a good job in the operation of electrode implantation into the cerebral cortex of rhesus monkeys can not only improve the success rate of the operation, use as few experimental animals as possible to obtain the data required for the experiment, but also reduce the pain and injury caused by the operation to the animals, which is of great significance for brain and cognitive science research and animal welfare protection.

Wireless electroencephalography (EEG) of small animal subjects typically utilizes miniaturized EEG devices which require a robust recording and electrode assembly that remains in place while also being well-tolerated by the animal so as not to impair the ability of the animal to perform normal living activities or experimental tasks. We developed simple and fast electrode assembly and method of electrode implantation using electrode wires and wire-wrap technology that provides both higher survival and success rates in obtaining recordings from the electrodes than methods using screws as electrodes. The new wire method results in a 51% improvement in the number of electrodes that successfully record EEG signal. Also, the electrode assembly remains affixed and provides EEG signal for at least a month after implantation. Screws often serve as recording electrodes, which require either drilling holes into the skull to insert screws or affixing screws to the surface of the skull with adhesive. Drilling holes large enough to insert screws can be invasive and damaging to brain tissue, using adhesives may interfere with conductance and result in a poor signal, and soldering screws to wire leads results in fragile connections. The methods presented in this article provide a robust implant that is minimally invasive and has a significantly higher success rate of electrode implantation. In addition, the implant remains affixed and produces good recordings for over a month, while using economical, easily obtained materials and skills readily available in most animal research laboratories.

Cardiac resynchronization therapy (CRT) is an important and effective therapy for end-stage heart failure. Non-response to CRT is one of the main obstacles to its application in clinical practice. There is no uniform consensus or definition of CRT "response." Clinical symptoms, ventricular remodeling indices, and cardiovascular events have been reported to be associated with non-responders. To prevent non-response to CRT, three aspects should be thoroughly considered: preoperative patient selection, electrode implantation, and postoperative management. Preoperative selection of appropriate patients for CRT treatment is an important step in preventing non-response. Currently, the CRT inclusion criteria are mainly based on the morphology of QRS waves in deciding ventricular dyssynchrony. Echocardiography and cardiac magnetic resonance are being explored to predict nonresponse to CRT. The location of left ventricular electrode implantation is a current hot spot of research; it is important to identify the location of the latest exciting ventricular segment and avoid scars. Cardiac magnetic resonance and ultrasonic spot tracking are being progressively developed in this field. Some new techniques such as His Bundle pacing, endocardial electrodes, and novel sensors are also being investigated. Postoperative management of patients is another essential step towards preventing non-response; it mainly focuses on the treatment of the disease itself and CRT program control optimization. CRT treatment is just one part of the overall treatment of heart failure, and multidisciplinary efforts are needed to improve the overall outcome. [ABSTRACT FROM AUTHOR]

Robot-assisted implantation of deep electrodes for stereo-EEG monitoring has become popular in recent years in patients with drug-resistant epilepsy. However, there are still few data on safety of this technique., Objective: To assess the incidence of complications in patients with drug-resistant epilepsy undergoing robot-assisted implantation of stereo-EEG electrodes., Material and Methods: We retrospectively studied the results of implantation of stereo-EEG electrodes in 187 patients with drug-resistant epilepsy. All patients underwent non-invasive preoperative examination (video-EEG, MRI, PET, SPECT, MEG). In case of insufficient data, stereo-EEG monitoring was prescribed. We determined electrode insertion trajectory using a robotic station and MR images. Implantation of electrodes was carried out using a Rosa robot (Medtech, France). All patients underwent invasive EEG monitoring after implantation., Results: There were 11.25±3 electrodes per a patient. Implantation of one electrode took 7.5±4.9 min. Postoperative MRI revealed electrode malposition in 2.3% of cases. None was associated with complications. The complication rate per electrode was 0.6%. Complications affected stereo-EEG monitoring only in 3 cases (1.6%). The mortality rate was 0.5%. Bilateral implantation ( p =0.005), insular ( p =0.040) and occipital ( p =0.045) deep electrode implantation were associated with lower incidence of complications. Longer duration of the procedure influenced the incidence of electrode placement in the lateral ventricle ( p =0.028), and implantation in the frontal lobe was more often associated with epidural placement of electrodes ( p =0.039)., Conclusion: Robot-assisted implantation of stereo-EEG electrodes is a safe procedure with minimal risk of complications. Rare electrode malposition does not usually affect invasive monitoring.

Implantation of subdural electrodes on the brain surface is still widely performed as one of the “gold standard methods” for the presurgical evaluation of epilepsy. Stereotactic insertion of depth electrodes to the brain can be added to detect brain activities in deep-seated lesions to which surface electrodes are insensitive. This study tried to clarify the efficacy and limitations of combined implantation of subdural and depth electrodes in intractable epilepsy patients. Fifty-three patients with drug-resistant epilepsy underwent combined implantation of subdural and depth electrodes for long-term intracranial electroencephalography (iEEG) before epilepsy surgery. The detectability of early ictal iEEG change (EIIC) were compared between the subdural and depth electrodes. We also examined clinical factors including resection of MRI lesion and EIIC with seizure freedom. Detectability of EIIC showed no significant difference between subdural and depth electrodes. However, the additional depth electrode was useful for detecting EIIC from apparently deep locations, such as the insula and mesial temporal structures, but not in detecting EIIC in patients with ulegyria (glial scar). Total removal of MRI lesion was associated with seizure freedom. Depth electrodes should be carefully used after consideration of the suspected etiology to avoid injudicious usage.

Wireless electroencephalography (EEG) of small animal subjects typically utilizes miniaturized EEG devices which require a robust recording and electrode assembly that remains in place while also being well-tolerated by the animal so as not to impair the ability of the animal to perform normal living activities or experimental tasks. We developed simple and fast electrode assembly and method of electrode implantation using electrode wires and wire-wrap technology that provides both higher survival and success rates in obtaining recordings from the electrodes than methods using screws as electrodes. The new wire method results in a 51% improvement in the number of electrodes that successfully record EEG signal. Also, the electrode assembly remains affixed and provides EEG signal for at least a month after implantation. Screws often serve as recording electrodes, which require either drilling holes into the skull to insert screws or affixing screws to the surface of the skull with adhesive. Drilling holes large enough to insert screws can be invasive and damaging to brain tissue, using adhesives may interfere with conductance and result in a poor signal, and soldering screws to wire leads results in fragile connections. The methods presented in this article provide a robust implant that is minimally invasive and has a significantly higher success rate of electrode implantation. In addition, the implant remains affixed and produces good recordings for over a month, while using economical, easily obtained materials and skills readily available in most animal research laboratories.

Background: Accurate implantation of a depth electrode into the brain is of the greatest importance in deep brain stimulation (DBS), and various stereotactic systems have been developed for electrode implantation. However, an updated analysis of depth electrode implantation in the modern era of DBS is lacking. Objective: This study aims at providing an updated review on targeting accuracy of DBS electrode implantation by analyzing contemporary DBS electrode implantation operations from the perspective of precision engineering. Methods: Eligible articles with information on targeting accuracy of DBS electrode implantation were searched in the PubMed database. Results: An average targeting error of DBS electrode implantation is reported to decrease toward 1 mm; the standard deviation of targeting error is decreasing toward 0.5 mm. Targeting accuracy is not only found to be affected by individual surgical steps, but also systematically affected by the architecture of the implantation operation. Conclusion: A systematic strategy should be adopted to further improve the targeting accuracy of depth electrode implantation. Attention should be paid to optimizing the whole electrode implantation operation, which can help minimize error accumulation or amplification throughout the serially connected procedures for DBS electrode implantation. [ABSTRACT FROM AUTHOR]

Advanced electrode designs have made single-unit neural recordings commonplace in modern neuroscience research. However, single-unit resolution remains out of reach for the intrinsic neurons of the gastrointestinal system. Single-unit recordings of the enteric (gut) nervous system have been conducted in anesthetized animal models and excised tissue, but there is a large physiological gap between awake and anesthetized animals, particularly for the enteric nervous system. Here, we describe the opportunity for advancing enteric neuroscience offered by single-unit recording capabilities in awake animals. We highlight the primary challenges to microelectrodes in the gastrointestinal system including structural, physiological, and signal quality challenges, and we provide design criteria recommendations for enteric microelectrodes.

Epilepsy has not always been considered a brain disease, but was believed to be a demonic possession in the past. Therefore, trepanation was done not only for medical but also for religious or spiritual reasons, originating in the Neolithic period (3000 BC). The earliest documentation of trepanation for epilepsy is found in the writings of the Hippocratic Corpus and consisted mainly of just skull surgery. The transition from skull surgery to brain surgery took place in the middle of the nineteenth century when the insight of epilepsy as a cortical disorder of the brain emerged. This led to the start of modern epilepsy surgery. The pioneer countries in which epilepsy surgery was performed in Europe were the UK, Germany, and The Netherlands. Neurosurgical forerunners like Sir Victor Horsley, William Macewen, Fedor Krause, and Otfrid Foerster started with 'modern' epilepsy surgery. Initially, epilepsy surgery was mainly done with the purpose to resect traumatic lesions or large surface tumours. In the course of the twentieth century, this changed to highly specialized microscopic navigation-guided surgery to resect lesional and non-lesional epileptogenic cortex. The development of epilepsy surgery in Southern Europe, which has not been described until now, will be elaborated in this manuscript. To summarize, in this paper, we provide (1) a detailed description of the evolution of European epilepsy surgery with special emphasis on the pioneer countries; (2) novel, never published information about the development of epilepsy surgery in Southern Europe; and (3) we review the historical dichotomy of invasive electrode implantation strategy (Anglo-Saxon surface electrodes versus French-Italian stereoencephalography (SEEG) model). [ABSTRACT FROM AUTHOR]

We introduce a new 3-D flexible microelectrode array for high performance electrographic neural signal recording and stimulation. The microelectrode architecture maximizes the number of channels on each shank and minimizes its footprint. The electrode was implemented on flexible polyimide substrate using microfabrication and thin-film processing. The electrode has a planar layout and comprises multiple shanks. Each shank is three mm in length and carries six gold pads representing the neuro-interfacing channels. The channels are used in recording important precursors with potential clinical relevance and consequent electrical stimulation to perturb the clinical condition. The polyimide structure satisfied the mechanical characteristics required for the proper electrode implantation and operation. Pad postprocessing technique was developed to improve the electrode electrical performance. The planar electrodes were used for creating 3-D “Waterloo Array” microelectrode with controlled gaps using custom designed stackers. Electrode characterization and benchmarking against commercial equivalents demonstrated the superiority of the Flex electrodes. The Flex and commercial electrodes were associated with low-power implantable responsive neuro-stimulation system. The electrodes performance in recording and stimulation application was quantified through in vitro and in vivo acute and chronic experiments on human brain slices and freely-moving rodents. The Flex electrodes exhibited remarkable drop in the electric impedance (100 times at 100 Hz), improved electrode-electrolyte interface noise (dropped by four times) and higher signal-to-noise ratio (3.3 times). [ABSTRACT FROM AUTHOR]

To determine the effect of implanting electrodes on electrographic features of nearby and connected brain regions in patients with drug-resistant epilepsy, we analyzed intracranial EEG recordings from 10 patients with drug-resistant epilepsy who underwent implant revision (placement of additional electrodes) during their hospitalization. We performed automated spike detection and measured EEG functional networks. We analyzed the original electrodes that remained in place throughout the full EEG recording, and we measured the change in spike rates and network connectivity in these original electrodes in response to implanting new electrodes. There was no change in overall spike rate pre- to post-implant revision ( t (9) = 0.1, p = 0.95). The peri-revision change in the distribution of spike rate and connectivity across electrodes was no greater than chance (Monte Carlo method, spikes: p = 0.40, connectivity: p = 0.42). Electrodes closer to or more functionally connected to the revision site had no greater change in spike rate or connectivity than more distant or less connected electrodes. Changes in electrographic features surrounding electrode implantation are no greater than baseline fluctuations occurring throughout the intracranial recording. These findings argue against an implant effect on spikes or network connectivity in nearby or connected brain regions., (© 2022 Massachusetts Institute of Technology.)

Pacemaker implants have always posed a continuing challenge to cardiac nurses in learning and handling new equipment and electronic devices. Working with temporary pacemakers, permanent single-chamber, through two-chamber then to multi-chamber devices and implantable cardioverter-defibrillators does not allow us to relax, but dedicated work and progress from all of us. His stimulation as a somewhat newer method of electrostimulation treatment, in addition to all the current technical aspects of the usual implantation of pacemakers, also provides us with some new, specific challenges.1 As this is an electrode implantation in a very narrow region of interest, knowledge of the anatomy and physiology of the conduction system of the heart is at most importance. Knowledge of the signal of His potential is also extremely important. And in order to successfully implant such a system, we also need specific materials for the delivery of an adequate (special) electrode to the His region. Due to the location of the His and its participation in the electrical impulse conduction system, it is necessary to be extremely accurate in order to prevent the development of the Exit block, either due to electrode dislocation or insufficient output current. In order to carry out a successful procedure with the operator, the whole team must adequately prepare the room, patient, devices (programmer, ECG, electrophysiology station, materials). Necessary materials in these procedures are adequate His electrodes without lumens, preformed His introducer for easier placement of the electrode in the region of interest, modification of the electrophysiology system for simultaneous recording of unipolar, bipolar His signals and measurement of stimulation parameters. Our goal is to show the challenges in the implantation of the His cardiac pacing system, and how we have developed procedure for the implantation of that specific system. [ABSTRACT FROM AUTHOR]

Background: Intracranial recordings with stereoelectroencephalography (SEEG) aims at defining the epileptogenic zone in patients with pharmacoresistant epilepsy. Currently used techniques for depth electrode implantation include stereotactic frame-based and navigated frameless applications, both either conventional or robot-assisted. Safety and diagnostic effectiveness depend on accuracy of implantation., Objective: To evaluate the planning experience, accuracy of stereotactic electrode placement as well as accuracy predictors with the use of latest generation planning software., Methods: Retrospective study of 15 consecutive patients who received depth electrodes using the Leksell stereotactic frame, after planning with Elements (Brainlab, Munich, Germany). For each electrode, we calculated the entry point error (EPE) as lateral deviation and target point error (TPE) both as lateral deviation and distance to tip. Multivariate regression analysis and computation of 95% confidence intervals using the bootstrap method were applied for statistical analysis and evaluation of accuracy predictors., Results: The mean EPE, lateral deviation at TP and distance to tip at TP were 0.6 ±0.5 mm, 1.1 ±0.7 mm and 1.5 ±0.8 mm respectively. Order of implantation (1-6 vs. >6) is predictor for distance to tip at TP and length of electrode predictor for the lateral deviation at TP. Localization of electrode generally did not correlate to error, but insular electrodes were significantly less accurate than lobar ones., Conclusion: Combination of frame-based stereotaxy with latest generation planning software may offer a better planning and implantation experience. Accuracy predictors should be analyzed and be considered for the improvement of accuracy and safety of SEEG implantation methods., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Implantation of subdural electrodes on the brain surface is still widely performed as one of the "gold standard methods" for the presurgical evaluation of epilepsy. Stereotactic insertion of depth electrodes to the brain can be added to detect brain activities in deep-seated lesions to which surface electrodes are insensitive. This study tried to clarify the efficacy and limitations of combined implantation of subdural and depth electrodes in intractable epilepsy patients. Fifty-three patients with drug-resistant epilepsy underwent combined implantation of subdural and depth electrodes for long-term intracranial electroencephalography (iEEG) before epilepsy surgery. The detectability of early ictal iEEG change (EIIC) were compared between the subdural and depth electrodes. We also examined clinical factors including resection of MRI lesion and EIIC with seizure freedom. Detectability of EIIC showed no significant difference between subdural and depth electrodes. However, the additional depth electrode was useful for detecting EIIC from apparently deep locations, such as the insula and mesial temporal structures, but not in detecting EIIC in patients with ulegyria (glial scar). Total removal of MRI lesion was associated with seizure freedom. Depth electrodes should be carefully used after consideration of the suspected etiology to avoid injudicious usage. [ABSTRACT FROM AUTHOR]

Background: The pursuit of improved accuracy for localization and electrode implantation in deep brain stimulation (DBS) and stereoelectroencephalography (sEEG) has fostered an abundance of disparate surgical/stereotactic practices. Specific practices/technologies directly modify implantation accuracy; however, no study has described their respective influence in multivariable context., Objective: To synthesize the known literature to statistically quantify factors affecting implantation accuracy., Methods: A systematic review and meta-analysis was conducted to determine the inverse-variance weighted pooled mean target error (MTE) of implanted electrodes among patients undergoing DBS or sEEG. MTE was defined as Euclidean distance between planned and final electrode tip. Meta-regression identified moderators of MTE in a multivariable-adjusted model., Results: A total of 37 eligible studies were identified from a search return of 2,901 potential articles (2002-2018) - 27 DBS and 10 sEEG. Random-effects pooled MTE = 1.91 mm (95% CI: 1.7-2.1) for DBS and 2.34 mm (95% CI: 2.1-2.6) for sEEG. Meta-regression identified study year, robot use, frame/frameless technique, and intraoperative electrophysiologic testing (iEPT) as significant multivariable-adjusted moderators of MTE (P < .0001, R2 = 0.63). Study year was associated with a 0.92-mm MTE reduction over the 16-yr study period (P = .0035), and robot use with a 0.79-mm decrease (P = .0019). Frameless technique was associated with a mean 0.50-mm (95% CI: 0.17-0.84) increase, and iEPT use with a 0.45-mm (95% CI: 0.10-0.80) increase in MTE. Registration method, imaging type, intraoperative imaging, target, and demographics were not significantly associated with MTE on multivariable analysis., Conclusion: Robot assistance for stereotactic electrode implantation is independently associated with improved accuracy and reduced target error. This remains true regardless of other procedural factors, including frame-based vs frameless technique., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Advanced electrode designs have made single-unit neural recordings commonplace in modern neuroscience research. However, single-unit resolution remains out of reach for the intrinsic neurons of the gastrointestinal system. Single-unit recordings of the enteric (gut) nervous system have been conducted in anesthetized animal models and excised tissue, but there is a large physiological gap between awake and anesthetized animals, particularly for the enteric nervous system. Here, we describe the opportunity for advancing enteric neuroscience offered by single-unit recording capabilities in awake animals. We highlight the primary challenges to microelectrodes in the gastrointestinal system including structural, physiological, and signal quality challenges, and we provide design criteria recommendations for enteric microelectrodes.