Invasive Electrical Stimulation Research Articles

Invasive electrical nerve stimulation for post-stroke motor rehabilitation.

Invasive electrical nerve stimulation for post-stroke motor rehabilitation.

Qualitative Analysis of Decision to Pursue Electrical Brain Stimulation by Patients With Drug-Resistant Epilepsy and Their Caregivers.

To understand why patients with drug-resistant epilepsy (DRE) pursue invasive electrical brain stimulation (EBS). We interviewed patients with DRE (n = 20) and their caregivers about their experiences in pursuing EBS approximately 1 year post device implant. Inductive analysis was applied to identify key motivating factors. The cohort included participants aged from teens to 50s with deep brain stimulation, vagus nerve stimulation, responsive neurostimulation, and chronic subthreshold cortical stimulation. Patients' motivations included (1) improved quality of life (2) intolerability of antiseizure medications, (3) desperation, and (4) patient-family dynamics. Both patients and caregivers described a desire to alleviate burdens of the other. Patient apprehensions about EBS focused on invasiveness and the presence of electrodes in the brain. Previous experiences with invasive monitoring and the ability to see hardware in person during clinical visits influenced patients' comfort in proceeding with EBS. Despite realistic expectations for modest and delayed benefits, patients held out hope for an exceptionally positive outcome. Our findings describe the motivations and decision-making process for patients with DRE who pursue invasive EBS. Patients balance feelings of desperation, personal goals, frustration with medication side effects, fears about surgery, and potential pressure from concerned caregivers. These factors together with the sense that patients have exhausted therapeutic alternatives may explain the limited decisional ambivalence observed in this cohort. These themes highlight opportunities for epilepsy care teams to support patient decision-making processes.

Invasive electrical stimulation in the treatment of avascular osteonecrosis of the femoral head - mid-term results.

The study aimed to evaluate the outcomes of osteonecrosis of the femoral head (ONFH) in adults after surgical treatment including invasive electromagnetic osteostimulation (E-Stim). Further, the influence of disease stage and several comorbidities on the joint preservation rate should be examined. Sixty patients (66 hip joints) with ONFH were included in this retrospective cross-sectional analysis (mean follow-up: 58 months, 19-110 months). Potential ONFH risk factors and comorbidities (ONFH stage, age, sex, alcohol, smoking, cortisone medication, chemotherapy) were recorded. The influence of specific parameters on the joint preservation rates was evaluated by a multivariate logistic regression analysis. Finally, patients with preserved hip joints underwent an assessment of their last available X-rays. The joint preservation rate depended on the initial ONFH Steinberg stage (I+II: 82.8%, III: 70.8%, ≥ IVa: 38.5%). Initially collapsed ONFH (p ≤ 0.001) and cortisone therapy (p = 0.004) significantly decreased the joint preservation rates. In case of progressed ONFH, the presence of ≥ 2 risk factors resulted in higher THA conversion rates (stage III: OR 18.8; stage ≥IVa: OR 12). In 94% of the available X-rays, the ONFH stage improved or did not progress. No complications could be attributed to the E-Stim device or procedure. The present surgical protocol including minimally invasive E-Stim revealed high joint preservation rates for non-collapsed ONFH after mid-term postoperative follow-up. Especially in progressed ONFH, the-risk profile seems to be crucial and hence, for joint preserving surgery, careful patient selection is recommended.

Long-term invasive electrical stimulation of peripheral nerve in the functional recovery of neuromuscular complex in experiment

Background. Limb damage dominates in the structure of combat trauma, making up to 75 % in modern wars and the number of wounded with peripheral nerve injuries of the limbs can be up to 25 %. The degree of disability of patients is 65–70 %, which makes the problem of restoring peripheral nerves extremely actual. The purpose of the study was to determine the effect of long-term invasive electrical stimulation on the functional restoration of the neuromuscular complex in experiment. Materials and methods. The study was performed on 29 white outbred rabbits (2500 ± 250 g, 5–6 months) according to all norms of bio­ethics. Animals were divided into the following experimental groups: group 1 (n = 8, controls) — epineural suture of the sciatic nerve and implantation of a non-working antenna of the electrical stimulation device; group 2 (n = 7): similar operation of epineural suture of the sciatic nerve with implantation of the electric stimulator antenna and stimulation on beginning at the 2nd day after the operation; group 3 (n = 7): a similar operation of the sciatic nerve epineural suture with implantation of an electric stimulator antenna and the start of stimulation after 2 weeks, when the initial signs of nerve regeneration were observed; group 4 (n = 7): autografting of the sciatic nerve and implantation of an electrical stimulator and the beginning of stimulation at a time point that will coincide with the signs of nerve regeneration. Results. Therefore, in group 2, where electrical stimulation was started the day after the operation, the indicators of functional recovery of the neuromuscular complex were better than in its absence, as well as under the conditions of starting the stimulation in the period when the initial signs of regeneration were observed. Therefore, it can be assumed that the invasive electrical stimulation of the peripheral nerve, started in the acute period after the injury, has a positive effect on the regeneration of the peripheral nerves, as well as on the results of the functional restoration of the neuromuscular complex. The positive effect of electrical stimulation on the functional state of muscles is indirectly evidenced by the larger amplitude of the compound muscle action potential (CMAP) in the group where the stimulation was started faster. A larger amplitude of the CMAP during the observation indicates a greater number of axons that reached the muscle during 8 weeks. Given that the growth cone of the regenerating nerve contains a certain number of axons that first grow to the effector organ, in this case the muscle, with a relatively unchanged action potential latency, it can be assumed that direct electrical stimulation of the peripheral nerve leads to an increase speed of axons sprouting, with their relatively unchanged number. The absence of a significant difference in the action potential latency in the groups where autografting and suture were performed under the same conditions of stimulation indicates a positive effect of stimulation on the myelination of nerve fibers. A better CMAP indirectly indicates a satisfactory functional state of the muscle, which in conditions of denervation allows to preserve its potential for recovery and prevent atrophy. Conclusions. Summarizing all of the above, according to the data of electrophysiological research, we can indirectly conclude that: 1) the impact of invasive electrical stimulation on the regeneration of the neuromuscular complex is positive, and is accompanied by a better effect if it is performed early after the injury; 2) invasive electrical stimulation of the peripheral nerve is a procedure that allows to accelerate the growth of nerve fibers, improve their myelination and prevent the loss of functional capacity of the denervated muscle.

Electrostimulation as a method of correction of respiratory disorders in patients with cervical spinal cord injury: A review

BACKGROUND:Patients with cervical spinal cord injury have the highest risk of developing respiratory dysfunction and associated complications such as pneumonia, atelectasis, and respiratory failure. Respiratory dysfunction is the leading cause of comorbid, somatic, and infectious pathology, and mortality following traumatic cervical spinal cord injuries. Mechanical ventilation of the lungs is the standard treatment for such patients; however, it is associated with atrophy and diaphragm dysfunction.
 AIM:To analyze literature data on the use of electrical stimulation techniques of the spinal cord, nerves, and muscles for the correction of respiratory disorders in patients with cervical spinal cord trauma.
 MATERIALS AND METHODS:This study presented the results of the search and analysis of peer-reviewed articles that examined the effects of various electrical stimulation techniques on respiratory function in patients with cervical spinal cord injury. ScienceDirect, Google Scholar, and PubMed were searched from 2000 to 2022.
 RESULTS:Currently, new treatment options are available for patients with tetraplegia, with reduced ventilatory function. Many studies have shown the positive effect of electrostimulation techniques on ventilatory function such as reduced time spent on mechanical ventilation and reduced incidence of infections and other lung complications.
 CONCLUSIONS:Electrical stimulation promotes neuromuscular plasticity and results in improved spontaneous activation of the diaphragm and respiratory muscles. Electrostimulation inacomprehensive rehabilitation program of patients with traumatic spinal cord injuries at the cervical level is currently employed to promote weaning from mechanical ventilation and prevent accompanying complications such as respiratory failure, pneumonia, and atelectasis. In addition to invasive electrical stimulation of the diaphragmatic nerve and/or spinal cord, existing less invasive electrostimulation techniques require further investigation in patients with spinal cord injury and respiratory dysfunction.

The impact of brain atrophy on invasive electrical stimulation – A computational study

The impact of brain atrophy on invasive electrical stimulation – A computational study

Modeling of a New Percutaneous Orthopedic Implant System to Control the Post-surgery Osseointegration Process.

This study presents a mechanical model of a novel medical device designed to optimize the osseointegration process in upper and lower limb amputees, leading to the promotion of optimal rehabilitation. The medical device is developed to reduce the risk of implant failure, leading to re-amputation above the implant. The proposed model serves several purposes: 1) to guide the osseointegration process by providing electrical endo-stimulation directly to the bone-implant contact site, using an invasive electrical stimulation system, which is implanted in the bone permanently, 2) to locally transmit stem cells after implantation, without the need for opening the skin or perforating the bone, which is particularly useful for regenerative medicine after partial healing of the implant, 3) to transmit necessary nutrients from the bone, also without opening the skin or puncturing the bone, and 4) to combat infections by locally administering drugs after implantation.

A Closed-Loop Approach to Fight Coronavirus: Early Detection and Subsequent Treatment.

The recent COVID-19 pandemic has caused tremendous damage to the social economy and people’s health. Some major issues fighting COVID-19 include early and accurate diagnosis and the shortage of ventilator machines for critical patients. In this manuscript, we describe a novel solution to deal with COVID-19: portable biosensing and wearable photoacoustic imaging for early and accurate diagnosis of infection and magnetic neuromodulation or minimally invasive electrical stimulation to replace traditional ventilation. The solution is a closed-loop system in that the three modules are integrated together and form a loop to cover all-phase strategies for fighting COVID-19. The proposed technique can guarantee ubiquitous and onsite detection, and an electrical hypoglossal stimulator can be more effective in helping severe patients and reducing complications caused by ventilators.

Biofeedback electrostimulation for bionic and long-lasting neural modulation

Invasive electrical stimulation (iES) is prone to cause neural stimulus-inertia owing to its excessive accumulation of exogenous charges, thereby resulting in many side effects and even failure of nerve regeneration and functional recovery. Here, a wearable neural iES system is well designed and built for bionic and long-lasting neural modulation. It can automatically yield biomimetic pulsed electrical signals under the driven of respiratory motion. These electrical signals are full of unique physiological synchronization can give biofeedback to respiratory behaviors, self-adjusting with different physiological states of the living body, and thus realizing a dynamic and biological self-matched modulation of voltage-gated calcium channels on the cell membrane. Abundant cellular and animal experimental evidence confirm an effective elimination of neural stimulus-inertia by these bioelectrical signals. An unprecedented nerve regeneration and motor functional reconstruction are achieved in long-segmental peripheral nerve defects, which is equal to the gold standard of nerve repair -- autograft. The wearable neural iES system provides an advanced platform to overcome the common neural stimulus-inertia and gives a broad avenue for personalized iES therapy of nerve injury and neurodegenerative diseases.

Erratum: Patel et al., "Improved Speech Hearing in Noise with Invasive Electrical Brain Stimulation".

In the article “Improved Speech Hearing in Noise with Invasive Electrical Brain Stimulation,” by Prachi Patel, Bahar Khalijhinejad, Jose L. Herrero, Stephan Bickel, Ashesh D. Mehta, and Nima Mesgarani, which appeared on pages [3648–3658][1] of the April 27, 2022 issue, an author's name was

Electric hearing and tinnitus suppression by noninvasive ear stimulation

While noninvasive brain stimulation is convenient and cost effective, its utility is limited by the substantial distance between scalp electrodes and their intended neural targets in the head. The tympanic membrane, or eardrum, is a thin flap of skin deep in an orifice of the head that may serve as a port for improved efficiency of noninvasive stimulation. Here we chose the cochlea as a target because it resides in the densest bone of the skull and is adjacent to many deep-brain-stimulation structures. We also tested the hypothesis that noninvasive electric stimulation of the cochlea may restore neural activities that are missing in acoustic stimulation. We placed an electrode in the ear canal or on the tympanic membrane in 25 human adults (10 females) and compared their stimulation efficiency by characterizing the electrically-evoked auditory sensation. Relative to ear canal stimulation, tympanic membrane stimulation was four times more likely to produce an auditory percept, required eight times lower electric current to reach the threshold and produced two-to-four times more linear suprathreshold responses. We further measured tinnitus suppression in 14 of the 25 subjects who had chronic tinnitus. Compared with ear canal stimulation, tympanic membrane stimulation doubled both the probability (22% vs. 55%) and the amount (−15% vs. −34%) of tinnitus suppression. These findings extended previous work comparing evoked perception and tinnitus suppression between electrodes placed in the ear canal and on the scalp. Together, the previous and present results suggest that the efficiency of conventional scalp-based noninvasive electric stimulation can be improved by at least one order of magnitude via tympanic membrane stimulation. This increased efficiency is most likely due to the shortened distance between the electrode placed on the tympanic membrane and the targeted cochlea. The present findings have implications for the management of tinnitus by offering a potential alternative to interventions using invasive electrical stimulation such as cochlear implantation, or other non-invasive transcranial electrical stimulation methods.

Targeting the motor cortex to restore walking after incomplete spinal cord injury.

Targeting the motor cortex to restore walking after incomplete spinal cord injury.

Design considerations for piezoelectrically powered electrical stimulation: The balance between power generation and fatigue resistance

Quality and timing of bone healing from orthopedic surgeries, especially lumbar spinal fusion procedures, is problematic for many patients. To address this issue, clinicians often use electrical stimulation to improve surgery success rates and decrease healing time in patients with increased risk of pseudarthrosis, including smokers and diabetics. Current invasive electrical stimulation devices require an implantable battery and a second surgery for removal. Piezoelectric composites within an interbody implant generate sufficient power under physiologic loads to deliver pulsed electrical stimulation without a battery and have demonstrated promising preclinical bone growth and fusion success. The objective of the current study was to assess the power generation and fatigue resistance of three commercially manufactured piezocomposite configurations in a modified implant design to demonstrate efficacy as a robust biomaterial within osteogenic implants. The three configurations were electromechanically assessed under physiological lumbar loading conditions, and all configurations produced sufficient power to promote bone healing. Additionally, electrical and mechanical fatigue performance was assessed under high load, low cycle conditions. All configurations demonstrated runout with no gross mechanical failure and two configurations demonstrated electrical fatigue resistance. Future piezoelectric implant design decisions should be based on power generation needs to stimulate bone growth, as mechanical fatigue efficacy was proven for all piezocomposite configurations tested.

Nonpharmacological therapies for central poststroke pain: A systematic review.

Background:Central poststroke pain (CPSP) is a neuropathic pain syndrome that can occur after a cerebrovascular accident. It has negative effects on mood, sleep, rehabilitation, and quality of life in stroke patients. This systematic review assessed the efficacy and safety of nonpharmacological therapies for treating CPSP.Methods:The Cochrane, PubMed, Embase, and Web of Science databases were systematically searched for studies from inception to August 2020. Two authors worked independently and in duplicate to identify suitable studies.Results:Eleven studies were identified. Pain related to CPSP was ameliorated by precentral gyrus stimulation (P = .01), caloric vestibular stimulation (P = 0.004), transcranial direct current stimulation (P < .05), and bee venom acupuncture point injection (P = .009). Acupuncture (P = .72) and electroacupuncture therapies (P > .05) were as effective for thalamic pain as oral carbamazepine treatment. Motor cortex stimulation, but not deep brain stimulation (DBS), was effective for treating refractory CPSP, and appeared to be more effective than thalamic stimulation for controlling bulbar pain secondary to Wallenberg syndrome. However, DBS in the ventral striatum or anterior limb of the internal capsule improved depression (P = .020) and anxiety in patients with refractory CPSP. Some serious adverse events were reported in response to invasive electrical brain stimulation, but most of these effects recovered with treatment.Conclusions:Nonpharmacological therapies appear to be effective in CPSP, but the evidence is relatively weak. Invasive electrical brain stimulation can be accompanied by serious adverse events, but most patients recover from these effects.

Combined behavioral and electrophysiological evidence for a direct cortical effect of prefrontal tDCS on disorders of consciousness

Severe brain injuries can lead to long-lasting disorders of consciousness (DoC) such as vegetative state/unresponsive wakefulness syndrome (VS/UWS) or minimally conscious state (MCS). While behavioral assessment remains the gold standard to determine conscious state, EEG has proven to be a promising complementary tool to monitor the effect of new therapeutics. Encouraging results have been obtained with invasive electrical stimulation of the brain, and recent studies identified transcranial direct current stimulation (tDCS) as an effective approach in randomized controlled trials. This non-invasive and inexpensive tool may turn out to be the preferred treatment option. However, its mechanisms of action and physiological effects on brain activity remain unclear and debated. Here, we stimulated 60 DoC patients with the anode placed over left-dorsolateral prefrontal cortex in a prospective open-label study. Clinical behavioral assessment improved in twelve patients (20%) and none deteriorated. This behavioral response after tDCS coincided with an enhancement of putative EEG markers of consciousness: in comparison with non-responders, responders showed increases of power and long-range cortico-cortical functional connectivity in the theta-alpha band, and a larger and more sustained P300 suggesting improved conscious access to auditory novelty. The EEG changes correlated with electric fields strengths in prefrontal cortices, and no correlation was found on the scalp. Taken together, this prospective intervention in a large cohort of DoC patients strengthens the validity of the proposed EEG signatures of consciousness, and is suggestive of a direct causal effect of tDCS on consciousness.

Sub-millimeter fMRI reveals multiple topographical digit representations that form action maps in human motor cortex

The human brain coordinates a wide variety of motor activities. On a large scale, the cortical motor system is topographically organized such that neighboring body parts are represented by neighboring brain areas. This homunculus-like somatotopic organization along the central sulcus has been observed using neuroimaging for large body parts such as the face, hands and feet. However, on a finer scale, invasive electrical stimulation studies show deviations from this somatotopic organization that suggest an organizing principle based on motor actions rather than body part moved. It has not been clear how the action-map organization principle of the motor cortex in the mesoscopic (sub-millimeter) regime integrates into a body map organization principle on a macroscopic scale (cm). Here we developed and applied advanced mesoscopic (sub-millimeter) fMRI and analysis methodology to non-invasively investigate the functional organization topography across columnar and laminar structures in humans. Compared to previous methods, in this study, we could capture locally specific blood volume changes across entire brain regions along the cortical curvature. We find that individual fingers have multiple mirrored representations in the primary motor cortex depending on the movements they are involved in. We find that individual digits have cortical representations up to 3 ​mm apart from each other arranged in a column-like fashion. These representations are differentially engaged depending on whether the digits’ muscles are used for different motor actions such as flexion movements, like grasping a ball or retraction movements like releasing a ball. This research provides a starting point for non-invasive investigation of mesoscale topography across layers and columns of the human cortex and bridges the gap between invasive electrophysiological investigations and large coverage non-invasive neuroimaging.

Research advances in vagus nerve stimulation for traumatic brain injury

Patients with coma caused by traumatic brain injury (TBI) suffer from poor quality of life and many complications, which brings heavy burden to their families. The exploration of TBI treatment will help patients restore function, reduce disability rate and improve quality of life. At present, the clinical treatment of TBI mainly includes mild hypothermia treatment, hyperbaric oxygen treatment, awakening drugs and median nerve electrical stimulation, which have their own limitations. Currently, a number of studies have focused on the application of vagus nerve stimulation (VNS) in TBI. The possible mechanisms of VNS include anti-inflammatory effect, brain edema reduction and stabilization of intracranial pressure, promoting nerve function recovery, attenuation of blood-brain barrier breakdown, glutamate-mediated excitotoxicity, synaptic plasticity and recruitment of endogenous neural stem cells. VNS can be used as a new method of clinical treatment for patients with TBI, but it also carries risks of complication as an invasive electrical stimulation. The author summarizes the usage, possible mechanism and safety of VNS, so as to provide reference for further understanding the application of VNS in TBI treatment. Key words: Brain injuries; Vagus nerve; Electric stimulation therapy

Consistent linear and non-linear responses to invasive electrical brain stimulation across individuals and primate species with implanted electrodes

BackgroundElectrical neuromodulation via implanted electrodes is used in treating numerous neurological disorders, yet our knowledge of how different brain regions respond to varying stimulation parameters is sparse. Objective/HypothesisWe hypothesized that the neural response to electrical stimulation is both region-specific and non-linearly related to amplitude and frequency. MethodsWe examined evoked neural responses following 400 ms trains of 10–400 Hz electrical stimulation ranging from 0.1 to 10 mA. We stimulated electrodes implanted in cingulate cortex (dorsal anterior cingulate and rostral anterior cingulate) and subcortical regions (nucleus accumbens, amygdala) of non-human primates (NHP, N = 4) and patients with intractable epilepsy (N = 15) being monitored via intracranial electrodes. Recordings were performed in prefrontal, subcortical, and temporal lobe locations. ResultsIn subcortical regions as well as dorsal and rostral anterior cingulate cortex, response waveforms depended non-linearly on frequency (Pearson's linear correlation r < 0.39), but linearly on current (r > 0.58). These relationships between location, and input-output characteristics were similar in homologous brain regions with average Pearson's linear correlation values r > 0.75 between species and linear correlation values between participants r > 0.75 across frequency and current values per brain region. Evoked waveforms could be described by three main principal components (PCs) which allowed us to successfully predict response waveforms across individuals and across frequencies using PC strengths as functions of current and frequency using brain region specific regression models. ConclusionsThese results provide a framework for creation of an atlas of input-output relationships which could be used in the principled selection of stimulation parameters per brain region.

Chronic optical pacing conditioning of h-iPSC engineered cardiac tissues

The immaturity of human induced pluripotent stem cell derived engineered cardiac tissues limits their ability to regenerate damaged myocardium and to serve as robust in vitro models for human disease and drug toxicity studies. Several chronic biomimetic conditioning protocols, including mechanical stretch, perfusion, and/or electrical stimulation promote engineered cardiac tissue maturation but have significant technical limitations. Non-contacting chronic optical stimulation using heterologously expressed channelrhodopsin light-gated ion channels, termed optogenetics, may be an advantageous alternative to chronic invasive electrical stimulation for engineered cardiac tissue conditioning. We designed proof-of-principle experiments to successfully transfect human induced pluripotent stem cell derived engineered cardiac tissues with a desensitization resistant, chimeric channelrhodopsin protein, and then optically paced engineered cardiac tissues to accelerate maturation. We transfected human induced pluripotent stem cell engineered cardiac tissues using an adeno-associated virus packaged chimeric channelrhodopsin and then verified optically paced by whole cell patch clamp. Engineered cardiac tissues were then chronically optically paced above their intrinsic beat rates in vitro from day 7 to 14. Chronically optically paced resulted in improved engineered cardiac tissue electrophysiological properties and subtle changes in the expression of some cardiac relevant genes, though active force generation and histology were unchanged. These results validate the feasibility of a novel chronically optically paced paradigm to explore non-invasive and scalable optically paced–induced engineered cardiac tissue maturation strategies.

Major surgical strategies of the upper and middle trunks of adult brachial plexus injury by Erb­ — Duchenne palsy type

Objective — to increase the effectiveness of surgical treatment of patients with injury to the upper and middle trunks of the brachial plexus based on the comprehensive involvement of compensatory regenerative mechanisms by applying original neurotic, autoplastic, long‑term electrostimulation and orthopedic correction of the upper limb function.Methods and subjects. The analysis of the results of surgical treatment of 64 patients with brachial plexus trauma, accompanied by detachment or injury of the C5—C7 spinal nerves, upper and middle trunks, or their anterior and posterior portions, was performed. For the reconstruction of the structures of the shoulder plexus and its long branches, the technique of nerve autoplasty and the method of neurotication were most often used. In the cases of maintaining the anatomical integrity of damaged structures of the brachial plexus, which was manifested during the course of neurology, especially in cases of positive intraoperative diagnostics, the technique of long‑term electrostimulation of damaged structures in the postoperative period was used with the help of domestic electrostimulation systems Ney C 3M (Ukraine).Results. 86.7 % of cases showed good recovery (4 points or higher on 86.7 % MRCS) of the shoulder abduction and elbow flexion with no dependence on applied surgical procedure (whether grafting or nerve transfer). Chronic invasive electrical stimulation of the anatomically preserved structures of the adult brachial plexus led to significant improvement of the shoulder abduction and elbow flexion in 53.9 % of cases.Conclusions. In the absence of signs of regeneration during restorative conservative therapy for two months in cases of damages of the upper and middle trunk of the brachial plexus in the type of Erb­ — Duchenne paralysis, surgical treatment with the maximum full involvement of compensatory and regenerative properties of the nervous system through the application of original techniques of neuroticisation, long‑term electrostimulation and orthopedic correction of the function of the upper limb. Neuroticisation of the structures of the upper trunk of the brachial plexus in all cases gave satisfactory restoration of flexion in the elbow and shoulder removal.