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Sample records for nerve magnetic stimulation

  1. Magnetic nerve stimulation without interlinkage between nerve and magnetic flux

    SciTech Connect

    Ueno, S.; Harada, K.; Ji, C.; Oomura, Y.

    1984-09-01

    A new method of magnetic stimulation of nerves is proposed. Nerves are located on a core aperture outside the core which is implanted in the body. Nerves can be stimulated by the secondary currents which flow in the body fluids around the core when the magnetic flux in the core is changed. One of the advantages in this method is to be able to avoid the interlinkage between the core and nerves. The equivalent resistance of tissues around the core is calculated, and current density for nerve excitation is estimated. The validity of the new method is demonstrated by experiments using frog nerve-muscle preparations. The results show that the nerve can be excited by a change of magnetic flux which generates an EMF of 0.8-volts peak amplitude and 0.8-ms duration in a monitor wire. The current density in the vicinity of the core aperture for nerve excitation is 3.2 mA/cm/sup 2/.

  2. Vagus nerve stimulation and magnet use: optimizing benefits.

    PubMed

    Tatum, William O; Helmers, Sandra L

    2009-07-01

    More than 10 years ago, the vagus nerve stimulator became the first device approved by the Food and Drug Administration for use in persons with epilepsy. The vagus nerve stimulator has subsequently served to spearhead the concept of neurostimulation for seizures. Chronic intermittent electrical stimulation of the left vagus nerve is the foundation for vagus nerve stimulation, yet little is known about its capability to deliver acute, on-demand, activation of stimulation through use of a magnet. Thus far, clinical use of magnet-induced vagus nerve stimulation has not been elucidated. In an effort to help guide management, we highlight current and potential uses of acute abortive therapy with vagus nerve stimulation. We review the current evidence that is available for vagus nerve stimulator magnet use, discuss potential clinical applications that exist, offer a protocol for magnet application within the institutional setting, provide our approach to titrating the magnet parameters, and make recommendations for magnet use that support an evolving standard of care.

  3. Peripheral nerve magnetic stimulation: influence of tissue non-homogeneity.

    PubMed

    Krasteva, Vessela T Z; Papazov, Sava P; Daskalov, Ivan K

    2003-12-23

    Peripheral nerves are situated in a highly non-homogeneous environment, including muscles, bones, blood vessels, etc. Time-varying magnetic field stimulation of the median and ulnar nerves in the carpal region is studied, with special consideration of the influence of non-homogeneities. A detailed three-dimensional finite element model (FEM) of the anatomy of the wrist region was built to assess the induced currents distribution by external magnetic stimulation. The electromagnetic field distribution in the non-homogeneous domain was defined as an internal Dirichlet problem using the finite element method. The boundary conditions were obtained by analysis of the vector potential field excited by external current-driven coils. The results include evaluation and graphical representation of the induced current field distribution at various stimulation coil positions. Comparative study for the real non-homogeneous structure with anisotropic conductivities of the tissues and a mock homogeneous media is also presented. The possibility of achieving selective stimulation of either of the two nerves is assessed. The model developed could be useful in theoretical prediction of the current distribution in the nerves during diagnostic stimulation and therapeutic procedures involving electromagnetic excitation. The errors in applying homogeneous domain modeling rather than real non-homogeneous biological structures are demonstrated. The practical implications of the applied approach are valid for any arbitrary weakly conductive medium.

  4. Differential activation of nerve fibers with magnetic stimulation in humans

    PubMed Central

    Tuday, Eric C; Olree, Kenneth S; Horch, Kenneth W

    2006-01-01

    Background Earlier observations in our lab had indicated that large, time-varying magnetic fields could elicit action potentials that travel in only one direction in at least some of the myelinated axons in peripheral nerves. The objective of this study was to collect quantitative evidence for magnetically induced unidirectional action potentials in peripheral nerves of human subjects. A magnetic coil was maneuvered to a location on the upper arm where physical effects consistent with the creation of unidirectional action potentials were observed. Electromyographic (EMG) and somatosensory evoked potential (SEP) recordings were then made from a total of 20 subjects during stimulation with the magnetic coil. Results The relative amplitudes of the EMG and SEP signals changed oppositely when the current direction in the magnetic coil was reversed. This effect was consistent with current direction in the coil relative to the arm for all subjects. Conclusion A differential evocation of motor and sensory fibers was demonstrated and indicates that it may be possible to induce unidirectional action potentials in myelinated peripheral nerve fibers with magnetic stimulation. PMID:16863593

  5. Neuroprotection trek--the next generation: neuromodulation I. Techniques--deep brain stimulation, vagus nerve stimulation, and transcranial magnetic stimulation

    NASA Technical Reports Server (NTRS)

    Andrews, Russell J.

    2003-01-01

    Neuromodulation denotes controlled electrical stimulation of the central or peripheral nervous system. The three forms of neuromodulation described in this paper-deep brain stimulation, vagus nerve stimulation, and transcranial magnetic stimulation-were chosen primarily for their demonstrated or potential clinical usefulness. Deep brain stimulation is a completely implanted technique for improving movement disorders, such as Parkinson's disease, by very focal electrical stimulation of the brain-a technique that employs well-established hardware (electrode and pulse generator/battery). Vagus nerve stimulation is similar to deep brain stimulation in being well-established (for the treatment of refractory epilepsy), completely implanted, and having hardware that can be considered standard at the present time. Vagus nerve stimulation differs from deep brain stimulation, however, in that afferent stimulation of the vagus nerve results in diffuse effects on many regions throughout the brain. Although use of deep brain stimulation for applications beyond movement disorders will no doubt involve placing the stimulating electrode(s) in regions other than the thalamus, subthalamus, or globus pallidus, the use of vagus nerve stimulation for applications beyond epilepsy-for example, depression and eating disorders-is unlikely to require altering the hardware significantly (although stimulation protocols may differ). Transcranial magnetic stimulation is an example of an external or non-implanted, intermittent (at least given the current state of the hardware) stimulation technique, the clinical value of which for neuromodulation and neuroprotection remains to be determined.

  6. Basic study on the influence of inhibition induced by the magnetic stimulation on the peripheral nerve

    NASA Astrophysics Data System (ADS)

    Sato, Aya; Torii, Tetsuya; Iwahashi, Masakuni; Iramina, Keiji

    2015-05-01

    The purpose of this study is to analyze the inhibition mechanism of magnetic stimulation on motor function. A magnetic stimulator with a flat figure-eight coil was used to stimulate the peripheral nerve of the antebrachium. The intensity of magnetic stimulation was 0.8 T, and the stimulation frequency was 1 Hz. The amplitudes of the motor-evoked potentials (MEPs) at the abductor pollicis brevis muscle and first dorsal interosseous muscle were used to evaluate the effects of magnetic stimulation. The effects of magnetic stimulation were evaluated by analyzing the MEP amplitude before and after magnetic stimulation to the primary motor cortex. The results showed that MEP amplitude after magnetic stimulation compared with before magnetic stimulation decreased. Because there were individual differences in MEP amplitude induced by magnetic stimulation, the MEP amplitude after stimulation was normalized by the amplitude of each participant before stimulation. The MEP amplitude after stimulation decreased by approximately 58% (p < 0.01) on average compared with before stimulation. Previous studies suggested that magnetic stimulation to the primary motor cortex induced an increase or a decrease in MEP amplitude. Furthermore, previous studies have shown that the alteration in MEP amplitude was induced by cortical excitability based on magnetic stimulation. The results of this study showed that MEP amplitude decreased following magnetic stimulation to the peripheral nerve. We suggest that the decrease in MEP amplitude found in this study was obtained via the feedback from a peripheral nerve through an afferent nerve to the brain. This study suggests that peripheral excitement by magnetic stimulation of the peripheral nerve may control the central nervous system via afferent feedback.

  7. Vagus nerve stimulation magnet activation for seizures: a critical review.

    PubMed

    Fisher, R S; Eggleston, K S; Wright, C W

    2015-01-01

    Some patients receiving VNS Therapy report benefit from manually activating the generator with a handheld magnet at the time of a seizure. A review of 20 studies comprising 859 subjects identified patients who reported on-demand magnet mode stimulation to be beneficial. Benefit was reported in a weighted average of 45% of patients (range 0-89%) using the magnet, with seizure cessation claimed in a weighted average of 28% (range 15-67%). In addition to seizure termination, patients sometimes reported decreased intensity or duration of seizures or the post-ictal period. One study reported an isolated instance of worsening with magnet stimulation (Arch Pediatr Adolesc Med, 157, 2003 and 560). All of the reviewed studies assessed adjunctive magnet use. No studies were designed to provide Level I evidence of efficacy of magnet-induced stimulation. Retrospective analysis of one pivotal randomized trial of VNS therapy showed significantly more seizures terminated or improved in the active stimulation group vs the control group. Prospective, controlled studies would be required to isolate the effect and benefit of magnet mode stimulation and to document that the magnet-induced stimulation is the proximate cause of seizure reduction. Manual application of the magnet to initiate stimulation is not always practical because many patients are immobilized or unaware of their seizures, asleep or not in reach of the magnet. Algorithms based on changes in heart rate at or near the onset of the seizure provide a methodology for automated responsive stimulation. Because literature indicates additional benefits from on-demand magnet mode stimulation, a potential role exists for automatic activation of stimulation.

  8. Nerve cuff electrode using embedded magnets and its application to hypoglossal nerve stimulation

    NASA Astrophysics Data System (ADS)

    Seo, Jungmin; Hye Wee, Jee; Hoan Park, Jeong; Park, Pona; Kim, Jeong-Whun; Kim, Sung June

    2016-12-01

    Objective. A novel nerve cuff electrode with embedded magnets was fabricated and developed. In this study, a pair of magnets was fully embedded and encapsulated in a liquid crystal polymer (LCP) substrate to utilize magnetic force in order to replace the conventional installing techniques of cuff electrodes. In vitro and in vivo experiments were conducted to evaluate the feasibility of the magnet-embedded nerve cuff electrode (MENCE). Lastly, several issues pertaining to the MENCE such as the cuff-to-nerve diameter ratio, the force of the magnets, and possible concerns were discussed in the discussion section. Approach. Electrochemical impedance spectrum and cyclic voltammetry assessments were conducted to measure the impedance and charge storage capacity of the cathodal phase (CSCc). The MENCE was installed onto the hypoglossal nerve (HN) of a rabbit and the movement of the genioglossus was recorded through C-arm fluoroscopy while the HN was stimulated by a pulsed current. Main results. The measured impedance was 0.638 ∠ -67.8° kΩ at 1 kHz and 5.27 ∠ -82.1° kΩ at 100 Hz. The average values of access resistance and cut-off frequency were 0.145 kΩ and 3.98 kHz, respectively. The CSCc of the electrode was measured as 1.69 mC cm-2 at the scan rate of 1 mV s-1. The movement of the genioglossus contraction was observed under a pulsed current with an amplitude level of 0.106 mA, a rate of 0.635 kHz, and a duration of 0.375 ms applied through the MENCE. Significance. A few methods to close and secure cuff electrodes have been researched, but they are associated with several drawbacks. To overcome these, we used magnetic force as a closing method of the cuff electrode. The MENCE can be precisely installed on a target nerve without any surgical techniques such as suturing or molding. Furthermore, it is convenient to remove the installed MENCE because it requires little force to detach one magnet from the other, enabling repeatable installation and removal. We

  9. Impulse magnetic stimulation facilitates synaptic regeneration in rats following sciatic nerve injury.

    PubMed

    Zhivolupov, Sergey A; Odinak, Miroslav M; Rashidov, Nariman A; Onischenko, Ludmila S; Samartsev, Igor N; Jurin, Anton A

    2012-06-15

    The current studies describing magnetic stimulation for treatment of nervous system diseases mainly focus on transcranial magnetic stimulation and rarely focus on spinal cord magnetic stimulation. Spinal cord magnetic stimulation has been confirmed to promote neural plasticity after injuries of spinal cord, brain and peripheral nerve. To evaluate the effects of impulse magnetic stimulation of the spinal cord on peripheral nerve regneration, we compressed a 3 mm segment located in the middle third of the hip using a sterilized artery forceps to induce ischemia. Then, all animals underwent impulse magnetic stimulation of the lumbar portion of spinal crod and spinal nerve roots daily for 1 month. Electron microscopy results showed that in and below the injuryed segment, the inflammation and demyelination of neural tissue were alleviated, apoptotic cells were reduced, and injured Schwann cells and myelin fibers were repaired. These findings suggest that high-frequency impulse magnetic stimulation of spinal cord and corresponding spinal nerve roots promotes synaptic regeneration following sciatic nerve injury.

  10. Vagus Nerve Stimulation

    MedlinePlus

    Vagus nerve stimulation Overview By Mayo Clinic Staff Vagus nerve stimulation is a procedure that involves implantation of a device that stimulates the vagus nerve with electrical impulses. There's one vagus nerve on ...

  11. A conduction block in sciatic nerves can be detected by magnetic motor root stimulation.

    PubMed

    Matsumoto, Hideyuki; Konoma, Yuko; Fujii, Kengo; Hanajima, Ritsuko; Terao, Yasuo; Ugawa, Yoshikazu

    2013-08-15

    Useful diagnostic techniques for the acute phase of sciatic nerve palsy, an entrapment neuropathy, are not well established. The aim of this paper is to demonstrate the diagnostic utility of magnetic sacral motor root stimulation for sciatic nerve palsy. We analyzed the peripheral nerves innervating the abductor hallucis muscle using both electrical stimulations at the ankle and knee and magnetic stimulations at the neuro-foramina and conus medullaris levels in a patient with sciatic nerve palsy at the level of the piriformis muscle due to gluteal compression related to alcohol consumption. On the fourth day after onset, magnetic sacral motor root stimulation using a MATS coil (the MATS coil stimulation method) clearly revealed a conduction block between the knee and the sacral neuro-foramina. Two weeks after onset, needle electromyography supported the existence of the focal lesion. The MATS coil stimulation method clearly revealed a conduction block in the sciatic nerve and is therefore a useful diagnostic tool for the abnormal neurophysiological findings associated with sciatic nerve palsy even at the acute phase.

  12. Magnetic stimulation of the human motor cortex evokes skin sympathetic nerve activity.

    PubMed

    Silber, D H; Sinoway, L I; Leuenberger, U A; Amassian, V E

    2000-01-01

    Single-pulse magnetic coil stimulation (Cadwell MES 10) over the cranium induces without pain an electric pulse in the underlying cerebral cortex. Stimulation over the motor cortex can elicit a muscle twitch. In 10 subjects, we tested whether motor cortical stimulation could also elicit skin sympathetic nerve activity (SSNA; n = 8) and muscle sympathetic nerve activity (MSNA; n = 5) in the peroneal nerve. Focal motor cortical stimulation predictably elicited bursts of SSNA but not MSNA; with successive stimuli, the SSNA responses did not readily extinguish (94% of discharges to the motor cortex evoked SSNA responses) and had predictable latencies [739 +/- 33 (SE) to 895 +/- 13 ms]. The SSNA responses were similar after stimulation of dominant and nondominant sides. Focal stimulation posterior to the motor cortex elicited extinguishable SSNA responses. In three of six subjects, anterior cortical stimulation evoked SSNA responses similar to those seen with motor cortex stimulation but without detectable movement; in the other subjects, anterior stimulation evoked less SSNA discharge than that seen with motor cortex stimulation. Contrasting with motor cortical stimulation, evoked SSNA responses were more readily extinguished with 1) peripheral stimulation that directly elicited forearm muscle activation accompanied by electromyograms similar to those with motor cortical stimulation; 2) auditory stimulation by the click of the energized coil when off the head; and 3) in preliminary experiments, finger afferent stimulation sufficient to cause tingling. Our findings are consistent with the hypothesis that motor cortex stimulation can cause activation of both alpha-motoneurons and SSNA.

  13. Detection of a diabetic sural nerve from the magnetic field after electric stimulation

    NASA Astrophysics Data System (ADS)

    Hayami, Takehito; Iramina, Keiji; Hyodo, Akira; Chen, Xian; Sunagawa, Kenji

    2009-04-01

    In this study, we proposed a new diagnostic technique for diabetic neuropathy using biomagnetic measurement. Peripheral neuropathy is one of the most common complications of diabetes. To examine the injury, the skin potential around the nerve is often measured after electric stimulation. However, measuring the magnetic field may reveal precise condition of the injury. To evaluate the effect of measuring the magnetic field, a simulation study was performed. A diabetic sural nerve was simulated as a bundle of myelinated nerve fibers. Each fiber was modeled as an electric cable of Ranvier's nodes. Anatomical data were used to determine the number of nerve fibers and distribution of nerve fiber diameters. The electric potential and the magnetic field on the skin after electric stimulation were computed to the boundary element method. Biphasic time courses were obtained as the electric potential and the magnetic flux density at measurement points. In diabetic nerves, the longer interpeak latency of the electric potential wave and the shorter interpeak latency of the magnetic flux wave were obtained. Measuring both the electric potential and the magnetic flux density seemed to provide a noninvasive and objective marker for diabetic neuropathy.

  14. A complete model for the evaluation of the magnetic stimulation of peripheral nerves.

    PubMed

    Pisa, Stefano; Apollonio, Francesca; d'Inzeo, Guglielmo

    2014-01-01

    In this paper, a numerical procedure for the analysis of peripheral nerve excitation through magnetic stimulation is presented and used to investigate the physical parameters influencing stimulation. The finite difference technique is used to evaluate the electric field distribution induced inside an arm by the current flowing through a coil, and a nonlinear cable model is used to describe the response of the nerve fiber to the induced electric field. The comparison among several forearm structures has evidenced that the heterogeneous non dispersive forearm model is a good reference condition. With this model, the lowest charging voltage on the stimulator capacitance, able to produce the nerve stimulation, is achieved when the coil is shifted, with respect to the nerve, of a quantity slightly lower than the coil radius but it is also possible to excite the nerve fiber by applying a shift equal to zero. The charging voltage increases when the coil radius is increased and when a three-dimensional coil geometry is considered. Moreover, this voltage is strongly dependent on the nerve position inside the forearm and on the kind of tissue surrounding the nerve.

  15. A Complete Model for the Evaluation of the Magnetic Stimulation of Peripheral Nerves

    PubMed Central

    Pisa, Stefano; Apollonio, Francesca; d'Inzeo, Guglielmo

    2014-01-01

    In this paper, a numerical procedure for the analysis of peripheral nerve excitation through magnetic stimulation is presented and used to investigate the physical parameters influencing stimulation. The finite difference technique is used to evaluate the electric field distribution induced inside an arm by the current flowing through a coil, and a nonlinear cable model is used to describe the response of the nerve fiber to the induced electric field. The comparison among several forearm structures has evidenced that the heterogeneous non dispersive forearm model is a good reference condition. With this model, the lowest charging voltage on the stimulator capacitance, able to produce the nerve stimulation, is achieved when the coil is shifted, with respect to the nerve, of a quantity slightly lower than the coil radius but it is also possible to excite the nerve fiber by applying a shift equal to zero. The charging voltage increases when the coil radius is increased and when a three-dimensional coil geometry is considered. Moreover, this voltage is strongly dependent on the nerve position inside the forearm and on the kind of tissue surrounding the nerve. PMID:24511330

  16. [Physiological approach to peripheral neuropathy. Conventional nerve conduction studies and magnetic motor root stimulation].

    PubMed

    Ugawa, Yoshikazu

    2004-11-01

    In this communication, I first show some points we should mind in the conventional peripheral nerve conduction studies and later present clinical usefulness of motor root stimulation for peripheral neuropathy. CONVENTIONAL NERVE CONDUCTION STUDIES (NCS): The most important point revealed by the conventional NCSs is whether neuropathy is due to axonal degeneration or demyelinating process. Precise clinical examination with this neurophysiological information leads us to a diagnosis and treatment. Poor clinical examination makes these findings useless. Long standing axonal degeneration sometimes induces secondary demyelination at the most distal part of involved nerves. On the other hand, severe segmental demyelination often provokes secondary axonal degeneration at distal parts to the site of demyelination. These secondary changes show the same abnormal neurophysiological findings as those of the primary involvement. We should be careful of this possibility when interpreting the results of NCS. NCS of sensory nerves is not good at revealing demyelinating process. Mild temporal dispersion of potentials often reduces an amplitude of SNAP or loss of responses, which usually suggests axonal degeneration, because of short duration of sensory nerve potentials. MOTOR ROOT STIMULATION IN PERIPHERAL NEUROPATHY: Magnetic stimulation with a coil placed over the spine activates motor roots and evokes EMG responses from upper and lower limb muscles. The site of activation with this method was determined to be where the motor roots exit from the spinal canal (intervertebral foramina) (J Neurol Neurosurg Psychiatry 52 (9): 1025-1032, 1989) because induced currents are very dense at such a foramen made by electric resistant bones. In several kinds of peripheral neuropathy, this method has been used to detect a lesion at a proximal part of the peripheral nerves which can not be detected by the conventional NCSs. I present a few cases in whom motor root stimulation had a clinical

  17. Combination of Static Magnetic Fields and Peripheral Nerve Stimulation Can Alter Focal Cortical Excitability.

    PubMed

    Nojima, Ippei; Koganemaru, Satoko; Mima, Tatsuya

    2016-01-01

    For clinical application of transcranial static magnetic stimulation (tSMS), it is important to achieve a focal target cortical stimulation. Previous study suggested that the associative stimulation combining non-invasive stimulation of the motor cortex (M1) and the peripheral nerve stimulation (PNS) may be useful to produce cortical excitability change. To test this hypothesis, we measured the M1 excitability and intracortical circuits by using transcranial magnetic stimulation (TMS) before and after the tSMS of short duration (5 min) combined with PNS. Thirty-three normal volunteers were participated; tSMS+PNS (n = 11), sham+PNS (n = 11), and tSMS alone (n = 11). We found the transient suppression of the motor-evoked potential (MEP) of the right abductor pollicis brevis (APB) muscle, but not of the abductor digiti minimi (ADM) muscle, when combining tSMS with PNS over median nerve at the wrist. The lack of suppressive effect on APB in tSMS alone with short duration is in accord with the previous observation. In addition, the tendency of transient enhancement of the short-latency intracortical inhibition was observed immediately after intervention in the tSMS±PNS group. These findings show that the combination of tSMS and PNS can induce the cortical excitability change in target cortical motor area and potentiate the suppression effect.

  18. Combination of Static Magnetic Fields and Peripheral Nerve Stimulation Can Alter Focal Cortical Excitability

    PubMed Central

    Nojima, Ippei; Koganemaru, Satoko; Mima, Tatsuya

    2016-01-01

    For clinical application of transcranial static magnetic stimulation (tSMS), it is important to achieve a focal target cortical stimulation. Previous study suggested that the associative stimulation combining non-invasive stimulation of the motor cortex (M1) and the peripheral nerve stimulation (PNS) may be useful to produce cortical excitability change. To test this hypothesis, we measured the M1 excitability and intracortical circuits by using transcranial magnetic stimulation (TMS) before and after the tSMS of short duration (5 min) combined with PNS. Thirty-three normal volunteers were participated; tSMS+PNS (n = 11), sham+PNS (n = 11), and tSMS alone (n = 11). We found the transient suppression of the motor-evoked potential (MEP) of the right abductor pollicis brevis (APB) muscle, but not of the abductor digiti minimi (ADM) muscle, when combining tSMS with PNS over median nerve at the wrist. The lack of suppressive effect on APB in tSMS alone with short duration is in accord with the previous observation. In addition, the tendency of transient enhancement of the short-latency intracortical inhibition was observed immediately after intervention in the tSMS±PNS group. These findings show that the combination of tSMS and PNS can induce the cortical excitability change in target cortical motor area and potentiate the suppression effect. PMID:27932966

  19. Comparison of electrical nerve stimulation, electrical muscle stimulation and magnetic nerve stimulation to assess the neuromuscular function of the plantar flexor muscles.

    PubMed

    Neyroud, Daria; Temesi, John; Millet, Guillaume Y; Verges, Samuel; Maffiuletti, Nicola A; Kayser, Bengt; Place, Nicolas

    2015-07-01

    As it might lead to less discomfort, magnetic nerve stimulation (MNS) is increasingly used as an alternative to electrical stimulation methods. Yet, MNS and electrical nerve stimulation (ENS) and electrical muscle stimulation (EMS) have not been formally compared for the evaluation of plantar flexor neuromuscular function. We quantified plantar flexor neuromuscular function with ENS, EMS and MNS in 10 volunteers in fresh and fatigued muscles. Central alterations were assessed through changes in voluntary activation level (VAL) and peripheral function through changes in M-wave, twitch and doublet (PS100) amplitudes. Discomfort associated with 100-Hz paired stimuli delivered with each method was evaluated on a 10-cm visual analog scale. VAL, agonist and antagonist M-wave amplitudes and PS100 were similar between the different methods in both fresh and fatigued states. Potentiated peak twitch was lower in EMS compared to ENS, whereas no difference was found between ENS and MNS for any parameter. Discomfort associated with MNS (1.5 ± 1.4 cm) was significantly less compared to ENS (5.5 ± 1.9 cm) and EMS (4.2 ± 2.6 cm) (p < 0.05). When PS100 is used to evaluate neuromuscular properties, MNS, EMS and ENS can be used interchangeably for plantar flexor neuromuscular function assessment as they provide similar evaluation of central and peripheral factors in unfatigued and fatigued states. Importantly, electrical current spread to antagonist muscles was similar between the three methods while discomfort from MNS was much less compared to ENS and EMS. MNS may be potentially employed to assess neuromuscular function of plantar flexor muscles in fragile populations.

  20. Noninvasive techniques for probing neurocircuitry and treating illness: vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS)

    PubMed Central

    George, Mark S; Aston-Jones, Gary

    2010-01-01

    Although the preceding chapters discuss much of the new knowledge of neurocircuitry of neuropsychiatric diseases, and an invasive approach to treatment, this chapter describes and reviews the noninvasive methods of testing circuit-based theories and treating neuropsychiatric diseases that do not involve implanting electrodes into the brain or on its surface. These techniques are transcranial magnetic stimulation, vagus nerve stimulation, and transcranial direct current stimulation. Two of these approaches have FDA approval as therapies. PMID:19693003

  1. A compact theory of magnetic nerve stimulation: predicting how to aim

    PubMed Central

    2014-01-01

    Background A compact theory that predicts quantitatively when and where magnetic neurostimulation will occur is needed as a guide to therapy, ideally providing a single equation that defines the target volume of tissue excited by single or dual coils. Methods A first-principles analysis of magnetic stimulation incorporating a simplified description of electromagnetic fields and a simplified cable theory of the axon yields a mathematical synthesis predicting how to aim. Results Nerve stimulation produced by a single circular coil having one or more closely packed turns occurs in donut shaped volume of tissue beneath the coil. Axons spanning several millimeters are the sites of magnetic stimulation. The sites of maximal transmembrane depolarization in nerve fibers correspond to points where the axons enter or exit this volume of magnetically induced voltage and current. The axonal membrane at one end is depolarized locally during the rising phase of current in the coil. The axonal membrane at the opposite end is depolarized locally during the falling phase of current in the coil. Penetration depths of several centimeters from the skin surface or approximately one to two coil radii are practical. With two coils placed in a figure-of-eight configuration the separate clockwise and counterclockwise currents generate magnetic fields that add, producing maximal stimulation of a spindle shaped volume, centered at a depth of one-third to one-half coil radius from the body surface. Conclusions This condensed synthesis of electromagnetic theory and cable theories of axon physiology provides a partial solution to the targeting problem in peripheral and in transcranial magnetic stimulation. PMID:24885299

  2. Pharyngeal airway wall mechanics using tagged magnetic resonance imaging during medial hypoglossal nerve stimulation in rats

    PubMed Central

    Brennick, Michael J; Pickup, Stephen; Dougherty, Lawrence; Cater, Jacqueline R; Kuna, Samuel T

    2004-01-01

    To better understand pharyngeal airway mechanics as it relates to the pathogenesis and treatment of obstructive sleep apnoea, we have developed a novel application of magnetic resonance imaging (MRI) with non-invasive tissue tagging to measure pharyngeal wall tissue motion during active dilatation of the airway. Eleven anaesthetized Sprague-Dawley rats were surgically prepared with platinum electrodes for bilateral stimulation of the medial branch of the hypoglossus nerve that supplies motor output to the protrudor and intrinsic tongue muscles. Images of the pharyngeal airway were acquired before and during stimulation using a gated multislice, spoiled gradient recalled (SPGR) imaging protocol in a 4.7 T magnet. The tag pulses, applied before stimulation, created a grid pattern of magnetically imbedded dark lines that revealed tissue motion in images acquired during stimulation. Stimulation significantly increased cross-sectional area, and anteroposterior and lateral dimensions in the oropharyngeal and velopharyngeal airways when results were averaged across the rostral, mid- and caudal pharynx (P < 0.001). Customized software for tissue motion-tracking and finite element-analysis showed that changes in airway size were associated with ventral displacement of tissues in the ventral pharyngeal wall in the rostral, mid- and caudal pharyngeal regions (P < 0.0032) and ventral displacement of the lateral walls in the mid- and caudal regions (P < 0.0001). In addition, principal maximum stretch was significantly increased in the lateral walls (P < 0.023) in a ventral–lateral direction in the mid- and caudal pharyngeal regions and principal maximum compression (perpendicular to stretch) was significantly increased in the ventral walls in all regions (P < 0.0001). Stimulation did not cause lateral displacement of the lateral pharyngeal walls at any level. The results reveal that the increase in pharyngeal airway size resulting from stimulation of the medial branch of the

  3. Influence of pulse sequence, polarity and amplitude on magnetic stimulation of human and porcine peripheral nerve

    PubMed Central

    Maccabee, P J; Nagarajan, S S; Amassian, V E; Durand, D M; Szabo, A Z; Ahad, A B; Cracco, R Q; Lai, K S; Eberle, L P

    1998-01-01

    Mammalian phrenic nerve, in a trough filled with saline, was excited by magnetic coil (MC)-induced stimuli at defined stimulation sites, including the negative-going first spatial derivative of the induced electric field along a straight nerve, at a bend in the nerve, and at a cut nerve ending. At all such sites, the largest amplitude response for a given stimulator output setting was elicited by an induced damped polyphasic pulse consisting of an initial quarter-cycle hyperpolarization followed by a half-cycle depolarization compared with a predominantly ‘monophasic’ quarter-cycle depolarization.Simulation studies demonstrated that the increased efficacy of the induced quarter-cycle hyperpolarizing-half-cycle depolarizing polyphasic pulse was mainly attributed to the greater duration of the outward membrane current phase, resulting in a greater outward charge transfer afforded by the half-cycle (i.e. quarter-cycles 2 and 3). The advantage of a fast rising initial quarter-cycle depolarization was more than offset by the slower rising, but longer duration depolarizing half-cycle.Simulation further revealed that the quarter-cycle hyperpolarization-half-cycle depolarization showed only a 2.6 % lowering of peak outward current and a 3.5 % lowering of outward charge transfer at threshold, compared with a half-cycle depolarization alone. Presumably, this slight increase in efficacy reflects modest reversal of Na+ inactivation by the very brief initial hyperpolarization.In vitro, at low bath temperature, the nerve response to an initial quarter-cycle depolarization declined in amplitude as the second hyperpolarizing phase progressively increased in amplitude and duration. This ‘pull-down’ phenomenon nearly disappeared as the bath temperature approached 37 °C. Possibly, at the reduced temperature, delay in generation of the action potential permitted the hyperpolarization phase to reduce excitation.Pull-down was not observed in the thenar muscle responses to

  4. Peripheral nerve stimulation: definition.

    PubMed

    Abejón, David; Pérez-Cajaraville, Juan

    2011-01-01

    Recently, there has been a tremendous evolution in the field of neurostimulation, both from the technological point of view and from development of the new and different indications. In some areas, such as peripheral nerve stimulation, there has been a boom in recent years due to the variations in the surgical technique and the improved results documented by in multiple published papers. All this makes imperative the need to classify and define the different types of stimulation that are used today. The confusion arises when attempting to describe peripheral nerve stimulation and subcutaneous stimulation. Peripheral nerve stimulation, in its pure definition, involves implanting a lead on a nerve, with the aim to produce paresthesia along the entire trajectory of the stimulated nerve. Copyright © 2011 S. Karger AG, Basel.

  5. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  6. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  7. Magnetic Field Reference Levels for Arbitrary Periodic Waveforms for Prevention of Peripheral Nerve Stimulation.

    PubMed

    Gajda, Gregory B; Bly, Stephen H

    2017-06-01

    Guidelines for prevention of peripheral nerve stimulation from exposure to low frequency magnetic fields have been developed by standard-setting bodies. Exposure limits or reference levels (RLs) are typically set in terms of the maximum root-mean-square amplitude of a sinusoidal waveform; however, environmental flux densities are often periodic, non-sinusoidal waveforms. This work presents a procedure for deriving RLs for any generalized periodic waveform using the empirical nerve-stimulation threshold data obtained from human volunteer MRI experiments. For this purpose, the "Law of Electrostimulation" (LOE), which sets forth conditions of a waveform necessary to trigger the action potential required to depolarize cell membranes, is applied to various waveforms. The results of the LOE analysis are waveform-specific, amplitude thresholds of stimulation that are found in terms of the empirically-derived rheobase threshold time-rate-of-change flux density and chronaxie from trapezoidal pulse MRI experiments. The thresholds are converted to amplitude RLs in two asymptotic frequency regimes as per the usual practice in standard setting. The resulting RLs have the same frequency dependence as in existing standards (i.e., inverse-frequency below a transition frequency and flat above). It is shown that the transition frequency is dependent only on the shape of the waveform. Both sinusoidal and non-sinusoidal waveforms have identical peak-to-peak amplitude RLs above their respective transition frequencies. Below these frequencies, all peak-to-peak amplitude RLs have the same functional dependence on frequency when the frequency is normalized to the waveform-specific transition frequency. This results in simple criteria for testing the amplitude of any arbitrary periodic waveform against potential for stimulation. These criteria are compared to guidance given for non-sinusoidal waveforms in the ICNIRP 1 Hz-100 kHz exposure standard.

  8. Vagus Nerve Stimulation.

    PubMed

    Howland, Robert H

    2014-06-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality.

  9. Vagus Nerve Stimulation

    PubMed Central

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  10. The effect of single-pulse transcranial magnetic stimulation and peripheral nerve stimulation on complexity of EMG signal: fractal analysis.

    PubMed

    Cukic, M; Oommen, J; Mutavdzic, D; Jorgovanovic, N; Ljubisavljevic, M

    2013-07-01

    The aim of this study was to examine whether single-pulse transcranial magnetic stimulation (spTMS) affects the pattern of corticospinal activity once voluntary drive has been restored after spTMS-induced EMG silence. We used fractal dimension (FD) to explore the 'complexity' of the electromyography (EMG) signal, and median frequency of the spectra (MDF) to examine changes in EMG spectral characteristics. FD and MDF of the raw EMG epochs immediately before were compared with those obtained from epochs after the EMG silence. Changes in FD and MDF after spTMS were examined with three levels of muscle contraction corresponding to weak (20-40%), moderate (40-60%) and strong (60-80% of maximal voluntary contraction) and three intensities of stimulation set at 10, 20 and 30% above the resting motor threshold. FD was calculated using the Higuchi fractal dimension algorithm. Finally, to discern the origin of FD changes between the CNS and muscle, we compared the effects of spTMS with the effects of peripheral nerve stimulation (PNS) on FD and MDF. The results show that spTMS induced significant decrease in both FD and MDF of EMG signal after stimulation. PNS did not have any significant effects on FD nor MDF. Changes in TMS intensity did not have any significant effect on FD or MDF after stimulation nor had the strength of muscle contraction. However, increase in contraction strength decreased FD before stimulation but only between weak and moderate contraction. The results suggest that the effects of spTMS on corticospinal activity, underlying voluntary motor output, outlast the TMS stimulus. It appears that the complexity of the EMG signal is reduced after spTMS, suggesting that TMS alters the dynamics of the ongoing corticospinal activity most likely temporarily synchronizing the neural network activity. Further studies are needed to confirm whether observed changes after TMS occur at the cortical level.

  11. Influence of peripheral nerve stimulation on the responses in small hand muscles to transcranial magnetic cortex stimulation.

    PubMed

    Date, M; Schmid, U D; Hess, C W; Schmid, J

    1991-01-01

    The influence of afferent median nerve stimulation on the responses of small hand muscles (CMAPs) to cortical stimulation (CortStim) was investigated by applying short stimulus trains to the median nerve at the wrist and slightly suprathreshold magnetic stimuli to the scalp. Train stimulus frequency (TSF), train stimulus intensity (TSI), and train onset (TO) in relation to the CortStim were varied. Amplitudes and latencies of CMAPs were compared with those obtained by CortStim alone. When applying short trains of 10 msec duration, of 300/sec-400/sec TSF, and of threshold or supramaximal intensity for motor fibers, both facilitatory and inhibitory effects on the responses to CortStim were achieved depending on the timing of the train onset. With a TO of 8-10 msec before CortStim, mean amplitudes of CMAPs were enhanced 3-10 times; mean amplitudes reached up to 20 times the baseline values when the TO was greater than 45 msec before CortStim. With a TO of 15-35 msec before CortStim, amplitudes were diminished below control values. No systematic changes in latency were noted with TO of 8-10 msec, but when the TO was 45-60 msec before CortStim the latencies of CMAPs were 1.5-3 msec shorter than baseline latencies. With afferent stimuli that were subthreshold for motor fibers facilitation only occurred when the TO was about 45 msec before CortStim. The differences were statistically significant (Wilcoxon-Mann-Whitney Test). This biphasic pattern of facilitation and inhibition probably reflects spinal and supraspinal reflex phenomena mediated by spindle receptor and various cutaneous afferents.

  12. Effects of stimulus parameters and tissue inhomogeneity on nerve excitation processes in magnetic stimulation of the brain: A simulation study

    NASA Astrophysics Data System (ADS)

    Hyodo, Akira; Hayami, Takehito; Tsuyama, Seichi; Iramina, Keiji; Ueno, Shoogo

    2009-04-01

    In this study, we used a computer simulation to investigate the nerve excitation processes of the nerve axon in an inhomogeneous volume conductor in magnetic stimulation. We assumed that the nerve axon was located in an inhomogeneous conducting medium with two regions having different conductivities that simulate different tissue types. The distribution of induced electric fields was calculated with the finite element method. The nerve fiber was modeled after equivalent electrical circuits having active nodes of Ranvier. We observed the excitation threshold when the coil current waveforms and direction are changed with varying the electrical properties of the tissue. The simulation results show that the threshold is lower when biphasic waveforms are used and that the optimal current direction depends on tissue conductivity. The results also suggest that the nerve is excited even when the coil current flow is perpendicular to the axon in inhomogeneous conducting media. The results in this study give useful information to explain the experimental results in magnetic stimulation of the brain.

  13. Magnetoneurographic registration of propagating magnetic fields in the lumbar spine after stimulation of the posterior tibial nerve

    NASA Astrophysics Data System (ADS)

    Klein, Anita; van Leeuwen, Peter; Hoormann, Jörg; Grönemeyer, Dietrich

    2006-06-01

    Stimulation of the posterior tibial nerve has been associated with different somatosensory evoked potentials (SEP) recorded along the spine and thorax. The aim of this study was to register and describe the magnetic fields corresponding to different components of spinal SEP after stimulation of tibial nerves. In nine healthy subjects, right and left posterior tibial nerves were transcutaneously electrostimulated at the ankles. Neuromagnetic fields were registered over a circular 800 cm2 area of the lumbosacral spine using a 61-channel biomagnetometer. Magnetic field maps were constructed and examined visually for dipolar patterns. Equivalent current dipoles (ECD) were calculated for each somatosensory evoked field (SEF) using a least-squares fit in a spherical model. In seven subjects dipolar SEF were detected over the lower back at two separate latencies and locations and propagating ECD could be localized. Both the first and second components found agreed anatomically and functionally with respect to propagation in the underlying nerve fibers. It was possible to record and identify SEF which correspond to the SEP described in the literature. Dipole localization based on an equivalent current dipole model allowed a basic evaluation of the plausibility of the measurements with respect to the processes being examined.

  14. Magnetic Nanoparticles for Efficient Delivery of Growth Factors: Stimulation of Peripheral Nerve Regeneration.

    PubMed

    Giannaccini, Martina; Calatayud, M Pilar; Poggetti, Andrea; Corbianco, Silvia; Novelli, Michela; Paoli, Melania; Battistini, Pietro; Castagna, Maura; Dente, Luciana; Parchi, Paolo; Lisanti, Michele; Cavallini, Gabriella; Junquera, Concepción; Goya, Gerardo F; Raffa, Vittoria

    2017-04-01

    The only clinically approved alternative to autografts for treating large peripheral nerve injuries is the use of synthetic nerve guidance conduits (NGCs), which provide physical guidance to the regenerating stump and limit scar tissue infiltration at the injury site. Several lines of evidence suggest that a potential future strategy is to combine NGCs with cellular or molecular therapies to deliver growth factors that sustain the regeneration process. However, growth factors are expensive and have a very short half-life; thus, the combination approach has not been successful. In the present paper, we proposed the immobilization of growth factors (GFs) on magnetic nanoparticles (MNPs) for the time- and space-controlled release of GFs inside the NGC. We tested the particles in a rat model of a peripheral nerve lesion. Our results revealed that the injection of a cocktail of MNPs functionalized with nerve growth factor (NGF) and with vascular endothelial growth factor (VEGF) strongly accelerate the regeneration process and the recovery of motor function compared to that obtained using the free factors. Additionally, we found that injecting MNPs in the NGC is safe and does not impair the regeneration process, and the MNPs remain in the conduit for weeks. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Occipital nerve stimulation.

    PubMed

    Mammis, Antonios; Agarwal, Nitin; Mogilner, Alon Y

    2015-01-01

    Occipital nerve stimulation (ONS) is a form of neuromodulation therapy aimed at treating intractable headache and craniofacial pain. The therapy utilizes neurostimulating electrodes placed subcutaneously in the occipital region and connected to a permanently implanted programmable pulse generator identical to those used for dorsal column/spinal cord stimulation. The presumed mechanisms of action involve modulation of the trigeminocervical complex, as well as closure of the physiologic pain gate. ONS is a reversible, nondestructive therapy, which can be tailored to a patient's individual needs. Typically, candidates for successful ONS include those patients with migraines, Chiari malformation, or occipital neuralgia. However, recent MRSA infections, unrealistic expectations, and psychiatric comorbidities are generally contraindications. As with any invasive procedure, complications may occur including lead migration, infection, wound erosion, device failure, muscle spasms, and pain. The success of this therapy is dependent on careful patient selection, a preimplantation trial, meticulous implantation technique, programming strategies, and complication avoidance.

  16. Repetitive magnetic stimulation affects the microenvironment of nerve regeneration and evoked potentials after spinal cord injury.

    PubMed

    Jiang, Jin-Lan; Guo, Xu-Dong; Zhang, Shu-Quan; Wang, Xin-Gang; Wu, Shi-Feng

    2016-05-01

    Repetitive magnetic stimulation has been shown to alter local blood flow of the brain, excite the corticospinal tract and muscle, and induce motor function recovery. We established a rat model of acute spinal cord injury using the modified Allen's method. After 4 hours of injury, rat models received repetitive magnetic stimulation, with a stimulus intensity of 35% maximum output intensity, 5-Hz frequency, 5 seconds for each sequence, and an interval of 2 minutes. This was repeated for a total of 10 sequences, once a day, 5 days in a week, for 2 consecutive weeks. After repetitive magnetic stimulation, the number of apoptotic cells decreased, matrix metalloproteinase 9/2 gene and protein expression decreased, nestin expression increased, somatosensory and motor-evoked potentials recovered, and motor function recovered in the injured spinal cord. These findings confirm that repetitive magnetic stimulation of the spinal cord improved the microenvironment of neural regeneration, reduced neuronal apoptosis, and induced neuroprotective and repair effects on the injured spinal cord.

  17. Vagus Nerve Stimulation

    PubMed Central

    Ekmekçi, Hakan; Kaptan, Hülagu

    2017-01-01

    BACKGROUND: The vagus nerve stimulation (VNS) is an approach mainly used in cases of intractable epilepsy despite all the efforts. Also, its benefits have been shown in severe cases of depression resistant to typical treatment. AIM: The aim of this study was to present current knowledge of vagus nerve stimulation. MATERIAL AND METHODS: A new value has emerged just at this stage: VNS aiming the ideal treatment with new hopes. It is based on the placement of a programmable generator on the chest wall. Electric signals from the generator are transmitted to the left vagus nerve through the connection cable. Control on the cerebral bioelectrical activity can be achieved by way of these signal sent from there in an effort for controlling the epileptic discharges. RESULTS: The rate of satisfactory and permanent treatment in epilepsy with monotherapy is around 50%. This rate will increase by one-quarters (25%) with polytherapy. However, there is a patient group roughly constituting one-thirds of this population, and this group remains unresponsive or refractory to all the therapies and combined regimes. The more the number of drugs used, the more chaos and side effects are observed. The anti-epileptic drugs (AEDs) used will have side effects on both the brain and the systemic organs. Cerebral resection surgery can be required in some patients. The most commonly encountered epilepsy type is the partial one, and the possibility of benefiting from invasive procedures is limited in most patients of this type. Selective amygdala-hippocampus surgery is a rising value in complex partial seizures. Therefore, as epilepsy surgery can be performed in very limited numbers and rather developed centres, success can also be achieved in limited numbers of patients. The common ground for all the surgical procedures is the target of preservation of memory, learning, speaking, temper and executive functions as well as obtaining a good control on seizures. However, the action mechanism of VNS

  18. Magnetic stimulation of the radial nerve in dogs and cats with brachial plexus trauma: a report of 53 cases.

    PubMed

    Van Soens, Iris; Struys, Michel M; Polis, Ingeborgh E; Bhatti, Sofie F; Van Meervenne, Sofie A; Martlé, Valentine A; Nollet, Heidi; Tshamala, Mulenda; Vanhaesebrouck, An E; Van Ham, Luc M

    2009-10-01

    Brachial plexus trauma is a common clinical entity in small animal practice and prognostic indicators are essential early in the course of the disease. Magnetic stimulation of the radial nerve and consequent recording of the magnetic motor evoked potential (MMEP) was examined in 36 dogs and 17 cats with unilateral brachial plexus trauma. Absence of deep pain perception (DPP), ipsilateral loss of panniculus reflex, partial Horner's syndrome and a poor response to MMEP were related to the clinical outcome in 29 of the dogs and 13 of the cats. For all animals, a significant difference was found in MMEP between the normal and the affected limb. Absence of DPP and unilateral loss of the panniculus reflex were indicative of an unsuccessful outcome in dogs. Additionally, the inability to evoke a MMEP was associated with an unsuccessful outcome in all animals. It was concluded that magnetic stimulation of the radial nerve in dogs and cats with brachial plexus trauma may provide an additional diagnostic and prognostic tool.

  19. [Structural changes in the sensory ganglia of the spinal nerves after repeated magnetic stimulation on the model of ischemic myelopathy].

    PubMed

    Onishchenko, l S; Iskra, D A

    2013-01-01

    The aim of this study was to examine the association of morphological changes in the-sensory ganglia of the spinal nerves (SGSN) with the cilinical symptomatology in rats with the experimentally induced ischemic myelopathy (IM), untreated or treated with repeated magnetic stimulation (RMS). The efficacy and mechanisms of RMS action on SGSN were studied by electron microscopy in 16 rats with IM. According to the results of treatment, in SGSN both at a distance from the damaged area (lumbar SGSN) and close to it (cervical SGSN) the morphological signs of regenerative-reparative processes were found in the cells and nerve fibers (restoration of the organelle structure in the cytoplasm o0f neurons and neurolemmocytes, the increase in the number of he latter and fiber remyelination). The expression of the structural changes correlated with the degree of functional recovery.

  20. The impact of high-frequency magnetic stimulation of peripheral nerves: muscle hardness, venous blood flow, and motor function of upper extremity in healthy subjects.

    PubMed

    Okudera, Yoshihiko; Matsunaga, Toshiki; Sato, Mineyoshi; Chida, Satoaki; Hatakeyama, Kazutoshi; Watanabe, Motoyuki; Shimada, Yoichi

    2015-01-01

    The purpose of this study was to investigate the impact of high-frequency peripheral nerve magnetic stimulation on the upper limb function. Twenty-five healthy adults (16 men and 9 women) participated in this study. The radial nerve of the non-dominant hand was stimulated by high-frequency magnetic stimulation device. A total of 600 impulses were applied at a frequency of 20 Hz and intensity of 1.2 resting motor threshold (rMT). At three time points (before, immediately after, and 15 min after stimulation), muscle hardness of the extensor digitorum muscle on the stimulated side was measured using a mechanical tissue hardness meter and a shear wave imaging device, cephalic venous blood flow on the stimulated side was measured using an ultrasound system, and the Box and Block test (BBT) was performed. Mechanical tissue hardness results did not show any significant differences between before, immediately after, and 15 min after stimulation. Measurements via shear wave imaging showed that muscle hardness significantly decreased both immediately and 15 min after stimulation compared to before stimulation (P < 0.05). Peripheral venous blood flow and BBT score significantly increased both immediately and 15 min after stimulation compared to before stimulation (P < 0.01). High-frequency peripheral nerve magnetic stimulation can achieve effects similar to electrical stimulation in a less invasive manner, and may therefore become an important element in next-generation rehabilitation.

  1. Noninvasive and painless magnetic stimulation of nerves improved brain motor function and mobility in a cerebral palsy case.

    PubMed

    Flamand, Véronique H; Schneider, Cyril

    2014-10-01

    Motor deficits in cerebral palsy disturb functional independence. This study tested whether noninvasive and painless repetitive peripheral magnetic stimulation could improve motor function in a 7-year-old boy with spastic hemiparetic cerebral palsy. Stimulation was applied over different nerves of the lower limbs for 5 sessions. We measured the concurrent aftereffects of this intervention on ankle motor control, gait (walking velocity, stride length, cadence, cycle duration), and function of brain motor pathways. We observed a decrease of ankle plantar flexors resistance to stretch, an increase of active dorsiflexion range of movement, and improvements of corticospinal control of ankle dorsiflexors. Joint mobility changes were still present 15 days after the end of stimulation, when all gait parameters were also improved. Resistance to stretch was still lower than prestimulation values 45 days after the end of stimulation. This case illustrates the sustained effects of repetitive peripheral magnetic stimulation on brain plasticity, motor function, and gait. It suggests a potential impact for physical rehabilitation in cerebral palsy. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. Assessment of nerve morphology in nerve activation during electrical stimulation

    NASA Astrophysics Data System (ADS)

    Gomez-Tames, Jose; Yu, Wenwei

    2013-10-01

    The distance between nerve and stimulation electrode is fundamental for nerve activation in Transcutaneous Electrical Stimulation (TES). However, it is not clear the need to have an approximate representation of the morphology of peripheral nerves in simulation models and its influence in the nerve activation. In this work, depth and curvature of a nerve are investigated around the middle thigh. As preliminary result, the curvature of the nerve helps to reduce the simulation amplitude necessary for nerve activation from far field stimulation.

  3. Assessement of quadriceps strength, endurance and fatigue in FSHD and CMT: benefits and limits of femoral nerve magnetic stimulation.

    PubMed

    Bachasson, D; Temesi, J; Bankole, C; Lagrange, E; Boutte, C; Millet, G Y; Verges, S; Levy, P; Feasson, L; Wuyam, B

    2014-02-01

    To (i) evaluate the feasibility and the reliability of a test assessing quadriceps strength, endurance and fatigue in patients with fascioscapulohumeral dystrophy (FSHD) and Charcot-Marie-Tooth disease (CMT), (ii) compare quadriceps function between patients and healthy controls. Controls performed the test once and patients twice on two separate visits. It involved progressive sets of 10 isometric contractions each followed by neuromuscular assessments with FNMS. Volitional assessment of muscle strength, endurance and fatigue appeared to be reliable in FSHD and CMT patients. Supramaximal FNMS was achieved in ∼70% of FSHD patients and in no CMT patients. In FSHD patients, Femoral nerve magnetic stimulation (FNMS) provided reliable assessment of central (typical error as a coefficient of variation (CVTE)<8% for voluntary activation) and peripheral (CVTE<10% and intraclass coefficient correlation >0.85 for evoked responses) function. Patients and controls had similar reductions in evoked quadriceps responses, voluntary activation and similar endurance. This test provides reliable evaluation but FNMS exhibits limitations due to insufficient stimulation intensity particularly in neurogenic conditions. It showed similar central and peripheral quadriceps fatigability in patients and controls. This test may be a valuable tool for patient follow-up although further development of magnetic stimulation devices is needed to extend its applicability. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study

    PubMed Central

    Shitara, H.; Shinozaki, T.; Takagishi, K.; Honda, M.; Hanakawa, T.

    2013-01-01

    Neuroimaging combined with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or gave electrical right median nerve stimulation (MNS) in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG). We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10–20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging. PMID:24062660

  5. A precision mechanical nerve stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1988-01-01

    An electromechanical device, used to apply and monitor stimulating pulses to a mammalian motor nerve, has been successfully developed at NASA Langley Research Center. Two existing force transducers, a flight skin friction balance and a miniature skin friction balance which were designed for making aerodynamic drag measurements, were modified and incorporated to form this precision instrument. The nerve stimulator is a type one servomechanism capable of applying and monitoring stimulating pulses of 0 to 10 grams with a precision of better than +/- 0.05 grams. Additionally, the device can be independently used to apply stimulating pulses by displacing the nerve from 0 to 0.25 mm with a precision of better than +/- 0.001 mm while measuring the level of the load applied.

  6. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Magnetic Field Structure and Induced Electric Current Distribution on a Cylindrical Model: Application to Magnetic Nerve Stimulation

    NASA Astrophysics Data System (ADS)

    Taishi, Okita; Toshiyuki, Takagi

    2009-07-01

    We study the relation between the magnetic field structure and the induced electric-current distribution based on a cylindrical model composed of a uniform electrically conductive medium. When the time-varying magnetic fields are axisymmetrically applied in the axial direction of the model, the electric fields are induced around the central axis in accordance with Faraday's law. We examine the eddy-current distributions generated by loop-coils with various geometries carrying an alternating electric current. It is shown that the radial structure of the induced fields can significantly be controlled by the loop coil geometry, which will be suitable for practical use especially in magnetic nerve stimulation on bioelectromagnetics, if we appropriately place the exciting coil with optimum geometry.

  7. Single fibre motor evoked potentials to brain, spinal roots and nerve stimulation. Comparisons of the 'central' and 'peripheral' response jitter to magnetic and electric stimuli.

    PubMed

    Zarola, F; Caramia, M D; Paradiso, C; Mariorenzi, R; Martino, G; Traversa, R; Rossini, P M

    1989-08-28

    Single fibre motor evoked potentials to magnetic and electric non-invasive stimulation of brain, spinal cord and peripheral nerve were recorded in 8 healthy volunteers. The 'central motor jitter' and the 'peripheral motor jitter' were respectively calculated and a comparison between the magnetic and electric modalities was made. The highest degree of latency variability was observed for both magnetic and electric central motor jitter, whilst the peripheral motor jitter to nerve stimulation was as low as the neuromuscular one (range 16-60 microsecond). The magnetic 'central motor jitter' (range 94-1024 microsecond) was much larger than the electric one (range 55-280 microsecond), which was in the order of jitter calculated on H-reflex studies; moreover, the former was organized in a bi- or trimodal distribution. On the contrary, no significant differences were observed between the two modalities when the jitter to nerve stimulation was taken into account. Possible contributions of corticocortical circuitries containing several synaptic interruptions during magnetic as opposed to electric transcranial stimulation, is discussed.

  8. Impact of stepwise mandibular advancement on upper airway mechanics in obstructive sleep apnea using phrenic nerve magnetic stimulation.

    PubMed

    Gakwaya, Simon; Melo-Silva, César Augusto; Borel, Jean-Christian; Rousseau, Eric; Masse, Jean-François; Sériès, Frédéric

    2014-01-01

    Mandibular advancement devices (MAD) represent a potential treatment for obstructive sleep apnea (OSA). However, their mechanisms of actions are not completely understood. This study was aimed to explore the effects of MAD-induced mandibular protrusion on upper airway mechanics. 25 men commencing treatment for OSA with MAD were recruited. Phrenic nerve magnetic stimulation (PNMS) was used to measure flow/pressure relationship during progressive protrusion in three conditions (without MAD, MAD at minimum protrusion, and MAD at maximum tolerable protrusion). Pressures were recorded simultaneously at three different upper airway segments (naso-, velo-, and oro-pharynx). Without MAD, PNMS twitches induced flow-limitation at the velopharyngeal level in 19 subjects and six of them experienced a shift in the flow-limitation site to the lower segment with MAD at maximum protrusion. An association was found between having a velopharyngeal limitation site without MAD and the increase in maximum flow with the advanced MAD. These data suggest that mandibular advancement devices are acting predominantly at the velopharyngeal level.

  9. Vagus Nerve Stimulation for Treating Epilepsy

    MedlinePlus

    ... and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you ... how vagus nerve stimulation (VNS) may help treat epilepsy. The American Academy of Neurology (AAN) is the ...

  10. Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients.

    PubMed

    Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

    2016-07-01

    [Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients.

  11. Preoperative transcutaneous electrical nerve stimulation for localizing superficial nerve paths.

    PubMed

    Natori, Yuhei; Yoshizawa, Hidekazu; Mizuno, Hiroshi; Hayashi, Ayato

    2015-12-01

    During surgery, peripheral nerves are often seen to follow unpredictable paths because of previous surgeries and/or compression caused by a tumor. Iatrogenic nerve injury is a serious complication that must be avoided, and preoperative evaluation of nerve paths is important for preventing it. In this study, transcutaneous electrical nerve stimulation (TENS) was used for an in-depth analysis of peripheral nerve paths. This study included 27 patients who underwent the TENS procedure to evaluate the peripheral nerve path (17 males and 10 females; mean age: 59.9 years, range: 18-83 years) of each patient preoperatively. An electrode pen coupled to an electrical nerve stimulator was used for superficial nerve mapping. The TENS procedure was performed on patients' major peripheral nerves that passed close to the surgical field of tumor resection or trauma surgery, and intraoperative damage to those nerves was apprehensive. The paths of the target nerve were detected in most patients preoperatively. The nerve paths of 26 patients were precisely under the markings drawn preoperatively. The nerve path of one patient substantially differed from the preoperative markings with numbness at the surgical region. During surgery, the nerve paths could be accurately mapped preoperatively using the TENS procedure as confirmed by direct visualization of the nerve. This stimulation device is easy to use and offers highly accurate mapping of nerves for surgical planning without major complications. The authors conclude that TENS is a useful tool for noninvasive nerve localization and makes tumor resection a safe and smooth procedure.

  12. Vagus nerve stimulation regulates hemostasis in swine.

    PubMed

    Czura, Christopher J; Schultz, Arthur; Kaipel, Martin; Khadem, Anna; Huston, Jared M; Pavlov, Valentin A; Redl, Heinz; Tracey, Kevin J

    2010-06-01

    The central nervous system regulates peripheral immune responses via the vagus nerve, the primary neural component of the cholinergic anti-inflammatory pathway. Electrical stimulation of the vagus nerve suppresses proinflammatory cytokine release in response to endotoxin, I/R injury, and hypovolemic shock and protects against lethal hypotension. To determine the effect of vagus nerve stimulation on coagulation pathways, anesthetized pigs were subjected to partial ear resection before and after electrical vagus nerve stimulation. We observed that electrical vagus nerve stimulation significantly decreased bleeding time (pre-electrical vagus nerve stimulation = 1033 +/- 210 s versus post-electrical vagus nerve stimulation = 585 +/- 111 s; P < 0.05) and total blood loss (pre-electrical vagus nerve stimulation = 48.4 +/- 6.8 mL versus post-electrical vagus nerve stimulation = 26.3 +/- 6.7 mL; P < 0.05). Reduced bleeding time after vagus nerve stimulation was independent of changes in heart rate or blood pressure and correlated with increased thrombin/antithrombin III complex generation in shed blood. These data indicate that electrical stimulation of the vagus nerve attenuates peripheral hemorrhage in a porcine model of soft tissue injury and that this protective effect is associated with increased coagulation factor activity.

  13. Transdermal optogenetic peripheral nerve stimulation

    NASA Astrophysics Data System (ADS)

    Maimon, Benjamin E.; Zorzos, Anthony N.; Bendell, Rhys; Harding, Alexander; Fahmi, Mina; Srinivasan, Shriya; Calvaresi, Peter; Herr, Hugh M.

    2017-06-01

    Objective: A fundamental limitation in both the scientific utility and clinical translation of peripheral nerve optogenetic technologies is the optical inaccessibility of the target nerve due to the significant scattering and absorption of light in biological tissues. To date, illuminating deep nerve targets has required implantable optical sources, including fiber-optic and LED-based systems, both of which have significant drawbacks. Approach: Here we report an alternative approach involving transdermal illumination. Utilizing an intramuscular injection of ultra-high concentration AAV6-hSyn-ChR2-EYFP in rats. Main results: We demonstrate transdermal stimulation of motor nerves at 4.4 mm and 1.9 mm depth with an incident laser power of 160 mW and 10 mW, respectively. Furthermore, we employ this technique to accurately control ankle position by modulating laser power or position on the skin surface. Significance: These results have the potential to enable future scientific optogenetic studies of pathologies implicated in the peripheral nervous system for awake, freely-moving animals, as well as a basis for future clinical studies.

  14. Vagus nerve stimulation in clinical practice.

    PubMed

    Farmer, Adam D; Albu-Soda, Ahmed; Aziz, Qasim

    2016-11-02

    The diverse array of end organ innervations of the vagus nerve, coupled with increased basic science evidence, has led to vagus nerve stimulation becoming a management option in a number of clinical disorders. This review discusses methods of electrically stimulating the vagus nerve and its current and potential clinical uses.

  15. Vagus Nerve Stimulation and Headache.

    PubMed

    Yuan, Hsiangkuo; Silberstein, Stephen D

    2017-04-01

    Neuromodulation is an emerging area in headache management. Through neurostimulation, multiple brain areas can be modulated to alleviate pain, hence reducing the pharmacological need. In this review, we discuss the recent development of the vagus nerve stimulation (VNS) for headache management. Early case series from epilepsy and depression cohorts using invasive VNS showed a serendipitous reduction in headache frequency and/or severity. Noninvasive VNS (nVNS), which stimulates the carotid vagus nerve with the use of a personal handheld device, also demonstrated efficacy for acute migraine or cluster headache attacks. Long-term use of nVNS seemed to exert a prophylactic effect for both chronic migraine and chronic cluster headache. In animal studies, nVNS modulated multiple pain pathways and even lessen cortical spreading depression. Progression in nVNS clinical efficacy over time suggests an underlying disease-modifying neuromodulation. Noninvasive VNS appears to be as effective as the invasive counterpart for many indications. With an enormous potential therapeutic gain and a high safety profile, further development and application of nVNS is promising. © 2015 American Headache Society.

  16. Magnetic-motor-root stimulation: review.

    PubMed

    Matsumoto, Hideyuki; Hanajima, Ritsuko; Terao, Yasuo; Ugawa, Yoshikazu

    2013-06-01

    Magnetic stimulation can activate the human central and peripheral nervous systems non-invasively and virtually painlessly. Magnetic stimulation over the spinal enlargements can activate spinal nerves at the neuroforamina (magnetic-neuroforamina stimulation). This stimulation method provides us with information related to the latency of compound-muscle action potential (CMAP), which is usually interpreted as peripheral motor-conduction time (PMCT). However, this stimulation method has faced several problems in clinical applications. One is that supramaximal CMAPs were unobtainable. Another is that magnetic stimulation did not usually activate the spinal nerves in the spinal canal, i.e., the cauda equina, which prevented an evaluation of its conduction. For these reasons, magnetic-neuroforamina stimulation was rarely used to evaluate the conduction of peripheral nerves. It was mainly used to evaluate the conduction of the corticospinal tract using the parameter of central motor-conduction time (CMCT), which was calculated by subtracting PMCT from the latency of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex. Recently, supramaximal stimulation has been achieved in magnetic-neuroforamina stimulation, and this has contributed to the measurement of both CMAP size and latency. The achievement of supramaximal stimulation is ascribed to the increase in magnetic-stimulator output and a novel coil, the magnetic augmented translumbosacral stimulation (MATS) coil. The most proximal part of the cauda equina can be reliably activated using the MATS coil (magnetic-conus stimulation), thus contributing to the measurement of cauda equina conduction time (CECT) and cortico-conus motor-conduction time (CCCT). These recent developments in magnetic-motor-root stimulation enable us to more precisely evaluate the conduction of the proximal part of peripheral nerves and that of the corticospinal tract for lower-limb muscles

  17. Vagus nerve stimulation inhibits cortical spreading depression.

    PubMed

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng, Yi; Sadeghian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-04-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura and is a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its antimigraine effect. Unilateral vagus nerve stimulation was delivered either noninvasively through the skin or directly by electrodes placed around the nerve. Systemic physiology was monitored throughout the study. Both noninvasive transcutaneous and invasive direct vagus nerve stimulations significantly suppressed spreading depression susceptibility in the occipital cortex in rats. The electrical stimulation threshold to evoke a spreading depression was elevated by more than 2-fold, the frequency of spreading depressions during continuous topical 1 M KCl was reduced by ∼40%, and propagation speed of spreading depression was reduced by ∼15%. This effect developed within 30 minutes after vagus nerve stimulation and persisted for more than 3 hours. Noninvasive transcutaneous vagus nerve stimulation was as efficacious as direct invasive vagus nerve stimulation, and the efficacy did not differ between the ipsilateral and contralateral hemispheres. Our findings provide a potential mechanism by which vagus nerve stimulation may be efficacious in migraine and suggest that susceptibility to spreading depression is a suitable platform to optimize its efficacy.

  18. Using the nerve stimulator for peripheral or plexus nerve blocks.

    PubMed

    Urmey, W F

    2006-06-01

    Conventional methodology for nerve location utilizes anatomical landmarks followed by invasive exploration with a needle to a suitable endpoint. An appropriate endpoint can be either anatomical in nature (e.g. transaterial technique) or functional (paresthesia or motor response to electrical stimulation). Ability to electrically stimulate a peripheral nerve or plexus depends upon many variables, including; 1) conductive area at the electrode, 2) electrical impedance, 3) electrode-to-nerve distance, 4) current flow (amperage), and 5) pulse duration. Electrode conductive area follows the equation R = rhoL/A, where R = electrical resistance, p = tissue resistivity, L = electrode-to-nerve distance, and A = electrode conductive area. Therefore resistance varies to the inverse of the electrode's conductive area. Tissue electrical impedance varies as a function of the tissue composition. In general, tissues with higher lipid content have higher impedances. Modern electrical nerve stimulators are designed to keep current constant, in spite of varying impedance. The electrode-to-nerve distance has the most influence on the ability to elicit a motor response to electrical stimulation. This is governed by Coulomb's law: E = K(Q/r2) where E = required stimulating charge, K= constant, Q = minimal required stimulating current, and r = electrode-to-nerve distance. Therefore, ability to stimulate the nerve at low amperage (e.g. < 0.5 mA), indicates an extremely close position to the nerve. Similarly, increasing current flow (amperage) increases the ability to stimulate the nerve at a distance. Increasing pulse duration increases the flow of electrons during a current pulse at any given amperage. Therefore, reducing pulse duration to very short times (e.g. 0.1 or 0.05 ms) diminishes current dispersion, requiring the needle tip to be extremely close to the nerve to elicit a motor response. The above parameters can be varied optimally to enhance successful nerve location and

  19. Adopting reciprocity theorem in deep transcranial magnetic stimulation problem to design an efficient single source coil array based on nerve cell direction.

    PubMed

    Mohtadi Jafari, Ali; Abdolali, Ali

    2017-06-29

    Deep transcranial magnetic stimulation (dTMS) plays an important role in the treatment of many diseases. Previous designs rarely considered the direction of the induced electric field (E) with respect to nerve fibers. However, it can be observed from related formulae that the tangential component of E (E effective) has a more significant role in the stimulation of nerve cells. In this paper, a new approach is proposed for designing a single-source coil array (CA) by combining tractography and the reciprocity theorem (RT). This method is a non-iterative procedure that can directly design CAs for the stimulation of each desired target zone without any complicated and slow iterative algorithm. Specifications of CA such as the optimum spatial angle and the best placement of coils are important because the location of the coil around the head and its spatial angle have been shown to have a major effect on induced E. Adoption of the RT yields the optimum specifications of CA and maximum E effective at the stimulation zone. This novel technique can introduce a new approach for the application of CA since it entails a high flexibility, high speed, and good accuracy.

  20. Electrical Stimulation Enhances Reinnervation After Nerve Injury

    PubMed Central

    2015-01-01

    Electrical muscle stimulation following peripheral nerve injury has been a controversial method of treatment due primarily to the inconsistent literature surrounding it. In this presentation transcript I outline ongoing experiments investigating a clinically translatable daily muscle stimulation paradigm in rats following nerve injury. Results show that reinnervation of muscle and functional behavioural metrics are enhanced with daily stimulation with upregulation of intramuscular neurotrophic factors as a potential mechanism. In addition, the impact of stimulation on terminal sprouting, a mentioned negative aspect of electrical muscle stimulation, was a minor contributor to long term functional reinnervation of stimulated muscles in our studies. PMID:26913163

  1. Brain imaging correlates of peripheral nerve stimulation

    PubMed Central

    Bari, Ausaf A.; Pouratian, Nader

    2012-01-01

    Direct peripheral nerve stimulation is an effective treatment for a number of disorders including epilepsy, depression, neuropathic pain, cluster headache, and urological dysfunction. The efficacy of this stimulation is ultimately due to modulation of activity in the central nervous system. However, the exact brain regions involved in each disorder and how they are modulated by peripheral nerve stimulation is not fully understood. The use of functional neuroimaging such as SPECT, PET and fMRI in patients undergoing peripheral nerve stimulation can help us to understand these mechanisms. We review the literature for functional neuroimaging performed in patients implanted with peripheral nerve stimulators for the above-mentioned disorders. These studies suggest that brain activity in response to peripheral nerve stimulation is a complex interaction between the stimulation parameters, disease type and severity, chronicity of stimulation, as well as nonspecific effects. From this information we may be able to understand which brain structures are involved in the mechanism of peripheral nerve stimulation as well as define the neural substrates underlying these disorders. PMID:23230531

  2. Nerves on magnetic resonance imaging.

    PubMed Central

    Collins, J. D.; Shaver, M. L.; Batra, P.; Brown, K.

    1989-01-01

    Nerves are often visualized on magnetic resonance imaging (MRI) studies of the soft tissues on the chest and shoulder girdle. To learn the reasons for the contrast between the nerves and adjacent tissues, the authors obtained a fresh specimen containing part of the brachial plexus nerves from the left axilla and compared MRI with x-ray projections and photomicrographs of histologic sections. The results suggest that the high signals from the nerves stand out in contrast to the low signals from their rich vascular supply. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6A Figure 6B Figure 7 PMID:2733051

  3. Optical stimulation of peripheral nerves in vivo

    NASA Astrophysics Data System (ADS)

    Wells, Jonathon D.

    This dissertation documents the emergence and validation of a new clinical tool that bridges the fields of biomedical optics and neuroscience. The research herein describes an innovative method for direct neurostimulation with pulsed infrared laser light. Safety and effectiveness of this technique are first demonstrated through functional stimulation of the rat sciatic nerve in vivo. The Holmium:YAG laser (lambda = 2.12 mum) is shown to operate at an optimal wavelength for peripheral nerve stimulation with advantages over standard electrical neural stimulation; including contact-free stimulation, high spatial selectivity, and lack of a stimulation artifact. The underlying biophysical mechanism responsible for transient optical nerve stimulation appears to be a small, absorption driven thermal gradient sustained at the axonal layer of nerve. Results explicitly prove that low frequency optical stimulation can reliably stimulate without resulting in tissue thermal damage. Based on the positive results from animal studies, these optimal laser parameters were utilized to move this research into the clinic with a combined safety and efficacy study in human subjects undergoing selective dorsal rhizotomy. The clinical Holmium:YAG laser was used to effectively stimulate human dorsal spinal roots and elicit functional muscle responses recorded during surgery without evidence of nerve damage. Overall these results predict that this technology can be a valuable clinical tool in various neurosurgical applications.

  4. Outcome of sacral nerve stimulation for fecal incontinence in patients refractory to percutaneous tibial nerve stimulation.

    PubMed

    Hotouras, Alexander; Murphy, Jamie; Thin, Noel N; Allison, Marion; Horrocks, Emma; Williams, Norman S; Knowles, Charles H; Chan, Christopher L

    2013-07-01

    Percutaneous tibial nerve stimulation and sacral nerve stimulation are both second-line treatments for fecal incontinence, but the comparative efficacy of the 2 therapies is unknown. In our institution, patients with refractory fecal incontinence are generally treated with percutaneous tibial nerve stimulation before being considered for sacral nerve stimulation. The aim of this study was to assess the outcome associated with this treatment algorithm in order to guide future management strategies. All patients with fecal incontinence treated over a 3-year period with tibial nerve stimulation before receiving sacral nerve stimulation were identified from a prospectively recorded database. Demographics and pretreatment anorectal physiological data were available for all patients. This study was conducted at an academic colorectal unit in a tertiary center. Twenty patients (17 female:3 male, median age 55 (33-79) years) were identified to be refractory to percutaneous tibial nerve stimulation. Clinical outcome data were collected prospectively before and after treatment, including 1) Cleveland Clinic Florida-Fecal Incontinence scores and 2) number of incontinence episodes per week. The mean (±SD) pretreatment incontinence score (11.7 ± 3.5) did not differ from the mean incontinence score after 12 sessions of tibial nerve stimulation (10.9 ± 3.6, p = 0.42). All patients were subsequently counseled for sacral nerve stimulation, and 68.4% of them reported a significant therapeutic benefit with an improved incontinence score (7.7 ± 4.1, p = 0.014). This was a nonrandomized study with a relatively small number of patients Sacral nerve stimulation appears to be an effective treatment for patients who do not gain an adequate therapeutic benefit from percutaneous tibial nerve stimulation and, thus, should be routinely considered for this patient cohort.

  5. Phrenic nerve stimulation: the Australian experience.

    PubMed

    Khong, Peter; Lazzaro, Amanda; Mobbs, Ralph

    2010-02-01

    Phrenic nerve stimulation is a technique whereby a nerve stimulator provides electrical stimulation of the phrenic nerve to cause diaphragmatic contraction. The most common indications for this procedure are central alveolar hypoventilation and high quadriplegia. This paper reviews the available data on the 19 patients treated with phrenic nerve stimulation in Australia to date. Of the 19 patients, 14 required pacing due to quadriplegia, one had congenital central hypoventilation syndrome and one had brainstem encephalitis. Information was unavailable for the remaining three patients. Currently, 11 of the pacers are known to be actively implanted, with the total pacing duration ranging from 1 to 21 years (mean 13 years). Eight of the 19 patients had revision surgeries. Four of these were to replace the original I-107 system (which had a 3-5-year life expectancy) with the current I-110 system, which is expected to perform electrically for the patient's lifetime. Three patients had revisions due to mechanical failure. The remaining patients' notes were incomplete. These data suggest that phrenic nerve stimulation can be used instead of mechanical ventilators for long-term ongoing respiratory support.

  6. Optical nerve stimulation for a vestibular prosthesis

    NASA Astrophysics Data System (ADS)

    Harris, David M.; Bierer, Steven M.; Wells, Jonathon D.; Phillips, James O.

    2009-02-01

    Infrared Nerve Stimulation (INS) offers several advantages over electrical stimulation, including more precise spatial selectivity and improved surgical access. In this study, INS and electrical stimulation were compared in their ability to activate the vestibular branch of the VIIIth nerve, as a potential way to treat balance disorders. The superior and lateral canals of the vestibular system of Guinea pigs were identified and approached with the aid of precise 3-D reconstructions. A monopolar platinum stimulating electrode was positioned near the ampullae of the canals, and biphasic current pulses were used to stimulate vestibular evoked potentials and eye movements. Thresholds and input/output functions were measured for various stimulus conditions. A short pulsed diode laser (Capella, Lockheed Martin-Aculight, Inc., Bothell WA) was placed in the same anatomical position and various stimulus conditions were evaluated in their ability to evoke similar potentials and eye movements.

  7. Treatment of abdominal nerve entrapment syndrome using a nerve stimulator.

    PubMed Central

    McGrady, E. M.; Marks, R. L.

    1988-01-01

    Seventy-six patients treated at York Pain Relief Clinic for Abdominal Nerve Entrapment Syndrome (ANES) between 1982 and 1986, using aqueous phenol and nerve stimulator control are reviewed. A questionnaire was sent to all the patients who had been discharged from the clinic to try to confirm that the initial improvements had been maintained and 60 patients replied. Group A (n = 44) had been diagnosed with confidence; 95% had gained complete or partial relief of symptoms. Group B (n = 32) had other symptoms making the diagnosis less certain; 50% gained some relief. Clinical presentation of ANES and the method of treatment are described. Images Fig. 1 PMID:2970241

  8. Mentalis muscle responses to median nerve stimulation.

    PubMed

    Liao, Kwong-Kum; Chen, Jen-Tse; Lai, Kuan-Lin; Kao, Chuen-Der; Lin, Chia-Yi; Liu, Chih-Yang; Lin, Yung-Yang; Shan, Din-E; Wu, Zin-An

    2006-08-31

    Electrical stimulation may produce excitation or inhibition of the motor neurons, as represented the blink reflex and masseter silent period in response to trigeminal nerve stimulation. Clinically, a light touch on the palm may evoke a mentalis muscle response (MMR), i.e. a palmomental reflex. In this study, we attempted to characterize the MMR to median nerve stimulation. Electrical stimulation was applied at the median nerve with recordings at the mentalis muscles. An inhibition study was done with continuous stimuli during muscle contraction (I1 and I2 of MMRaverage). Excitation was done with a single shot during muscle relaxation (MMRsingle) or by continuous stimuli during muscle contraction (E1 and E2 of MMRaverage). The characteristic differences between MMRaverage and MMRsingle were as follows: earlier onset latencies of MMRaverage (MMRaverage < 45 ms; MMRsingle > 60 ms), and a lower amplitude of MMRaverage (MMRaverage < 50 microV; MMRsingle > 150 microV). The receptive field of MMRsingle was widespread over the body surface and that of MMRaverage was limited to the trigeminal, median and index digital nerves. Series of stimuli usually significantly decreased the amplitude of MMRsingle, as a phenomenon of habituation. On the other hand, it was difficult to evoke the earlier response (i.e. MMRaverage) without continuous stimuli and an average technique. MMRaverage had the components of both excitation (E) and inhibition (I); for example, E1-I1-E2-I2 or I1-E2-I2. E2 was the most consistent component. In patients with dorsal column dysfunction, median nerve stimulation could successfully elicit MMRsingle, but not MMRaverage. Contrarily, in patients with pain sensory loss, it was more difficult to reproduce MMRsingle than MMRaverage. It seemed that MMRaverage and MMRsingle did not have equivalents across the different modalities of stimulation.

  9. Neuro magnetic stimulation: Engineering aspects

    NASA Astrophysics Data System (ADS)

    Al-Mutawaly, Nafia

    Magnetic nerve stimulation has proven to be an effective, non-invasive technique to excite peripheral and central nervous systems. In this technique, the excitement of the neural tissue depends on exposure to a transient magnetic field generated by passing a high pulse of current through a coil. By positioning the coil in a specific orientation over the targeted tissue, the transient magnetic field will induce an electric field in the conductive milieu of the body. If this field reaches a certain threshold within a specific time period, neural depolarization is then evident. The primary objective of this thesis is the development and testing of new coil designs that can focus the magnetic field more effectively. Two such coils have been built. The first coil has an air core, while the other has a magnetic core. The magnetic fields of these coils, applied to the human upper limb, have been determined theoretically, and the results compared to the field generated by the most common commercial coil, the Figure-8 coil. To design these coils and to test them experimentally, a current pulse generator has been designed and built. Further, a novel measurement system using surface mount inductances and a computer based data acquisition system has been designed and built. The experimental results confirm the theoretical findings, that the air core coil is slightly better than the Figure-8, as far as field strength and focality are concerned. In addition, the experimental results, prove that the coil with the ferromagnetic core, is superior. The second objective is to investigate the effect of stimulus waveforms theoretically, experimentally, and through in vivo study. The goals of the study are to establish a quantitative relationship among various waveforms and to investigate the effect of these waveforms in determining the site of stimulation. Accordingly, a multi subject trial was conducted: a Figure-8 coil was applied to the median nerve of ten subjects at the upper limb

  10. Transcutaneous Electrical Nerve Stimulation: Research Update.

    ERIC Educational Resources Information Center

    Johns, Florene Carnicelli

    Currently, research is being performed in the area of nonsurgical and nonchemical means for influencing the body's threshold for pain. Today, transcutaneous electrical nerve stimulation (TENS) is being widely used for this purpose. Application of this treatment can be confusing, however, because determining such things as selection of the proper…

  11. Transcutaneous Electrical Nerve Stimulation: Research Update.

    ERIC Educational Resources Information Center

    Johns, Florene Carnicelli

    Currently, research is being performed in the area of nonsurgical and nonchemical means for influencing the body's threshold for pain. Today, transcutaneous electrical nerve stimulation (TENS) is being widely used for this purpose. Application of this treatment can be confusing, however, because determining such things as selection of the proper…

  12. Vagal Nerve Stimulation Therapy: What Is Being Stimulated?

    PubMed Central

    Kember, Guy; Ardell, Jeffrey L.; Armour, John A.; Zamir, Mair

    2014-01-01

    Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity. PMID:25479368

  13. 21 CFR 874.1820 - Surgical nerve stimulator/locator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1820 Surgical nerve stimulator/locator. (a) Identification. A surgical nerve stimulator/locator is a device that is intended...

  14. 21 CFR 874.1820 - Surgical nerve stimulator/locator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1820 Surgical nerve stimulator/locator. (a) Identification. A surgical nerve stimulator/locator is a device that is intended...

  15. Central mechanisms of cranial nerve stimulation for epilepsy

    PubMed Central

    Fanselow, Erika E.

    2012-01-01

    Stimulation of peripheral cranial nerves has been shown to exert anticonvulsant effects in animal models as well as in human patients. Specifically, stimulation of both the trigeminal and vagus nerves has been shown in multiple clinical trials to be anticonvulsant, and stimulation of these nerves at therapeutic levels does not cause pain or negatively affect brain function. However, the neuronal mechanisms by which such stimulation exerts therapeutic effects are not well understood. In this review, the possible locations of action for trigeminal nerve stimulation (TNS) and vagus nerve stimulation (VNS) are explored. Additionally, the multiple time scales on which TNS and VNS function are discussed. PMID:23230529

  16. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee.

    PubMed

    Rossini, P M; Burke, D; Chen, R; Cohen, L G; Daskalakis, Z; Di Iorio, R; Di Lazzaro, V; Ferreri, F; Fitzgerald, P B; George, M S; Hallett, M; Lefaucheur, J P; Langguth, B; Matsumoto, H; Miniussi, C; Nitsche, M A; Pascual-Leone, A; Paulus, W; Rossi, S; Rothwell, J C; Siebner, H R; Ugawa, Y; Walsh, V; Ziemann, U

    2015-06-01

    These guidelines provide an up-date of previous IFCN report on "Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application" (Rossini et al., 1994). A new Committee, composed of international experts, some of whom were in the panel of the 1994 "Report", was selected to produce a current state-of-the-art review of non-invasive stimulation both for clinical application and research in neuroscience. Since 1994, the international scientific community has seen a rapid increase in non-invasive brain stimulation in studying cognition, brain-behavior relationship and pathophysiology of various neurologic and psychiatric disorders. New paradigms of stimulation and new techniques have been developed. Furthermore, a large number of studies and clinical trials have demonstrated potential therapeutic applications of non-invasive brain stimulation, especially for TMS. Recent guidelines can be found in the literature covering specific aspects of non-invasive brain stimulation, such as safety (Rossi et al., 2009), methodology (Groppa et al., 2012) and therapeutic applications (Lefaucheur et al., 2014). This up-dated review covers theoretical, physiological and practical aspects of non-invasive stimulation of brain, spinal cord, nerve roots and peripheral nerves in the light of more updated knowledge, and include some recent extensions and developments.

  17. Resetting voluntary movement using peripheral nerve stimulation: influence of loading conditions and relative effectiveness.

    PubMed

    Colebatch, J G; Wagener, D S

    1999-03-01

    The effect of peripheral nerve stimulation on voluntary rhythmic flexion-extension movements at the wrist was studied in nine normal volunteers, and the results compared with the effect of cortical stimulation on the same task. In the first part of the study, magnetic stimulation was given over the inner aspect of the right arm at levels which, at rest, resulted in a wrist flexion twitch of at least 10 degrees. We were able to confirm that this form of (peripheral-nerve) stimulation is an effective means of phase-resetting voluntary wrist movements. In addition, and unlike magnetic stimulation applied over the contralateral motor cortex, changes in the standing torque load, against which the subjects moved, had little influence on the effectiveness of this form of stimulation. Similarly, the amplitude and direction of the averaged first post-stimulus position peak ("P1"), previously identified as important determinants of the resetting induced by a cortical stimulus, were largely independent of the loading torque. In a second part to the study, we directly compared, for a constant loading torque, the resetting induced by magnetic cortical stimulation with that following magnetic stimulation of peripheral nerves. The relationship between the amplitude of P1 and the associated resetting index was identical for both forms of stimulation. Our observations indicate that magnetic stimulation of peripheral nerves is an effective means of resetting voluntary movement. It differs from magnetic cortical stimulation in that the effects of peripheral nerve stimulation are little altered by changes in loading torque. When differences in the size of P1 are allowed for, both peripheral nerve and cortical stimulation are equally effective means of resetting voluntary rhythmical movement.

  18. Optogenetic Stimulation of the Auditory Nerve

    PubMed Central

    Hernandez, Victor H.; Gehrt, Anna; Jing, Zhizi; Hoch, Gerhard; Jeschke, Marcus; Strenzke, Nicola; Moser, Tobias

    2014-01-01

    Direct electrical stimulation of spiral ganglion neurons (SGNs) by cochlear implants (CIs) enables open speech comprehension in the majority of implanted deaf subjects1-6. Nonetheless, sound coding with current CIs has poor frequency and intensity resolution due to broad current spread from each electrode contact activating a large number of SGNs along the tonotopic axis of the cochlea7-9. Optical stimulation is proposed as an alternative to electrical stimulation that promises spatially more confined activation of SGNs and, hence, higher frequency resolution of coding. In recent years, direct infrared illumination of the cochlea has been used to evoke responses in the auditory nerve10. Nevertheless it requires higher energies than electrical stimulation10,11 and uncertainty remains as to the underlying mechanism12. Here we describe a method based on optogenetics to stimulate SGNs with low intensity blue light, using transgenic mice with neuronal expression of channelrhodopsin 2 (ChR2)13 or virus-mediated expression of the ChR2-variant CatCh14. We used micro-light emitting diodes (µLEDs) and fiber-coupled lasers to stimulate ChR2-expressing SGNs through a small artificial opening (cochleostomy) or the round window. We assayed the responses by scalp recordings of light-evoked potentials (optogenetic auditory brainstem response: oABR) or by microelectrode recordings from the auditory pathway and compared them with acoustic and electrical stimulation. PMID:25350571

  19. Radial plus musculocutaneous nerve stimulation for axillary block is inferior to triple nerve stimulation with 2% mepivacaine.

    PubMed

    Rodríguez, Jaime; Taboada, Manuel; Oliveira, Juan; Ulloa, Beatriz; Bascuas, Begoña; Alvarez, Julián

    2008-06-01

    To compare the extent of sensory and motor block with two different nerve stimulation techniques in axillary blocks. Prospective, randomized, investigator-blinded study. Ambulatory surgery unit of a university hospital. 60 ASA physical status I, II, and III patients undergoing surgery at or below the elbow. Patients receiving axillary block were randomized into two nerve stimulation groups with either radial plus musculocutaneous or triple nerve stimulation (radial, median, and musculocutaneous nerves). Thirty milliliters of plain 2% mepivacaine was given to all patients either in a single or fractionated dosing for radial or for radial and median nerves, according to group assignment. Five milliliters of plain 1% mepivacaine for the musculocutaneous nerve was given to all patients. Blocks were assessed at 10, 20, and 30 minutes. Rates of supplementation given as a result of insufficient surgical anesthesia were also noted. Statistically significantly higher rates of anesthesia at the cutaneous distributions of median and medial cutaneous of the arm nerves with multiple nerve stimulation at 30 minutes were found as compared with radial plus musculocutaneous nerve stimulation. The rate of supplementation was lower with multiple nerve stimulation. Radial plus musculocutaneous nerve stimulation showed lower efficacy of axillary block than did triple nerve stimulation when using 2% mepivacaine.

  20. Investigation of assumptions underlying current safety guidelines on EM-induced nerve stimulation

    NASA Astrophysics Data System (ADS)

    Neufeld, Esra; Vogiatzis Oikonomidis, Ioannis; Iacono, Maria Ida; Angelone, Leonardo M.; Kainz, Wolfgang; Kuster, Niels

    2016-06-01

    An intricate network of a variety of nerves is embedded within the complex anatomy of the human body. Although nerves are shielded from unwanted excitation, they can still be stimulated by external electromagnetic sources that induce strongly non-uniform field distributions. Current exposure safety standards designed to limit unwanted nerve stimulation are based on a series of explicit and implicit assumptions and simplifications. This paper demonstrates the applicability of functionalized anatomical phantoms with integrated coupled electromagnetic and neuronal dynamics solvers for investigating the impact of magnetic resonance exposure on nerve excitation within the full complexity of the human anatomy. The impact of neuronal dynamics models, temperature and local hot-spots, nerve trajectory and potential smoothing, anatomical inhomogeneity, and pulse duration on nerve stimulation was evaluated. As a result, multiple assumptions underlying current safety standards are questioned. It is demonstrated that coupled EM-neuronal dynamics modeling involving realistic anatomies is valuable to establish conservative safety criteria.

  1. Vagus nerve stimulation for partial seizures.

    PubMed

    Panebianco, Mariangela; Rigby, Alexandra; Weston, Jennifer; Marson, Anthony G

    2015-04-03

    Vagus nerve stimulation (VNS) is a neuromodulatory treatment that is used as an adjunctive therapy for treating people with medically refractory epilepsy. VNS consists of chronic intermittent electrical stimulation of the vagus nerve, delivered by a programmable pulse generator. The majority of people given a diagnosis of epilepsy have a good prognosis, and their seizures will be controlled by treatment with a single antiepileptic drug (AED), but up to 20%-30% of patients will develop drug-resistant epilepsy, often requiring treatment with combinations of AEDs. The aim of this systematic review was to overview the current evidence for the efficacy and tolerability of vagus nerve stimulation when used as an adjunctive treatment for people with drug-resistant partial epilepsy. This is an updated version of a Cochrane review published in Issue 7, 2010. To determine:(1) The effects on seizures of VNS compared to controls e.g. high-level stimulation compared to low-level stimulation (presumed sub-therapeutic dose); and(2) The adverse effect profile of VNS compared to controls e.g. high-level stimulation compared to low-level stimulation. We searched the Cochrane Epilepsy Group's Specialised Register (23 February 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 23 February 2015), MEDLINE (1946 to 23 February 2015), SCOPUS (1823 to 23 February 2015), ClinicalTrials.gov (23 February 2015) and ICTRP (23 February 2015). No language restrictions were imposed. The following study designs were eligible for inclusion: randomised, double-blind, parallel or crossover studies, controlled trials of VNS as add-on treatment comparing high and low stimulation paradigms (including three different stimulation paradigms - duty cycle: rapid, mid and slow) and VNS stimulation versus no stimulation or a different intervention. Eligible participants were adults or children with drug-resistant partial seizures not eligible for surgery or who failed

  2. [Localization of peripheral nerves. Success and safety with electrical nerve stimulation].

    PubMed

    Neuburger, M; Schwemmer, U; Volk, T; Gogarten, W; Kessler, P; Steinfeldt, T

    2014-05-01

    Peripheral electrical nerve stimulation is one of the standard applications in peripheral regional anesthesia in addition to the ultrasound technique. Among other findings, the visualization of needle and nerve during ultrasound-guided blockade caused a change in clinical practice of peripheral nerve stimulation in the last decade. In the present article old and new aspects of principles and clinical practice of the nerve stimulation technique are presented and summarized in a total clinical concept in order to achieve safe and successful peripheral regional anesthesia using electrical peripheral nerve stimulation.

  3. Vagus nerve stimulation in Lafora body disease☆

    PubMed Central

    Hajnsek, Sanja; Petelin Gadze, Zeljka; Borovecki, Fran; Nankovic, Sibila; Mrak, Goran; Gotovac, Kristina; Sulentic, Vlatko; Kovacevic, Ivana; Bujan Kovac, Andreja

    2013-01-01

    Introduction Lafora body disease (LBD) is a rare autosomal recessive disorder characterized by progression to inexorable dementia and frequent occipital seizures, in addition to myoclonus and generalized tonic–clonic seizures (GTCSs). It belongs to the group of progressive myoclonus epilepsies (PMEs), rare inherited neurodegenerative diseases with great clinical and genetic differences, as well as poor prognosis. Since those patients have a pharmacoresistant disease, an adjunctive treatment option is vagus nerve stimulation (VNS). To date, there are four reported cases of the utility of VNS in PME — in Unverricht–Lundborg disease (ULD), myoclonic epilepsy with ragged-red fibers (MERRF), Gaucher's disease, and in one case that remained unclassified. Case presentation A 19-year-old male patient had progressive myoclonus, GTCSs that often progressed to status epilepticus (SE), progressive cerebellar and extrapyramidal symptomatology, and dementia, and his disease was pharmacoresistant. We confirmed the diagnosis of LBD by genetic testing. After VNS implantation, in the one-year follow-up period, there was a complete reduction of GTCS and SE, significant regression of myoclonus, and moderate regression of cerebellar symptomatology. Conclusion To our knowledge, this is the first reported case of the utility of VNS in LBD. Vagus nerve stimulation therapy may be considered a treatment option for different clinical entities of PME. Further studies with a larger number of patients are needed. PMID:25667850

  4. Vagus Nerve Stimulation in Experimental Heart Failure

    PubMed Central

    Sabbah, Hani N.; Ilsar, Itamar; Zaretsky, Asaph; Rastogi, Sharad; Wang, Mengjun; Gupta, Ramesh C.

    2013-01-01

    Chronic heart failure (HF) is associated with autonomic dysregulation characterized by a sustained increase of sympathetic drive and by withdrawal of parasympathetic activity. Sympathetic overdrive and increased heart rate are predictors of poor long-term outcome in patients with HF. Considerable evidence exists that supports the use of pharmacologic agents that partially inhibit sympathetic activity as effective long-term therapy for patients with HF; the classic example is the wide use of selective and non-selective beta-adrenergic receptor blockers. In contrast, modulation of parasympathetic activation as potential therapy for HF has received only limited attention over the years given its complex cardiovascular effects. In this article, we review results of recent experimental animal studies that provide support for the possible use of electrical Vagus nerve stimulation (VNS) as a long-term therapy for the treatment of chronic HF. In addition to exploring the effects of chronic VNS on left ventricular (LV) function, the review will also address the effects of VNS on potential modifiers of the HF state that include cytokine production and nitric oxide elaboration. Finally, we will briefly review other nerve stimulation approaches also currently under investigation as potential therapeutic modalities for treating chronic HF. PMID:21128115

  5. Early experiences with tachycardia-triggered vagus nerve stimulation using the AspireSR stimulator.

    PubMed

    El Tahry, Riëm; Hirsch, Martin; Van Rijckevorsel, Kenou; Santos, Susana Ferrao; de Tourtchaninoff, Marianne; Rooijakkers, Herbert; Coenen, Volker; Schulze-Bonhage, Andreas

    2016-06-01

    Many epilepsy patients treated with vagus nerve stimulation additionally use an "on-demand" function, triggering an extra stimulation to terminate a seizure or diminish its severity. Nevertheless, a substantial number of patients are not able to actively trigger stimulations by use of a magnet, due to the absence of an aura or inability for voluntary actions in the early phase of a seizure. To address this need, a novel implantable pulse generator, the AspireSR VNS system, was developed to provide automated ictal stimulation triggered by a seizure-detecting algorithm. We report our experience with three patients in assessing the functionality of ictal stimulation, illustrating the detection system in practice. Detection of ictal tachycardia and variable additional detections of physiological tachycardia depended on the individual seizure-detecting algorithm settings.

  6. Electrical stimulation promotes regeneration of injured oculomotor nerves in dogs

    PubMed Central

    Du, Lei; Yang, Min; Wan, Liang; Wang, Xu-hui; Li, Shi-ting

    2016-01-01

    Functional recovery after oculomotor nerve injury is very poor. Electrical stimulation has been shown to promote regeneration of injured nerves. We hypothesized that electrical stimulation would improve the functional recovery of injured oculomotor nerves. Oculomotor nerve injury models were created by crushing the right oculomotor nerves of adult dogs. Stimulating electrodes were positioned in both proximal and distal locations of the lesion, and non-continuous rectangular, biphasic current pulses (0.7 V, 5 Hz) were administered 1 hour daily for 2 consecutive weeks. Analysis of the results showed that electrophysiological and morphological recovery of the injured oculomotor nerve was enhanced, indicating that electrical stimulation improved neural regeneration. Thus, this therapy has the potential to promote the recovery of oculomotor nerve dysfunction. PMID:27904500

  7. Bladder emptying by intermittent electrical stimulation of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Boggs, Joseph W.; Wenzel, Brian J.; Gustafson, Kenneth J.; Grill, Warren M.

    2006-03-01

    Persons with a suprasacral spinal cord injury cannot empty their bladder voluntarily. Bladder emptying can be restored by intermittent electrical stimulation of the sacral nerve roots (SR) to cause bladder contraction. However, this therapy requires sensory nerve transection to prevent dyssynergic contraction of the external urethral sphincter (EUS). Stimulation of the compound pudendal nerve trunk (PN) activates spinal micturition circuitry, leading to a reflex bladder contraction without a reflex EUS contraction. The present study determined if PN stimulation could produce bladder emptying without nerve transection in cats anesthetized with α-chloralose. With all nerves intact, intermittent PN stimulation emptied the bladder (64 ± 14% of initial volume, n = 37 across six cats) more effectively than either distention-evoked micturition (40 ± 19%, p < 0.001, n = 27 across six cats) or bilateral intermittent SR stimulation (25 ± 23%, p < 0.005, n = 4 across two cats). After bilateral transection of the nerves innervating the urethral sphincter, intermittent SR stimulation voided 79 ± 17% (n = 12 across three cats), comparable to clinical results obtained with SR stimulation. Voiding via intermittent PN stimulation did not increase after neurotomy (p > 0.10), indicating that PN stimulation was not limited by bladder-sphincter dyssynergia. Intermittent PN stimulation holds promise for restoring bladder emptying following spinal injury without requiring nerve transection.

  8. Knee Osteoarthritis: Does Transcutaneous Electrical Nerve Stimulation Work?

    PubMed

    Cherian, Jeffrey J; Kapadia, Bhaveen H; McElroy, Mark J; Johnson, Aaron J; Bhave, Anil; Harwin, Steven F; Mont, Michael A

    2016-01-01

    Transcutaneous electrical nerve stimulation has been proposed as a nonoperative treatment for osteoarthritis. The purpose of this study was to evaluate the outcomes of a novel transcutaneous electrical nerve stimulation device compared with those of other standard nonoperative modalities for the treatment of osteoarthritis of the knee.

  9. Neuroprotective effects of vagus nerve stimulation on traumatic brain injury.

    PubMed

    Zhou, Long; Lin, Jinhuang; Lin, Junming; Kui, Guoju; Zhang, Jianhua; Yu, Yigang

    2014-09-01

    Previous studies have shown that vagus nerve stimulation can improve the prognosis of traumatic brain injury. The aim of this study was to elucidate the mechanism of the neuroprotective effects of vagus nerve stimulation in rabbits with brain explosive injury. Rabbits with brain explosive injury received continuous stimulation (10 V, 5 Hz, 5 ms, 20 minutes) of the right cervical vagus nerve. Tumor necrosis factor-α, interleukin-1β and interleukin-10 concentrations were detected in serum and brain tissues, and water content in brain tissues was measured. Results showed that vagus nerve stimulation could reduce the degree of brain edema, decrease tumor necrosis factor-α and interleukin-1β concentrations, and increase interleukin-10 concentration after brain explosive injury in rabbits. These data suggest that vagus nerve stimulation may exert neuroprotective effects against explosive injury via regulating the expression of tumor necrosis factor-α, interleukin-1β and interleukin-10 in the serum and brain tissue.

  10. Neuroprotective effects of vagus nerve stimulation on traumatic brain injury

    PubMed Central

    Zhou, Long; Lin, Jinhuang; Lin, Junming; Kui, Guoju; Zhang, Jianhua; Yu, Yigang

    2014-01-01

    Previous studies have shown that vagus nerve stimulation can improve the prognosis of traumatic brain injury. The aim of this study was to elucidate the mechanism of the neuroprotective effects of vagus nerve stimulation in rabbits with brain explosive injury. Rabbits with brain explosive injury received continuous stimulation (10 V, 5 Hz, 5 ms, 20 minutes) of the right cervical vagus nerve. Tumor necrosis factor-α, interleukin-1β and interleukin-10 concentrations were detected in serum and brain tissues, and water content in brain tissues was measured. Results showed that vagus nerve stimulation could reduce the degree of brain edema, decrease tumor necrosis factor-α and interleukin-1β concentrations, and increase interleukin-10 concentration after brain explosive injury in rabbits. These data suggest that vagus nerve stimulation may exert neuroprotective effects against explosive injury via regulating the expression of tumor necrosis factor-α, interleukin-1β and interleukin-10 in the serum and brain tissue. PMID:25368644

  11. Heart Stimulation by Time-Varying Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Masuhiro; Andoh, Tomio; Goto, Tsuneaki; Hosono, Akihiko; Kawakami, Tadashi; Okumura, Fukuichiro; Takenaka, Toshifumi; Yamamoto, Isao

    1992-07-01

    A strong magnetic stimulator adopted for cardiac muscle was constructed with the stored energy of 50 kJ. Pulsed magnetic fields were applied to dog hearts with normal activity from outside of the body. The magnetic stimulus triggered on the T wave of the electrocardiograph caused arrhythmias in the first and second beats after the stimulus. It has been confirmed that this magnetic effect is due to a direct stimulation of cardiac muscle, not to an indirect stimulation on the vagus nerve. The threshold strength was determined for different pulse durations. The obtained strength-duration relationship is comparable to that for the electric stimulation of the dog heart.

  12. Magnetic resonance imaging of optic nerve

    PubMed Central

    Gala, Foram

    2015-01-01

    Optic nerves are the second pair of cranial nerves and are unique as they represent an extension of the central nervous system. Apart from clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging (MRI), plays an important role in the complete evaluation of optic nerve and the entire visual pathway. In this pictorial essay, the authors describe segmental anatomy of the optic nerve and review the imaging findings of various conditions affecting the optic nerves. MRI allows excellent depiction of the intricate anatomy of optic nerves due to its excellent soft tissue contrast without exposure to ionizing radiation, better delineation of the entire visual pathway, and accurate evaluation of associated intracranial pathologies. PMID:26752822

  13. Pulsed laser versus electrical energy for peripheral nerve stimulation

    PubMed Central

    Wells, Jonathon; Konrad, Peter; Kao, Chris; Jansen, E. Duco; Mahadevan-Jansen, Anita

    2010-01-01

    Transient optical neural stimulation has previously been shown to elicit highly controlled, artifact-free potentials within the nervous system in a non-contact fashion without resulting in damage to tissue. This paper presents the physiologic validity of elicited nerve and muscle potentials from pulsed laser induced stimulation of the peripheral nerve in a comparative study with the standard method of electrically evoked potentials. Herein, the fundamental physical properties underlying the two techniques are contrasted. Key laser parameters for efficient optical stimulation of the peripheral nerve are detailed. Strength response curves are shown to be linear for each stimulation modality, although fewer axons can be recruited with optically evoked potentials. Results compare the relative transient energy requirements for stimulation using each technique and demonstrate that optical methods can selectively excite functional nerve stimulation. Adjacent stimulation and recording of compound nerve potentials in their entirety from optical and electrical stimulation are presented, with optical responses shown to be free of any stimulation artifact. Thus, use of a pulsed laser exhibits some advantages when compared to standard electrical means for excitation of muscle potentials in the peripheral nerve in the research domain and possibly for clinical diagnostics in the future. PMID:17537515

  14. Laryngeal elevation by selective stimulation of the hypoglossal nerve

    NASA Astrophysics Data System (ADS)

    Hadley, Aaron J.; Kolb, Ilya; Tyler, Dustin J.

    2013-08-01

    Objective. Laryngeal elevation protects the airway and assists opening of the esophagus during swallowing. The GH, thyrohyoid, and MH muscles provide a majority of this elevatory motion. This study applied functional electrical stimulation to the XII/C1 nerve complex using a nerve cuff electrode to determine the capabilities of neural stimulation to induce laryngeal elevation. Approach. Multi-contact FINE electrodes were implanted onto the XII/C1 nerve complex at locations proximal and distal to the thyrohyoid branching point in five anesthetized canines. Motion of the thyroid cartilage and the hyoid bone was recorded during stimulation of nerve cuffs and intramuscular electrodes. Main Results. Nerve stimulation induced 260% more laryngeal elevation than intramuscular stimulation (18.8 mm versus 5.2 mm, p ≪ 0.01), and 228% higher velocity (143.8 versus 43.9 mm s-1, p ≪ 0.01). While stimulation at all cuff and electrode locations elevated the larynx, only the proximal XII/C1 nerve cuff significantly elicited both thyroid-hyoid approximation and hyoid elevation. In all proximal XII/C1 nerve cuffs (n = 7), stimulation was able to obtain selectivity of greater than 75% of at least one elevatory muscle. Significance. These results support the hypothesis that an implanted neural interface system can produce increased laryngeal elevation, a significant protective mechanism of deglutition.

  15. Differential fiber-specific block of nerve conduction in mammalian peripheral nerves using kilohertz electrical stimulation.

    PubMed

    Patel, Yogi A; Butera, Robert J

    2015-06-01

    Kilohertz electrical stimulation (KES) has been shown to induce repeatable and reversible nerve conduction block in animal models. In this study, we characterized the ability of KES stimuli to selectively block specific components of stimulated nerve activity using in vivo preparations of the rat sciatic and vagus nerves. KES stimuli in the frequency range of 5-70 kHz and amplitudes of 0.1-3.0 mA were applied. Compound action potentials were evoked using either electrical or sensory stimulation, and block of components was assessed through direct nerve recordings and muscle force measurements. Distinct observable components of the compound action potential had unique conduction block thresholds as a function of frequency of KES. The fast component, which includes motor activity, had a monotonically increasing block threshold as a function of the KES frequency. The slow component, which includes sensory activity, showed a nonmonotonic block threshold relationship with increasing KES frequency. The distinct trends with frequency of the two components enabled selective block of one component with an appropriate choice of frequency and amplitude. These trends in threshold of the two components were similar when studying electrical stimulation and responses of the sciatic nerve, electrical stimulation and responses of the vagus nerve, and sensorimotor stimulation and responses of the sciatic nerve. This differential blocking effect of KES on specific fibers can extend the applications of KES conduction block to selective block and stimulation of neural signals for neuromodulation as well as selective control of neural circuits underlying sensorimotor function.

  16. The management of overactive bladder: percutaneous tibial nerve stimulation, sacral nerve stimulation, or botulinum toxin?

    PubMed

    Tubaro, Andrea; Puccini, Federica; De Nunzio, Cosimo

    2015-07-01

    We have reviewed the evidence published on botulinum toxin A (BoNT/A), percutaneous tibial nerve stimulation (PTNS), and sacral nerve stimulation (SNS) in the management of overactive bladder (OAB). BoNT/A is effective irrespectively of the number of previous anticholinergic treatments and of the reason for failure. Doses up to 360U 3-monthly are well tolerated. BoNT/A is well tolerated and effective also in the pediatric population. Bladder instillation of liposome encapsulated BoNT/A is a new approach, deserving further research. When using PTNS, motor response from the electrical stimulus is not required, a sensory response suffices. PTNS has a lasting effect compared to oxybutynin alone. SNS is superior to standard medical treatment but the combination of SNS and anticholinergics is more effective than anticholinergic alone. The evidence published in the last 18 months has increased the level of evidence on safety and effectiveness of BoNT/A, PTNS, and SNS in the management of OAB. BoNT/A is now recommended as standard third-line treatment for OAB (in the USA) and urgency incontinence (in the USA and in Europe) in selected patients refractory to pharmacological therapy. All available third-line treatment options for OAB/urgency urinary incontinence should be offered before surgery is contemplated. http://links.lww.com/COU/A7.

  17. Stimulation of the human auditory nerve with optical radiation

    NASA Astrophysics Data System (ADS)

    Fishman, Andrew; Winkler, Piotr; Mierzwinski, Jozef; Beuth, Wojciech; Izzo Matic, Agnella; Siedlecki, Zygmunt; Teudt, Ingo; Maier, Hannes; Richter, Claus-Peter

    2009-02-01

    A novel, spatially selective method to stimulate cranial nerves has been proposed: contact free stimulation with optical radiation. The radiation source is an infrared pulsed laser. The Case Report is the first report ever that shows that optical stimulation of the auditory nerve is possible in the human. The ethical approach to conduct any measurements or tests in humans requires efficacy and safety studies in animals, which have been conducted in gerbils. This report represents the first step in a translational research project to initiate a paradigm shift in neural interfaces. A patient was selected who required surgical removal of a large meningioma angiomatum WHO I by a planned transcochlear approach. Prior to cochlear ablation by drilling and subsequent tumor resection, the cochlear nerve was stimulated with a pulsed infrared laser at low radiation energies. Stimulation with optical radiation evoked compound action potentials from the human auditory nerve. Stimulation of the auditory nerve with infrared laser pulses is possible in the human inner ear. The finding is an important step for translating results from animal experiments to human and furthers the development of a novel interface that uses optical radiation to stimulate neurons. Additional measurements are required to optimize the stimulation parameters.

  18. Magnetically stimulated fluid flow patterns

    ScienceCinema

    Martin, Jim; Solis, Kyle

    2016-07-12

    Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

  19. Magnetically stimulated fluid flow patterns

    SciTech Connect

    Martin, Jim; Solis, Kyle

    2014-03-06

    Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

  20. Optical stimulation of the facial nerve: a surgical tool?

    NASA Astrophysics Data System (ADS)

    Richter, Claus-Peter; Teudt, Ingo Ulrik; Nevel, Adam E.; Izzo, Agnella D.; Walsh, Joseph T., Jr.

    2008-02-01

    One sequela of skull base surgery is the iatrogenic damage to cranial nerves. Devices that stimulate nerves with electric current can assist in the nerve identification. Contemporary devices have two main limitations: (1) the physical contact of the stimulating electrode and (2) the spread of the current through the tissue. In contrast to electrical stimulation, pulsed infrared optical radiation can be used to safely and selectively stimulate neural tissue. Stimulation and screening of the nerve is possible without making physical contact. The gerbil facial nerve was irradiated with 250-μs-long pulses of 2.12 μm radiation delivered via a 600-μm-diameter optical fiber at a repetition rate of 2 Hz. Muscle action potentials were recorded with intradermal electrodes. Nerve samples were examined for possible tissue damage. Eight facial nerves were stimulated with radiant exposures between 0.71-1.77 J/cm2, resulting in compound muscle action potentials (CmAPs) that were simultaneously measured at the m. orbicularis oculi, m. levator nasolabialis, and m. orbicularis oris. Resulting CmAP amplitudes were 0.3-0.4 mV, 0.15-1.4 mV and 0.3-2.3 mV, respectively, depending on the radial location of the optical fiber and the radiant exposure. Individual nerve branches were also stimulated, resulting in CmAP amplitudes between 0.2 and 1.6 mV. Histology revealed tissue damage at radiant exposures of 2.2 J/cm2, but no apparent damage at radiant exposures of 2.0 J/cm2.

  1. Functional MRI detection of hemodynamic response of repeated median nerve stimulation.

    PubMed

    Ai, Leo; Oya, Hiroyuki; Howard, Matthew; Xiong, Jinhu

    2013-05-01

    Median nerve stimulation is a commonly used technique in the clinical setting to determine areas of neuronal function in the brain. Neuronal activity of repeated median nerve stimulation is well studied. The cerebral hemodynamic response of the stimulation, on the other hand, is not very clear. In this study, we investigate how cerebral hemodynamics behave over time using the same repeated median nerve stimulation. Ten subjects received constant repeated electrical stimulation to the right median nerve. Each subject had functional magnetic resonance imaging scans while receiving said stimulations for seven runs. Our results show that the blood oxygen level-dependent (BOLD) signal significantly decreases across each run. Significant BOLD signal decreases can also be seen within runs. These results are consistent with studies that have studied the hemodynamic habituation effect with other forms of stimulation. However, the results do not completely agree with the findings of studies where evoked potentials were examined. Thus, further inquiry of how evoked potentials and cerebral hemodynamics are coupled when using constant stimulations is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Assessment of motor pathways by magnetic stimulation in human and veterinary medicine.

    PubMed

    Van Soens, Iris; Van Ham, Luc M

    2011-02-01

    Magnetic stimulation is a non-invasive and painless technique for studying the motor pathways in medical neurology. A time-varying magnetic field induces an electrical field in conducting objects, such as nervous tissue. The technique can be applied to nerve roots and peripheral nerves or to the motor cortex of the brain in human and veterinary medicine. In this review, the basic principles, applications and risk factors of peripheral nerve and motor cortex stimulation in human and veterinary medicine are discussed.

  3. Presacral abscess as a rare complication of sacral nerve stimulator implantation.

    PubMed

    Gumber, A; Ayyar, S; Varia, H; Pettit, S

    2017-03-01

    A 50-year-old man with intractable anal pain attributed to proctalgia fugax underwent insertion of a sacral nerve stimulator via the right S3 vertebral foramen for pain control with good symptomatic relief. Thirteen months later, he presented with signs of sepsis. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large presacral abscess. MRI demonstrated increased enhancement along the pathway of the stimulator electrode, indicating that the abscess was caused by infection introduced at the time of sacral nerve stimulator placement. The patient was treated with broad spectrum antibiotics, and the sacral nerve stimulator and electrode were removed. Attempts were made to drain the abscess transrectally using minimally invasive techniques but these were unsuccessful and CT guided transperineal drainage was then performed. Despite this, the presacral abscess progressed, developing enlarging gas locules and extending to the pelvic brim to involve the aortic bifurcation, causing hydronephrosis and radiological signs of impending sacral osteomyelitis. MRI showed communication between the rectum and abscess resulting from transrectal drainage. In view of the progressive presacral sepsis, a laparotomy was performed with drainage of the abscess, closure of the upper rectum and formation of a defunctioning end sigmoid colostomy. Following this, the presacral infection resolved. Presacral abscess formation secondary to an infected sacral nerve stimulator electrode has not been reported previously. Our experience suggests that in a similar situation, the optimal management is to perform laparotomy with drainage of the presacral abscess together with simultaneous removal of the sacral nerve stimulator and electrode.

  4. Motor Neuron Activation in Peripheral Nerves Using Infrared Neural Stimulation

    PubMed Central

    Peterson, EJ; Tyler, DJ

    2014-01-01

    Objective Localized activation of peripheral axons may improve selectivity of peripheral nerve interfaces. Infrared neural stimulation (INS) employs localized delivery to activate neural tissue. This study investigated INS to determine whether localized delivery limited functionality in larger mammalian nerves. Approach The rabbit sciatic nerve was stimulated extraneurally with 1875 nm-wavelength infrared light, electrical stimulation, or a combination of both. Infrared-sensitive regions (ISR) of the nerve surface and electromyogram (EMG) recruitment of the Medial Gastrocnemius, Lateral Gastrocnemius, Soleus, and Tibialis Anterior were the primary output measures. Stimulation applied included infrared-only, electrical-only, and combined infrared and electrical. Main results 81% of nerves tested were sensitive to INS, with 1.7± 0.5 ISR detected per nerve. INS was selective to a single muscle within 81% of identified ISR. Activation energy threshold did not change significantly with stimulus power, but motor activation decreased significantly when radiant power was decreased. Maximum INS levels typically recruited up to 2–9% of any muscle. Combined infrared and electrical stimulation differed significantly from electrical recruitment in 7% of cases. Significance The observed selectivity of INS indicates it may be useful in augmenting rehabilitation, but significant challenges remain in increasing sensitivity and response magnitude to improve the functionality of INS. PMID:24310923

  5. Motor neuron activation in peripheral nerves using infrared neural stimulation

    NASA Astrophysics Data System (ADS)

    Peterson, E. J.; Tyler, D. J.

    2014-02-01

    Objective. Localized activation of peripheral axons may improve selectivity of peripheral nerve interfaces. Infrared neural stimulation (INS) employs localized delivery to activate neural tissue. This study investigated INS to determine whether localized delivery limited functionality in larger mammalian nerves. Approach. The rabbit sciatic nerve was stimulated extraneurally with 1875 nm wavelength infrared light, electrical stimulation, or a combination of both. Infrared-sensitive regions (ISR) of the nerve surface and electromyogram (EMG) recruitment of the Medial Gastrocnemius, Lateral Gastrocnemius, Soleus, and Tibialis Anterior were the primary output measures. Stimulation applied included infrared-only, electrical-only, and combined infrared and electrical. Main results. 81% of nerves tested were sensitive to INS, with 1.7 ± 0.5 ISR detected per nerve. INS was selective to a single muscle within 81% of identified ISR. Activation energy threshold did not change significantly with stimulus power, but motor activation decreased significantly when radiant power was decreased. Maximum INS levels typically recruited up to 2-9% of any muscle. Combined infrared and electrical stimulation differed significantly from electrical recruitment in 7% of cases. Significance. The observed selectivity of INS indicates that it may be useful in augmenting rehabilitation, but significant challenges remain in increasing sensitivity and response magnitude to improve the functionality of INS.

  6. Modulation of brain dead induced inflammation by vagus nerve stimulation.

    PubMed

    Hoeger, S; Bergstraesser, C; Selhorst, J; Fontana, J; Birck, R; Waldherr, R; Beck, G; Sticht, C; Seelen, M A; van Son, W J; Leuvenink, H; Ploeg, R; Schnuelle, P; Yard, B A

    2010-03-01

    Because the vagus nerve is implicated in control of inflammation, we investigated if brain death (BD) causes impairment of the parasympathetic nervous system, thereby contributing to inflammation. BD was induced in rats. Anaesthetised ventilated rats (NBD) served as control. Heart rate variability (HRV) was assessed by ECG. The vagus nerve was electrically stimulated (BD + STIM) during BD. Intestine, kidney, heart and liver were recovered after 6 hours. Affymetrix chip-analysis was performed on intestinal RNA. Quantitative PCR was performed on all organs. Serum was collected to assess TNFalpha concentrations. Renal transplantations were performed to address the influence of vagus nerve stimulation on graft outcome. HRV was significantly lower in BD animals. Vagus nerve stimulation inhibited the increase in serum TNFalpha concentrations and resulted in down-regulation of a multiplicity of pro-inflammatory genes in intestinal tissue. In renal tissue vagal stimulation significantly decreased the expression of E-selectin, IL1beta and ITGA6. Renal function was significantly better in recipients that received a graft from a BD + STIM donor. Our study demonstrates impairment of the parasympathetic nervous system during BD and inhibition of serum TNFalpha through vagal stimulation. Vagus nerve stimulation variably affected gene expression in donor organs and improved renal function in recipients.

  7. Occipital nerve stimulation: technical and surgical aspects of implantation.

    PubMed

    Trentman, Terrence L; Zimmerman, Richard S

    2008-02-01

    The objective of this article is to review the surgical aspects of occipital stimulation. Since 1999 there has been a growing interest in neuromodulation of the distal branches of C2-3 in an effort to treat refractory headache disorders. This is accomplished via implantation of subcutaneous electrodes to stimulate peripheral nerves in the occipital region. "Occipital nerve stimulation" is a term generically used to describe the technique. Mechanisms and outcome of this modality are beyond the scope of this review, which will focus on the technical aspects of the procedure with its associated complications such as lead migration, localized pain, and infection. The history of peripheral nerve and spinal cord stimulation as pain treatment modalities will be briefly reviewed. The equipment and surgical technique for both trial and permanent implantation of occipital nerve stimulators will be described, in addition to patient selection considerations. The available literature will be summarized and a discussion of future directions will be provided. Occipital nerve stimulation may be an effective minimally invasive treatment modality for refractory headache disorders; clearly, further studies are needed.

  8. Glucagon Release Induced by Pancreatic Nerve Stimulation in the Dog

    PubMed Central

    Marliss, Errol B.; Girardier, Lucien; Seydoux, Josiane; Wollheim, Claes B.; Kanazawa, Yasunori; Orci, Lelio; Renold, Albert E.; Porte, Daniel

    1973-01-01

    A direct neural role in the regulation of immunoreactive glucagon (IRG) secretion has been investigated during stimulation of mixed autonomic nerves to the pancreas in anesthetized dogs. The responses were evaluated by measurement of blood flow and hormone concentration in the venous effluent from the stimulated region of pancreas. Electrical stimulation of the distal end of the discrete bundles of nerve fibers isolated along the superior pancreaticoduodenal artery was invariably followed by an increase in IRG output. With 10-min periods of nerve stimulation, the integrated response showed that the higher the control glucagon output, the greater was the increment. Atropinization did not influence the response to stimulation. That the preparation behaved in physiologic fashion was confirmed by a fall in IRG output, and a rise in immunoreactive insulin (IRI) output, during hyperglycemia induced by intravenous glucose (0.1 g/kg). The kinetics of this glucose effect on IRG showed characteristics opposite to those of nerve stimulation: the lower the control output, the less the decrement. Furthermore, during the control steady state, blood glucose concentration was tightly correlated with the IRI/IRG molar output ratio, the function relating the two parameters being markedly nonlinear. Injection or primed infusion of glucose diminished the IRG response to simultaneous nerve stimulation. Measurement of IRG was inferred to reflect response of pancreatic glucagon secretion on the basis of the site of sample collection (the superior pancreaticoduodenal vein), the absence of changes in arterial IRG, and similar responses being obtained using an antibody specific for pancreatic glucagon. These studies support a role for the autonomic nervous system in the control of glucagon secretion: direct nerve stimulation induces glucagon release. Such sympathetic activation may be interpreted as capable of shifting the sensitivity of the A cell to glucose in the direction of higher

  9. Current threshold for nerve stimulation depends on electrical impedance of the tissue: a study of ultrasound-guided electrical nerve stimulation of the median nerve.

    PubMed

    Sauter, Axel R; Dodgson, Michael S; Kalvøy, Håvard; Grimnes, Sverre; Stubhaug, Audun; Klaastad, Oivind

    2009-04-01

    Understanding the mechanisms causing variation in current thresholds for electrical nerve stimulation may improve the safety and success rate of peripheral nerve blocks. Electrical impedance of the tissue surrounding a nerve may affect the response to nerve stimulation. In this volunteer study, we investigated the relationship between impedance and current threshold needed to obtain a neuromuscular response. Electrical nerve stimulation and impedance measurements were performed for the median nerve in the axilla and at the elbow in 29 volunteers. The needletip was positioned at a distance of 5, 2.5, and 0 mm from the nerve as judged by ultrasound. Impulse widths of 0.1 and 0.3 ms were used for nerve stimulation. A significant inverse relationship between impedance and current threshold was found at the elbow, at nerve-to-needle distances of 5 and 2.5 mm (P = 0.001 and P = 0.036). Impedance values were significantly lower in the axilla (mean 21.1, sd 9.7 kohm) than at the elbow (mean 36.6, sd 13.4 kohm) (P < 0.001). Conversely, current thresholds for nerve stimulation were significantly higher in the axilla than at the elbow (P < 0.001, P < 0.001, P = 0.024). A mean ratio of 1.82 was found for the measurements of current thresholds with 0.1 versus 0.3 ms impulse duration. Our results demonstrate an inverse relationship between impedance measurements and current thresholds and suggest that current settings used for nerve stimulation may require adjustment based on the tissue type. Further studies should be performed to investigate the clinical impact of our findings.

  10. Diabetic neuropathy increases stimulation threshold during popliteal sciatic nerve block†

    PubMed Central

    Heschl, S.; Hallmann, B.; Zilke, T.; Gemes, G.; Schoerghuber, M.; Auer-Grumbach, M.; Quehenberger, F.; Lirk, P.; Hogan, Q.; Rigaud, M.

    2016-01-01

    Background Peripheral nerve stimulation is commonly used for nerve localization in regional anaesthesia, but recommended stimulation currents of 0.3–0.5 mA do not reliably produce motor activity in the absence of intraneural needle placement. As this may be particularly true in patients with diabetic neuropathy, we examined the stimulation threshold in patients with and without diabetes. Methods Preoperative evaluation included a neurological exam and electroneurography. During ultrasound-guided popliteal sciatic nerve block, we measured the current required to produce motor activity for the tibial and common peroneal nerve in diabetic and non-diabetic patients. Proximity to the nerve was evaluated post-hoc using ultrasound imaging. Results Average stimulation currents did not differ between diabetic (n=55) and non-diabetic patients (n=52). Although the planned number of patients was not reached, the power goal for the mean stimulation current was met. Subjects with diminished pressure perception showed increased thresholds for the common peroneal nerve (median 1.30 vs. 0.57 mA in subjects with normal perception, P=0.042), as did subjects with decreased pain sensation (1.60 vs. 0.50 mA in subjects with normal sensation, P=0.038). Slowed ulnar nerve conduction velocity predicted elevated mean stimulation current (r=−0.35, P=0.002). Finally, 15 diabetic patients required more than 0.5 mA to evoke a motor response, despite intraneural needle placement (n=4), or required currents ≥2 mA despite needle-nerve contact, vs three such patients (1 intraneural, 2 with ≥2 mA) among non-diabetic patients (P=0.003). Conclusions These findings suggest that stimulation thresholds of 0.3–0.5 mA may not reliably determine close needle-nerve contact during popliteal sciatic nerve block, particularly in patients with diabetic neuropathy. Clinical trial registration NCT01488474 PMID:26994231

  11. Diabetic neuropathy increases stimulation threshold during popliteal sciatic nerve block.

    PubMed

    Heschl, S; Hallmann, B; Zilke, T; Gemes, G; Schoerghuber, M; Auer-Grumbach, M; Quehenberger, F; Lirk, P; Hogan, Q; Rigaud, M

    2016-04-01

    Peripheral nerve stimulation is commonly used for nerve localization in regional anaesthesia, but recommended stimulation currents of 0.3-0.5 mA do not reliably produce motor activity in the absence of intraneural needle placement. As this may be particularly true in patients with diabetic neuropathy, we examined the stimulation threshold in patients with and without diabetes. Preoperative evaluation included a neurological exam and electroneurography. During ultrasound-guided popliteal sciatic nerve block, we measured the current required to produce motor activity for the tibial and common peroneal nerve in diabetic and non-diabetic patients. Proximity to the nerve was evaluated post-hoc using ultrasound imaging. Average stimulation currents did not differ between diabetic (n=55) and non-diabetic patients (n=52). Although the planned number of patients was not reached, the power goal for the mean stimulation current was met. Subjects with diminished pressure perception showed increased thresholds for the common peroneal nerve (median 1.30 vs. 0.57 mA in subjects with normal perception, P=0.042), as did subjects with decreased pain sensation (1.60 vs. 0.50 mA in subjects with normal sensation, P=0.038). Slowed ulnar nerve conduction velocity predicted elevated mean stimulation current (r=-0.35, P=0.002). Finally, 15 diabetic patients required more than 0.5 mA to evoke a motor response, despite intraneural needle placement (n=4), or required currents ≥2 mA despite needle-nerve contact, vs three such patients (1 intraneural, 2 with ≥2 mA) among non-diabetic patients (P=0.003). These findings suggest that stimulation thresholds of 0.3-0.5 mA may not reliably determine close needle-nerve contact during popliteal sciatic nerve block, particularly in patients with diabetic neuropathy. NCT01488474. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia.

  12. Magnetic Stimulation and Epilepsy

    DTIC Science & Technology

    2013-10-14

    the seizure-induced groups exhibited varying degrees of EEG activity reduction. Figure 2. The effects of TMS on penicillin-induced seizures...the EEG recording including (a) baseline (pre-penicillin injection), (b) 30-min post-penicillin injection (30min-PI), (c) 10-min post- TMS stimulation...stable conditions 55% faster, and the 5 pps TMS -treated group 78% faster. Figure 3. Maximum frequency relationships in EEG activity among the

  13. Histological Consequences of Needle-Nerve Contact following Nerve Stimulation in a Pig Model

    PubMed Central

    Steinfeldt, T.; Graf, J.; Schneider, J.; Nimphius, W.; Weihe, E.; Borgeat, A.; Wulf, H.; Wiesmann, T.

    2011-01-01

    Background. Nerve stimulation can facilitate correct needle placement in peripheral regional anesthesia. The aim of this study was to determine whether the high threshold current is associated with reduced nerve injury due to fewer needle-nerve contacts compared with low current. Methods. In anaesthetized pigs, thirty-two nerves of the brachial plexus underwent needle placement at low (0.2 mA) or high current (1.0 mA). The occurrence of needle-nerve contact was recorded. After 48 hours, the nerves were analyzed for occurrence of histological changes. Nerve injury was scored ranging from 0 (no injury) to 4 (severe injury). Results. The frequency of needle-nerve contact was 94% at low compared to 6% at high current. The score was significantly higher at low (median [interquartile range] 2.0 [1.0-2.0]) compared to high current (0.0 [0.0-1.0] P = .001). Conclusions. Inflammatory responses were directly related to needle-nerve contacts. Hence, posttraumatic inflammation may be diminished using higher current for nerve localization. PMID:21716736

  14. Respiratory motor responses to cranial nerve afferent stimulation in rats.

    PubMed

    Hayashi, F; McCrimmon, D R

    1996-10-01

    It was hypothesized that, because rats appear to lack a prominent disynaptic projection from the dorsal respiratory group to phrenic motoneurons (Phr), they would lack the short-latency excitation of Phr output seen in cats in response to stimulation of some cranial nerve afferents. Single-pulse superior laryngeal nerve (SLN) stimulation elicited a short-latency bilateral excitation of glossopharyngeal (IX) and hypoglossal (XII) nerves and an ipsilateral excitation of pharyngeal branch of vagus (PhX) in 67% of rats, but no excitation of Phr. Vagus (X) stimulation elicited a bilateral excitation of Phr and a predominantly ipsilateral excitation of IX and PhX. Single-pulse stimulation of SLN or X also elicited longer-latency, bilateral decreases in activity of all recorded nerves. Repetitive stimulation (50 Hz) of SLN or X suppressed inspiratory activity and prolonged expiration. Lung inflation (7.5 cmH2O) inhibited Phr and PhX activity; X stimulation inhibited Phr but prolonged PhX activity. In conclusion, rats predictably lack the SLN-induced short latency Phr excitation but exhibit other short latency reflexes for which the underlying circuitry is not clear.

  15. Edema and pain reduction using transcutaneous electrical nerve stimulation treatment

    PubMed Central

    Choi, Yeong-Deok; Lee, Jung-Ho

    2016-01-01

    [Purpose] The purpose of this study was to investigate the impact on the edema and pain when applying transcutaneous electrical nerve stimulation. [Subjects and Methods] Eleven patients who were diagnosed with lymphedema were selected as the subjects of the study. The experimental group received transcutaneous electrical nerve stimulation treatment on edema regions three times per week for four weeks. Surface tape measurement was used to measure changes in lower extremity edema. Pain intensity was measured using the visual analog scale. [Results] The edema decrements in the experimental group were significantly larger than those in the control group. The pain decrements in the experimental group were significantly larger than those in the control group. [Conclusion] In conclusion, application of transcutaneous electrical nerve stimulation was confirmed to be effective in reducing edema and pain. PMID:27942125

  16. Percutaneous tibial nerve stimulation and sacral neuromodulation: an update.

    PubMed

    Gupta, Priyanka; Ehlert, Michael J; Sirls, Larry T; Peters, Kenneth M

    2015-02-01

    Neuromodulation is an important treatment modality for a variety of pelvic floor disorders. Percutaneous tibial nerve stimulation (PTNS) and sacral neuromodulation (SNM) are currently the two approved methods for delivering this therapy. Percutaneous tibial nerve stimulation is a minimally invasive office-based procedure that has shown efficacy in the treatment of overactive bladder, fecal incontinence, and pelvic pain. It has the advantage of minimal side effects but is limited by the need for patients to make weekly office visits to receive the series of treatments. Sacral neuromodulation uses an implanted device that stimulates the S3 nerve root and can improve symptoms of overactive bladder, non-obstructive urinary retention, fecal incontinence, and pelvic pain. This paper will review the most recent literature regarding this topic and discuss their advantages and limitations and recent innovations in their use.

  17. Vagus nerve stimulation for the treatment of intractable epilepsy.

    PubMed

    Amar, Arun Paul

    2007-12-01

    Vagus nerve stimulation is a safe and reliable treatment adjunct for patients with medically intractable epilepsy. It is both a preventive and abortive form of therapy, potentially effective against both partial and generalized seizures in adults and children. Vagus nerve stimulation also has a number of serendipitous effects on mood, memory and attention, and has been approved for the treatment of refractory depression. Owing to its pleiotropic effects, it also holds promise for several other diseases. Its principal limitations are its unknown mechanism of action, the low likelihood of complete cure and the inability to predict which patients will derive substantial benefit. This article reviews the theoretical rationale, practical background and clinical applications of vagus nerve stimulation therapy.

  18. Vestibular stimulation by magnetic fields

    PubMed Central

    Ward, Bryan K.; Roberts, Dale C.; Della Santina, Charles C.; Carey, John P.; Zee, David S.

    2015-01-01

    Individuals working next to strong static magnetic fields occasionally report disorientation and vertigo. With the increasing strength of magnetic fields used for magnetic resonance imaging (MRI) studies, these reports have become more common. It was recently learned that humans, mice and zebrafish all demonstrate behaviors consistent with constant peripheral vestibular stimulation while inside a strong, static magnetic field. The proposed mechanism for this effect involves a Lorentz force resulting from the interaction of a strong static magnetic field with naturally occurring ionic currents flowing through the inner ear endolymph into vestibular hair cells. The resulting force within the endolymph is strong enough to displace the lateral semicircular canal cupula, inducing vertigo and the horizontal nystagmus seen in normal mice and in humans. This review explores the evidence for interactions of magnetic fields with the vestibular system. PMID:25735662

  19. Stimulating parameters and de-synchronization in vagus nerve stimulation therapy for epilepsy

    NASA Astrophysics Data System (ADS)

    Li, Y.-L.; Chen, Z.-Y.; Ma, J.; Feng, W.-J.

    2008-02-01

    The influence of the stimulation parameters on the de-synchronization of small world Hindmarsh-Rose (H-R) neural network is numerically investigated in the vagus nerve stimulation therapy for epilepsy. The simulation shows that synchronization evolves into de-synchronization when a part of neurons (about 10 percent) is stimulated with a pulse current signal. The network de-synchronization appears to be sensitive to the stimulation parameters. For the case of the same stimulation intensity, those weakly coupled networks reach de-synchronization more easily than strongly coupled networks. There exist an optimal stimulation interval and period of continuous stimulation time when other stimulation parameters remain invariable.

  20. Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation.

    PubMed

    Rozand, Vianney; Grosprêtre, Sidney; Stapley, Paul J; Lepers, Romuald

    2015-09-13

    Percutaneous electrical nerve stimulation is a non-invasive method commonly used to evaluate neuromuscular function from brain to muscle (supra-spinal, spinal and peripheral levels). The present protocol describes how this method can be used to stimulate the posterior tibial nerve that activates plantar flexor muscles. Percutaneous electrical nerve stimulation consists of inducing an electrical stimulus to a motor nerve to evoke a muscular response. Direct (M-wave) and/or indirect (H-reflex) electrophysiological responses can be recorded at rest using surface electromyography. Mechanical (twitch torque) responses can be quantified with a force/torque ergometer. M-wave and twitch torque reflect neuromuscular transmission and excitation-contraction coupling, whereas H-reflex provides an index of spinal excitability. EMG activity and mechanical (superimposed twitch) responses can also be recorded during maximal voluntary contractions to evaluate voluntary activation level. Percutaneous nerve stimulation provides an assessment of neuromuscular function in humans, and is highly beneficial especially for studies evaluating neuromuscular plasticity following acute (fatigue) or chronic (training/detraining) exercise.

  1. Patterned sensory nerve stimulation enhances the reactivity of spinal Ia inhibitory interneurons.

    PubMed

    Kubota, Shinji; Hirano, Masato; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

    2015-03-25

    Patterned sensory nerve stimulation has been shown to induce plastic changes in the reciprocal Ia inhibitory circuit. However, the mechanisms underlying these changes have not yet been elucidated in detail. The aim of the present study was to determine whether the reactivity of Ia inhibitory interneurons could be altered by patterned sensory nerve stimulation. The degree of reciprocal Ia inhibition, the conditioning effects of transcranial magnetic stimulation (TMS) on the soleus (SOL) muscle H-reflex, and the ratio of the maximum H-reflex amplitude versus maximum M-wave (H(max)/M(max)) were examined in 10 healthy individuals. Patterned electrical nerve stimulation was applied to the common peroneal nerve every 1 s (100 Hz-5 train) at the motor threshold intensity of tibialis anterior muscle to induce activity changes in the reciprocal Ia inhibitory circuit. Reciprocal Ia inhibition, the TMS-conditioned H-reflex amplitude, and H(max)/M(max) were recorded before, immediately after, and 15 min after the electrical stimulation. The patterned electrical nerve stimulation significantly increased the degree of reciprocal Ia inhibition and decreased the amplitude of the TMS-conditioned H-reflex in the short-latency inhibition phase, which was presumably mediated by Ia inhibitory interneurons. However, it had no effect on H(max)/M(max). Our results indicated that patterned sensory nerve stimulation could modulate the activity of Ia inhibitory interneurons, and this change may have been caused by the synaptic modification of Ia inhibitory interneuron terminals. These results may lead to a clearer understanding of the spinal cord synaptic plasticity produced by repetitive sensory inputs.

  2. Peripheral Nerve Regeneration Strategies: Electrically Stimulating Polymer Based Nerve Growth Conduits

    PubMed Central

    Anderson, Matthew; Shelke, Namdev B.; Manoukian, Ohan S.; Yu, Xiaojun; McCullough, Louise D.; Kumbar, Sangamesh G.

    2017-01-01

    Treatment of large peripheral nerve damages ranges from the use of an autologous nerve graft to a synthetic nerve growth conduit. Biological grafts, in spite of many merits, show several limitations in terms of availability and donor site morbidity, and outcomes are suboptimal due to fascicle mismatch, scarring, and fibrosis. Tissue engineered nerve graft substitutes utilize polymeric conduits in conjunction with cues both chemical and physical, cells alone and or in combination. The chemical and physical cues delivered through polymeric conduits play an important role and drive tissue regeneration. Electrical stimulation (ES) has been applied toward the repair and regeneration of various tissues such as muscle, tendon, nerve, and articular tissue both in laboratory and clinical settings. The underlying mechanisms that regulate cellular activities such as cell adhesion, proliferation, cell migration, protein production, and tissue regeneration following ES is not fully understood. Polymeric constructs that can carry the electrical stimulation along the length of the scaffold have been developed and characterized for possible nerve regeneration applications. We discuss the use of electrically conductive polymers and associated cell interaction, biocompatibility, tissue regeneration, and recent basic research for nerve regeneration. In conclusion, a multifunctional combinatorial device comprised of biomaterial, structural, functional, cellular, and molecular aspects may be the best way forward for effective peripheral nerve regeneration. PMID:27278739

  3. [Application of sacral nerve stimulation in patients with fecal incontinence].

    PubMed

    Ye, Yingjiang; Shen, Zhanlong; Wang, Shan

    2014-03-01

    Fecal incontinence is one of diseases effecting the quality of life and mental health. Germany surgeon used sacral nerve stimulation(SNS) to treat fecal incontinence at first in 1995. The aim of SNS is to mobilize the ability to control the feces through stimulating the nerves of dominating the sphincter muscles and pelvic floor muscles. Standard SNS includes two stages: evaluation stage of SNS and permanent implantation stage. Preoperative evaluation plays important role in guaranteeing the success of treatment. SNS is the primary treatment of choice for severe fecal incontinence. The complications of SNS include pain, shift of electronic probe, wound dehiscence, bowel dysfunction and infection.

  4. Effect of vagus nerve stimulation on thermal injury in rats.

    PubMed

    Song, Xue-Min; Li, Jian-Guo; Wang, Yan-Lin; Liang, Hui; Huang, Yue; Yuan, Xiang; Zhou, Qing; Zhang, Zong-Ze

    2010-02-01

    To investigate the effects of vagus nerve stimulation on haemodynamics, pulmonary histopathology, arterial blood gas and pro-inflammatory responses to thermal injury. Forty-eight male Sprague-Dawley (SD) rats were randomly divided into six equal groups: normal control (NC) group; thermal injury (TEM) group subjected to 40% total body surface area (%TBSA) third-degree thermal injury; vagotomy (VGX) group subjected to bilateral cervical vagotomy after thermal injury; electrical stimulation (STM) group subjected to bilateral cervical vagotomy plus the left vagus nerve trunk electrical stimulation (5 V, 2 ms and 1 Hz) after thermal injury; the antagonist of muscarinic acetylcholine receptor (MRA) group administrated with atropine (0.1 mg kg(-1)) before electrical stimulation and the antagonist of nicotinic acetylcholine receptor (NRA) group administrated with hexamethonium (10 mg kg(-1)) before electrical stimulation. The haemodynamics, histopathology of lung tissue, arterial blood gas, lactic acid, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels were measured. Vagus nerve electrical stimulation not only significantly increased the mean arterial pressure (MAP) and heart rate (HR), but also decreased the infiltration of inflammatory cells into interstitial and alveolar spaces after thermal challenge and attenuated TNF-alpha and IL-6 production. Hexamethonium pre-treatment significantly reversed the effects of vagal electrical stimulation, but atropine administration before electrical stimulation had no such effects. Direct electrical stimulation of the vagus nerve might produce therapeutic effect on thermal injury. The effect may be realised by limiting the inflammatory response via nicotinic acetylcholine receptors in rats. Copyright (c) 2009 Elsevier Ltd and ISBI. All rights reserved.

  5. Two Cases of Duchenne Muscular Dystrophy That Showed Different Reactions to Nerve Stimulation During Peripheral Nerve Block: A Case Report.

    PubMed

    So, MinHye; Sugiura, Takeshi; Yoshizawa, Saya; Sobue, Kazuya

    2017-07-15

    In recent years, the technique of combined ultrasound and electrical stimulation-guided nerve block has been recommended. We present 2 patients with Duchenne muscular dystrophy who exhibited different muscle responses to nerve stimulation during the performance of peripheral nerve blocks for surgeries. Whereas a 2-year-old boy without severe disability showed the expected muscle contraction to electrical nerve stimulation, a 14-year-old boy with severe disability showed no muscle response. Our experience suggests that muscle responses to electrical nerve stimulation will vary with the stage of Duchenne muscular dystrophy.

  6. A Case of Pneumothorax after Phrenic Nerve Block with Guidance of a Nerve Stimulator

    PubMed Central

    Tüfek, Adnan; Tokgöz, Orhan; Karaman, Haktan

    2011-01-01

    Hiccups have more than 100 etiologies. The most common etiology has gastrointestinal origins, related mainly to gastric distention and gastroesophageal reflux disease. Intractable hiccups are rare but may present as a severe symptom of various diseases. Hiccups are mostly treated with non-invasive or pharmacological therapies. If these therapies fail, invasive methods should be used. Here, we present a patient on whom we performed a blockage of the phrenic nerve with the guidance of a nerve stimulator. The patient also had pneumothorax as a complication. Three hours after intervention, a tube thoracostomy was performed. One week later, the patient was cured and discharged from the hospital. In conclusion, a stimulator provides the benefit of localizing the phrenic nerve, which leads to diaphragmatic contractions. Patients with thin necks have more risk of pneumothorax during phrenic nerve location. PMID:21716608

  7. Nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis.

    PubMed

    d'Ovidio, Dario; Noviello, Emilio; Adami, Chiara

    2015-07-01

    To describe the nerve stimulator-guided sciatic-femoral nerve block in raptors undergoing surgical treatment of pododermatitis. Prospective clinical trial. Five captive raptors (Falco peregrinus) aged 6.7 ± 1.3 years. Anaesthesia was induced and maintained with isoflurane in oxygen. The sciatic-femoral nerve block was performed with 2% lidocaine (0.05 mL kg(-1) per nerve) as the sole intra-operative analgesic treatment. Intraoperative physiological variables were recorded every 10 minutes from endotracheal intubation until the end of anaesthesia. Assessment of intraoperative nociception was based on changes in physiological variables above baseline values, while evaluation of postoperative pain relied on species-specific behavioural indicators. The sciatic-femoral nerve block was feasible in raptors and the motor responses following electrical stimulation of both nerves were consistent with those reported in mammalian species. During surgery no rescue analgesia was required. The anaesthesia plane was stable and cardiorespiratory variables did not increase significantly in response to surgical stimulation. Iatrogenic complications, namely nerve damage and local anaesthetic toxicity, did not occur. Recovery was smooth and uneventful. The duration (mean ± SD) of the analgesic effect provided by the nerve block was 130 ± 20 minutes. The sciatic-femoral nerve block as described in dogs and rabbits can be performed in raptors as well. Further clinical trials with a control groups are required to better investigate the analgesic efficacy and the safety of this technique in raptors. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  8. 21 CFR 882.5870 - Implanted peripheral nerve stimulator for pain relief.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implanted peripheral nerve stimulator for pain....5870 Implanted peripheral nerve stimulator for pain relief. (a) Identification. An implanted peripheral nerve stimulator for pain relief is a device that is used to stimulate electrically a peripheral...

  9. 21 CFR 882.5870 - Implanted peripheral nerve stimulator for pain relief.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implanted peripheral nerve stimulator for pain....5870 Implanted peripheral nerve stimulator for pain relief. (a) Identification. An implanted peripheral nerve stimulator for pain relief is a device that is used to stimulate electrically a peripheral...

  10. 21 CFR 882.5870 - Implanted peripheral nerve stimulator for pain relief.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted peripheral nerve stimulator for pain....5870 Implanted peripheral nerve stimulator for pain relief. (a) Identification. An implanted peripheral nerve stimulator for pain relief is a device that is used to stimulate electrically a peripheral...

  11. 21 CFR 882.5870 - Implanted peripheral nerve stimulator for pain relief.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implanted peripheral nerve stimulator for pain....5870 Implanted peripheral nerve stimulator for pain relief. (a) Identification. An implanted peripheral nerve stimulator for pain relief is a device that is used to stimulate electrically a peripheral...

  12. 21 CFR 882.5870 - Implanted peripheral nerve stimulator for pain relief.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implanted peripheral nerve stimulator for pain....5870 Implanted peripheral nerve stimulator for pain relief. (a) Identification. An implanted peripheral nerve stimulator for pain relief is a device that is used to stimulate electrically a peripheral...

  13. Patterning of sympathetic nerve activity in response to vestibular stimulation

    NASA Technical Reports Server (NTRS)

    Kerman, I. A.; McAllen, R. M.; Yates, B. J.

    2000-01-01

    Growing evidence suggests a role for the vestibular system in regulation of autonomic outflow during postural adjustments. In the present paper we review evidence for the patterning of sympathetic nerve activity elicited by vestibular stimulation. In response to electrical activation of vestibular afferents, firing of sympathetic nerves located throughout the body is altered. However, activity of the renal nerve is most sensitive to vestibular inputs. In contrast, high-intensity simultaneous activation of cutaneous and muscle inputs elicits equivalent changes in firing of the renal, superior mesenteric and lumbar colonic nerves. Responses of muscle vasoconstrictor (MVC) efferents to vestibular stimulation are either inhibitory (Type I) or are comprised of a combination of excitation and inhibition (Type II). Interestingly, single MVC units located in the hindlimb exhibited predominantly Type I responses while those located in the forelimb and face exhibited Type II responses. Furthermore, brachial and femoral arterial blood flows were dissociated in response to vestibular stimulation, such that brachial vascular resistance increased while femoral resistance decreased. These studies demonstrate that vestibulosympathetic reflexes are patterned according to both the anatomical location and innervation target of a particular sympathetic nerve, and can lead to distinct changes in local blood flow.

  14. Patterning of sympathetic nerve activity in response to vestibular stimulation

    NASA Technical Reports Server (NTRS)

    Kerman, I. A.; McAllen, R. M.; Yates, B. J.

    2000-01-01

    Growing evidence suggests a role for the vestibular system in regulation of autonomic outflow during postural adjustments. In the present paper we review evidence for the patterning of sympathetic nerve activity elicited by vestibular stimulation. In response to electrical activation of vestibular afferents, firing of sympathetic nerves located throughout the body is altered. However, activity of the renal nerve is most sensitive to vestibular inputs. In contrast, high-intensity simultaneous activation of cutaneous and muscle inputs elicits equivalent changes in firing of the renal, superior mesenteric and lumbar colonic nerves. Responses of muscle vasoconstrictor (MVC) efferents to vestibular stimulation are either inhibitory (Type I) or are comprised of a combination of excitation and inhibition (Type II). Interestingly, single MVC units located in the hindlimb exhibited predominantly Type I responses while those located in the forelimb and face exhibited Type II responses. Furthermore, brachial and femoral arterial blood flows were dissociated in response to vestibular stimulation, such that brachial vascular resistance increased while femoral resistance decreased. These studies demonstrate that vestibulosympathetic reflexes are patterned according to both the anatomical location and innervation target of a particular sympathetic nerve, and can lead to distinct changes in local blood flow.

  15. Effects of vagus nerve stimulation on cortical excitability in epileptic patients.

    PubMed

    Di Lazzaro, V; Oliviero, A; Pilato, F; Saturno, E; Dileone, M; Meglio, M; Colicchio, G; Barba, C; Papacci, F; Tonali, P A

    2004-06-22

    Vagus nerve stimulation (VNS) is used as adjunctive treatment for medically refractory epilepsy, but little is known about its mechanisms of action. The effects of VNS on the excitatory and inhibitory circuits of the motor cortex were evaluated in five patients with epilepsy using single- and paired-pulse transcranial magnetic stimulation (TMS). Patients were examined with the stimulator on and off. VNS determined a selective and pronounced increase in the inhibition produced by paired-pulse TMS with no effects on the excitability by single-pulse TMS.

  16. Hypoglossal nerve stimulation improves obstructive sleep apnea: 12-month outcomes.

    PubMed

    Kezirian, Eric J; Goding, George S; Malhotra, Atul; O'Donoghue, Fergal J; Zammit, Gary; Wheatley, John R; Catcheside, Peter G; Smith, Philip L; Schwartz, Alan R; Walsh, Jennifer H; Maddison, Kathleen J; Claman, David M; Huntley, Tod; Park, Steven Y; Campbell, Matthew C; Palme, Carsten E; Iber, Conrad; Eastwood, Peter R; Hillman, David R; Barnes, Maree

    2014-02-01

    Reduced upper airway muscle activity during sleep is a key contributor to obstructive sleep apnea pathogenesis. Hypoglossal nerve stimulation activates upper airway dilator muscles, including the genioglossus, and has the potential to reduce obstructive sleep apnea severity. The objective of this study was to examine the safety, feasibility and efficacy of a novel hypoglossal nerve stimulation system (HGNS; Apnex Medical, St Paul, MN, USA) in treating obstructive sleep apnea at 12 months following implantation. Thirty-one subjects (35% female, age 52.4 ± 9.4 years) with moderate to severe obstructive sleep apnea and unable to tolerate positive airway pressure underwent surgical implantation and activation of the hypoglossal nerve stimulation system in a prospective single-arm interventional trial. Primary outcomes were changes in obstructive sleep apnea severity (apnea-hypopnea index, from in-laboratory polysomnogram) and sleep-related quality of life [Functional Outcomes of Sleep Questionnaire (FOSQ)]. Hypoglossal nerve stimulation was used on 86 ± 16% of nights for 5.4 ± 1.4 h per night. There was a significant improvement (P < 0.001) from baseline to 12 months in apnea-hypopnea index (45.4 ± 17.5 to 25.3 ± 20.6 events h(-1) ) and Functional Outcomes of Sleep Questionnaire score (14.2 ± 2.0 to 17.0 ± 2.4), as well as other polysomnogram and symptom measures. Outcomes were stable compared with 6 months following implantation. Three serious device-related adverse events occurred: an infection requiring device removal; and two stimulation lead cuff dislodgements requiring replacement. There were no significant adverse events with onset later than 6 months following implantation. Hypoglossal nerve stimulation demonstrated favourable safety, feasibility and efficacy.

  17. Kilohertz frequency nerve block enhances anti-inflammatory effects of vagus nerve stimulation

    PubMed Central

    Patel, Yogi A.; Saxena, Tarun; Bellamkonda, Ravi V.; Butera, Robert J.

    2017-01-01

    Efferent activation of the cervical vagus nerve (cVN) dampens systemic inflammatory processes, potentially modulating a wide-range of inflammatory pathological conditions. In contrast, afferent cVN activation amplifies systemic inflammatory processes, leading to activation of the hypothalamic-pituitary-adrenal (HPA) axis, the sympathetic nervous system through the greater splanchnic nerve (GSN), and elevation of pro-inflammatory cytokines. Ideally, to clinically implement anti-inflammatory therapy via cervical vagus nerve stimulation (cVNS) one should selectively activate the efferent pathway. Unfortunately, current implementations, in animal and clinical investigations, activate both afferent and efferent pathways. We paired cVNS with kilohertz electrical stimulation (KES) nerve block to preferentially activate efferent pathways while blocking afferent pathways. Selective efferent cVNS enhanced the anti-inflammatory effects of cVNS. Our results demonstrate that: (i) afferent, but not efferent, cVNS synchronously activates the GSN in a dose-dependent manner; (ii) efferent cVNS enabled by complete afferent KES nerve block enhances the anti-inflammatory benefits of cVNS; and (iii) incomplete afferent KES nerve block exacerbates systemic inflammation. Overall, these data demonstrate the utility of paired efferent cVNS and afferent KES nerve block for achieving selective efferent cVNS, specifically as it relates to neuromodulation of systemic inflammation. PMID:28054557

  18. Co-activation of saphenous nerve fibers: a potential therapeutic mechanism of percutaneous tibial nerve stimulation?

    PubMed

    Elder, Christopher W; Yoo, Paul B

    2016-08-01

    Percutaneous tibial nerve stimulation (PTNS) is a minimally invasive and effective treatment for overactive bladder (OAB). However, clinical trials show that positive therapeutic outcomes among patients are difficult to predict (failure rate = 35% to 50%). Inconsistencies in the stimulation amplitudes used clinically and those used in preclinical animal studies led us to hypothesize that OAB therapy involves a secondary bladder-inhibitory pathway. In this paper, we implemented and tested a computer model of the human lower leg that investigated the differential activation of the saphenous nerve (SAFN) and tibial nerve (TN) during percutaneous electrical stimulation. Our preliminary findings show that concomitant activation of SAFN branches occurs during PTNS, which suggests the possibility that the SAFN may influence the clinical outcome of treatment.

  19. Infrared neural stimulation of human spinal nerve roots in vivo

    PubMed Central

    Cayce, Jonathan M.; Wells, Jonathon D.; Malphrus, Jonathan D.; Kao, Chris; Thomsen, Sharon; Tulipan, Noel B.; Konrad, Peter E.; Jansen, E. Duco; Mahadevan-Jansen, Anita

    2015-01-01

    Abstract. Infrared neural stimulation (INS) is a neurostimulation modality that uses pulsed infrared light to evoke artifact-free, spatially precise neural activity with a noncontact interface; however, the technique has not been demonstrated in humans. The objective of this study is to demonstrate the safety and efficacy of INS in humans in vivo. The feasibility of INS in humans was assessed in patients (n=7) undergoing selective dorsal root rhizotomy, where hyperactive dorsal roots, identified for transection, were stimulated in vivo with INS on two to three sites per nerve with electromyogram recordings acquired throughout the stimulation. The stimulated dorsal root was removed and histology was performed to determine thermal damage thresholds of INS. Threshold activation of human dorsal rootlets occurred in 63% of nerves for radiant exposures between 0.53 and 1.23  J/cm2. In all cases, only one or two monitored muscle groups were activated from INS stimulation of a hyperactive spinal root identified by electrical stimulation. Thermal damage was first noted at 1.09  J/cm2 and a 2∶1 safety ratio was identified. These findings demonstrate the success of INS as a fresh approach for activating human nerves in vivo and providing the necessary safety data needed to pursue clinically driven therapeutic and diagnostic applications of INS in humans. PMID:26157986

  20. Infrared neural stimulation of human spinal nerve roots in vivo.

    PubMed

    Cayce, Jonathan M; Wells, Jonathon D; Malphrus, Jonathan D; Kao, Chris; Thomsen, Sharon; Tulipan, Noel B; Konrad, Peter E; Jansen, E Duco; Mahadevan-Jansen, Anita

    2015-01-01

    Infrared neural stimulation (INS) is a neurostimulation modality that uses pulsed infrared light to evoke artifact-free, spatially precise neural activity with a noncontact interface; however, the technique has not been demonstrated in humans. The objective of this study is to demonstrate the safety and efficacy of INS in humans in vivo. The feasibility of INS in humans was assessed in patients ([Formula: see text]) undergoing selective dorsal root rhizotomy, where hyperactive dorsal roots, identified for transection, were stimulated in vivo with INS on two to three sites per nerve with electromyogram recordings acquired throughout the stimulation. The stimulated dorsal root was removed and histology was performed to determine thermal damage thresholds of INS. Threshold activation of human dorsal rootlets occurred in 63% of nerves for radiant exposures between 0.53 and [Formula: see text]. In all cases, only one or two monitored muscle groups were activated from INS stimulation of a hyperactive spinal root identified by electrical stimulation. Thermal damage was first noted at [Formula: see text] and a [Formula: see text] safety ratio was identified. These findings demonstrate the success of INS as a fresh approach for activating human nerves in vivo and providing the necessary safety data needed to pursue clinically driven therapeutic and diagnostic applications of INS in humans.

  1. A pilot study of chronic pudendal nerve stimulation for faecal incontinence for those who have failed sacral nerve stimulation.

    PubMed

    Thomas, G P; George, A T; Dudding, T C; Nicholls, R J; Vaizey, C J

    2014-08-01

    Sacral nerve stimulation (SNS) is used as a first-line treatment for faecal incontinence when conservative measures have failed. However, one-third of patients fail to benefit from this treatment. We hypothesised that sacral afferent stimulation can be maximised using pudendal nerve stimulation (PNS) and this may be of benefit in this patient group. The aim of this study was to assess chronic PNS for those who failed to improve with SNS. Ten patients who had failed SNS were recruited. All underwent percutaneous insertion of a stimulation lead with four-electrode array adjacent to the pudendal nerve. Continuous bipolar stimulation was administered using an external pulse generator over a 3-week period. Those who experienced a ≥50% reduction in the frequency of incontinent episodes over this period proceeded to chronic stimulation with an implantable pulse generator. Five patients experienced a ≥50% reduction of incontinent episodes during test stimulation and proceeded to chronic stimulation. In these five patients, at a median (range) follow-up of 24 (6-36) months, the median (inter quartile range) frequency of incontinent episodes reduced from 5 (18.25) to 2.5 (3) per week (p = 0.043). Three patients maintained a ≥50% improvement in soiling. There was an improvement in the St Mark's continence Score from 19 (15-24) to 16 (13-19), p = 0.042. There were no significant changes in ability to defer defecation or in quality of life scores. Pudendal nerve stimulation failed to improve the symptoms in the majority of patient who had failed SNS. Only a third experienced any improvement.

  2. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  3. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  4. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  5. Magnetoencephalographic analysis in patients with vagus nerve stimulator

    PubMed Central

    Tanaka, Naoaki; Thiele, Elizabeth A.; Madsen, Joseph R.; Bourgeois, Blaise F.; Stufflebeam, Steven M.

    2009-01-01

    The purpose of this study is to assess the feasibility of magnetoencephalography in epilepsy patients with vagus nerve stimulator. We performed magnetoencephalography in two patients (Patient 1 and 2) with medically intractable epilepsy who had a vagus nerve stimulator. Due to the artifacts caused by a vagus nerve stimulator, no spikes could be identified in the original magnetoencephalographic data in either patient. The temporally extended signal space separation method was used for removing artifacts. After processing by this method, left temporo-parietal spikes were clearly identified in Patient 1. Equivalent current dipoles calculated from these spikes were localized in the left posterior-temporal and parietal lobes. The location of the dipoles was consistent with the spike distribution on intracranial EEG. In Patient 2, bilateral, diffuse spikes were seen in the processed data. The contour maps demonstrated a bilateral pattern, not in agreement of single focal source. These findings supported the diagnosis of symptomatic generalized epilepsy in this patient. The present study demonstrates that magnetoencephalography may be a valuable option for evaluating intractable epilepsy patients with the vagus nerve stimulator. PMID:19818944

  6. Magnetoencephalographic analysis in patients with vagus nerve stimulator.

    PubMed

    Tanaka, Naoaki; Thiele, Elizabeth A; Madsen, Joseph R; Bourgeois, Blaise F; Stufflebeam, Steven M

    2009-11-01

    The objective of this study was to assess the feasibility of magnetoencephalography in epilepsy patients with a vagus nerve stimulator. Magnetoencephalography was performed in two patients with medically intractable epilepsy who had a vagus nerve stimulator. Because of the artifacts caused by the vagus nerve stimulator, no spikes could be identified in the original magnetoencephalographic data in either patient. The temporally extended signal space separation method was used to remove artifacts. After processing by this method, left temporoparietal spikes were clearly identified in patient 1. Equivalent current dipoles calculated from these spikes were localized in the left posterior-temporal and parietal lobes. The location of the dipoles was consistent with the spike distribution on intracranial electroencephalography. In patient 2, bilateral diffuse spikes were seen in the processed data. The contour maps demonstrated a bilateral pattern, not in agreement with a single focal source. These findings supported the diagnosis of symptomatic generalized epilepsy in this patient. Magnetoencephalography may thus be a useful option for evaluating patients with intractable epilepsy who have a vagus nerve stimulator.

  7. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid sinus...

  8. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid sinus...

  9. Percutaneous tibial nerve stimulation for patients with faecal incontinence.

    PubMed

    Allison, Marion

    Percutaneous tibial nerve stimulation (PTNS) is a new, non-invasive treatment for faecal incontinence. It is given in an outpatient setting and has few side effects. An increasing number of studies confirm its efficacy. This article discusses the procedure, reports early experiences of using PTNS at one centre in the UK and considers cost effectiveness.

  10. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral...

  11. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral...

  12. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral...

  13. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral...

  14. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... a device used to apply an electrical current to a patient to test the level of pharmacological... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrical peripheral nerve stimulator. 868.2775... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral...

  15. 21 CFR 874.1820 - Surgical nerve stimulator/locator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Surgical nerve stimulator/locator. 874.1820 Section 874.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1820 Surgical...

  16. 21 CFR 874.1820 - Surgical nerve stimulator/locator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Surgical nerve stimulator/locator. 874.1820 Section 874.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1820 Surgical...

  17. 21 CFR 874.1820 - Surgical nerve stimulator/locator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Surgical nerve stimulator/locator. 874.1820 Section 874.1820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1820 Surgical...

  18. Electrical stimulation accelerates nerve regeneration and functional recovery in delayed peripheral nerve injury in rats.

    PubMed

    Huang, Jinghui; Zhang, Yongguang; Lu, Lei; Hu, Xueyu; Luo, Zhuojing

    2013-12-01

    The present study aims to investigate the potential of brief electrical stimulation (ES; 3 V, 20 Hz, 20 min) in improving functional recovery in delayed nerve injury repair (DNIR). The sciatic nerve of Sprague Dawley rats was transected, and the repair of nerve injury was delayed for different time durations (2, 4, 12 and 24 weeks). Brief depolarizing ES was applied to the proximal nerve stump when the transected nerve stumps were bridged with a hollow nerve conduit (5 mm in length) after delayed periods. We found that the diameter and number of regenerated axons, the thickness of myelin sheath, as well as the number of Fluoro-Gold retrograde-labeled motoneurons and sensory neurons were significantly increased by ES, suggesting that brief ES to proximal nerve stumps is capable of promoting nerve regeneration in DNIR with different delayed durations, with the longest duration of 24 weeks. In addition, the amplitude of compound muscle action potential (gastrocnemius muscle) and nerve conduction velocity were also enhanced, and gastrocnemius muscle atrophy was partially reversed by brief ES, indicating that brief ES to proximal nerve stump was able to improve functional recovery in DNIR. Furthermore, brief ES was capable of increasing brain-derived neurotrophic factor (BDNF) expression in the spinal cord in DNIR, suggesting that BDNF-mediated neurotrophin signaling might be one of the contributing factors to the beneficial effect of brief ES on DNIR. In conclusion, the present findings indicate the potential of using brief ES as a useful method to improve functional recovery for delayed repair of peripheral nerve lesions. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  19. Treatment of epilepsy by stimulation of the vagus nerve.

    PubMed

    Uthman, B M; Wilder, B J; Penry, J K; Dean, C; Ramsay, R E; Reid, S A; Hammond, E J; Tarver, W B; Wernicke, J F

    1993-07-01

    We treated 14 patients with medically refractory partial seizures by stimulation of the vagus nerve in two single-blind pilot studies. Patients received stimulation through an implantable, programmable NeuroCybernetic Prosthesis, consisting of a pulse generator and a lead-electrode assembly. The mean reduction in seizure frequency after 14 to 35 months of vagal stimulation was 46.6%. Of the 14 patients, five (35.7%) had a 50% or greater reduction in seizure frequency. Two patients, one of whom had had 10 to 100 seizures per day before stimulation, have been seizure-free for over 1 year. Adverse events were primarily limited to initial hoarseness and a tingling sensation at the electrode site in the neck when the device was activated. Most patients tolerated the device and stimulation well. There were no permanent adverse events. Some cases of medically refractory partial seizures are improved by vagal stimulation.

  20. Electrical stimulation of nerve cells using conductive nanofibrous scaffolds for nerve tissue engineering.

    PubMed

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Ramakrishna, Seeram

    2009-11-01

    Fabrication of scaffolds with suitable chemical, mechanical, and electrical properties is critical for the success of nerve tissue engineering. Electrical stimulation was directly applied to electrospun conductive nanofibrous scaffolds to enhance the nerve regeneration process. In the present study, electrospun conductive nanofibers were prepared by mixing 10 and 15 wt% doped polyaniline (PANI) with poly (epsilon-caprolactone)/gelatin (PG) (70:30) solution (PANI/PG) by electrospinning. The fiber diameter, pore size, hydrophilicity, tensile properties, conductivity, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy spectra of nanofibers were determined, and the in vitro biodegradability of the different nanofibrous scaffolds was also evaluated. Nanofibrous scaffolds containing 15% PANI was found to exhibit the most balanced properties to meet all the required specifications for electrical stimulation for its enhanced conductivity and is used for in vitro culture and electrical stimulation of nerve stem cells. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and scanning electron microscopy results showed that conductive nanofibrous scaffolds are suitable substrates for the attachment and proliferation of nerve stem cells. Electrical stimulation through conductive nanofibrous PANI/PG scaffolds showed enhanced cell proliferation and neurite outgrowth compared to the PANI/PG scaffolds that were not subjected to electrical stimulation.

  1. Steady-state activation in somatosensory cortex after changes in stimulus rate during median nerve stimulation.

    PubMed

    Manganotti, Paolo; Formaggio, Emanuela; Storti, Silvia Francesca; Avesani, Mirko; Acler, Michele; Sala, Francesco; Magon, Stefano; Zoccatelli, Giada; Pizzini, Francesca; Alessandrini, Franco; Fiaschi, Antonio; Beltramello, Alberto

    2009-11-01

    Passive electrical stimulation activates various human somatosensory cortical systems including the contralateral primary somatosensory area (SI), bilateral secondary somatosensory area (SII) and bilateral insula. The effect of stimulation frequency on blood oxygenation level-dependent (BOLD) activity remains unclear. We acquired 3-T functional magnetic resonance imaging (fMRI) in eight healthy volunteers during electrical median nerve stimulation at frequencies of 1, 3 and 10 Hz. During stimulation BOLD signal changes showed activation in the contralateral SI, bilateral SII and bilateral insula. Results of fMRI analysis showed that these areas were progressively active with the increase of rate of stimulation. As a major finding, the contralateral SI showed an increase of peak of BOLD activation from 1 to 3 Hz but reached a plateau during 10-Hz stimulation. Our finding is of interest for basic research and for clinical applications in subjects unable to perform cognitive tasks in the fMRI scanner.

  2. The effects of sacral nerve stimulation on continence are temporarily maintained after turning the stimulator off.

    PubMed

    Altomare, D F; Giannini, I; Giuratrabocchetta, S; Digennaro, R

    2013-12-01

    Sacral nerve stimulation is an effective treatment for urinary and faecal incontinence even though its mechanism of action is uncertain. Central nervous system involvement by 'setting-up' neurological mechanisms appointed to control pelvic function has been hypothesized. The study aimed to evaluate whether the effects of long-term sacral nerve stimulation are memorized and therefore maintained after switching off the stimulator. Patients having sacral nerve stimulation for faecal and/or urinary incontinence for at least 1 year had the stimulator turned off and the results monitored. Data recorded with the stimulator off were compared with post-implant data. If symptoms recurred the stimulator was switched back on. Nineteen patients entered the study. Fourteen had faecal and/or urinary incontinence and five had faecal incontinence alone. The symptoms were assessed by means of a bowel function diary and dedicated questionnaire. In 10 patients symptoms recurred at different intervals after a median off period of 3.4 months with a probability of symptom relapse of 55%. The Fecal Incontinence Quality of Life (FIQL) score did not show any significant difference in nine patients with the stimulator off for at least 1 year. No factors predictive of symptom recurrence were identified although an idiopathic aetiology, severity of disease and urinary incontinence had higher hazard ratios. During the off period, none of the scores and episodes of incontinence showed significant changes compared with the on period. The effects of sacral nerve stimulation on faecal and urinary incontinence were maintained in about half of patients after switching the stimulator off, but in some symptoms returned after different periods of time. The data shed new light on possible effects of sacral nerve stimulation on brain neuroplasticity in the control of continence. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

  3. Effect of median-nerve electrical stimulation on BOLD activity in acute ischemic stroke patients.

    PubMed

    Manganotti, P; Storti, S F; Formaggio, E; Acler, M; Zoccatelli, G; Pizzini, F B; Alessandrini, F; Bertoldo, A; Toffolo, G M; Bovi, P; Beltramello, A; Moretto, G; Fiaschi, A

    2012-01-01

    To investigate blood oxygenation level-dependent (BOLD) activation during somatosensory electrical stimulation of the median nerve in acute stroke patients and to determine its correlation with ischemic damage and clinical recovery over time. Fourteen acute stroke patients underwent functional magnetic resonance imaging (fMRI) during contralesional median-nerve electrical stimulation 12-48 h after stroke. Findings were then validated by diffusion tensor imaging (DTI) and motor evoked potential by transcranial magnetic stimulation (TMS). Poor clinical recovery at three months was noted in four patients with no activation in the early days after stroke, whereas good clinical recovery was observed in eight patients with a normal activation pattern in the primary sensory motor area in the acute phase. In two patients BOLD activation correlated weakly with clinical recovery. Findings from TMS and DTI partially correlated with clinical recovery and functional scores. Clinically relevant insights into the "functional reserve" of stroke patients gained with peripheral nerve stimulation during fMRI may carry prognostic value already in the acute period of a cerebrovascular accident. BOLD activation maps could provide insights into the functional organization of the residual systems and could contribute to medical decision making in neurological and rehabilitative treatment. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Pudendal Nerve Stimulation and Block by a Wireless Controlled Implantable Stimulator in Cats

    PubMed Central

    Yang, Guangning; Wang, Jicheng; Shen, Bing; Roppolo, James R.; de Groat, William C.; Tai, Changfeng

    2014-01-01

    Objective To determine the functionality of a wireless controlled implantable stimulator designed for stimulation and block of the pudendal nerve. Materials and Methods In 5 cats under α-chloralose anesthesia, the stimulator was implanted underneath the skin on the left side in the lower back along the sacral spine. Two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves in addition to one bipolar cuff electrode that was implanted on the left side central to the tripolar cuff electrode. The stimulator provided high frequency (5-20 kHz) biphasic stimulation waveforms to the two tripolar electrodes and low frequency (1-100 Hz) rectangular pulses to the bipolar electrode. Bladder and urethral pressures were measured to determine the effects of pudendal nerve stimulation (PNS) or block. Results The maximal (70-100 cmH2O) urethral pressure generated by 20 Hz PNS applied via the bipolar electrode was completely eliminated by the pudendal nerve block induced by the high frequency stimulation (6-15 kHz, 6-10 V) applied via the two tripolar electrodes. In a partially filled bladder 20-30 Hz PNS (2-8 V, 0.2 ms) but not 5 Hz stimulation applied via the bipolar electrode elicited a large sustained bladder contraction (45.9±13.4 to 52.0±22 cmH2O). During cystometry, the 5 Hz PNS significantly (P<0.05) increased bladder capacity to 176.5±27.1% of control capacity. Conclusions The wireless controlled implantable stimulator successfully generated the required waveforms for stimulation and block of pudendal nerve, which will be useful for restoring bladder functions after spinal cord injury (SCI). PMID:24320615

  5. Nerve Stimulator versus Ultrasound-Guided Femoral Nerve Block; a Randomized Clinical Trial

    PubMed Central

    Forouzan, Arash; Masoumi, Kambiz; Motamed, Hasan; Gousheh, Mohammad Reza; Rohani, Akram

    2017-01-01

    Introduction: Pain control is the most important issue in emergency department management of patients with femoral bone fractures. The present study aimed to compare the procedural features of ultrasonography and nerve stimulator guided femoral nerve block in this regard. Method: In this randomized clinical trial, patients with proximal femoral fractures presenting to emergency department were randomly divided into two groups of ultrasonography or nerve stimulator guided femoral block and compared regarding success rate, procedural time, block time, and need for rescue doses of morphine sulfate, using SPSS 20. Results: 50 patients were randomly divided into two groups of 25 (60% male). The mean age of studied patients was 35.14 ± 12.95 years (19 – 69). The two groups were similar regarding age (p= 0.788), sex (p = 0.564), and initial pain severity (p = 0.513). In 2 cases of nerve stimulator guided block, loss of pinprick sensation did not happen within 30 minutes of injection (success rate: 92%; p = 0.490). Ultrasonography guided nerve block cases had significantly lower procedural time (8.06 ± 1.92 vs 13.60 ± 4.56 minutes; p < 0.001) and lower need for rescue doses of opioid (2.68 ± 0.74 vs 5.28 ± 1.88 minutes; p < 0.001). Conclusion: Ultrasonography and nerve stimulator guided femoral block had the same success rate and block duration. However, the ultrasonography guided group had lower procedure time and lower need for rescue doses of morphine sulfate. Therefore, ultrasonography guided femoral block could be considered as an available, safe, rapid, and efficient method for pain management of femoral fracture in emergency department. PMID:28286861

  6. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Transcutaneous electrical nerve stimulator...

  7. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Transcutaneous electrical nerve stimulator...

  8. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Transcutaneous electrical nerve stimulator...

  9. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Transcutaneous electrical nerve stimulator...

  10. 21 CFR 882.5890 - Transcutaneous electrical nerve stimulator for pain relief.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Devices § 882.5890 Transcutaneous electrical nerve stimulator for pain relief. (a) Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transcutaneous electrical nerve stimulator...

  11. Vagus nerve stimulation: An evolving adjunctive treatment for cardiac disease

    PubMed Central

    Akdemir, Barış; Benditt, David G.

    2016-01-01

    The vagus nerve is a major component of the autonomic nervous system and plays a critical role in many body functions including for example, speech, swallowing, heart rate and respiratory control, gastric secretion, and intestinal motility. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, with electrical stimulation being the most important. Implantable devices for VNS are approved therapy for refractory epilepsy and for treatment-resistant depression. In the case of heart disease applications, implantable VNS has been shown to be beneficial for treating heart failure in both preclinical and clinical studies. Adverse effects of implantable VNS therapy systems are generally associated with the implantation procedure or continuous on-off stimulation. The most serious implantation-associated adverse effect is infection. The effectiveness of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, heart failure, and other conditions remains under investigation. VNS merits further study for its potentially favorable effects on cardiovascular disease, especially heart failure. PMID:27723668

  12. Optical stimulation of the prostate nerves: A potential diagnostic technique

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat

    There is wide variability in sexual potency rates (9--86%) after nerve-sparing prostate cancer surgery due to limited knowledge of the location of the cavernous nerves (CN's) on the prostate surface, which are responsible for erectile function. Thus, preservation of the CN's is critical in preserving a man's ability to have spontaneous erections following surgery. Nerve-mapping devices, utilizing conventional Electrical Nerve Stimulation (ENS) techniques, have been used as intra-operative diagnostic tools to assist in preservation of the CN. However, these technologies have proven inconsistent and unreliable in identifying the CN's due to the need for physical contact, the lack of spatial selectivity, and the presence of electrical artifacts in measurements. Optical Nerve Stimulation (ONS), using pulsed infrared laser radiation, is studied as an alternative to ENS. The objective of this study is sevenfold: (1) to develop a laparoscopic laser probe for ONS of the CN's in a rat model, in vivo; (2) to demonstrate faster ONS using continuous-wave infrared laser radiation; (3) to describe and characterize the mechanism of successful ONS using alternative laser wavelengths; (4) to test a compact, inexpensive all-single-mode fiber configuration for optical stimulation of the rat CN studies; (5) to implement fiber optic beam shaping methods for comparison of Gaussian and flat-top spatial beam profiles during ONS; (6) to demonstrate successful ONS of CN's through a thin layer of fascia placed over the nerve and prostate gland; and (7) to verify the experimentally determined therapeutic window for safe and reliable ONS without thermal damage to the CN's by comparison with a computational model for thermal damage. A 5.5-Watt Thulium fiber laser operated at 1870 nm and two pigtailed, single mode, near-IR diode lasers (150-mW, 1455-nm laser and 500-mW, 1550-nm laser) were used for non-contact stimulation of the rat CN's. Successful laser stimulation, as measured by an

  13. An autopsy case of vagus nerve stimulation following acupuncture.

    PubMed

    Watanabe, Mayumi; Unuma, Kana; Fujii, Yusuke; Noritake, Kanako; Uemura, Koichi

    2015-03-01

    Acupuncture is one of the most popular oriental medical techniques in China, Korea and Japan. This technique is also popular as alternative therapy in the Western World. Serious adverse events are rare following acupuncture, and fatal cases have been rarely reported. A male in his late forties died right after acupuncture treatment. A medico-legal autopsy disclosed severe haemorrhaging around the right vagus nerve in the neck. Other organs and laboratory data showed no significant findings. Thus, it was determined that the man could have died from severe vagal bradycardia and/or arrhythmia resulting from vagus nerve stimulation following acupuncture. To the best of our knowledge, this is the first report of a death due to vagus nerve injury after acupuncture.

  14. Vagus nerve stimulation therapy for epilepsy in older adults.

    PubMed

    Sirven, J I; Sperling, M; Naritoku, D; Schachter, S; Labar, D; Holmes, M; Wilensky, A; Cibula, J; Labiner, D M; Bergen, D; Ristanovic, R; Harvey, J; Dasheiff, R; Morris, G L; O'Donovan, C A; Ojemann, L; Scales, D; Nadkarni, M; Richards, B; Sanchez, J D

    2000-03-14

    The authors assessed the efficacy, safety, and tolerability of vagus nerve stimulation (VNS) for refractory epilepsy in 45 adults 50 years of age and older. They determined seizure frequency, adverse effects, and quality of life. At 3 months, 12 patients had a >50% decrease in seizure frequency; at 1 year, 21 of 31 studied individuals had a >50% seizure decrease. Side effects were mild and transient. Quality of life scores improved significantly with time.

  15. Peripheral nerve stimulation for the treatment of truncal pain.

    PubMed

    Cairns, Kevin D; McRoberts, W Porter; Deer, Timothy

    2011-01-01

    Neuromodulation practitioners increasingly recognize the potential for peripheral nerve field stimulation (PNfS) to treat pain originating from the trunk. Conditions resulting in truncal pain that may respond to PNfS include cervical and lumbar postlaminectomy syndrome, inguinal neurapraxia, post-herpetic neuralgia, and post-thoracotomy pain. The focus of this chapter is to review the mechanism of action in PNfS, patient selection factors, programming strategies, and technical considerations.

  16. Occipital Nerve Stimulation for Migraine: Update from Recent Multicenter Trials.

    PubMed

    Schwedt, Todd J; Green, A Laine; Dodick, David W

    2015-01-01

    Occipital nerve stimulation (ONS) continues to be investigated for the treatment of refractory chronic migraine. Results from case series and from prospective, sham-controlled clinical trials remain inconclusive regarding the efficacy of ONS for migraine treatment. Safety and implantation techniques require improvements since rates of lead migration, infection, and persistent stimulator-related pain continue to be high. Existing data justify further ONS trials with carefully chosen primary outcome(s), adequate statistical power, and improved surgical techniques. © 2016 S. Karger AG, Basel.

  17. Transcutaneous vagus nerve stimulation boosts associative memory in older individuals.

    PubMed

    Jacobs, Heidi I L; Riphagen, Joost M; Razat, Chantalle M; Wiese, Svenja; Sack, Alexander T

    2015-05-01

    Direct vagus nerve stimulation (dVNS) is known to improve mood, epilepsy, and memory. Memory improvements have been observed in Alzheimer's disease patients after long-term stimulation. The potential of transcutaneous vagus nerve stimulation (tVNS), a noninvasive alternative to dVNS, to alter memory performance remains unknown. We aimed to investigate the effect of a single-session tVNS on associative memory performance in healthy older individuals. To investigate this, we performed a single-blind sham-controlled randomized crossover pilot study in healthy older individuals (n = 30, 50% female). During the stimulation or sham condition, participants performed an associative face-name memory task. tVNS enhanced the number of hits of the memory task, compared with the sham condition. This effect was specific to the experimental task. Participants reported few side effects. We conclude that tVNS is a promising neuromodulatory technique to improve associative memory performance in older individuals, even after a single session. More research is necessary to investigate its underlying neural mechanisms, the impact of varying stimulation parameters, and its applicability in patients with cognitive decline.

  18. Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin

    NASA Astrophysics Data System (ADS)

    Borovikova, Lyudmila V.; Ivanova, Svetlana; Zhang, Minghuang; Yang, Huan; Botchkina, Galina I.; Watkins, Linda R.; Wang, Haichao; Abumrad, Naji; Eaton, John W.; Tracey, Kevin J.

    2000-05-01

    Vertebrates achieve internal homeostasis during infection or injury by balancing the activities of proinflammatory and anti-inflammatory pathways. Endotoxin (lipopolysaccharide), produced by all gram-negative bacteria, activates macrophages to release cytokines that are potentially lethal. The central nervous system regulates systemic inflammatory responses to endotoxin through humoral mechanisms. Activation of afferent vagus nerve fibres by endotoxin or cytokines stimulates hypothalamic-pituitary-adrenal anti-inflammatory responses. However, comparatively little is known about the role of efferent vagus nerve signalling in modulating inflammation. Here, we describe a previously unrecognized, parasympathetic anti-inflammatory pathway by which the brain modulates systemic inflammatory responses to endotoxin. Acetylcholine, the principle vagal neurotransmitter, significantly attenuated the release of cytokines (tumour necrosis factor (TNF), interleukin (IL)-1β, IL-6 and IL-18), but not the anti-inflammatory cytokine IL-10, in lipopolysaccharide-stimulated human macrophage cultures. Direct electrical stimulation of the peripheral vagus nerve in vivo during lethal endotoxaemia in rats inhibited TNF synthesis in liver, attenuated peak serum TNF amounts, and prevented the development of shock.

  19. Continuous stimulation of transected distal nerves fails to prolong action potential propagation.

    PubMed

    O'Gara, Tadhg; Urban, William; Polishchuk, Daniil; Pierre-Louis, Alain; Stewart, Mark

    2006-06-01

    Wallerian degeneration of the distal portion of a cut nerve is considered irreversible. A possible reason for degeneration is lack of axon stimulation in the distal, cut nerves. We hypothesized greater rates of stimulation of distal nerve stumps would prolong time to action potential propagation failure, and uncut nerves would not be damaged by implanted nerve stimulators. We also hypothesized that action potentials measured from the body of the sciatic nerve would show similar response as motor-evoked potentials measured in the muscles innervated by branches of the sciatic nerve. We implanted a nerve stimulator onto distal cut sciatic nerves of rats and recorded motor-evoked potentials. Three groups were stimulated at 1 Hz (once per second), 0.1 Hz (once per 10 seconds), and 0.01 Hz (once per 100 seconds) respectively. Motor-evoked potentials progressively declined after nerve transection, failing faster at 1 Hz (26.8 hours +/- 108 minutes) and 0.1 Hz (22 hours +/- 66 minutes) compared with stimulation at 0.01 Hz (36.75 hours +/- 83 minutes). Intact axons were not damaged by implanted nerve stimulators. Action potentials recorded directly from nerves were equivalent to motor- evoked potentials. Failure of motor-evoked potential transmission in a transected nerve is accelerated by a greater rate of continuous stimulation of the distal stump.

  20. Giant early components of somatosensory evoked potentials to tibial nerve stimulation in cortical myoclonus.

    PubMed

    Anzellotti, Francesca; Onofrj, Marco; Bonanni, Laura; Saracino, Antonio; Franciotti, Raffaella

    2016-01-01

    Enlarged cortical components of somatosensory evoked potentials (giant SEPs) recorded by electroencephalography (EEG) and abnormal somatosensory evoked magnetic fields (SEFs) recorded by magnetoencephalography (MEG) are observed in the majority of patients with cortical myoclonus (CM). Studies on simultaneous recordings of SEPs and SEFs showed that generator mechanism of giant SEPs involves both primary sensory and motor cortices. However the generator sources of giant SEPs have not been fully understood as only one report describes clearly giant SEPs following lower limb stimulation. In our study we performed a combined EEG-MEG recording on responses elicited by electric median and tibial nerve stimulation in a patient who developed consequently to methyl bromide intoxication CM with giant SEPs to median and tibial nerve stimuli. SEPs wave shapes were identified on the basis of polarity-latency components (e.g. P15-N20-P25) as defined by earlier studies and guidelines. At EEG recording, the SEP giant component did not appear in the latency range of the first cortical component for median nerve SEP (N20), but appeared instead in the range of the P37 tibial nerve SEP, which is currently identified as the first cortical component elicited by tibial nerve stimuli. Our MEG and EEG SEPs recordings also showed that components in the latency range of P37 were preceded by other cortical components. These findings suggest that lower limb P37 does not correspond to upper limb N20. MEG results confirmed that giant SEFs are the second component from both tibial (N43m-P43m) and median (N27m-P27m) nerve stimulation. MEG dipolar sources of these giant components were located in the primary sensory and motor area.

  1. In Vivo Photonic Stimulation of Sciatic Nerve with a 1470 nm Laser

    PubMed Central

    Dautrebande, Marie; Doguet, Pascal; Gorza, Simon-Pierre; Delbeke, Jean; Botquin, Yohan; Nonclercq, Antoine

    2016-01-01

    Photonic stimulation is a new modality of nerve stimulation, which could overcome some of the electrical stimulation limitations. In this paper, we present the results of photonic stimulation of rodent sciatic nerve with a 1470 nm laser. Muscle activation was observed with radiant exposure of 0.084 J/cm². PMID:27990230

  2. Optimal pulse shapes for magnetic stimulation of fibers: An analytical approach using the excitation functional.

    PubMed

    Suarez-Bagnasco, Diego; Armentano-Feijoo, R; Suarez-Antola, R

    2010-01-01

    An analytical approach to threshold problems in functional magnetic stimulation of nerve and skeletal muscle fibers was recently proposed, framed in the concept of excitation functional. Three generations of available equipments for magnetic stimulation are briefly considered, stressing the corresponding pulse shape in the stimulation coils. Using the criterion of minimum energy dissipated in biological tissues, an optimal shape for a current pulse in the coil that produces a just threshold depolarization in a nerve or skeletal muscle fiber is found. The method can be further developed and applied to other threshold problems in functional electric stimulation.

  3. [Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

    PubMed

    Tang, Zheng-Yu; Wang, Hui-Quan; Xia, Xiao-Lei; Tang, Yi; Peng, Wei-Wei; Hu, Li

    2017-06-25

    Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

  4. Acceleration of peripheral nerve regeneration through asymmetrically porous nerve guide conduit applied with biological/physical stimulation.

    PubMed

    Kim, Jin Rae; Oh, Se Heang; Kwon, Gu Birm; Namgung, Uk; Song, Kyu Sang; Jeon, Byeong Hwa; Lee, Jin Ho

    2013-12-01

    Sufficient functional restoration of damaged peripheral nerves is a big clinical challenge. In this study, a nerve guide conduit (NGC) with selective permeability was prepared by rolling an asymmetrically porous polycaprolactone/Pluronic F127 membrane fabricated using a novel immersion precipitation method. Dual stimulation (nerve growth factor [NGF] as a biological stimulus and low-intensity pulse ultrasound [US] as a physical stimulus) was adapted to enhance nerve regeneration through an NGC. The animal study revealed that each stimulation (NGF or US) has a positive effect to promote the peripheral nerve regeneration through the NGC, however, the US-stimulated NGC group allowed more accelerated nerve regeneration compared with the NGF-stimulated group. The NGC group that received dual stimulation (NGF and US) showed more effective nerve regeneration behavior than the groups that received a single stimulation (NGF or US). The asymmetrically porous NGC with dual NGF and US stimulation may be a promising strategy for the clinical treatment of delayed and insufficient functional recovery of a peripheral nerve.

  5. Spinal cord stimulation suppresses bradycardias and atrial tachyarrhythmias induced by mediastinal nerve stimulation in dogs.

    PubMed

    Cardinal, René; Pagé, Pierre; Vermeulen, Michel; Bouchard, Caroline; Ardell, Jeffrey L; Foreman, Robert D; Armour, J Andrew

    2006-11-01

    Spinal cord stimulation (SCS) applied to the dorsal aspect of the cranial thoracic cord imparts cardioprotection under conditions of neuronally dependent cardiac stress. This study investigated whether neuronally induced atrial arrhythmias can be modulated by SCS. In 16 anesthetized dogs with intact stellate ganglia and in five with bilateral stellectomy, trains of five electrical stimuli were delivered during the atrial refractory period to right- or left-sided mediastinal nerves for up to 20 s before and after SCS (20 min). Recordings were obtained from 191 biatrial epicardial sites. Before SCS (11 animals), mediastinal nerve stimulation initiated bradycardia alone (12 nerve sites), bradycardia followed by tachyarrhythmia/fibrillation (50 sites), as well as tachyarrhythmia/fibrillation without a preceding bradycardia (21 sites). After SCS, the number of responsive sites inducing bradycardia was reduced by 25% (62 to 47 sites), and the cycle length prolongation in residual bradycardias was reduced. The number of responsive sites inducing tachyarrhythmia was reduced by 60% (71 to 29 sites). Once elicited, residual tachyarrhythmias arose from similar epicardial foci, displaying similar dynamics (cycle length) as in control states. In the absence of SCS, bradycardias and tachyarrhythmias induced by repeat nerve stimulation were reproducible (five additional animals). After bilateral stellectomy, SCS no longer influenced neuronal induction of bradycardia and atrial tachyarrhythmias. These data indicate that SCS obtunds the induction of atrial arrhythmias resulting from excessive activation of intrinsic cardiac neurons and that such protective effects depend on the integrity of nerves coursing via the subclavian ansae and stellate ganglia.

  6. Ultrasound and electrical nerve stimulation-guided S1 nerve root block.

    PubMed

    Sato, Masaki; Mikawa, Yasuhito; Matuda, Akiko

    2013-10-01

    A selective lumbosacral nerve root block is generally is performed under X-ray fluoroscopy, which has the disadvantage of radiation exposure and the need for fluoroscopy equipment. In this study, we assessed the effectiveness of ultrasound and nerve stimulation-guided S1 nerve root block on 37 patients with S1 radicular syndrome. With the patient in a prone position, an ultrasound scan was performed by placing the probe parallel to the body axis. The needle was pointed slightly medial from the lateral side of the probe and advanced toward a hyperechoic area in the sacral foramina with ultrasound guidance. Contrast medium was then injected and its dispersion confirmed by fluoroscopy. The acquired contrast images were classified into intraneural, perineural, and paraneural patterns. The significance of differences in the effect of the block among the contrast image patterns was analyzed. After nerve block, decreased sensation at the S1 innervated region and pain relief was achieved in all patients. No significant difference was noted in the effect of the block between perineural and paraneural patterns. In conclusion, this technique provided reliable S1 nerve root block in patients with S1 radicular syndrome and minimized radiation exposure.

  7. Hypothalamic stimulation and baroceptor reflex interaction on renal nerve activity.

    NASA Technical Reports Server (NTRS)

    Wilson, M. F.; Ninomiya, I.; Franz, G. N.; Judy, W. V.

    1971-01-01

    The basal level of mean renal nerve activity (MRNA-0) measured in anesthetized cats was found to be modified by the additive interaction of hypothalamic and baroceptor reflex influences. Data were collected with the four major baroceptor nerves either intact or cut, and with mean aortic pressure (MAP) either clamped with a reservoir or raised with l-epinephrine. With intact baroceptor nerves, MRNA stayed essentially constant at level MRNA-0 for MAP below an initial pressure P1, and fell approximately linearly to zero as MAP was raised to P2. Cutting the baroceptor nerves kept MRNA at MRNA-0 (assumed to represent basal central neural output) independent of MAP. The addition of hypothalamic stimulation produced nearly constant increments in MRNA for all pressure levels up to P2, with complete inhibition at some level above P2. The increments in MRNA depended on frequency and location of the stimulus. A piecewise linear model describes MRNA as a linear combination of hypothalamic, basal central neural, and baroceptor reflex activity.

  8. Hypothalamic stimulation and baroceptor reflex interaction on renal nerve activity.

    NASA Technical Reports Server (NTRS)

    Wilson, M. F.; Ninomiya, I.; Franz, G. N.; Judy, W. V.

    1971-01-01

    The basal level of mean renal nerve activity (MRNA-0) measured in anesthetized cats was found to be modified by the additive interaction of hypothalamic and baroceptor reflex influences. Data were collected with the four major baroceptor nerves either intact or cut, and with mean aortic pressure (MAP) either clamped with a reservoir or raised with l-epinephrine. With intact baroceptor nerves, MRNA stayed essentially constant at level MRNA-0 for MAP below an initial pressure P1, and fell approximately linearly to zero as MAP was raised to P2. Cutting the baroceptor nerves kept MRNA at MRNA-0 (assumed to represent basal central neural output) independent of MAP. The addition of hypothalamic stimulation produced nearly constant increments in MRNA for all pressure levels up to P2, with complete inhibition at some level above P2. The increments in MRNA depended on frequency and location of the stimulus. A piecewise linear model describes MRNA as a linear combination of hypothalamic, basal central neural, and baroceptor reflex activity.

  9. Vagus nerve stimulation therapy in partial epilepsy: a review.

    PubMed

    Panebianco, Mariangela; Zavanone, Chiara; Dupont, Sophie; Restivo, Domenico A; Pavone, Antonino

    2016-09-01

    Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked epileptic seizures. The majority of people given a diagnosis of epilepsy have a good prognosis, but 20-30 % will develop drug-resistant epilepsy. Vagus nerve stimulation (VNS) is a neuromodulatory treatment that is used as an adjunctive therapy for treating people with medically refractory epilepsy. It consists of chronic intermittent electrical stimulation of the vagus nerve, delivered by a programmable pulse generator (Neuro-Cybernetic Prosthesis). In 1997, the Food and Drug Administration approved VNS as adjunctive treatment for medically refractory partial-onset seizures in adults and adolescents. This article reviews the literature from 1988 to nowadays. We discuss thoroughly the anatomy and physiology of vagus nerve and the potential mechanisms of actions and clinical applications involved in VNS therapy, as well as the management, safety, tolerability and effectiveness of VNS therapy. VNS for partial seizures appears to be an effective and well tolerated treatment in adult and pediatric patients. People noted improvements in feelings of well-being, alertness, memory and thinking skills, as well as mood. The adverse effect profile is substantially different from the adverse effect profile associated with antiepileptic drugs, making VNS a potential alternative for patients with difficulty tolerating antiepileptic drug adverse effects. Despite the passing years and the advent of promising neuromodulation technologies, VNS remains an efficacy treatment for people with medically refractory epilepsy. Past and ongoing investigations in other indications have provided signals of the therapeutic potential in a wide variety of conditions.

  10. Investigation of facial motor pathways by electrical and magnetic stimulation: sites and mechanisms of excitation.

    PubMed Central

    Rösler, K M; Hess, C W; Schmid, U D

    1989-01-01

    A refined technique is described for non invasive examination of the facial motor pathways by stimulation of the extra- and intracranial segment of the facial nerve and the facial motor cortex. Surface recordings from the nasalis muscle rather than from the orbicularis oris muscle were used, since the compound muscle action potential (CMAP) from this muscle showed a more clearly defined onset. Electrical extracranial stimulation of the facial nerve at the stylomastoid fossa in 14 healthy subjects yielded a mean distal motor latency of 3.7 ms (SD 0.46), comparable with reported latencies to the orbicularis oris muscle. Using a magnetic stimulator, transcranial stimulation of the facial nerve was performed. The mechanism of transcranial magnetic facial nerve stimulation was studied using recordings on 12 patients who had facial nerve lesions at different locations, and with intraoperative direct measurements in four patients undergoing posterior fossa surgery. The actual site of stimulation could be localised to the proximal part of the facial canal, and a mean "transosseal conduction time" of 1.2 ms (SD 0.18) was calculated. The cerebrospinal fluid (CSF) played an important role in mediating the magnetically induced stimulating currents. Finally, with transcranial magnetic stimulation of the facial motor cortex, clearly discernible CMAPs could be produced when voluntary activation of several facial muscles was used to facilitate the responses. From this, a central motor conduction time of 5.1 ms was calculated (SD 0.60, 6 subjects). PMID:2795040

  11. Alternative Paradigm of Selective Vagus Nerve Stimulation Tested on an Isolated Porcine Vagus Nerve

    PubMed Central

    2014-01-01

    Alternative paradigm for spatial and fibre-type selective vagus nerve stimulation (VNS) was developed using realistic structural topography and tested in an isolated segment of a porcine cervical left vagus nerve (LVN). A spiral cuff (cuff) containing a matrix of ninety-nine electrodes was developed for selective VNS. A quasitrapezoidal stimulating pulse (stimulus) was applied to the LVN via an appointed group of three electrodes (triplet). The triplet and stimulus were configured to predominantly stimulate the B-fibres, minimizing stimulation of the A-fibres and by-passing the stimulation of the C-fibres. To assess which fibres made the most probable contribution to the neural response (NR) during selective VNS, the distribution of conduction velocity (CV) within the LVN was considered. Experimental testing of the paradigm showed the existence of certain parameters and waveforms of the stimulus, for which the contribution of the A-fibres to the NR was slightly reduced and that of the B-fibres was slightly enlarged. The cuff provided satisfactory fascicle discrimination in selective VNS as well as satisfactory fascicle discrimination during NR recording. However, in the present stage of development, fibre-type VNS remained rather limited. PMID:24683328

  12. Percutaneous tibial nerve stimulation vs sacral nerve stimulation for faecal incontinence: a comparative case-matched study.

    PubMed

    Al Asari, S; Meurette, G; Mantoo, S; Kubis, C; Wyart, V; Lehur, P-A

    2014-11-01

    The study assessed the initial experience with posterior tibial nerve stimulation (PTNS) for faecal incontinence and compared it with sacral nerve stimulation (SNS) performed in a single centre during the same timespan. A retrospective review of a prospectively collected database was conducted at the colorectal unit, University Hospital, Nantes, France, from May 2009 to December 2010. Seventy-eight patients diagnosed with chronic severe faecal incontinence underwent neurostimulation including PTNS in 21 and SNS in 57. The main outcome measures were faecal incontinence (Wexner score) and quality of life (Fecal Incontinence Quality of Life, FIQL) scores in a short-term follow-up. No significant differences were observed in patients' characteristics. Of 57 patients having SNS, 18 (32%) failed peripheral nerve evaluation and 39 (68%) received a permanent implant. Two (5%) developed a wound infection. No adverse effects were recorded in the PTNS group. There was no significant difference in the mean Wexner and FIQL scores between patients having PTNS and SNS at 6 (P = 0.39 and 0.09) and 12 months (P = 0.79 and 0.37). A 50% or more improvement in Wexner score was seen at 6 and 12 months in 47% and 30% of PTNS patients and in 50% and 58% of SNS patients with no significant difference between the groups. Posterior tibial nerve stimulation is a valid method of treating faecal incontinence in the short term when conservative treatment has failed. It is easier, simpler, cheaper and less invasive than SNS with a similar short-term outcome. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

  13. Temporal pattern of stimulation modulates reflex bladder activation by pudendal nerve stimulation.

    PubMed

    McGee, Meredith J; Grill, Warren M

    2016-11-01

    Reflex bladder activation and inhibition by electrical stimulation of pudendal nerve (PN) afferents is a promising approach to restore control of bladder function in persons with lower urinary tract dysfunction caused by disease or injury. The objective of this work was to determine whether bladder activation evoked by pudendal afferent stimulation was dependent on the temporal pattern of stimulation, and whether specific temporal patterns of stimulation produced larger bladder contractions than constant frequency stimulation. The mean and maximum contraction pressures evoked by different temporal patterns of stimulation of the dorsal genital branch of the pudendal nerve were measured under isovolumetric conditions in α-chloralose anesthetized cats. A computational model of the spinal neural network mediating the pudendo-vesical reflex was used to understand the mechanisms of different bladder responses to patterned stimulation. The pattern of stimulation significantly affected the magnitude of evoked bladder contractions; several temporal patterns were as effective as regular stimulation, but no pattern evoked larger bladder contractions. Random patterns and patterns with pauses, burst-like activity, or high frequency components evoked significantly smaller bladder contractions, supporting the use of regular frequency stimulation in the development of neural prosthetic approaches for bladder control. These results reveal that the bladder response to pudendal afferent stimulation is dependent on the pattern, as well as the frequency, of stimulation. The computational model revealed that the effects of patterned pudendal afferent stimulation were determined by the dynamic properties of excitatory and inhibitory interneurons in the lumbosacral spinal cord. Neurourol. Urodynam. 35:882-887, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  14. The pig as preclinical model for laparoscopic vagus nerve stimulation.

    PubMed

    Wolthuis, A M; Stakenborg, N; D'Hoore, A; Boeckxstaens, G E

    2016-02-01

    Cervical vagus nerve stimulation (VNS) prevents manipulation-induced intestinal inflammation and improves intestinal transit in a mouse model of postoperative ileus (POI). Cervical VNS, however, is accompanied by cardiovascular and respiratory side effects. In view of potential clinical application, we therefore evaluated the safety and feasibility of abdominal VNS via laparoscopic approach in a porcine model. Six pigs were used in a non-survival study for both cervical and abdominal VNS. Two cardiac pacing electrodes were positioned around the right cervical and posterior abdominal vagus nerve and connected to an external stimulator. VNS was performed using four different settings (5 and 20 Hz, 0.5 and 1 ms pulse width) during 2 min with ECG recording. Laparoscopic VNS was timed and videotaped, and technical difficulties were noted. A validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire was used to evaluate the task and workload. The procedure was completed in all pigs with 4-port laparoscopic technique. Cervical and abdominal VNS were performed after correct identification and isolation of the nerve, and positioning of the electrodes around the nerve. Median laparoscopic operating time was 16 min (range 8-33 min), and median NASA-TLX was 31 (range 11-74). No major complications were encountered. Reduction of heart rate was between 5.5 and 14% for cervical VNS and undetectable for abdominal VNS. In a porcine model, laparoscopic VNS is feasible and safe with cardiac pacing electrodes and may lead to a similar novel approach in humans in the near future.

  15. Operative and technical complications of vagus nerve stimulator implantation.

    PubMed

    Spuck, Sebastian; Tronnier, Volker; Orosz, Iren; Schönweiler, Rainer; Sepehrnia, Abolgassem; Nowak, Georg; Sperner, Jürgen

    2010-12-01

    The treatment of refractory epilepsy by vagus nerve stimulation (VNS) is a well-established therapy option for patients not suitable for epilepsy surgery and therapy refractory depressions. To analyze surgical and technical complications after implantation of left-sided VNS in patients with therapy-refractory epilepsy and depression. One hundred five patients receiving a VNS or VNS-related operations (n = 118) from 1999 to 2008 were investigated retrospectively. At the time of operation, 84 patients were younger than 18 years, with a mean age of 10.5 years. Twenty (19%) patients had technical problems or complications. In 6 (5.7%) patients these problems were caused by the operation. The device was removed in 8 cases. The range of surgically and technically induced complications included electrode fractures, early and late onset of deep wound infections, transient vocal cord palsy, cardiac arrhythmia under test stimulation, electrode malfunction, and posttraumatic dysfunction of the stimulator. VNS therapy is combined with a wide spread of possible complications. Technical problems are to be expected, including electrode fracture, dislocation, and generator malfunction. The major complication in younger patients is the electrode fracture, which might be induced by growth during adolescence. Surgically induced complications of VNS implantation are comparably low. Cardiac symptoms and recurrent nerve palsy need to be taken into consideration.

  16. Mapping for Acute Transvenous Phrenic Nerve Stimulation Study (MAPS Study).

    PubMed

    Dekker, Lukas R C; Gerritse, Bart; Scheiner, Avram; Kornet, Lilian

    2017-03-01

    Central sleep apnea syndrome, correlated with the occurrence of heart failure, is characterized by periods of insufficient ventilation during sleep. This acute study in 15 patients aims to map the venous system and determine if diaphragmatic movement can be achieved by phrenic nerve stimulation at various locations within the venous system. Subjects underwent a scheduled catheter ablation procedure. During the procedural waiting time, one multielectrode electrophysiology catheter was subsequently placed at the superior and inferior vena cava and the junctions of the left jugular and left brachiocephalic vein and right jugular and right brachiocephalic vein, for phrenic nerve stimulation (1-2 seconds ON/2-3 seconds OFF, 40 Hz, pulse width 210 μs). Diaphragmatic movement was assessed manually and by a breathing mask. During a follow-up assessment between 2 and 4 weeks postprocedure, occurrence of adverse events was assessed. In all patients diaphragmatic movement was induced at one or more locations using a median threshold of at least 2 V and maximally 7.5 V (i.e., e 3.3 mA, 14.2 mA). The lowest median current to obtain diaphragmatic stimulation without discomfort was found for the right brachiocephalic vein (4.7 mA). In 12/15 patients diaphragmatic movement could be induced without any discomfort, but in three patients hiccups occurred. Diaphragmatic stimulation from the brachiocephalic and caval veins is feasible. Potential side effects should be eliminated by adapting the stimulation pattern. This information could be used to design a catheter, combining cardiac pacing with enhancing diaphragm movement during a sleep apnea episode. © 2017 Wiley Periodicals, Inc.

  17. Bilateral transcutaneous tibial nerve stimulation for chronic constipation.

    PubMed

    Iqbal, F; Collins, B; Thomas, G P; Askari, A; Tan, E; Nicholls, R J; Vaizey, C J

    2016-02-01

    Chronic constipation is difficult to treat when symptoms are intractable. Colonic propulsion may be altered by distal neuromodulation but this is conventionally delivered percutaneously. Transcutaneous tibial nerve stimulation is noninvasive and cheap: this study aimed to assess its efficacy in chronic constipation. Eighteen patients (median age 46 years, 12 female) with chronic constipation were recruited consecutively. Conservative and behavioural therapy had failed to improve symptoms in all 18. Thirty minutes of daily bilateral transcutaneous tibial nerve stimulation was administered by each patient at home for 6 weeks. The primary outcome measure was a change in the Patient Assessment of Constipation Quality of Life (PAC-QoL) score. Change in Patient Assessment of Constipation Symptoms (PAC-SYM), weekly bowel frequency and visual analogue scale (VAS) score were also measured. Fifteen patients (12 female) completed the trial. The PAC-QoL score improved significantly with treatment [pretreatment, median 2.95, interquartile range (IQR) 1.18; posttreatment, median 2.50, IQR 0.70; P = 0.047]. There was no change in PAC-SYM score (pretreatment, median 2.36, IQR 1.59; posttreatment, median 2.08, IQR 0.92; P = 0.53). Weekly stool frequency improved as did VAS score, but these did not reach statistical significance (P = 0.229 and 0.161). The PAC-QoL and PAC-SYM scores both improved in four (26%) patients. Two patients reported complete cure. There were no adverse events reported. Bilateral transcutaneous tibial nerve stimulation appears to be effective in a quarter of patients with chronic constipation. Carefully selected patients with less severe disease may benefit more. This requires further study. Colorectal Disease © 2015 The Association of Coloproctology of Great Britain and Ireland.

  18. Treatment of post-amputation pain with peripheral nerve stimulation.

    PubMed

    Rauck, Richard L; Cohen, Steven P; Gilmore, Christopher A; North, James M; Kapural, Leonardo; Zang, Rosemary H; Grill, Julie H; Boggs, Joseph W

    2014-02-01

    Present treatment methods are often unsatisfactory in reducing post-amputation pain. Peripheral nerve stimulation (PNS) could reduce the pain, but it is rarely used because present methods require invasive surgical access and precise placement of the leads in close proximity (≤ 2 mm) with the nerve. The present study investigated the feasibility of delivering PNS to patients with moderate-to-severe post-amputation pain in the lower extremity using a fine-wire lead placed percutaneously under ultrasound guidance a remote distance (0.5-3.0 cm) away from the sciatic and/or femoral nerves. Fourteen of the 16 subjects who completed in-clinic testing responded to stimulation, reported ≥ 75% paresthesia coverage, obtained clinically significant pain relief, and proceeded to a two-week home trial with a percutaneous PNS system. Two of the 14 responders had their leads removed early because of accidental dislodgement (N = 2), two had temporary discomfort near the lead (N = 2), and one had return of post-amputation pain despite stimulation (N = 1) and did not complete the home trial. The nine responders who completed the home trial reported reductions in their mean daily worst post-amputation pain (56 ± 26%, 56 ± 26%, N = 9), average residual limb pain (72 ± 28%, 42 ± 27%, N = 7), average phantom limb pain (81 ± 28%, 47 ± 48%, N = 7), residual limb pain interference (81 ± 27%, 53 ± 17%, N = 6), phantom limb pain interference (83 ± 31%, 56 ± 46%, N = 7), and Pain Disability Index (70 ± 38%, 55 ± 32%, N = 9) during the second week of stimulation and four weeks after the end of stimulation, respectively. All nine responders rated their change in quality of life as improved at the end of stimulation and at the end of the four-week follow-up period. Subjects reported minor decreases in the Beck Depression Inventory scores (43 ± 51%, 32 ± 57%, N = 9). Most subjects had no substantial changes other than minor decreases (N = 3) in pain medication. Achievement of

  19. Review of Recent Advances in Peripheral Nerve Stimulation (PNS).

    PubMed

    Chakravarthy, Krishnan; Nava, Andrew; Christo, Paul J; Williams, Kayode

    2016-11-01

    Peripheral nerve stimulation (PNS) for the treatment of chronic pain has become an increasingly important field in the arena of neuromodulation, given the ongoing advances in electrical neuromodulation technology since 1999 permitting minimally invasive approaches using an percutaneous approach as opposed to implantable systems. Our review aims to provide clinicians with the recent advances and studies in the field, with specific emphasis on clinical data and indications that have been accumulated over the last several years. In addition, we aim to address key basic science studies to further emphasize the importance of translational research outcomes driving clinical management.

  20. Vagus nerve stimulation therapy summary: five years after FDA approval.

    PubMed

    Schachter, Steven C

    2002-09-24

    With more than 16,000 patients implanted with the vagus nerve stimulation (VNS) therapy system (Cyberonics, Inc., Houston, Texas), VNS therapy has assumed an increasingly important role in the treatment of medically refractory seizures since its approval 5 years ago by the United States FDA. This review discusses the clinical trials that provided evidence for the approval, long-term efficacy, efficacy in special populations and co-morbid conditions, and safety and tolerability. Additional studies are suggested to further explore the capabilities of VNS therapy.

  1. Peripheral nerve stimulation for the treatment of neuropathic craniofacial pain.

    PubMed

    Slavin, K V

    2007-01-01

    Treatment of neuropathic pain in the region of head and face presents a challenging problem for pain specialists. In particular, those patients who do not respond to conventional treatment modalities usually continue to suffer from pain due to lack of reliable medical and surgical approaches. Peripheral nerve stimulation (PNS) has been used for treatment of neuropathic pain for many decades, but only recently it has been systematically applied to the craniofacial region. Here we summarize published experience with PNS in treatment of craniofacial pain and discuss some technical details of the craniofacial PNS procedure.

  2. Sacral Nerve Stimulation for the Management of Voiding Dysfunction

    PubMed Central

    Das, Anurag K; White, Mark D; Longhurst, Penelope A

    2000-01-01

    Voiding dysfunction is common, and patients with urge incontinence, frequency/urgency syndromes, and chronic urinary retention are challenging to treat once conservative therapies (such as pharmacologic agents, pelvic floor rehabilitation, and intermittent catheterization) have been exhausted. Sacral nerve stimulation (SNS) is a new, minimally invasive, reversible therapy for the management of refractory voiding dysfunction and provides an attractive therapeutic alternative for patients with this condition. In this review, the role of SNS in the management of voiding dysfunction is examined critically, and the efficacy, risks, and benefits of this new modality are evaluated. PMID:16985735

  3. BOLD fMRI activation induced by vagus nerve stimulation in seizure patients

    PubMed Central

    Liu, W; Mosier, K; Kalnin, A; Marks, D

    2003-01-01

    Design: Blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) was employed to detect areas of the brain activated by vagus nerve stimulation in five patients with documented complex partial seizures. Methods: Functional MRI was done on a GE 1.5T Echospeed horizon scanner. Before each patient entered the scanner, the vagal nerve stimulator was set to a specific ON–OFF paradigm so that the data could be analysed using a box-car type of design. The brains were scanned both anatomically and functionally. The functional images were corrected for head motion and co-registered to the anatomical images. Maps of the activated areas were generated and analysed using the brain mapping software, SPM99. The threshold for activation was chosen as p < 0.001. Results: All patients showed activation in the frontal and occipital lobes. However, activation in the thalamus was seen only in the two patients with improved seizure control. Conclusions: BOLD fMRI can detect activation associated with vagus nerve stimulation. There may be a relation between thalamic activation and a favourable clinical outcome. PMID:12754361

  4. Vagus Nerve and Vagus Nerve Stimulation, a Comprehensive Review: Part II.

    PubMed

    Yuan, Hsiangkuo; Silberstein, Stephen D

    2016-02-01

    The development of vagus nerve stimulation (VNS) began in the 19th century. Although it did not work well initially, it introduced the idea that led to many VNS-related animal studies for seizure control. In the 1990s, with the success of several early clinical trials, VNS was approved for the treatment of refractory epilepsy, and later for the refractory depression. To date, several novel electrical stimulating devices are being developed. New invasive devices are designed to automate the seizure control and for use in heart failure. Non-invasive transcutaneous devices, which stimulate auricular VN or carotid VN, are also undergoing clinical trials for treatment of epilepsy, pain, headache, and others. Noninvasive VNS (nVNS) exhibits greater safety profiles and seems similarly effective to their invasive counterpart. In this review, we discuss the history and development of VNS, as well as recent progress in invasive and nVNS.

  5. A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty

    PubMed Central

    Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre

    2014-01-01

    Objective: To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. Data Sources: PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Review Methods: Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. Results: A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. Conclusion: This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality. PMID:26770730

  6. A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty.

    PubMed

    Beckwée, David; Bautmans, Ivan; Swinnen, Eva; Vermet, Yorick; Lefeber, Nina; Lievens, Pierre; Vaes, Peter

    2014-01-01

    To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2) that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.

  7. Percutaneous tibial nerve stimulation: the Urgent PC device.

    PubMed

    van Balken, Michael R

    2007-09-01

    Lower urinary tract disorders, with its main representative the overactive bladder, are an increasing problem that impact patients' quality of life tremendously. Neuromodulative treatment may fill the gap between conservative measures and invasive surgery. Percutaneous tibial nerve stimulation (Urgent PC) is a neuromodulation technique that is minimally invasive and easy to perform. Stimulation is carried out in 12 weekly sessions of 30 min each, through a percutaneously placed needle cephalad to the medial malleolus. Success can be obtained in approximately two-thirds of patients, but the therapy has the disadvantage of the necessity of maintenance therapy. The development of a small implantable device may be the future next step in the evolution of the technique.

  8. Post-stimulation block of frog sciatic nerve by high-frequency (kHz) biphasic stimulation.

    PubMed

    Yang, Guangning; Xiao, Zhiying; Wang, Jicheng; Shen, Bing; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2017-04-01

    This study determined if high-frequency biphasic stimulation can induce nerve conduction block that persists after the stimulation is terminated, i.e., post-stimulation block. The frog sciatic nerve-muscle preparation was used in the study. Muscle contraction force induced by low-frequency (0.5 Hz) nerve stimulation was recorded to indicate the occurrence and recovery of nerve block induced by the high-frequency (5 or 10 kHz) biphasic stimulation. Nerve block was observed during high-frequency stimulation and after termination of the stimulation. The recovery from post-stimulation block occurred in two distinct phases. During the first phase, the complete block induced during high-frequency stimulation was maintained. The average maximal duration for the first phase was 107 ± 50 s. During the second phase, the block gradually or abruptly reversed. The duration of both first and second phases was dependent on stimulation intensity and duration but not frequency. Stimulation of higher intensity (1.4-2 times block threshold) and longer duration (5 min) produced the longest period (249 ± 58 s) for a complete recovery. Post-stimulation block can be induced by high-frequency biphasic stimulation, which is important for future investigations of the blocking mechanisms and for optimizing the stimulation parameters or protocols in clinical applications.

  9. Continuous-wave infrared optical nerve stimulation for potential diagnostic applications

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Cilip, Christopher M.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2010-09-01

    Optical nerve stimulation using infrared laser radiation has recently been developed as a potential alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuous-wave (cw) infrared laser radiation for potential diagnostic applications. A thulium fiber laser (λ=1870 nm) is used for noncontact optical stimulation of the rat prostate cavernous nerves in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, is achieved with the laser operating in either cw mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation is observed to be primarily dependent on a threshold nerve temperature (42 to 45 °C), rather than an incident fluence, as previously reported. cw optical nerve stimulation provides a significantly faster ICP response time using a lower power (and also less expensive) laser than pulsed stimulation. cw optical nerve stimulation may therefore represent an alternative mode of stimulation for intraoperative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

  10. Continuous-wave vs. pulsed infrared laser stimulation of the rat prostate cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Cilip, Christopher M.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2011-03-01

    Optical nerve stimulation has recently been developed as an alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuouswave (CW) infrared laser radiation, for potential diagnostic applications. A Thulium fiber laser (λ = 1870 nm) was used for non-contact optical stimulation of the rat prostate cavernous nerves, in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, was achieved with the laser operating in either CW mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation was observed to be primarily dependent on a threshold nerve temperature (42-45 °C), not an incident fluence, as previously reported. CW optical nerve stimulation provides a significantly faster ICP response time using a laser with lower power output than pulsed stimulation. CW optical nerve stimulation may therefore represent an alternative mode of stimulation for intra-operative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

  11. Continuous-wave infrared optical nerve stimulation for potential diagnostic applications.

    PubMed

    Tozburun, Serhat; Cilip, Christopher M; Lagoda, Gwen A; Burnett, Arthur L; Fried, Nathaniel M

    2010-01-01

    Optical nerve stimulation using infrared laser radiation has recently been developed as a potential alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuous-wave (cw) infrared laser radiation for potential diagnostic applications. A thulium fiber laser (λ=1870 nm) is used for noncontact optical stimulation of the rat prostate cavernous nerves in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, is achieved with the laser operating in either cw mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation is observed to be primarily dependent on a threshold nerve temperature (42 to 45 °C), rather than an incident fluence, as previously reported. cw optical nerve stimulation provides a significantly faster ICP response time using a lower power (and also less expensive) laser than pulsed stimulation. cw optical nerve stimulation may therefore represent an alternative mode of stimulation for intraoperative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.

  12. Sacral nerve stimulation lead implantation using the o-arm

    PubMed Central

    2013-01-01

    Background Sacral neuromodulation operations have usually been performed based on 2D fluoro images. However, sacral nerve stimulation lead implantation may be challenging when the normal anatomy is confused by obesity or congenital anomalies. Thus the surgical navigation and intraoperative imaging methods could be helpful as those same methods have proven to be feasible methods for guiding other surgical operations. Our recent knowledge about the O-arm in trauma pelvic operations encouraged us to evaluate the usefulness of O-arm guided navigation in sacral neuromodulation. Similar navigation would be useful for complex sacral nerve stimulation lead implantations. Methods In this preliminary article we report our experience of utilizing the orthopedically optimized O-arm to implant the S3 stimulation electrode in a patient. The 3D O-arm imaging was performed intraoperatively under surgical navigation control. General anesthesia was used. The obtained 3D image dataset was registered automatically into the patient’s anatomy. The stimulation needle was guided and the tined lead electrode was implanted using navigation. Results The bony sacral structures were clearly visualized. Due to automatic registration, the navigation was practicable instantly after the O-arm scanning and operation could be performed successfully under navigation control. Conclusions To our knowledge, this is the first published tined lead implantation which was guided based on the surgical navigation and intraoperative O-arm images. In this case, the applied method was useful and helped the surgeon to demarcate the region of surgical interest. The method is slightly more invasive than the formal technique but could be an option in anatomically challenging cases and reoperations. However, further evaluation with larger patient series is required before definitive recommendations can be made. PMID:24131790

  13. Vagus Nerve and Vagus Nerve Stimulation, a Comprehensive Review: Part I.

    PubMed

    Yuan, Hsiangkuo; Silberstein, Stephen D

    2016-01-01

    The vagus nerve (VN), the "great wondering protector" of the body, comprises an intricate neuro-endocrine-immune network that maintains homeostasis. With reciprocal neural connections to multiple brain regions, the VN serves as a control center that integrates interoceptive information and responds with appropriate adaptive modulatory feedbacks. While most VN fibers are unmyelinated C-fibers from the visceral organs, myelinated A- and B-fiber play an important role in somatic sensory, motor, and parasympathetic innervation. VN fibers are primarily cholinergic but other noncholinergic nonadrenergic neurotransmitters are also involved. VN has four vagal nuclei that provide critical controls to the cardiovascular, respiratory, and alimentary systems. Latest studies revealed that VN is also involved in inflammation, mood, and pain regulation, all of which can be potentially modulated by vagus nerve stimulation (VNS). With a broad vagal neural network, VNS may exert a neuromodulatory effect to activate certain innate "protective" pathways for restoring health.

  14. Mechanism of orientation of stimulating currents in magnetic brain stimulation (abstract)

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Matsuda, T.

    1991-04-01

    We made a functional map of the human motor cortex related to the hand and foot areas by stimulating the human brain with a focused magnetic pulse. We observed that each functional area in the cortex has an optimum direction for which stimulating currents can produce neural excitation. The present report focuses on the mechanism which is responsible for producing this anisotropic response to brain stimulation. We first obtained a functional map of the brain related to the left ADM (abductor digiti minimi muscles). When the stimulating currents were aligned in the direction from the left to the right hemisphere, clear EMG (electromyographic) responses were obtained only from the left ADM to magnetic stimulation of both hemisphere. When the stimulating currents were aligned in the direction from the right to the left hemisphere, clear EMG signals were obtained only from the right ADM to magnetic stimulation of both hemisphere. The functional maps of the brain were sensitive to changes in the direction of the stimulating currents. To explain the phenomena obtained in the experiments, we developed a model of neural excitation elicited by magnetic stimulation. When eddy currents which are induced by pulsed magnetic fields flow in the direction from soma to the distal part of neural fiber, depolarized area in the distal part are excited, and the membrane excitation propagates along the nerve fiber. In contrast, when the induced currents flow in the direction from the distal part to soma, hyperpolarized parts block or inhibit neural excitation even if the depolarized parts near the soma can be excited. The model explains our observation that the orientation of the induced current vectors reflect both the functional and anatomical organization of the neural fibers in the brain.

  15. Electrophysiologic nerve stimulation for identifying the recurrent laryngeal nerve in thyroid surgery: review of 70 consecutive thyroid surgeries.

    PubMed

    Echeverri, A; Flexon, P B

    1998-04-01

    To describe a simple technique for identifying the recurrent laryngeal nerve (RLN) with a nerve stimulator to prevent damage to the nerve during thyroid surgery. A retrospective review of 70 thyroidectomies performed from October 1989 to January 1995 by one surgeon using electrophysiologic nerve stimulation to identify the RLN was conducted. The technique is described. Outpatient flexible fiberoptic laryngoscopy was performed preoperatively and postoperatively in all patients. From 70 thyroidectomies, 80 RLNs were identified to be at risk for injury. Five patients had transient unilateral vocal cord paresis postoperatively. No RLN transection or permanent vocal cord paralysis occurred. This is the first large series of patients undergoing the use of electrophysiologic nerve stimulation for identifying the RLN during thyroid surgery. We found the technique to be useful and safe for identifying the RLN. We present this technique as a less costly and time-consuming alternative to intraoperative RLN monitoring.

  16. Nerve stimulator-guided thoracic paravertebral block for gynecomastia surgery

    PubMed Central

    Jadon, Ashok

    2012-01-01

    Thoracic paravertebral block (TPVB) is gaining popularity for female breast surgeries due to various advantages like less nausea and vomiting and better post-operative pain relief, which helps in early ambulation and discharge from the hospital. Use of nerve stimulator during this block has further enhanced its success and safety profile. Male breast surgery is usually done either under general anaesthesia or local infiltrative anaesthesia combining with intravenous sedation. We postulated that the advantages of TPVB could be helpful for early mobilization and discharge of minor breast surgery in male patients. However, to our knowledge, there is no such report suggestive of TPVB for exclusive male breast surgery. We used nerve stimulator-guided TPVB for gynecomastia surgery in two patients where general anaesthesia was not feasible. Both patients had successful block and showed good post-operative recovery and were discharged on the same day. They had long post-operative pain relief without any block-related complication. A case report of two such cases of gynecomastia surgery (male breast surgery) done under TPVB is presented. PMID:22923833

  17. Nerve stimulator-guided thoracic paravertebral block for gynecomastia surgery.

    PubMed

    Jadon, Ashok

    2012-05-01

    Thoracic paravertebral block (TPVB) is gaining popularity for female breast surgeries due to various advantages like less nausea and vomiting and better post-operative pain relief, which helps in early ambulation and discharge from the hospital. Use of nerve stimulator during this block has further enhanced its success and safety profile. Male breast surgery is usually done either under general anaesthesia or local infiltrative anaesthesia combining with intravenous sedation. We postulated that the advantages of TPVB could be helpful for early mobilization and discharge of minor breast surgery in male patients. However, to our knowledge, there is no such report suggestive of TPVB for exclusive male breast surgery. We used nerve stimulator-guided TPVB for gynecomastia surgery in two patients where general anaesthesia was not feasible. Both patients had successful block and showed good post-operative recovery and were discharged on the same day. They had long post-operative pain relief without any block-related complication. A case report of two such cases of gynecomastia surgery (male breast surgery) done under TPVB is presented.

  18. Posterior tibial nerve stimulation for fecal incontinence: where are we?

    PubMed

    George, Anil Thomas; Maitra, Rudra Krishna; Maxwell-Armstrong, Charles

    2013-12-28

    Neurostimulation remains the mainstay of treatment for patients with faecal incontinence who fails to respond to available conservative measures. Sacral nerve stimulation (SNS) is the main form of neurostimulation that is in use today. Posterior tibial nerve stimulation (PTNS)--both the percutaneous and the transcutaneous routes--remains a relatively new entry in neurostimulation. Though in its infancy, PTNS holds promise to be an effective, patient friendly, safe and cheap treatment. However, presently PTNS only appears to have a minor role with SNS having the limelight in treating patients with faecal incontinence. This seems to have arisen as the strong, uniform and evidence based data on SNS remains to have been unchallenged yet by the weak, disjointed and unsupported evidence for both percutaneous and transcutaneous PTNS. The use of PTNS is slowly gaining acceptance. However, several questions remain unanswered in the delivery of PTNS. These have raised dilemmas which as long as they remain unsolved can considerably weaken the argument that PTNS could offer a viable alternative to SNS. This paper reviews available information on PTNS and focuses on these dilemmas in the light of existing evidence.

  19. Median nerve stimulation reduces ventricular arrhythmias induced by dorsomedial hypothalamic stimulation.

    PubMed

    Zhao, Shuang; Tang, Min; Yuan, Kexin; Gu, Jingli; Yu, Jun; Long, Xiaoyang; Liu, Miaomiao; Cao, Ji-Min; Zhang, Shu

    2016-12-01

    This study tested the hypothesis that median nerve stimulation (MNS) prevents ventricular arrhythmias (VAs) induced by dorsomedial hypothalamus stimulation (DMHS) and investigated the electrophysiological mechanisms underlying the anti-arrhythmic effects of MNS by recording left stellate ganglion activity (LSGA). Eighteen rabbits were anesthetized, the median nerve was anchored by stimulating electrodes, and a bipolar electrode was implanted into the LSG to record nerve activity. The DMH was stimulated to induce arrhythmia. All animals underwent six repetitions of DMHS (30 s). The 18 rabbits were divided into the following 3 groups: a control group, which underwent only DMHS (n = 6); an MNS group, which underwent MNS during both the third and fourth DMHS repetitions (n = 6); and an LSGA-recording group, for which LSGA was recorded at baseline, immediately following DMHS and again immediately following MNS and DMHS (n = 6). Repeated DMHS-induced multiple VAs, in the rabbits. Compared with the DMHS-only group, the concurrent administration of MNS during DMHS significantly reduced the incidence of VAs (7 ± 3 and 9 ± 2 beats for the third and fourth DMHS + MNS repetitions vs. 29 ± 8 and 27 ± 9 beats for the first two DMHS repetitions, p < 0.05). The total duration of the abnormal discharges of the LSG (ADLSG) following MNS and DMHS was significantly reduced compared with that of the DMHS-only group (40 ± 18 vs. 14 ± 6 s, p < 0.05). MNS reduced VAs induced by DMHS, which is thought to be mediated through suppressing of ADLSG. Median nerve electrical stimulation prevented ventricular arrhythmias induced by DMHS through the mechanism of suppressing abnormal discharges of left stellate ganglion.

  20. Posterior tibial nerve stimulation vs parasacral transcutaneous neuromodulation for overactive bladder in children.

    PubMed

    Barroso, Ubirajara; Viterbo, Walter; Bittencourt, Joana; Farias, Tiago; Lordêlo, Patrícia

    2013-08-01

    Parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation have emerged as effective methods to treat overactive bladder in children. However, to our knowledge no study has compared the 2 methods. We evaluated the results of parasacral transcutaneous electrical nerve stimulation and posterior tibial nerve stimulation in children with overactive bladder. We prospectively studied children with overactive bladder without dysfunctional voiding. Success of treatment was evaluated by visual analogue scale and dysfunctional voiding symptom score, and by level of improvement of each specific symptom. Parasacral transcutaneous electrical nerve stimulation was performed 3 times weekly and posterior tibial nerve stimulation was performed once weekly. A total of 22 consecutive patients were treated with posterior tibial nerve stimulation and 37 with parasacral transcutaneous electrical nerve stimulation. There was no difference between the 2 groups regarding demographic characteristics or types of symptoms. Concerning the evaluation by visual analogue scale, complete resolution of symptoms was seen in 70% of the group undergoing parasacral transcutaneous electrical nerve stimulation and in 9% of the group undergoing posterior tibial nerve stimulation (p = 0.02). When the groups were compared, there was no statistically significant difference (p = 0.55). The frequency of persistence of urgency and diurnal urinary incontinence was nearly double in the group undergoing posterior tibial nerve stimulation. However, this difference was not statistically significant. We found that parasacral transcutaneous electrical nerve stimulation is more effective in resolving overactive bladder symptoms, which matches parental perception. However, there were no statistically significant differences in the evaluation by dysfunctional voiding symptom score, or in complete resolution of urgency or diurnal incontinence. Copyright © 2013 American Urological

  1. Vagus nerve stimulation for standardized monitoring: technical notes for conventional and endoscopic thyroidectomy.

    PubMed

    Dionigi, Gianlorenzo; Kim, Hoon Yub; Wu, Che-Wei; Lavazza, Matteo; Ferrari, Cesare; Leotta, Andrea; Spampatti, Sebastiano; Rovera, Francesca; Rausei, Stefano; Boni, Luigi; Chiang, Feng-Yu

    2013-09-01

    Standardization of the intraoperative neuromonitoring (IONM) technique is an essential aspect of modern monitored thyroid surgery. The standardized technique involves vagal nerve stimulation. VN stimulation is useful for technical problem solving, detecting non-recurrent laryngeal nerve (non-RLN), recognizing any recurrent laryngeal nerve (RLN) lesions, and precisely predicting RLN postoperative function. Herein, we present technical notes for the VN identification to achieve the critical view of safety of the VN stimulation with or without dissection.

  2. Electrical nerve stimulation to promote micturition in spinal cord injury patients: A review of current attempts.

    PubMed

    Ren, Jian; Chew, Daniel J; Biers, Suzanne; Thiruchelvam, Nikesh

    2016-03-01

    In this review, we focus on the current attempts of electrical nerve stimulation for micturition in spinal cord injury (SCI) patients. A literature search was performed through PubMed using "spinal cord injury," "electrical nerve stimulation AND bladder," "sacral anterior root stimulation/stimulator" and "Brindley stimulator" from January 1975 to January 2014. Twenty studies were selected for this review. Electrical nerve stimulation is a clinical option for promoting micturition in SCI patients. Well-designed, randomized and controlled studies are essential for further investigation. © 2015 Wiley Periodicals, Inc.

  3. Pressure changes under the ischial tuberosities during gluteal neuromuscular stimulation in spinal cord injury: a comparison of sacral nerve root stimulation with surface functional electrical stimulation.

    PubMed

    Liu, Liang Qin; Ferguson-Pell, Martin

    2015-04-01

    To compare the magnitude of interface pressure changes during gluteal maximus contraction by stimulating sacral nerve roots with surface electrical stimulations in patients with spinal cord injuries (SCIs). Pilot interventional study. Spinal injury research laboratory. Adults (N=18) with suprasacral complete SCI. Sacral nerve root stimulation (SNRS) via a functional magnetic stimulator (FMS) or a sacral anterior root stimulator (SARS) implant; and surface functional electrical stimulation (FES). Interface pressure under the ischial tuberosity (IT) defined as peak pressure, gradient at peak pressure, and average pressure. With optimal FMS, a 29% average reduction of IT peak pressure was achieved during FMS (mean ± SD: 160.1±24.3mmHg at rest vs 114.7±18.0mmHg during FMS, t5=6.3, P=.002). A 30% average reduction of peak pressure during stimulation via an SARS implant (143.2±31.7mmHg at rest vs 98.5±21.5mmHg during SARS, t5=4.4, P=.007) and a 22% average decrease of IT peak pressure during FES stimulation (153.7±34.8mmHg at rest vs 120.5±26.1mmHg during FES, t5=5.3, P=.003) were obtained. In 4 participants who completed both the FMS and FES studies, the percentage of peak pressure reduction with FMS was slightly greater than with FES (mean difference, 7.8%; 95% confidence interval, 1.6%-14.0; P=.04). SNRS or surface FES can induce sufficient gluteus maximus contraction and significantly reduce ischial pressure. SNRS via an SARS implant may be more convenient and efficient for frequently activating the gluteus maximus. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  4. Prolonged electrical stimulation causes no damage to sacral nerve roots in rabbits.

    PubMed

    Yan, Peng; Yang, Xiaohong; Yang, Xiaoyu; Zheng, Weidong; Tan, Yunbing

    2014-06-15

    Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root remains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9-10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimulation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation.

  5. Prolonged electrical stimulation causes no damage to sacral nerve roots in rabbits

    PubMed Central

    Yan, Peng; Yang, Xiaohong; Yang, Xiaoyu; Zheng, Weidong; Tan, Yunbing

    2014-01-01

    Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root remains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9–10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimulation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation. PMID:25206785

  6. Transcutaneous Electrical Nerve Stimulation Increases Rectal Activity in Children.

    PubMed

    Moeller Joensson, Iben; Hagstroem, Soren; Siggaard, Charlotte; Bower, Wendy; Djurhuus, Jens Christian; Krogh, Klaus

    2015-07-01

    Neurostimulation is increasingly used in treating bladder and bowel dysfunction, but its effect on rectal motility is obscure. The aim of the study was to evaluate the acute effect of transcutaneous electrical nerve stimulation (TENS) on rectal motility in children with overactive bladder (OAB). In this double-blind placebo-controlled study in 20 children with OAB (mean age 8.6 ± 1.8 years; 7 girls), 48-hour urodynamic monitoring including rectal manometry was performed. After 24-hours of baseline investigation without stimulation the children were randomised to either active TENS (n = 10) or placebo (n = 10). Surface electrodes were placed over the sacral bone. The exterior of active and placebo stimulators was identical. Starting in the morning, the children received either continuous TENS stimulation or placebo until bedtime. Rectal contractions were defined as pressure runs exceeding 5 cm H2O and lasting ≥3 minutes. At baseline there was no significant difference in proportion of time with rectal contractions in the 2 groups (TENS group median 31% [range 12%-66%] vs placebo group median 31% [range 10%-66%]; P = 0.75); however, on the day of stimulation there was more time with rectal contractions in the group receiving TENS (median 51% [range 25%-78%]) compared with placebo (median 32% [range 4%-68%]; P = 0.02). Also, there was an increase in time with rectal contractions in the TENS group (P = 0.007) but not in the placebo group (P = 0.39). The night after the TENS was disabled, rectal activity in both groups returned to baseline level. TENS acutely increases time with rectal contractions in children undergoing urodynamic investigation. The effect disappears when the stimulator is turned off.

  7. Neuromodulative treatment of overactive bladder--noninvasive tibial nerve stimulation.

    PubMed

    Svihra, J; Kurca, E; Luptak, J; Kliment, J

    2002-01-01

    Conservative treatment of overactive bladder employes behavioral or invasive neuromodulatory inhibition of miction reflex and administration of anticholinergic drugs. The aim of this study was to use non-invasive stimulation of the tibial nerve with the intention to achieve desired therapeutic effects without iatrogenic nerve damage using a superficial electrostimulation. All patients suffered from overactive bladder (OAB) without bladder outlet obstruction. OAB was examined by the Behavioral urge score BUS (0.0--the best and 1.0--the worst score), the International prostate symptom score IPSS (0--the best and 35--the worst score) and the Incontinence quality of life questionnaire IQOL (0.0--the worst and 1.0--the best index). The patients were divided into 3 groups: Group I--patients with electrode attached behind the medial ankle of the left lower extremity. The intensity of stimulation corresponded to 70% of the maximum amplitude of response from musculus abductor hallucis. Frequency of stimulation was 1 Hz and duration of the square impulse was 0.1 ms. Surface stimulation lasted 30 minutes and was repeated once a week. Group II--patients were treated by oral oxybutynin 5 mg t.i.d. Group III--patients without treatment. The BUS, IPSS, and IQOL were repeated after the treatment. The study included 28 females of average age 54 year (range 45 to 63). Mean IPSS was 17 (range 12 to 21), mean index of quality of life IQOL was 30 (range 12 to 78) and mean BUS score was 0.68 (range 0.50 to 0.86). Group I with stimulation did achieve statistically significant changes following the treatment: decrease of mean IPSS from 17 +/- 3 points to 6 +/- 4 points after the treatment, increase in mean IQOL from 36 +/- 10 to 68 +/- 20 and decrease of mean BUS from 0.65 +/- 0.12 to 0.43 +/- 0.16. Group II had similar statistically significant differences after the treatment of OAB. Group III noted no changes in the complaints. Noninvasive stimulation had improved subjective symptom

  8. The effects of nerve stimulation and hemicholinium on synaptic vesicles at the mammalian neuromuscular junction

    PubMed Central

    Jones, S. F.; Kwanbunbumpen, Suthiwan

    1970-01-01

    1. Electron micrographs of nerve terminals in rat phrenic nerve—diaphragm preparations have been studied. This has been done before and after prolonged nerve stimulation. The effectiveness of nerve stimulation has been monitored by intracellular micro-electrode recordings from the muscle cells. 2. Characteristic changes in the form and distribution of the nerve terminal mitochondria were noted after nerve stimulation. 3. Synaptic vesicle numbers in the region of nerve terminal less than 1800 Å from the synaptic cleft were significantly greater in tissue taken 2 and 3 min after nerve stimulation, than in unstimulated preparations. 4. The long and short diameters of the synaptic vesicle profiles less than 1800 Å from the synaptic cleft were measured. Analysis of the distribution of the diameters indicated synaptic vesicles to be basically spherical structures. Estimates of synaptic vesicle volume were made from the measurements. Synaptic vesicle volume was significantly reduced in tissue taken 2 and 4 min following nerve stimulation. 5. If hemicholinium, a compound which inhibits acetylcholine synthesis, was present during the period of nerve stimulation, much greater reductions in synaptic vesicle volume occurred. Synaptic vesicle numbers in the region of nerve terminal less than 1800 Å from the synaptic cleft were also reduced, compared with unstimulated control preparations. 6. These results are regarded as support for the hypothesis that the synaptic vesicles in nerve terminals at the mammalian neuromuscular junction represent stores of the transmitter substance, acetylcholine. ImagesABABPlate 2AB PMID:5503879

  9. Right Median Nerve Electrical Stimulation for Acute Traumatic Coma Patients.

    PubMed

    Lei, Jin; Wang, Lei; Gao, Guoyi; Cooper, Edwin; Jiang, Jiyao

    2015-10-15

    The right median nerve as a peripheral portal to the central nervous system can be electrically stimulated to help coma arousal after traumatic brain injury (TBI). The present study set out to examine the efficacy and safety of right median nerve electrical stimulation (RMNS) in a cohort of 437 comatose patients after severe TBI from August 2005 to December 2011. The patients were enrolled 2 weeks after their injury and assigned to the RMNS group (n=221) receiving electrical stimulation for 2 weeks or the control group (n = 216) treated by standard management according to the date of birth in the month. The baseline data were similar. After the 2-week treatment, the RMNS-treated patients demonstrated a more rapid increase of the mean Glasgow Coma Score, although statistical significance was not reached (8.43 ± 4.98 vs. 7.47 ± 5.37, p = 0.0532). The follow-up data at 6-month post-injury showed a significantly higher proportion of patients who regained consciousness (59.8% vs. 46.2%, p = 0.0073). There was a lower proportion of vegetative persons in the RMNS group than in the control group (17.6% vs. 22.0%, p = 0.0012). For persons regaining consciousness, the functional independence measurement (FIM) score was higher among the RMNS group patients (91.45 ± 8.65 vs. 76.23 ± 11.02, p < 0.001). There were no unique complications associated with the RMNS treatment. The current study, although with some limitations, showed that RMNS may serve as an easy, effective, and noninvasive technique to promote the recovery of traumatic coma in the early phase.

  10. Different Learning Curves for Axillary Brachial Plexus Block: Ultrasound Guidance versus Nerve Stimulation

    PubMed Central

    Luyet, C.; Schüpfer, G.; Wipfli, M.; Greif, R.; Luginbühl, M.; Eichenberger, U.

    2010-01-01

    Little is known about the learning of the skills needed to perform ultrasound- or nerve stimulator-guided peripheral nerve blocks. The aim of this study was to compare the learning curves of residents trained in ultrasound guidance versus residents trained in nerve stimulation for axillary brachial plexus block. Ten residents with no previous experience with using ultrasound received ultrasound training and another ten residents with no previous experience with using nerve stimulation received nerve stimulation training. The novices' learning curves were generated by retrospective data analysis out of our electronic anaesthesia database. Individual success rates were pooled, and the institutional learning curve was calculated using a bootstrapping technique in combination with a Monte Carlo simulation procedure. The skills required to perform successful ultrasound-guided axillary brachial plexus block can be learnt faster and lead to a higher final success rate compared to nerve stimulator-guided axillary brachial plexus block. PMID:21318138

  11. Electrical stimulation of anal sphincter or pudendal nerve improves anal sphincter pressure.

    PubMed

    Damaser, Margot S; Salcedo, Levilester; Wang, Guangjian; Zaszczurynski, Paul; Cruz, Michelle A; Butler, Robert S; Jiang, Hai-Hong; Zutshi, Massarat

    2012-12-01

    Stimulation of the pudendal nerve or the anal sphincter could provide therapeutic options for fecal incontinence with little involvement of other organs. The goal of this project was to assess the effects of pudendal nerve and anal sphincter stimulation on bladder and anal pressures. Ten virgin female Sprague Dawley rats were randomly allocated to control (n = 2), perianal stimulation (n = 4), and pudendal nerve stimulation (n = 4) groups. A monopolar electrode was hooked to the pudendal nerve or placed on the anal sphincter. Aballoon catheter was inserted into the anus to measure anal pressure, and a catheter was inserted into the bladder via the urethra to measure bladder pressure. Bladder and anal pressures were measured with different electrical stimulation parameters and different timing of electrical stimulation relative to spontaneous anal sphincter contractions. Increasing stimulation current had the most dramatic effect on both anal and bladder pressures. An immediate increase in anal pressure was observed when stimulating either the anal sphincter or the pudendal nerve at stimulation values of 1 mA or 2 mA. No increase in anal pressure was observed for lower current values. Bladder pressure increased at high current during anal sphincter stimulation, but not as much as during pudendal nerve stimulation. Increased bladder pressure during anal sphincter stimulation was due to contraction of the abdominal muscles. Electrical stimulation caused an increase in anal pressures with bladder involvement only at high current. These initial results suggest that electrical stimulation can increase anal sphincter pressure, enhancing continence control.

  12. Sacral nerve stimulation versus percutaneous posterior tibial nerve stimulation in the treatment of severe fecal incontinence in men.

    PubMed

    Moya, P; Parra, P; Arroyo, A; Peña, E; Benavides, J; Calpena, R

    2016-05-01

    Sacral nerve stimulation and percutaneous posterior tibial nerve stimulation have been described previously as effective treatments for fecal incontinence. Nevertheless, there does not exist any study that compares the efficiency of both. The aim of this study was to compare the use of SNS and PPTNS in males with FI. We conducted a prospective cohort study on men with FI treated with SNS or PTNS in the Coloproctology Unit of the University General Hospital of Elche and Reina Sofia of Murcia between January 2010 and December 2011. Preoperative assessment included physical examination, anorectal manometry, and anal endosonography. Anal continence was evaluated using the Wexner continence grading system. Quality of life was evaluated using the Fecal Incontinence Quality of life Scale. Nineteen patients were included (ten patients SNS and nine PPTNS). SNS improved FI in nine of the ten patients. The mean Wexner score decreased significantly from a median of 14 (12-16) (preoperative) to 4 (1-8) (6-month revision) (p = 0.007). PTNS improved FI in seven of the nine patients. The mean Wexner score decreased significantly from a median of 12 (11-19) (preoperative) to 5 (4-7) (6-month revision) (p = 0.018). Both treatments produced symptomatic improvement without statistical differences between them. Our study was nonrandomized with a relatively small number of patients. PPTNS had similar efficiency to the SNS in our men population. However, more studies are necessary to exclude selection bias and analyze long-term results.

  13. Microscopic magnetic stimulation of neural tissue.

    PubMed

    Bonmassar, Giorgio; Lee, Seung Woo; Freeman, Daniel K; Polasek, Miloslav; Fried, Shelley I; Gale, John T

    2012-06-26

    Electrical stimulation is currently used to treat a wide range of cardiovascular, sensory and neurological diseases. Despite its success, there are significant limitations to its application, including incompatibility with magnetic resonance imaging, limited control of electric fields and decreased performance associated with tissue inflammation. Magnetic stimulation overcomes these limitations but existing devices (that is, transcranial magnetic stimulation) are large, reducing their translation to chronic applications. In addition, existing devices are not effective for deeper, sub-cortical targets. Here we demonstrate that sub-millimeter coils can activate neuronal tissue. Interestingly, the results of both modelling and physiological experiments suggest that different spatial orientations of the coils relative to the neuronal tissue can be used to generate specific neural responses. These results raise the possibility that micro-magnetic stimulation coils, small enough to be implanted within the brain parenchyma, may prove to be an effective alternative to existing stimulation devices.

  14. Microscopic magnetic stimulation of neural tissue

    PubMed Central

    Bonmassar, Giorgio; Lee, Seung Woo; Freeman, Daniel K.; Polasek, Miloslav; Fried, Shelley I.; Gale, John T.

    2012-01-01

    Electrical stimulation is currently used to treat a wide range of cardiovascular, sensory and neurological diseases. Despite its success, there are significant limitations to its application, including incompatibility with magnetic resonance imaging, limited control of electric fields and decreased performance associated with tissue inflammation. Magnetic stimulation overcomes these limitations but existing devices (that is, transcranial magnetic stimulation) are large, reducing their translation to chronic applications. In addition, existing devices are not effective for deeper, sub-cortical targets. Here we demonstrate that sub-millimeter coils can activate neuronal tissue. Interestingly, the results of both modelling and physiological experiments suggest that different spatial orientations of the coils relative to the neuronal tissue can be used to generate specific neural responses. These results raise the possibility that micro-magnetic stimulation coils, small enough to be implanted within the brain parenchyma, may prove to be an effective alternative to existing stimulation devices. PMID:22735449

  15. Endoscopic laryngeal patterns in vagus nerve stimulation therapy for drug-resistant epilepsy.

    PubMed

    Felisati, Giovanni; Gardella, Elena; Schiavo, Paolo; Saibene, Alberto Maria; Pipolo, Carlotta; Bertazzoli, Manuela; Chiesa, Valentina; Maccari, Alberto; Franzini, Angelo; Canevini, Maria Paola

    2014-01-01

    In 30% of patients with epilepsy seizure control cannot be achieved with medications. When medical therapy is not effective, and epilepsy surgery cannot be performed, vagus nerve stimulator (VNS) implantation is a therapeutic option. Laryngeal patterns in vagus nerve stimulation have not been extensively studied yet. The objective was to evaluate laryngeal patterns in a cohort of patients affected by drug-resistant epilepsy after implantation and activation of a vagus nerve stimulation therapy device. 14 consecutive patients underwent a systematic otolaryngologic examination between 6 months and 5 years after implantation and activation of a vagus nerve stimulation therapy device. All patients underwent fiberoptic endoscopic evaluation, which was recorded on a portable device allowing a convenient slow-motion analysis of laryngeal patterns. All recordings were blindly evaluated by two of the authors. We observed three different laryngeal patterns. Four patients showed left vocal cord palsy at the baseline and during vagus nerve stimulation; seven showed left vocal cord palsy at the baseline and left vocal cord adduction during vagus nerve stimulation; and three patients showed a symmetric pattern at the baseline and constant left vocal cord adduction during vagus nerve stimulation. These laryngeal findings are here described for the first time in the literature and can be only partially explained by existing knowledge of laryngeal muscles and vagus nerve physiology. This might represent a new starting point for studies concerning laryngeal physiology and phonation, while the vagus nerve stimulation therapy could act as a new and ethical experimental model for human laryngeal physiology.

  16. Phrenic nerve stimulation for the treatment of central sleep apnea.

    PubMed

    Abraham, William T; Jagielski, Dariusz; Oldenburg, Olaf; Augostini, Ralph; Krueger, Steven; Kolodziej, Adam; Gutleben, Klaus-Jürgen; Khayat, Rami; Merliss, Andrew; Harsch, Manya R; Holcomb, Richard G; Javaheri, Shahrokh; Ponikowski, Piotr

    2015-05-01

    The aim of this study was to evaluate chronic, transvenous, unilateral phrenic nerve stimulation to treat central sleep apnea (CSA) in a prospective, multicenter, nonrandomized study. CSA occurs predominantly in patients with heart failure and increases the risk for morbidity and mortality. Established therapies for CSA are lacking, and those available are limited by poor patient adherence. Fifty-seven patients with CSA underwent baseline polysomnography followed by transvenous phrenic nerve stimulation system implantation and follow-up. Feasibility was assessed by implantation success rate and therapy delivery. Safety was evaluated by monitoring of device- and procedure-related adverse events. Efficacy was evaluated by changes in the apnea-hypopnea index at 3 months. Quality of life at 6 months was evaluated using a sleepiness questionnaire, patient global assessment, and, in patients with heart failure at baseline, the Minnesota Living With Heart Failure Questionnaire. The study met its primary end point, demonstrating a 55% reduction in apnea-hypopnea index from baseline to 3 months (49.5 ± 14.6 episodes/h vs. 22.4 ± 13.6 episodes/h of sleep; p < 0.0001; 95% confidence interval for change: -32.3 to -21.9). Central apnea index, oxygenation, and arousals significantly improved. Favorable effects on quality of life and sleepiness were noted. In patients with heart failure, the Minnesota Living With Heart Failure Questionnaire score significantly improved. Device- or procedure-related serious adverse events occurred in 26% of patients through 6 months post therapy initiation, predominantly due to lead repositioning early in the study. Therapy was well tolerated. Efficacy was maintained at 6 months. Transvenous, unilateral phrenic nerve stimulation appears safe and effective for treating CSA. These findings should be confirmed in a prospective, randomized, controlled trial. (Chronic Evaluation of Respicardia Therapy; NCT01124370). Copyright © 2015 American

  17. Transcutaneous electrical nerve stimulation for spasticity: A systematic review.

    PubMed

    Fernández-Tenorio, E; Serrano-Muñoz, D; Avendaño-Coy, J; Gómez-Soriano, J

    2016-07-26

    Although transcutaneous electrical nerve stimulation (TENS) has traditionally been used to treat pain, some studies have observed decreased spasticity after use of this technique. However, its use in clinical practice is still limited. Our purpose was twofold: to determine whether TENS is effective for treating spasticity or associated symptoms in patients with neurological involvement, and to determine which stimulation parameters exert the greatest effect on variables associated with spasticity. Two independent reviewers used PubMed, PEDro, and Cochrane databases to search for randomised clinical trials addressing TENS and spasticity published before 12 May 2015, and selected the articles that met the inclusion criteria. Of the initial 96 articles, 86 were excluded. The remaining 10 articles present results from 207 patients with a cerebrovascular accident, 84 with multiple sclerosis, and 39 with spinal cord lesions. In light of our results, we recommend TENS as a treatment for spasticity due to its low cost, ease of use, and absence of adverse reactions. However, the great variability in the types of stimulation used in the studies, and the differences in parameters and variables, make it difficult to assess and compare any results that might objectively determine the effectiveness of this technique and show how to optimise parameters. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Study of stimulators of DNA synthesis in nerve tissue cells

    SciTech Connect

    Vitvitskii, V.N.

    1986-04-10

    Changes in proliferative activity in different regions of the brain during ontogenesis are connected with changes in the composition and properties of regulators of cell proliferation. Extracts of regions of the brain in which active cell division takes place in a given stage of development (cortex of 15- to 17-day-old embryos or cerebellum of 8- to 10-day-old rats) can stimulate the incorporation of labeled precursors into the brain cell DNA of both newborn and adult rats. Salting out at increasing ammonium sulfate concentrations, gel filtration on Sephadex, and isoelectric focusing led to the isolation of three fractions of stimulators of DNA synthesis: in acid, neutral, and alkaline pH regions. A method is described for obtaining purified preparations and for determining some physicochemical properties of the acid activator, which is a low-molecular-weight peptide capable of noticeably stimulating the incorporation of labeled precursors into the DNA of nerve tissue cells when added to an in vitro system in a concentration of the order of 1 ..mu..g/ml.

  19. Electrical stimulation vs. pulsed and continuous-wave optical stimulation of the rat prostate cavernous nerves, in vivo

    NASA Astrophysics Data System (ADS)

    Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur; Fried, Nathaniel M.

    2015-07-01

    Identification and preservation of the cavernous nerves (CNs) during prostate cancer surgery is critical for post-operative sexual function. Electrical nerve stimulation (ENS) mapping has previously been tested as an intraoperative tool for CN identification, but was found to be unreliable. ENS is limited by the need for electrode-tissue contact, poor spatial precision from electrical current spreading, and stimulation artifacts interfering with detection. Alternatively, optical nerve stimulation (ONS) provides noncontact stimulation, improved spatial selectivity, and elimination of stimulation artifacts. This study compares ENS to pulsed/CW ONS to explore the ONS mechanism. A total of eighty stimulations were performed in 5 rats, in vivo. ENS (4 V, 5 ms, 10 Hz) was compared to ONS using a pulsed diode laser nerve stimulator (1873 nm, 5 ms, 10 Hz) or CW diode laser nerve stimulator (1455 nm). Intracavernous pressure (ICP) response and nerve compound action potentials (nCAPs) were measured. All three stimulation modes (ENS, ONS-CW, ONS-P) produced comparable ICP magnitudes. However, ENS demonstrated more rapid ICP response times and well defined nCAPs compared to unmeasurable nCAPs for ONS. Further experiments measuring single action potentials during ENS and ONS are warranted to further understand differences in the ENS and ONS mechanisms.

  20. Vagus nerve stimulation delivered during motor rehabilitation improves recovery in a rat model of stroke.

    PubMed

    Khodaparast, Navid; Hays, Seth A; Sloan, Andrew M; Fayyaz, Tabbassum; Hulsey, Daniel R; Rennaker, Robert L; Kilgard, Michael P

    2014-09-01

    Neural plasticity is widely believed to support functional recovery following brain damage. Vagus nerve stimulation paired with different forelimb movements causes long-lasting map plasticity in rat primary motor cortex that is specific to the paired movement. We tested the hypothesis that repeatedly pairing vagus nerve stimulation with upper forelimb movements would improve recovery of motor function in a rat model of stroke. Rats were separated into 3 groups: vagus nerve stimulation during rehabilitation (rehab), vagus nerve stimulation after rehab, and rehab alone. Animals underwent 4 training stages: shaping (motor skill learning), prelesion training, postlesion training, and therapeutic training. Rats were given a unilateral ischemic lesion within motor cortex and implanted with a left vagus nerve cuff. Animals were allowed 1 week of recovery before postlesion baseline training. During the therapeutic training stage, rats received vagus nerve stimulation paired with each successful trial. All 17 trained rats demonstrated significant contralateral forelimb impairment when performing a bradykinesia assessment task. Forelimb function was recovered completely to prelesion levels when vagus nerve stimulation was delivered during rehab training. Alternatively, intensive rehab training alone (without stimulation) failed to restore function to prelesion levels. Delivering the same amount of stimulation after rehab training did not yield improvements compared with rehab alone. These results demonstrate that vagus nerve stimulation repeatedly paired with successful forelimb movements can improve recovery after motor cortex ischemia and may be a viable option for stroke rehabilitation.

  1. Effects of sciatic nerve stimulation on the propagation of cortical spreading depression

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoli; Yu, Zhidong; Zeng, Shaoqun; Luo, Qingming; Li, Pengcheng

    2008-02-01

    Cortical spreading depression (CSD) is an important pathological model of migraine and is related to other neural disorders, such as cerebral ischemia and epilepsy. It has been reported that brain stimulation is a quite effective way to treat neural diseases. However, direct stimulation could cause harm to brain. If peripheral nerve stimulation could have the same treatment, it would be essential to investigate the mechanisms of peripheral nerve and the study of sciatic nerve stimulation would have profound clinical meaning. In this paper, we used optical intrinsic signal imaging (OISI) and extracellular electrophysiologic recording techniques to study the effects of sciatic nerve stimulation on the propagation of CSD. We found that: (1) continuous sciatic nerve stimulation on rats caused a decrease in light intensity on the whole cortex, which meant an increase in cerebral blood volume(CBV); (2) the spreading velocity of CSD declined from 3.63+/- 0.272 mm/min to 3.06+/-0.260 mm/min during sciatic nerve stimulation, compared with that without sciatic nerve stimulation. In summary, data suggests that sciatic nerve stimulation elicits a response of cortex and causes a slowdown in the propagation of CSD.

  2. [Electrical failure with nerve stimulation: cases report and check list for prevention].

    PubMed

    Choquet, O; Feugeas, J-L; Capdevila, X; Manelli, J-C

    2007-03-01

    Functionality of the nerve stimulator and integrity of the electrical circuit should be verified and confirmed before performing peripheral nerve blockade. The clinical cases reported here demonstrate that electrical disconnection or malfunction during nerve localization can unpredictably occur and a checklist is described to prevent the unknown electrical circuit failure.

  3. A comparison of the accuracy of ulnar versus median nerve stimulation for neuromuscular monitoring.

    PubMed

    Lee, Hee Jong; Kim, Kyo Sang; Shim, Jae Chul; Yoon, Sung Wook

    2011-05-01

    Inexperienced anesthesiologists are frequently unclear as to whether to stimulate the ulnar or median nerve to monitor the adductor pollicis. The primary purpose of this study was to determine whether monitoring the adductor pollicis by positioning the stimulating electrodes over the median nerve is an acceptable alternative to applying electrodes over the ulnar nerve. In 20 patients anesthetized with propofol and remifentanil, one pair of stimulating electrodes was positioned over the ulnar nerve. A second pair was placed over the median nerve on the other hand. The acceleromyographic response was monitored on both hands. Rocuronium 0.6 mg/kg was administered. Single twitch (ST) and train-of-four (TOF) stimulations were applied alternatively to both sites. None of the patients showed a twitch response at either site after injection of rocuronium. There were no differences in the mean supramaximal threshold, mean initial TOF ratio, or mean initial ST ratio between the two sites. Bland-Altman analysis revealed a bias (limit of agreement) in the TOF and ST ratios over the median nerve of 7% (± 31%) and 26% (± 73%), respectively, as compared with the ulnar nerve. The median nerve TOF ratio was overestimated by 16.2%, as compared with that of the ulnar nerve value, and the median nerve ST ratio was overestimated by 72.9%, as compared to that of the ulnar nerve. The ulnar and median nerves cannot be used interchangeably for accurate neuromuscular monitoring.

  4. Magnetic fields in noninvasive brain stimulation.

    PubMed

    Vidal-Dourado, Marcos; Conforto, Adriana Bastos; Caboclo, Luis Otávio Sales Ferreira; Scaff, Milberto; Guilhoto, Laura Maria de Figueiredo Ferreira; Yacubian, Elza Márcia Targas

    2014-04-01

    The idea that magnetic fields could be used therapeutically arose 2000 years ago. These therapeutic possibilities were expanded after the discovery of electromagnetic induction by the Englishman Michael Faraday and the American Joseph Henry. In 1896, Arsène d'Arsonval reported his experience with noninvasive brain magnetic stimulation to the scientific French community. In the second half of the 20th century, changing magnetic fields emerged as a noninvasive tool to study the nervous system and to modulate neural function. In 1985, Barker, Jalinous, and Freeston presented transcranial magnetic stimulation, a relatively focal and painless technique. Transcranial magnetic stimulation has been proposed as a clinical neurophysiology tool and as a potential adjuvant treatment for psychiatric and neurologic conditions. This article aims to contextualize the progress of use of magnetic fields in the history of neuroscience and medical sciences, until 1985.

  5. Chronic stability and selectivity of four-contact spiral nerve-cuff electrodes in stimulating the human femoral nerve

    NASA Astrophysics Data System (ADS)

    Fisher, L. E.; Tyler, D. J.; Anderson, J. S.; Triolo, R. J.

    2009-08-01

    This study describes the stability and selectivity of four-contact spiral nerve-cuff electrodes implanted bilaterally on distal branches of the femoral nerves of a human volunteer with spinal cord injury as part of a neuroprosthesis for standing and transfers. Stimulation charge threshold, the minimum charge required to elicit a visible muscle contraction, was consistent and low (mean threshold charge at 63 weeks post-implantation: 23.3 ± 8.5 nC) for all nerve-cuff electrode contacts over 63 weeks after implantation, indicating a stable interface with the peripheral nervous system. The ability of individual nerve-cuff electrode contacts to selectively stimulate separate components of the femoral nerve to activate individual heads of the quadriceps was assessed with fine-wire intramuscular electromyography while measuring isometric twitch knee extension moment. Six of eight electrode contacts could selectively activate one head of the quadriceps while selectively excluding others to produce maximum twitch responses of between 3.8 and 8.1 N m. The relationship between isometric twitch and tetanic knee extension moment was quantified, and selective twitch muscle responses scaled to between 15 and 35 N m in tetanic response to pulse trains with similar stimulation parameters. These results suggest that this nerve-cuff electrode can be an effective and chronically stable tool for selectively stimulating distal nerve branches in the lower extremities for neuroprosthetic applications.

  6. An ultrasonographic assessment of nerve stimulation-guided median nerve block at the elbow: a local anesthetic spread, nerve size, and clinical efficacy study.

    PubMed

    Dufour, Eric; Cymerman, Alexandre; Nourry, Gérard; Balland, Nicolas; Couturier, Christian; Liu, Ngai; Dreyfus, Jean-François; Fischler, Marc

    2010-08-01

    Nerve stimulation is an effective technique for peripheral nerve blockade. However, the local anesthetic (LA) distribution pattern obtained with this blind approach is unknown and may explain its clinical effects. One hundred patients received a median nerve block at the elbow using a nerve stimulator approach. After correct needle placement defined by a minimal stimulating current < or = 0.5 mA (2 Hz, 0.1 millisecond), 6 mL lidocaine 1.5%with epinephrine 1:200,000 was injected. A linear 5- to 13-MHz probe (12L-RS) was used to assess a cross-section area of median nerve, which was calculated by 3 consecutive measurements before and after injection, and LA circumferential spread around the nerve during static and longitudinal examination. Intraneural injection defined as an increase in nerve area was detected using an iterative method for outlier detection. Results of sensory tests (cold and light touch) on 3 nerve territories and of motor blockade were compared with the imaging aspects. We performed clinical neurological examination at 3 days and 1 month after block. Nerve swelling, considered significant when an increase in cross-sectional area was > or = 75%, was observed in 43 patients. Nerve swelling associated with a circumferential LA spread image, present in 37 patients, was associated with a sensory success rate of 86%. The success rate was 34% for 32 patients in whom none of these signs was visualized. A circumferential spread around a nonswollen nerve, present in 25 patients, was followed by a sensory success rate of 76% within the 30-minute evaluation period. No major early neurological complications were observed. Nerve stimulation does not prevent intraneural injection. In the absence of intraneural injection, the presence of circumferential LA spread image seemed predictive of successful sensory block in almost 75% of the cases within the 30-minute evaluation period.

  7. Nerve excitation and recovery processes under strong static magnetic fields

    NASA Astrophysics Data System (ADS)

    Eguchi, Yawara; Ueno, Shoogo; Tatsuoka, Hozumi

    2003-05-01

    The membrane excitation and refractory processes of nerve fibers exposed to strong static magnetic fields of 8 T were studied. Sciatic nerve bundles of frogs were electrically excited by a pair of pulses with varying interpulse intervals, and the compound action potentials were measured under magnetic field exposures. Our experimental results show that the conduction velocity was not affected by 8 T magnetic fields; however, the membrane excitation during the recovery process in the relative refractory period was enhanced by 10% of maximal peak of nerve excitation by magnetic field exposure for 3 h. In this study, the optimal time interval for increased membrane excitation during the recovery process was between 1.0 and 1.1 ms. In other words, membrane excitation during the recovery process in the relative refractory period was affected by the magnetic fields just after Na+ channels were inactivated.

  8. Transcutaneous electrical nerve stimulation in the relief of primary dysmenorrhea.

    PubMed

    Lewers, D; Clelland, J A; Jackson, J R; Varner, R E; Bergman, J

    1989-01-01

    The purpose of this study was to replicate a previous study to determine the effectiveness of acupuncture-like transcutaneous electrical nerve stimulation in treating primary dysmenorrhea. Twenty-one women with dysmenorrhea received a placebo pill or 30 minutes of acupuncture-like TENS. All subjects completed two pain questionnaires before treatment; immediately posttreatment; 30, 60, 120, and 180 minutes posttreatment; and the next morning upon awakening. Each woman also participated in a separate study measuring electrical resistance at four auricular acupuncture points before and immediately after treatment. The data were analyzed with a two-factor repeated-measures analysis of variance, which revealed statistical significance over time but not for group or interaction between group and time. Results revealed an average pain relief of at least 50% immediately posttreatment, indicating that acupuncture-like TENS may be useful for dysmenorrheic pain. This study also suggests that auriculotherapy via acupressure may relieve the pain of primary dysmenorrhea.

  9. Deqi Sensations of Transcutaneous Electrical Nerve Stimulation on Auricular Points

    PubMed Central

    Wang, Xiaoling; Fang, Jiliang; Zhao, Qing; Fan, Yangyang; Liu, Jun; Hong, Yang; Wang, Honghong; Ma, Yunyao; Xu, Chunhua; Shi, Shan; Kong, Jian; Rong, Peijing

    2013-01-01

    Deqi sensation, a psychophysical response characterized by a spectrum of different needling sensations, is essential for Chinese acupuncture clinical efficacy. Previous research works have investigated the component of Deqi response upon acupuncture on acupoints on the trunk and limbs. However, the characteristics of Deqi sensations of transcutaneous electrical nerve stimulation (TENS) on auricular points are seldom reported. In this study, we investigated the individual components of Deqi during TENS on auricular concha area and the superior scapha using quantitative measurements in the healthy subjects and depression patients. The most striking characteristics of Deqi sensations upon TENS on auricular points were tingling, numbness, and fullness. The frequencies of pressure, warmness, heaviness, and soreness were relatively lower. The dull pain and coolness are rare. The characteristics of Deqi were similar for the TENS on concha and on the superior scapha. PMID:23935663

  10. Deqi sensations of transcutaneous electrical nerve stimulation on auricular points.

    PubMed

    Wang, Xiaoling; Fang, Jiliang; Zhao, Qing; Fan, Yangyang; Liu, Jun; Hong, Yang; Wang, Honghong; Ma, Yunyao; Xu, Chunhua; Shi, Shan; Kong, Jian; Rong, Peijing

    2013-01-01

    Deqi sensation, a psychophysical response characterized by a spectrum of different needling sensations, is essential for Chinese acupuncture clinical efficacy. Previous research works have investigated the component of Deqi response upon acupuncture on acupoints on the trunk and limbs. However, the characteristics of Deqi sensations of transcutaneous electrical nerve stimulation (TENS) on auricular points are seldom reported. In this study, we investigated the individual components of Deqi during TENS on auricular concha area and the superior scapha using quantitative measurements in the healthy subjects and depression patients. The most striking characteristics of Deqi sensations upon TENS on auricular points were tingling, numbness, and fullness. The frequencies of pressure, warmness, heaviness, and soreness were relatively lower. The dull pain and coolness are rare. The characteristics of Deqi were similar for the TENS on concha and on the superior scapha.

  11. Vagus nerve stimulation for treatment of epilepsy in Rett syndrome.

    PubMed

    Wilfong, Angus A; Schultz, Rebecca J

    2006-08-01

    This case series presents the outcomes of seven females with Rett syndrome and medically refractory epilepsy who were treated with adjunctive vagus nerve stimulation (VNS) therapy for a minimum of 12 months. Patients ranged in age from 1 to 14 years (median age 9 y) at the time of implantation, had experienced seizures for a median period of approximately 6 years, and had failed at least two trials of antiepileptic drugs before receiving VNS. The median number of seizures per month was 150 (range 12-3600). At 12 months, six females had >or=50% reduction in seizure frequency. VNS was safe and well tolerated, with no surgical complications and no patients requiring explantation of the device. Quality of life outcomes of note among these patients included reports at 12 months of increased alertness among all seven patients. No change in mood or communication abilities was noted.

  12. Transcutaneous electric nerve stimulation (TENS) in dentistry- A review

    PubMed Central

    Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

    2014-01-01

    Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS. PMID:25674327

  13. Nerve growth factor: stimulation of polymorphonuclear leukocyte chemotaxis in vitro.

    PubMed Central

    Gee, A P; Boyle, M D; Munger, K L; Lawman, M J; Young, M

    1983-01-01

    Topical application of mouse nerve growth factor (NGF) to superficial skin wounds of mice has previously been shown to accelerate the rate of wound contraction. Results of the present study reveal that NGF in the presence of plasma is also chemotactic for human polymorphonuclear leukocytes in vitro, and the concentration of NGF required for this effect is similar to that which stimulates ganglionic neurite outgrowth. This property does not arise from liberation of the C5a fragment of complement, nor does it require the known enzymic activity of NGF. (NGF inactivated with diisopropyl fluorophosphate is equally active.) We conclude that NGF can display biological effects on cells of nonneural origin and function, and this feature might play a role in the early inflammatory response to injury. PMID:6580641

  14. Transcutaneous electric nerve stimulation (TENS) in dentistry- A review.

    PubMed

    Kasat, Vikrant; Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

    2014-12-01

    Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS.

  15. Placebo-controlled vagus nerve stimulation paired with tones in a patient with refractory tinnitus: a case report.

    PubMed

    De Ridder, Dirk; Kilgard, Michael; Engineer, Navzer; Vanneste, Sven

    2015-04-01

    Classical neuromodulation consists of applying electrical or magnetic stimuli to the nervous system to modulate ongoing activity and connectivity. However, recently, an exciting novel neuromodulation technique was developed in which stimulation of the vagal nerve was paired with simultaneous presentation of tones, demonstrating that it reverses a tinnitus percept in noise-exposed rats. To determine whether this therapy could also be effective in humans, we delivered a similar therapy in a patient with chronic tinnitus unresponsive to previous therapies. In this report, we describe the case of a 59-year-old man who suffered from bilateral tinnitus for 14 years that arose after a cervical fusion operation. Pharmacotherapy, transcranial magnetic stimulation, transcranial direct current stimulation, neurofeedback, and bilateral auditory cortex stimulation via implanted electrodes did not improve the tinnitus. After implanting the vagal nerve stimulator, the patient received daily vagus nerve stimulation tone pairings for 4 weeks in a non-placebo-controlled way. At the end of therapy, the patient experienced a significant reduction in tinnitus symptoms that lasted for 2 months after treatment. Tinnitus Handicap Inventory and Tinnitus Reaction Questionnaire were reduced by 48% and 68%, respectively. Symptoms of depression were also improved by 40%, as quantified by the Beck Depression Inventory. Three months after ending therapy, placebo stimulation was performed consisting of only tone presentation without the simultaneous electrical stimuli. This resulted in further continuation of the gradual relapse to the baseline state, without renewed improvement. Our results suggest that vagus nerve stimulation paired with tones could become an effective therapy for the treatment of tinnitus.

  16. Combined Spinal Cord Stimulation and Peripheral Nerve Stimulation for Brachial Plexopathy: A Case Report.

    PubMed

    Choi, Ji Hye; Choi, Shu Chung; Kim, Dong Kyu; Sung, Choon Ho; Chon, Jin Young; Hong, Sung Jin; Lee, Ji Young; Moon, Ho Sik

    2016-03-01

    Brachial plexopathy usually results from an iatrogenic brachial plexus injury and can sometimes cause severe chronic pain and disability. There are a number of possible treatments for this condition, including medication, physical therapy, nerve blocks, and neuromodulation, but they are not always successful. Recently, combined spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) have been tried for various chronic pain diseases because of their different mechanisms of action.Here, we describe the case of a 54-year-old man who was diagnosed with brachial plexopathy 8 years ago. He underwent video-assisted thoracoscopic surgery to remove a superior mediastinal mass. However, his brachial plexus was damaged during the surgery. Although he had received various treatments, the pain did not improve. For the management of intractable severe pain, he underwent SCS 2 years ago, which initially reduced his pain from numeric rating scale (NRS) 10/10 to NRS 4 - 5/10, but the pain then gradually increased, reaching NRS 8/10, 6 months ago. At that time, he was refractory to other treatments, and we therefore applied PNS in combination with SCS. The PNS electrode was positioned on the radial nerve under ultrasound guidance. After combined PNS and SCS, his background pain disappeared, although a breakthrough pain (NRS 3 - 4/10) was caused intermittently by light touch. Furthermore, the patient's need for analgesics decreased, and he was satisfied with the outcome of this combined treatment. We concluded that combined SCS and PNS is a very useful treatment modality, which can stimulate the target nerve both directly and indirectly, and hence, relieve pain from brachial plexopathy.

  17. A probe for measuring current density during magnetic stimulation.

    PubMed

    Tay, G; Chilbert, M A; Battocletti, J; Sances, A; Swiontek, T

    1991-01-01

    Time-varying magnetic fields induce currents in conductive media, and when the induced current is large enough in excitable tissue, stimulation occurs. This phenomenon has been applied to the human brain and peripheral nerves for diagnostic evaluation of the neural system. One important aspect that is presently unknown is the current level necessary in tissue for stimulation induced by magnetic fields. This study presents a method of measuring the induced current density from pulsed magnetic fields in vitro and in vivo. The current-density probe was inserted into three concentrations of saline and into the brains of ten anesthetized cats. Two stimulation systems with coils 9 cm and 5 cm in diameter were used. The two systems provided sinusoidal and pulsatile coil currents. Measurements made in saline were compared with those calculated theoretically for a semi-infinite medium. The measured values were within 5% of the calculated values. Measurements made in the cat brain showed a 67% decrease compared with the theoretic model. This variance is attributed to the finite bounds of the skull. The results indicate that direct measurement of current density is possible. Subsequent measurements will aid in the design of improved magnetic stimulation systems.

  18. Vagus nerve stimulation modulates visceral pain-related affective memory.

    PubMed

    Zhang, Xu; Cao, Bing; Yan, Ni; Liu, Jin; Wang, Jun; Tung, Vivian Oi Vian; Li, Ying

    2013-01-01

    Within a biopsychosocial model of pain, pain is seen as a conscious experience modulated by mental, emotional and sensory mechanisms. Recently, using a rodent visceral pain assay that combines the colorectal distension (CRD) model with the conditioned place avoidance (CPA) paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC) activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Electrical vagus nerve stimulation (VNS) has become an established therapy for treatment-resistant epilepsy. VNS has also been shown to enhance memory performance in rats and humans. High-intensity VNS (400 μA) immediately following conditional training significantly increases the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, VNS (400 μA) had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593). Low-intensity VNS (40 μA) had no effect on CRD-induced CPA. Electrophysiological recording showed that VNS (400 μA) had no effect on basal and CRD-induced ACC neuronal firing. Further, VNS did not alter CRD-induced visceral pain responses suggesting high intensity VNS facilitates visceral pain aversive memory independent of sensory discriminative aspects of visceral pain processing. The findings that vagus nerve stimulation facilities visceral pain-related affective memory underscore the importance of memory in visceral pain perception, and support the theory that postprandial factors may act on vagal afferents to modulate ongoing nature of visceral pain-induced affective disorder observed in the clinic, such as irritable bowel syndrome. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Manual stimulation, but not acute electrical stimulation prior to reconstructive surgery, improves functional recovery after facial nerve injury in rats.

    PubMed

    Skouras, Emmanouil; Merkel, Daniel; Grosheva, Maria; Angelova, Srebrina K; Schiffer, Gereon; Thelen, Ulrich; Kaidoglou, Katerina; Sinis, Nektarios; Igelmund, Peter; Dunlop, Sarah A; Pavlov, Stoyan; Irintchev, Andrey; Angelov, Doychin N

    2009-01-01

    The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work suggested that electrical stimulation (ES) of the proximal nerve stump to produce repeated discharges of the parent motoneurons for one hour could be a beneficial therapy if delivered immediately prior to reconstructive surgery of mixed peripheral nerves. We tested whether ES has a positive influence on functional recovery after repair of a purely motor nerve, the facial nerve. Electrical stimulation (20 Hz) was delivered to the proximal nerve stump of the transected facial nerve for 1 hour prior to nerve reconstruction by end-to-end suture (facial-facial anastomosis, FFA). For manual stimulation (MS), animals received daily rhythmic stroking of the whisker pads. Restoration of vibrissal motor performance following ES or MS was evaluated using video-based motion analysis. We also assessed the degree of collateral axonal branching at the lesion site, by counting motoneuronal perikarya after triple retrograde labeling, and estimated the quality of motor end-plate reinnervation in the target musculature. Outcomes at 4 months were compared to animals receiving sham stimulation (SS) or MS. Neither protocol reduced the degree of collateral sprouting. ES did not improve functional outcome and failed to reduce the proportion of polyinnervated motor end-plates. By contrast, MS restored normal whisking function and reduced polyinnervation. Whereas acute ES is not beneficial for facial nerve repair, MS provides long-term benefits.

  20. Regeneration of the radial nerve in a dog influenced by electrical stimulation.

    PubMed

    Rozman, J; Zorko, B; Seliskar, A

    2000-01-01

    The effect of biphasic electric fields on nerve regeneration that follows injury to the left radial nerve of a dog was examined using electromyography (EMG). The left and right radial nerves were crushed with a serrated hemostat and the stimulating electrodes were positioned proximally and distally relative to the site of the injury. The left nerves received rectangular, biphasic current pulses (30 microA, 0.5 Hz) through the lesion for two months. The right radial nerves were treated as controls and regenerated without electrical stimulation. EMG activity was recorded intramuscularly from left and right musculus extensor digitorum (from Medical dictionary) communis (MEDC). Results obtained at the end of the two-month stimulation period showed a significant difference between the EMG activity of the stimulated and the unstimulated MEDC suggesting that the electrical treatment enhanced the nerve regeneration.

  1. Regeneration of the radial nerve in a dog influenced by electrical stimulation.

    PubMed

    Rozman, J; Zorko, B; Seliškar, A

    2000-01-01

    The effect of biphasic electric fields on nerve regeneration that follows injury to the left radial nerve of a dog was examined using electromyography (EMG). The left and right radial nerves were crushed with a serrated hemostat and the stimulating electrodes were positioned proximally and distally relative to the site of the injury. The left nerves received rectangular, biphasic current pulses (30μA, 0.5Hz) through the lesion for two months. The right radial nerves were treated as controls and regenerated without electrical stimulation. EMG activity was recorded intramuscularly from left and right musculus extensor digitorum (from Medical dictionary) communis (MEDC). Results obtained at the end of the two-month stimulation period showed a significant difference between the EMG activity of the stimulated and the unstimulated MEDC suggesting that the electrical treatment enhanced the nerve regeneration.

  2. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Special payment rules for transcutaneous electrical nerve stimulators (TENS). (a) General payment rule. Except as provided in paragraph (b) of this section, payment for TENS is made on a purchase basis...

  3. Sacral nerve stimulation for faecal incontinence and constipation in adults.

    PubMed

    Thaha, Mohamed A; Abukar, Amin A; Thin, Noel N; Ramsanahie, Anthony; Knowles, Charles H

    2015-08-24

    Faecal incontinence (FI) and constipation are both socially-embarrassing and physically-disabling conditions that impair quality of life. For both, surgery may be required in a minority of people when more conservative measures fail. However, the invasiveness and irreversible nature of direct surgery on bowel and sphincter muscles, poor long-term outcomes and well-established compIications makes such procedures unappealing for these benign conditions. A less-invasive surgical option to treat faecal incontinence and constipation is direct, low-voltage stimulation of the sacral nerve roots, termed sacral nerve stimulation (SNS). SNS has become the first line surgical treatment for FI in people failing conservative therapies. Its value in the treatment of constipation is less clear. To assess the effects of sacral nerve stimulation using implanted electrodes for the treatment of faecal incontinence and constipation in adults. We searched the Cochrane Incontinence Group Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, ClinicalTrials.gov, the World Health Organization (WHO) ICTRP and handsearched journals and conference proceedings (searched 5 February 2015), EMBASE (1 January 1947 to 2015 Week 5), and the reference lists of retrieved relevant articles. All randomised or quasi-randomised trials assessing the effects of SNS for faecal incontinence or constipation in adults. Two review authors independently screened the search results, assessed the methodological quality of the included trials, and undertook data extraction. Six crossover trials and two parallel group trials were included.Six trials assessed the effects of SNS for FI. In the parallel group trial conducted by Tjandra, 53 participants with severe FI in the SNS group experienced fewer episodes of faecal incontinence compared to the control group who received optimal medical therapy (mean difference (MD) -5

  4. Characterization of cerebral blood flow response to sciatic nerve stimulation using laser speckle imaging

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Luo, Qingming; Cheng, Haiying; Lu, Qiang

    2003-12-01

    Laser speckle imaging (LSI) through a thinned skull over the somatosensory cortex was utilized to map the spatiotemporal characteristics of local cerebral flood flow (CBF) in anesthetized rats during sciatic nerve stimulation. Region-of-interest selection and Temporal clustering analysis (TCA) method was illustrated on the dataset from high-resolution optical imaging to detect the timing and location of CBF activation. Contralateral hindlimb sensory cortical microflow was activated to increase promptly in less than 1 s after the onset of 2 s electrical stimulation then evolved in different discrete regions. Individual arteries, veins and capillaries in different diameters were activated with the time going. This pattern is similar but slightly elaborated to the results obtained from laser Doppler flowmetry (LDF), functional magnetic resonance imaging (fMRI). We presented this combination to characterize the behaviors of CBF response to neuronal activity, which might possibly lead to a better understanding of neurovascular coupling and fMRI signals.

  5. Epidermal Laser Stimulation of Action Potentials in the Frog Sciatic Nerve

    DTIC Science & Technology

    2008-10-01

    Laser Stimulation of Action Potentials in the Frog Sciatic Nerve Nichole M. Jindra Robert J. Thomas Human Effectiveness Directorate Directed...in the Frog Sciatic Nerve 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62202F 6. AUTHOR(S) .Nichole M. Jindra, Robert J. Thomas, Douglas N...Alan Rice 14. ABSTRACT Measurements of laser stimulated action potentials in the sciatic nerve of leopard frogs (Rana pipiens) were made using

  6. Tibial nerve stimulation with a miniature, wireless stimulator in chronic peripheral neuropathic pain

    PubMed Central

    Sokal, Paweł; Harat, Marek; Zieliński, Piotr; Kierońska, Sara

    2017-01-01

    Peripheral neuropathic pain (PNP) and complex regional pain syndrome (CRPS) can be effectively treated with peripheral nerve stimulation. In this clinical trial report, effectiveness of novel, miniature, wirelessly controlled microstimulator of tibial nerve in PNP and CRPS was evaluated. In this pilot study the average preoperative visual analog scale (VAS) score in six patients was 7.5, with 1, 3 and 6 months: 2.6 (p=0.03), 1.6 (p=0.03), and 1.3 (p=0.02), respectively. The mean average score in the six patients a week preceding the baseline visit was 7.96, preceding the 1, 3 and 6 month visits: 3.32 (p=0.043), 3.65 (p=0.045), and 2.49 (p=0.002), respectively. The average short-form McGill pain score before surgery was 23.8, and after 1, 3 and 6 months it was 11.0 (p=0.45), 6.3 (p=0.043), and 4.5 (p=0.01), respectively. Applied therapy caused a reduction of pain immediately after its application and clinical improvement was sustained on a similar level in all patients for six months. No complications of the treatment were observed. Intermittent tibial nerve stimulation by using a novel, miniature, wirelessly controlled device can be effective and feasible in PNP and CRPS. It is a safe, minimally invasive, and convenient neuromodulative method. PMID:28352201

  7. Transcranial magnetic stimulation and the human brain

    NASA Astrophysics Data System (ADS)

    Hallett, Mark

    2000-07-01

    Transcranial magnetic stimulation (TMS) is rapidly developing as a powerful, non-invasive tool for studying the human brain. A pulsed magnetic field creates current flow in the brain and can temporarily excite or inhibit specific areas. TMS of motor cortex can produce a muscle twitch or block movement; TMS of occipital cortex can produce visual phosphenes or scotomas. TMS can also alter the functioning of the brain beyond the time of stimulation, offering potential for therapy.

  8. Magnetic stimulation in the diagnosis of lumbosacral radiculopathy.

    PubMed Central

    Chokroverty, S; Sachdeo, R; Dilullo, J; Duvoisin, R C

    1989-01-01

    Five patients presenting with sensory-motor disturbances consistent with a clinical diagnosis of L5 or S1 radiculopathy were studied. All had conventional nerve conduction tests and electromyography. The lumbosacral roots were stimulated in the lumbosacral region by using the Cadwell MES-10 Magneto-electric stimulator. The compound muscle action potentials were recorded bilaterally by surface electrodes applied to the soleus and tibialis anterior muscles. The latencies to the affected muscles were significantly prolonged. The appropriate root dysfunction was confirmed at operation or by the imaging techniques. It was concluded that surface stimulation of the lumbosacral roots by a magnetic coil is a potentially useful technique for the non-invasive evaluation of the function of the lumbosacral roots. Images PMID:2746269

  9. Tongue muscle plasticity following hypoglossal nerve stimulation in aged rats

    PubMed Central

    Connor, Nadine P.; Russell, John A.; Jackson, Michelle A.; Kletzien, Heidi; Wang, Hao; Schaser, Allison J.; Leverson, Glen E.; Zealear, David L.

    2012-01-01

    Introduction Age-related decreases in tongue muscle mass and strength have been reported. It may be possible to prevent age-related tongue muscle changes using neuromuscular electrical stimulation (NMES). Our hypothesis was that alterations in muscle contractile properties and myosin heavy chain composition would be found following NMES. Methods Fifty-four young, middle-aged and old Fischer 344/Brown Norway rats were included. Twenty-four rats underwent bilateral electrical stimulation of the hypoglossal nerves for 8 weeks and were compared with control or sham rats. Muscle contractile properties and myosin heavy chain (MHC) in the genioglossus (GG), styloglossus (SG) and hyoglossus (HG) muscles were examined. Results In comparison with unstimulated control rats, we found reduced muscle fatigue, increased contraction and half decay times and increased twitch and tetanic tension. Increased Type I MHC was found, except for GG in old and middle-aged rats. Discussion Transitions in tongue muscle contractile properties and phenotype were found following NMES. PMID:23169566

  10. Vagus nerve stimulation for refractory epilepsy: a transatlantic experience.

    PubMed

    Vonck, Kristl; Thadani, Vijay; Gilbert, Karen; Dedeurwaerdere, Stefanie; De Groote, Liesbeth; De Herdt, Veerle; Goossens, Lut; Gossiaux, Fleur; Achten, Erik; Thiery, Evert; Vingerhoets, Guy; Van Roost, Dirk; Caemaert, Jacques; De Reuck, Jacques; Roberts, David; Williamson, Peter; Boon, Paul

    2004-01-01

    Vagus nerve stimulation (VNS) is an alternative treatment for medically or surgically refractory epilepsy. The long-term efficacy and safety of VNS were evaluated in a large patient series at Ghent University Hospital and Dartmouth-Hitchcock Medical Center. Between March 1995 and February 2003, seizure frequency and type as well as prescribed antiepileptic drugs and side effects were prospectively assessed in 131 patients treated with VNS in either center. Patients with a minimum follow-up duration of 6 months were included in the efficacy and safety analysis. A total of 118 of 131 implanted patients had a minimum postimplantation follow-up period of 6 months (mean, 33 months). The mean age of these patients was 32 years and the mean duration of refractory epilepsy was 22 years. The mean reduction in monthly seizure frequency in all patients was 55% (range, 0-100; SD = 31.6). Seven percent of patients were free of seizures with impaired consciousness, 50% of patients had a seizure frequency reduction of more than 50%, and 21% of patients were nonresponders. Fifteen patients reported stimulation-related side effects such as hoarseness or gagging. In a large patient series from two geographically distinct epilepsy centers located in two different continents, VNS proved to be efficacious and safe during long-term follow-up.

  11. Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

    NASA Technical Reports Server (NTRS)

    Tang, P. C.

    1973-01-01

    Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

  12. Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

    NASA Technical Reports Server (NTRS)

    Tang, P. C.

    1973-01-01

    Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

  13. The effects of general anaesthesia on nerve-motor response characteristics (rheobase and chronaxie) to peripheral nerve stimulation.

    PubMed

    Tsui, B C

    2014-04-01

    Using a simple surface nerve stimulation system, I examined the effects of general anaesthesia on rheobase (the minimum current required to stimulate nerve activity) and chronaxie (the minimum time for a stimulus twice the rheobase to elicit nerve activity). Nerve stimulation was used to elicit a motor response from the ulnar nerve at varying pulse widths before and after induction of general anaesthesia. Mean (SD) rheobase before and after general anaesthesia was 0.91 (0.37) mA (95% CI 0.77-1.04 mA) and 1.11 (0.53) mA (95% CI 0.92-1.30 mA), respectively. Mean (SD) chronaxie measured before and after general anaesthesia was 0.32 (0.17) ms (95% CI 0.26-0.38 ms) and 0.29 (0.13) ms (95% CI 0.24-0.33 ms), respectively. Under anaesthesia, rheobase values increased by an average of 20% (p = 0.05), but chronaxie values did not change significantly (p = 0.39). These results suggest that threshold currents used for motor response from nerve stimulation under general anaesthesia might be higher than those used in awake patients. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

  14. Tinnitus suppression by electric stimulation of the auditory nerve

    PubMed Central

    Chang, Janice E.; Zeng, Fan-Gang

    2012-01-01

    Electric stimulation of the auditory nerve via a cochlear implant (CI) has been observed to suppress tinnitus, but parameters of an effective electric stimulus remain unexplored. Here we used CI research processors to systematically vary pulse rate, electrode place, and current amplitude of electric stimuli, and measure their effects on tinnitus loudness and stimulus loudness as a function of stimulus duration. Thirteen tinnitus subjects who used CIs were tested, with nine (70%) being “Responders” who achieved greater than 30% tinnitus loudness reduction in response to at least one stimulation condition and the remaining four (30%) being “Non-Responders” who had less than 30% tinnitus loudness reduction in response to any stimulus condition tested. Despite large individual variability, several interesting observations were made between stimulation parameters, tinnitus characteristics, and tinnitus suppression. If a subject's tinnitus was suppressed by one stimulus, then it was more likely to be suppressed by another stimulus. If the tinnitus contained a “pulsating” component, then it would be more likely suppressed by a given combination of stimulus parameters than tinnitus without these components. There was also a disassociation between the subjects' clinical speech processor and our research processor in terms of their effectiveness in tinnitus suppression. Finally, an interesting dichotomy was observed between loudness adaptation to electric stimuli and their effects on tinnitus loudness, with the Responders exhibiting higher degrees of loudness adaptation than the Non-Responders. Although the mechanisms underlying these observations remain to be resolved, their clinical implications are clear. When using a CI to manage tinnitus, the clinical processor that is optimized for speech perception needs to be customized for optimal tinnitus suppression. PMID:22479238

  15. Intractable sacroiliac joint pain treated with peripheral nerve field stimulation

    PubMed Central

    Chakrabortty, Shushovan; Kumar, Sanjeev; Gupta, Deepak; Rudraraju, Sruthi

    2016-01-01

    As many as 62% low back pain patients can have sacroiliac joint (SIJ) pain. There is limited (to poor) evidence in regards to long-term pain relief with therapeutic intra-articular injections and/or conventional (heat or pulsed) radiofrequency ablations (RFAs) for SIJ pain. We report our pain-clinic experience with peripheral nerve field stimulation (PNFS) for two patients of intractable SIJ pain. They had reported absence of long-term pain relief (pain relief >50% for at least 2 weeks postinjection and at least 3 months post-RFA) with SIJ injections and SIJ RFAs. Two parallel permanent 8-contact subcutaneous stimulating leads were implanted under the skin overlying their painful SIJ. Adequate stimulation in the entire painful area was confirmed. For implantable pulse generator placement, a separate subcutaneous pocket was made in the upper buttock below the iliac crest level ipsilaterally. During the pain-clinic follow-up period, the patients had reduced their pain medications requirements by half with an additional report of more than 50% improvement in their functional status. The first patient passed away 2 years after the PNFS procedure due to medical causes unrelated to his chronic pain. The second patient has been comfortable with PNFS-induced analgesic regimen during her pain-clinic follow-up during last 5 years. In summary, PNFS can be an effective last resort option for SIJ pain wherein conventional interventional pain techniques have failed, and analgesic medication requirements are escalating or causing unwarranted side-effects. PMID:27625495

  16. Nerve Fascicles and Epineurium Volume Segmentation of Peripheral Nerve Using Magnetic Resonance Micro-neurography.

    PubMed

    Felisaz, Paolo Florent; Balducci, Francesco; Gitto, Salvatore; Carne, Irene; Montagna, Stefano; De Icco, Roberto; Pichiecchio, Anna; Baldi, Maurizia; Calliada, Fabrizio; Bastianello, Stefano

    2016-08-01

    The aims of this study were to propose a semiautomated technique to segment and measure the volume of different nerve components of the tibial nerve, such as the nerve fascicles and the epineurium, based on magnetic resonance microneurography and a segmentation tool derived from brain imaging; and to assess the reliability of this method by measuring interobserver and intraobserver agreement. The tibial nerve of 20 healthy volunteers (age range = 23-69; mean = 47; standard deviation = 15) was investigated at the ankle level. High-resolution images were obtained through tailored microneurographic sequences, covering 28 mm of nerve length. Two operators manually segmented the nerve using the in-phase image. This region of interest was used to mask the nerve in the water image, and two-class segmentation was performed to measure the fascicular volume, epineurial volume, nerve volume, and fascicular to nerve volume ratio (FNR). Interobserver and intraobserver agreements were calculated. The nerve structure was clearly visualized with distinction of the fascicles and the epineurium. Segmentation provided absolute volumes for nerve volume, fascicular volume, and epineurial volume. The mean FNR resulted in 0.69 with a standard deviation of 0.04 and appeared to be not correlated with age and sex. Interobserver and intraobserver agreements were excellent with alpha values >0.9 for each parameter investigated, with measurements free of systematic errors at the Bland-Altman analysis. We concluded that the method is reproducible and the parameter FNR is a novel feature that may help in the diagnosis of neuropathies detecting changes in volume of the fascicles or the epineurium. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  17. Vagus Nerve and Vagus Nerve Stimulation, a Comprehensive Review: Part III.

    PubMed

    Yuan, Hsiangkuo; Silberstein, Stephen D

    2016-03-01

    Vagus nerve stimulation (VNS) is currently undergoing multiple trials to explore its potential for various clinical disorders. To date, VNS has been approved for the treatment of refractory epilepsy and depression. It exerts antiepileptic or antiepileptogenic effect possibly through neuromodulation of certain monoamine pathways. Beyond epilepsy, VNS is also under investigation for the treatment of inflammation, asthma, and pain. VNS influences the production of inflammatory cytokines to dampen the inflammatory response. It triggers the systemic release of catecholamines that alleviates the asthma attack. VNS induces antinociception by modulating multiple pain-associated structures in the brain and spinal cord affecting peripheral/central nociception, opioid response, inflammation process, autonomic activity, and pain-related behavior. Progression in VNS clinical efficacy over time suggests an underlying disease-modifying neuromodulation, which is an emerging field in neurology. With multiple potential clinical applications, further development of VNS is encouraging.

  18. Magnetic stimulation of marigold seed

    NASA Astrophysics Data System (ADS)

    Afzal, I.; Mukhtar, K.; Qasim, M.; Basra, S. M. A.; Shahid, M.; Haq, Z.

    2012-10-01

    The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

  19. Noninvasive vagus nerve stimulation in the management of cluster headache: clinical evidence and practical experience

    PubMed Central

    Holle-Lee, Dagny; Gaul, Charly

    2016-01-01

    The efficacy of invasive vagal nerve stimulation as well as other invasive neuromodulatory approaches such as deep brain stimulation, occipital nerve stimulation, and ganglion sphenopalatine stimulation has been shown in the treatment of headache disorders in several studies in the past. However, these invasive treatment options were quite costly and often associated with perioperative and postoperative side effects, some severe. As such, they were predominantly restricted to chronic and therapy refractory patients. Transcutaneous vagal nerve stimulation now offers a new, noninvasive neuromodulatory treatment approach. Recently published studies showed encouraging results of noninvasive vagus nerve stimulation (nVNS), especially with respect to cluster headache, with high tolerability and a low rate of side effects; however, randomized controlled trials are needed to prove its efficacy. Further data also indicate therapeutic benefits regarding treatment of migraine and medication overuse headache. This review summarizes current knowledge and personal experiences of nVNS in the treatment of cluster headache. PMID:27134678

  20. [Magnetic stimulation of the human nervous system. Theoretic basis and clinical application].

    PubMed

    Jaskólski, D J; Jarrat, J A; Jakubowski, J

    1990-01-01

    Magnetic stimulation of the nervous system is a new technique introduced in 1985 by Barker, Jalinous and Freeston. Using short pulses of a time-varying magnetic field it allows a noninvasive stimulation of the motor cortex and deeply placed peripheral nerves. The authors presented basic principles and applications of this method. Stimulation procedures were described and the problem of safety and possible side-effects was discussed. Advantages and disadvantages of the method were presented in comparison to electrical stimulation. Preliminary results of the clinical studies conducted chiefly in patients with multiple sclerosis and cervical spondylosis were reviewed.

  1. Optimizing nerve cuff stimulation of targeted regions through use of genetic algorithms.

    PubMed

    Brill, Natalie; Tyler, Dustin

    2011-01-01

    A nerve cuff electrode is a viable technology for use in a neuroprostheses system to restore loss of function due to neurological injury. The Flat Interface Nerve Electrode (FINE) is a nerve cuff that gently reshapes the nerve to bring the axons closer to the stimulating contacts. The overall goal of this work is to optimize nerve cuff stimulation in upper extremity nerves. Recently, highly efficient and accurate linear models of neuronal activation have been developed in our lab. Using the fast calculations from the newly developed linear activation method, nerve stimulation parameters such as current pulse width and pulse amplitude at many electrode contacts can be explored by employing optimization algorithms. Finite element nerve models with high density electrodes were constructed based on upper extremity cadaveric nerve cross sections. An objective function was developed to target specific groups of nerve fascicles and minimize overlap amongst these groups. By changing the objective function and using a genetic search algorithm, stimulation parameters can be optimized for many contacts.

  2. Recognition of local anesthetic maldistribution in axillary brachial plexus block guided by ultrasound and nerve stimulation.

    PubMed

    Veneziano, Giorgio C; Rao, Vidya K; Orebaugh, Steven L

    2012-03-01

    Nerve stimulation may occur despite the presence of a fascial barrier between the needle tip and the nerve, which may prevent appropriate flow or distribution of local anesthetic solution. During an axillary nerve block, ultrasound (US) guidance was used to identify the median nerve. Insertion of a needle with US and nerve stimulator guidance resulted in the appearance of the needle tip in contact with the nerve. However, as local anesthetic injection was begun, it was clear that the injectate was accumulating superficial to the investing fascia of the neurovascular bundle. No injectate was seen below the fascia. With US guidance, the needle was repositioned at a greater depth. Repeat injection of local anesthetic clearly flowed around the nerve. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. A Nerve Clamp Electrode Design for Indirect Stimulation of Skeletal Muscle

    DTIC Science & Technology

    2010-10-01

    Reports www.BioTechniques.com739Vol. 49 | No. 4 | 2010 Ex vivo assays to measure muscle paralysis induced by botulinum neurotoxin (BoNT) have been...Keywords: stimulating electrode; botulinum neurotoxin; skeletal muscle; paralysis A nerve clamp electrode was developed to indirectly stimulate skeletal...attached nerve. Indirect muscle stimulation is critical for studying the para- lytic actions of presynaptic-acting toxins such as botulinum neurotoxins

  4. Electrical stimulation threshold in chronically compressed lumbar nerve roots: Observational study.

    PubMed

    Plata-Bello, Julio; Pérez-Lorensu, Pedro Javier; Brage, Liberto; Hernández-Hernández, Vanessa; Dóniz, Ayoze; Roldán-Delgado, Héctor; Febles, Pablo; García-Conde, Mario; Pérez-Orribo, Luis; García-Marín, Víctor

    2015-12-01

    Intraoperative neuromonitoring (IONM) is a common practice in spinal surgery, mostly during pedicle screw placement. However, there is not enough information about the factors that can interfere with IONM data. One of these factors may be existing damage of the nerve root whose function must be preserved. The main purpose of the present study is to evaluate the effect of chronic compression in lumbar nerve roots in terms of stimulation thresholds during direct nerve stimulation. Direct electrical stimulation was performed in 201 lumbar nerve roots during lumbar spinal procedures under general anaesthesia in 80 patients with different lumbar spinal pathologies. Clinical and radiological data were reviewed in order to establish the presence of chronic compression. Chronically compressed nerve roots showed a higher stimulation threshold than non compressed nerve roots (11.93 mA vs. 4.33 mA). This difference was confirmed with intra-subject comparison (paired sample t test, p=0.012). No other clinical factors were associated with this higher stimulation threshold in lumbar nerve roots. A higher stimulation threshold is present in compressed lumbar nerve roots than non compressed roots. This needs to be taken into consideration during pedicle screw placement, where intraoperative neurophysiological monitoring is being used. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Electrical stimulation of dog pudendal nerve regulates the excitatory pudendal-to-bladder reflex.

    PubMed

    Ju, Yan-He; Liao, Li-Min

    2016-04-01

    Pudendal nerve plays an important role in urine storage and voiding. Our hypothesis is that a neuroprosthetic device placed in the pudendal nerve trunk can modulate bladder function after suprasacral spinal cord injury. We had confirmed the inhibitory pudendal-to-bladder reflex by stimulating either the branch or the trunk of the pudendal nerve. This study explored the excitatory pudendal-to-bladder reflex in beagle dogs, with intact or injured spinal cord, by electrical stimulation of the pudendal nerve trunk. The optimal stimulation frequency was approximately 15-25 Hz. This excitatory effect was dependent to some extent on the bladder volume. We conclude that stimulation of the pudendal nerve trunk is a promising method to modulate bladder function.

  6. Adaptation of Continuous Intraoperative Vagus Nerve Stimulation for Monitoring of Recurrent Laryngeal Nerve During Minimally Invasive Esophagectomy.

    PubMed

    Tsang, Raymond K; Law, Simon

    2016-01-01

    Esophagectomy has risk of recurrent laryngeal nerve (RLN) injury. Conventional nerve monitoring has been used to help identify and protect the RLN. A new concept of continuous intraoperative nerve monitoring (CIONM) by stimulation of the ipsilateral vagus nerve has been used in thyroidectomy. The current report describes adapting the CIONM method for use in video-assisted thoracoscopic (VATS) esophagectomy. The nerve monitor employed is NIM 3.0 with automatic periodic stimulation (Medtronics Inc., USA). Patient is intubated with NIM contact-reinforced EMG endotracheal tube (Medtronics Inc., USA). The operation starts with a left lower neck incision, and the stimulating electrode is secured around the left vagus nerve. The patient is then turned to the left lateral position for VATS esophagectomy. CIONM of the left RLN is achieved by regular stimulation of the left vagus nerve, and intact nerve conduction is detected by the electromyography (EMG) of the left vocalis muscle. The alarm is set to activate when EMG amplitude reduces by 50% or latency prolongs by 10%. Initial experience of ten cases showed that a mean time of 35 min was required to complete the electrode insertion in the neck. There was one event in which there was more than 50% reduction of EMG amplitude that persisted but the patient had no vocal cord paralysis after operation. In another patient, the EMG reduced by 75% and persisted. The patient had temporary vocal cord paralysis. CIONM is feasible during VATS esophagectomy and can alert the surgeon of imminent injury to the RLNs, thereby preventing permanent injury.

  7. Optimization of epilepsy treatment with vagus nerve stimulation

    NASA Astrophysics Data System (ADS)

    Uthman, Basim; Bewernitz, Michael; Liu, Chang-Chia; Ghacibeh, Georges

    2007-11-01

    Epilepsy is one of the most common chronic neurological disorders that affects close to 50 million people worldwide. Antiepilepsy drugs (AEDs), the main stay of epilepsy treatment, control seizures in two thirds of patients only. Other therapies include the ketogenic diet, ablative surgery, hormonal treatments and neurostimulation. While other approaches to stimulation of the brain are currently in the experimental phase vagus nerve stimulation (VNS) has been approved by the FDA since July 1997 for the adjunctive treatment of intractable partial onset epilepsy with and without secondary generalization in patients twelve years of age or older. The safety and efficacy of VNS have been proven and duplicated in two subsequent double-blinded controlled studies after two pilot studies demonstrated the feasibility of VNS in man. Long term observational studies confirmed the safety of VNS and that its effectiveness is sustained over time. While AEDs influence seizure thresholds via blockade or modulation of ionic channels, inhibit excitatory neurotransmitters or enhance inhibitory neurotransmitters the exact mechanism of action of VNS is not known. Neuroimaging studies revealed that VNS increases blood flow in certain regions of the brain such as the thalamus. Chemical lesions in the rat brains showed that norepinephrine is an important link in the anticonvulsant effect of VNS. Analysis of cerebrospinal fluid obtained from patients before and after treatment with VNS showed modest decreases in excitatory neurotransmitters. Although Hammond et al. reported no effect of VNS on scalp EEG by visual analysis and Salinsky et al. found no effect of VNS on scalp EEG by spectral analysis, Kuba et al. suggested that VNS reduces interictal epileptiform activity. Further, nonlinear dynamical analysis of the electroencephalogram in the rat and man have reportedly shown predictable changes (decrease in the short term Lyapunov exponent STLmax and T-index) more than an hour prior to the

  8. Ultrasound-stimulated peripheral nerve regeneration within asymmetrically porous PLGA/Pluronic F127 nerve guide conduit.

    PubMed

    Park, Sang Chul; Oh, Se Heang; Seo, Tae Beom; Namgung, Uk; Kim, Jin Man; Lee, Jin Ho

    2010-08-01

    Recently, we developed a novel method to fabricate a nerve guide conduit (NGC) with asymmetrical pore structure and hydrophilicity using poly(lactic-co-glycolic acid) (PLGA) and Pluronic F127 by a modified immersion precipitation method. From the animal study using a rat model (sciatic nerve defect of rat), we recognized that the unique PLGA/Pluronic F127 tube provided good environments for nerve regeneration. In this study, we applied low-intensity pulsed ultrasound as a simple and noninvasive stimulus at the PLGA/F127 NGC-implanted site transcutaneously in rats to investigate the feasibility of ultrasound for the enhanced nerve regeneration through the tube. The nerve regeneration behaviors within the ultrasound-stimulated PLGA/Pluronic F127 NGCs were compared with the NGCs without the ultrasound treatment as well as normal nerve by histological and immunohistochemical observations. It was observed that the PLGA/Pluronic F127 tube-implanted group applied with the ultrasound had more rapid nerve regeneration behavior (approximately 0.71 mm/day) than the tube-implanted group without the ultrasound treatment (approximately 0.48 mm/day). The ultrasound-treated tube group also showed greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the ultrasound treatment, indicating better nerve regeneration. The better nerve regeneration behavior in the our NGC/ultrasound system may be caused by the synergistic effect of the asymmetrically porous PLGA/Pluronic F127 tube with unique properties (selective permeability, hydrophilicity, and structural stability, which can provide good environment for nerve regeneration) and physical stimulus (stimulation of the Schwann cells and activation of the neurotrophic factors).

  9. Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation.

    PubMed

    Kauff, D W; Moszkowski, T; Wegner, C; Heimann, A; Hoffmann, K-P; Krüger, T B; Lang, H; Kneist, W

    2017-07-06

    The current standard for pelvic intraoperative neuromonitoring (pIONM) is based on intermittent direct nerve stimulation. This study investigated the potential use of transcutaneous sacral nerve stimulation for non-invasive verification of pelvic autonomic nerves. A consecutive series of six pigs underwent low anterior rectal resection. For transcutaneous sacral nerve stimulation, an array of ten electrodes (cathodes) was placed over the sacral foramina (S2 to S4). Anodes were applied on the back, right and left thigh, lower abdomen, and intra-anally. Stimulation using the novel method and current standard were performed at different phases of the experiments under electromyography of the autonomic innervated internal anal sphincter (IAS). Transcutaneous stimulation induced increase of IAS activity could be observed in each animal under specific cathode-anode configurations. Out of 300 tested configurations, 18 exhibited a change in the IAS activity correlated with intentional autonomic nerve damage. The damage resulted in a significant decrease of the relative area under the curve of the IAS frequency spectrum (P<.001). Comparison of the IAS spectra under transcutaneous and direct stimulation revealed no significant difference (after rectal resection: median 5.99 μV•Hz vs 7.78 μV•Hz, P=.12; after intentional nerve damage: median -0.27 μV•Hz vs 3.35 μV•Hz, P=.29). Non-invasive selective transcutaneous sacral nerve stimulation could be used for verification of IAS innervation. © 2017 John Wiley & Sons Ltd.

  10. Effect of Fixed Versus Adjusted Transcutaneous Electrical Nerve Stimulation Amplitude on Chronic Mechanical Low Back Pain.

    PubMed

    Elserty, Noha; Kattabei, Omaima; Elhafez, Hytham

    2016-07-01

    This study aimed to investigate the effect of adjusting pulse amplitude of transcutaneous electrical nerve stimulation versus fixed pulse amplitude in treatment of chronic mechanical low back pain. Randomized clinical trial. El-sahel Teaching Hospital, Egypt. Forty-five patients with chronic low back pain assigned to three equal groups. Their ages ranged from 20 to 50 years. The three groups received the same exercise program. Group A received transcutaneous electrical nerve stimulation with fixed pulse amplitude for 40 minutes. Group B received transcutaneous electrical nerve stimulation with adjusted pulse amplitude for 40 minutes, with the pulse amplitude adjusted every 5 minutes. Group C received exercises only. Treatment sessions were applied three times per week for 4 weeks for the three groups. A visual analogue scale was used to assess pain severity, the Oswestry Disability Index was used to assess functional level, and a dual inclinometer was used to measure lumbar range of motion. Evaluations were performed before and after treatment. Visual analogue scale, Oswestry Disability Index, and back range of motion significantly differed between the two groups that received transcutaneous electrical nerve stimulation and the control group and did not significantly differ between fixed and adjusted pulse amplitude of transcutaneous electrical nerve stimulation. Adjusting pulse amplitude of transcutaneous electrical nerve stimulation does not produce a difference in the effect of transcutaneous electrical nerve stimulation used to treat chronic low back pain.

  11. Vagus nerve stimulation therapy: indications, programing, and outcomes.

    PubMed

    Yamamoto, Takamichi

    2015-01-01

    Vagus nerve stimulation (VNS) provides palliation of seizure reduction for patients with medically refractory epilepsy. VNS is indicated for symptomatic localization-related epilepsy with multiple and bilateral independent foci, symptomatic generalized epilepsy with diffuse epileptogenic abnormalities, refractory idiopathic generalized epilepsy, failed intracranial epilepsy surgery, and other several reasons of contraindications to epilepsy surgery. Programing of the parameters is a principal part in VNS. Output current and duty cycle should be adjusted to higher settings particularly when a patient does not respond to the initial setting, since the pivotal randomized trials performed in the United States demonstrated high stimulation made better responses in seizure frequency. These trials revealed that a ≥ 50% seizure reduction occurred in 36.8% of patients at 1 year, in 43.2% at 2 years, and in 42.7% at 3 years in 440 patients. Safety of VNS was also confirmed because side effects including hoarseness, throat discomfort, cough, paresthesia, and headache improved progressively during the period of 3 years. The largest retrospective study with 436 patients demonstrated the mean seizure reduction of 55.8% in nearly 5 years, and also found 75.5% at 10 years in 65 consecutive patients. The intermediate analysis report of the Japan VNS Registry showed that 60% of 164 cases got a ≥ 50% seizure reduction in 12 months. In addition to seizure reduction, VNS has positive effects in mood and improves energy level, memory difficulties, social aspects, and fear of seizures. VNS is an effective and safe option for patients who are not suitable candidates for intracranial epilepsy surgery.

  12. Vagus Nerve Stimulation Therapy: Indications, Programing, and Outcomes

    PubMed Central

    YAMAMOTO, Takamichi

    2015-01-01

    Vagus nerve stimulation (VNS) provides palliation of seizure reduction for patients with medically refractory epilepsy. VNS is indicated for symptomatic localization-related epilepsy with multiple and bilateral independent foci, symptomatic generalized epilepsy with diffuse epileptogenic abnormalities, refractory idiopathic generalized epilepsy, failed intracranial epilepsy surgery, and other several reasons of contraindications to epilepsy surgery. Programing of the parameters is a principal part in VNS. Output current and duty cycle should be adjusted to higher settings particularly when a patient does not respond to the initial setting, since the pivotal randomized trials performed in the United States demonstrated high stimulation made better responses in seizure frequency. These trials revealed that a ≥ 50% seizure reduction occurred in 36.8% of patients at 1 year, in 43.2% at 2 years, and in 42.7% at 3 years in 440 patients. Safety of VNS was also confirmed because side effects including hoarseness, throat discomfort, cough, paresthesia, and headache improved progressively during the period of 3 years. The largest retrospective study with 436 patients demonstrated the mean seizure reduction of 55.8% in nearly 5 years, and also found 75.5% at 10 years in 65 consecutive patients. The intermediate analysis report of the Japan VNS Registry showed that 60% of 164 cases got a ≥ 50% seizure reduction in 12 months. In addition to seizure reduction, VNS has positive effects in mood and improves energy level, memory difficulties, social aspects, and fear of seizures. VNS is an effective and safe option for patients who are not suitable candidates for intracranial epilepsy surgery. PMID:25925759

  13. Hypoglossal Nerve Stimulation Improves Obstructive Sleep Apnea: 12 Month Outcomes

    PubMed Central

    Kezirian, Eric J.; Goding, George S.; Malhotra, Atul; O'Donoghue, Fergal J.; Zammit, Gary; Wheatley, John R.; Catcheside, Peter G.; Smith, Philip L.; Schwartz, Alan R.; Walsh, Jennifer H.; Maddison, Kathleen J.; Claman, David M.; Huntley, Tod; Park, Steven Y.; Campbell, Matthew C.; Palme, Carsten E.; Iber, Conrad; Eastwood, Peter R.; Hillman, David R.; Barnes, Maree

    2013-01-01

    Reduced upper airway muscle activity during sleep is a key contributor to obstructive sleep apnoea (OSA) pathogenesis. Hypoglossal nerve stimulation (HGNS) activates upper airway dilator muscles, including the genioglossus, and has the potential to reduce OSA severity. The objective of this study was to examine the safety, feasibility, and efficacy of a novel HGNS system (HGNS®, Apnex Medical, Inc., St. Paul, MN) in treating OSA at 12 months following implantation. Thirty-one subjects (35% female, age 52·4±9·4 years) with moderate to severe OSA and unable to tolerate positive airway pressure underwent surgical implantation and activation of the HGNS system in a prospective single-arm interventional trial. Primary outcomes were changes in OSA severity (apnoea-hypopnoea index, AHI, from in-laboratory polysomnogram) and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire, FOSQ). HGNS was used on 86±16% of nights for 5·4±1·4 hours per night. There was a significant improvement (p < 0·001) from baseline to 12 months in AHI (45.4±17·5 to 25·3±20·6 events/h) and FOSQ score (14·2±2·0 to 17·0±2·4) as well as other polysomnogram and symptom measures. Outcomes were stable compared to 6 months following implantation. Three serious device-related adverse events occurred: an infection requiring device removal and two stimulation lead cuff dislodgements requiring replacement. There were no significant adverse events with onset later than 6 months following implantation. HGNS demonstrated favourable safety, feasibility, and efficacy. PMID:24033656

  14. Electrical stimulation does not enhance nerve regeneration if delayed after sciatic nerve injury: the role of fibrosis

    PubMed Central

    Han, Na; Xu, Chun-gui; Wang, Tian-bing; Kou, Yu-hui; Yin, Xiao-feng; Zhang, Pei-xun; Xue, Feng

    2015-01-01

    Electrical stimulation has been shown to accelerate and enhance nerve regeneration in sensory and motor neurons after injury, but there is little evidence that focuses on the varying degrees of fibrosis in the delayed repair of peripheral nerve tissue. In this study, a rat model of sciatic nerve transection injury was repaired with a biodegradable conduit at 1 day, 1 week, 1 month and 2 months after injury, when the rats were divided into two subgroups. In the experimental group, rats were treated with electrical stimuli of frequency of 20 Hz, pulse width 100 ms and direct current voltage of 3 V; while rats in the control group received no electrical stimulation after the conduit operation. Histological results showed that stained collagen fibers comprised less than 20% of the total operated area in the two groups after delayed repair at both 1 day and 1 week but after longer delays, the collagen fiber area increased with the time after injury. Immunohistochemical staining revealed that the expression level of transforming growth factor β (an indicator of tissue fibrosis) decreased at both 1 day and 1 week after delayed repair but increased at both 1 and 2 months after delayed repair. These findings indicate that if the biodegradable conduit repair combined with electrical stimulation is delayed, it results in a poor outcome following sciatic nerve injury. One month after injury, tissue degeneration and distal fibrosis are apparent and are probably the main reason why electrical stimulation fails to promote nerve regeneration after delayed repair. PMID:25788926

  15. Use of transcutaneous electrical nerve stimulation for chronic pruritus.

    PubMed

    Mohammad Ali, Basma Mourad; Hegab, Doaa Salah; El Saadany, Hanan Mohammad

    2015-01-01

    Pruritus is a distressing symptom in many dermatological as well as systemic conditions, and it is sometimes very chronic and relapsing. Transcutaneous electrical nerve stimulation (TENS) is an inexpensive form of analgesia that could also ameliorate itching. This study aimed to evaluate TENS efficacy in patients with pruritus due to some types of chronic eczema, and in patients with chronic hepatic disease. Ten patients with atopic dermatitis (AD), 20 patients with lichen simplex chronicus (LSC), and 16 patients with chronic liver disease having chronic distressing pruritus received three sessions of TENS weekly for 12 sessions, and the effect on the visual analogue scale (VAS) scores was recorded after 2 weeks of therapy, at treatment end, and after an additional month for follow up. There was a statistically significant decline in the mean VAS score for studied groups at weeks 2 and 4 of therapy compared to baseline, but the improvement was more significant in patients with AD, and LSC (p < 0.001 for both) than in those with chronic liver disease (p < 0.01) who also showed an early re-elevation of VAS score on follow up. TENS therapy holds promise as a palliative, alternative, safe and inexpensive treatment for patients with some chronic pruritic conditions.

  16. Microcurrent Electrical Nerve Stimulation Facilitates Regrowth of Mouse Soleus Muscle

    PubMed Central

    Ohno, Yoshitaka; Fujiya, Hiroto; Goto, Ayumi; Nakamura, Ayane; Nishiura, Yuka; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Goto, Katsumasa

    2013-01-01

    Microcurrent electrical nerve stimulation (MENS) has been used to facilitate recovery from skeletal muscle injury. However, the effects of MENS on unloading-associated atrophied skeletal muscle remain unclear. Effects of MENS on the regrowing process of unloading-associated atrophied skeletal muscle were investigated. Male C57BL/6J mice (10-week old) were randomly assigned to untreated normal recovery (C) and MENS-treated (M) groups. Mice of both groups are subjected to continuous hindlimb suspension (HS) for 2 weeks followed by 7 days of ambulation recovery. Mice in M group were treated with MENS for 60 min 1, 3, and 5 days following HS, respectively, under anesthesia. The intensity, the frequency, and the pulse width of MENS were set at 10 μA, 0.3 Hz, and 250 msec, respectively. Soleus muscles were dissected before and immediately after, 1, 3 and 7 days after HS. Soleus muscle wet weight and protein content were decreased by HS. The regrowth of atrophied soleus muscle in M group was faster than that in C group. Decrease in the reloading-induced necrosis of atrophied soleus was facilitated by MENS. Significant increases in phosphorylated levels of p70 S6 kinase and protein kinase B (Akt) in M group were observed, compared with C group. These observations are consistent with that MENS facilitated regrowth of atrophied soleus muscle. MENS may be a potential extracellular stimulus to activate the intracellular signals involved in protein synthesis. PMID:23983587

  17. Microcurrent electrical nerve stimulation facilitates regrowth of mouse soleus muscle.

    PubMed

    Ohno, Yoshitaka; Fujiya, Hiroto; Goto, Ayumi; Nakamura, Ayane; Nishiura, Yuka; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Goto, Katsumasa

    2013-01-01

    Microcurrent electrical nerve stimulation (MENS) has been used to facilitate recovery from skeletal muscle injury. However, the effects of MENS on unloading-associated atrophied skeletal muscle remain unclear. Effects of MENS on the regrowing process of unloading-associated atrophied skeletal muscle were investigated. Male C57BL/6J mice (10-week old) were randomly assigned to untreated normal recovery (C) and MENS-treated (M) groups. Mice of both groups are subjected to continuous hindlimb suspension (HS) for 2 weeks followed by 7 days of ambulation recovery. Mice in M group were treated with MENS for 60 min 1, 3, and 5 days following HS, respectively, under anesthesia. The intensity, the frequency, and the pulse width of MENS were set at 10 μA, 0.3 Hz, and 250 msec, respectively. Soleus muscles were dissected before and immediately after, 1, 3 and 7 days after HS. Soleus muscle wet weight and protein content were decreased by HS. The regrowth of atrophied soleus muscle in M group was faster than that in C group. Decrease in the reloading-induced necrosis of atrophied soleus was facilitated by MENS. Significant increases in phosphorylated levels of p70 S6 kinase and protein kinase B (Akt) in M group were observed, compared with C group. These observations are consistent with that MENS facilitated regrowth of atrophied soleus muscle. MENS may be a potential extracellular stimulus to activate the intracellular signals involved in protein synthesis.

  18. Refractory status epilepticus treated with trigeminal nerve stimulation.

    PubMed

    Moseley, Brian D; Degiorgio, Christopher M

    2014-03-01

    Refractory status epilepticus (RSE) is a neurologic emergency associated with significant morbidity and mortality. Alternative therapies are needed for patients who do not respond to more traditional therapies for RSE. We report on a patient with RSE treated with external trigeminal nerve stimulation (eTNS). On admission, the patient was experiencing consecutive focal dyscognitive seizures with secondary generalization without recovery in between. His seizures remained refractory to multiple therapies, including IV lorazepam, valproic acid, levetiracetam, phenobarbital, and midazolam. Although a burst suppression pattern was achieved with a continuous pentobarbital infusion, seizures returned following attempts to taper it. Given his beneficial response to eTNS during a previous clinical trial, eTNS was initiated. Four days after starting eTNS, the pentobarbital infusion was finally weaned, and his EEG revealed no further seizures. The patient's mental status improved and he was ultimately discharged with only moderately severe disability. Our case demonstrates that eTNS may have antiseizure effects in RSE. Given our patient's quick response, such benefit may have arisen from EEG-desynchronization. If confirmed in larger studies, eTNS could one day be considered along with other adjuvant treatments for RSE.

  19. How sacral nerve stimulation works in patients with faecal incontinence.

    PubMed

    Gourcerol, G; Vitton, V; Leroi, A M; Michot, F; Abysique, A; Bouvier, M

    2011-08-01

    Sacral nerve stimulation (SNS) reduces incontinence episodes and improves the quality of life of patients treated for faecal incontinence. However, the exact mechanism of action of this technique remains unclear. The present article reviews the pertinent neuroanatomy and neurophysiology related to SNS and provides explanations for potential mechanisms of action. A systematic review of the literature was performed for studies of the potential mechanisms of action of SNS, using MEDLINE, PubMed, Embase and the Cochrane Library. Articles dealing with the technique, adverse events and economic evaluations of SNS, as well as literature reviews, were excluded, except for reviews dealing with the mechanisms of action of SNS. The following inclusion criteria were used to select articles: (i) articles in English, (ii) randomized, double-blinded, sham-controlled studies, and (iii) cohort studies. Case-control studies or retrospective studies were cited only when randomized or cohort studies could not be found. We propose three hypotheses to explain the mechanism of action of SNS: (i) a somato-visceral reflex, (ii) a modulation of the perception of afferent information, and (iii) an increase in external anal sphincter activity. The mechanism of action of SNS in patients with faecal incontinence almost certainly depends on the modulation of spinal and/or supraspinal afferent inputs. Further research on humans and animals will be required to gain a better understanding of the mechanisms of action of SNS. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.

  20. Long pacing pulses reduce phrenic nerve stimulation in left ventricular pacing.

    PubMed

    Hjortshøj, Søren; Heath, Finn; Haugland, Morten; Eschen, Ole; Thøgersen, Anna Margrethe; Riahi, Sam; Toft, Egon; Struijk, Johannes Jan

    2014-05-01

    Phrenic nerve stimulation is a major obstacle in cardiac resynchronization therapy (CRT). Activation characteristics of the heart and phrenic nerve are different with higher chronaxie for the heart. Therefore, longer pulse durations could be beneficial in preventing phrenic nerve stimulation during CRT due to a decreased threshold for the heart compared with the phrenic nerve. We investigated if long pulse durations decreased left ventricular (LV) thresholds relatively to phrenic nerve thresholds in humans. Eleven patients, with indication for CRT and phrenic nerve stimulation at the intended pacing site, underwent determination of thresholds for the heart and phrenic nerve at different pulse durations (0.3-2.9 milliseconds). The resulting strength duration curves were analyzed by determining chronaxie and rheobase. Comparisons for those parameters were made between the heart and phrenic nerve, and between the models of Weiss and Lapicque as well. In 9 of 11 cases, the thresholds decreased faster for the LV than for the phrenic nerve with increasing pulse duration. In 3 cases, the thresholds changed from unfavorable for LV stimulation to more than a factor 2 in favor of the LV. The greatest change occurred for pulse durations up to 1.5 milliseconds. The chronaxie of the heart was significantly higher than the chronaxie of the phrenic nerve (0.47 milliseconds vs. 0.22 milliseconds [P = 0.029, Lapicque] and 0.79 milliseconds vs. 0.27 milliseconds [P = 0.033, Weiss]). Long pulse durations lead to a decreased threshold of the heart relatively to the phrenic nerve and may prevent stimulation of the phrenic nerve in a clinical setting. © 2013 Wiley Periodicals, Inc.

  1. Innervation of the Human Cavum Conchae and Auditory Canal: Anatomical Basis for Transcutaneous Auricular Nerve Stimulation

    PubMed Central

    Bermejo, P.; López, M.; Larraya, I.; Chamorro, J.; Cobo, J. L.; Ordóñez, S.

    2017-01-01

    The innocuous transcutaneous stimulation of nerves supplying the outer ear has been demonstrated to be as effective as the invasive direct stimulation of the vagus nerve for the treatment of some neurological and nonneurological disturbances. Thus, the precise knowledge of external ear innervation is of maximal interest for the design of transcutaneous auricular nerve stimulation devices. We analyzed eleven outer ears, and the innervation was assessed by Masson's trichrome staining, immunohistochemistry, or immunofluorescence (neurofilaments, S100 protein, and myelin-basic protein). In both the cavum conchae and the auditory canal, nerve profiles were identified between the cartilage and the skin and out of the cartilage. The density of nerves and of myelinated nerve fibers was higher out of the cartilage and in the auditory canal with respect to the cavum conchae. Moreover, the nerves were more numerous in the superior and posterior-inferior than in the anterior-inferior segments of the auditory canal. The present study established a precise nerve map of the human cavum conchae and the cartilaginous segment of the auditory canal demonstrating regional differences in the pattern of innervation of the human outer ear. These results may provide additional neuroanatomical basis for the accurate design of auricular transcutaneous nerve stimulation devices. PMID:28396871

  2. Innervation of the Human Cavum Conchae and Auditory Canal: Anatomical Basis for Transcutaneous Auricular Nerve Stimulation.

    PubMed

    Bermejo, P; López, M; Larraya, I; Chamorro, J; Cobo, J L; Ordóñez, S; Vega, J A

    2017-01-01

    The innocuous transcutaneous stimulation of nerves supplying the outer ear has been demonstrated to be as effective as the invasive direct stimulation of the vagus nerve for the treatment of some neurological and nonneurological disturbances. Thus, the precise knowledge of external ear innervation is of maximal interest for the design of transcutaneous auricular nerve stimulation devices. We analyzed eleven outer ears, and the innervation was assessed by Masson's trichrome staining, immunohistochemistry, or immunofluorescence (neurofilaments, S100 protein, and myelin-basic protein). In both the cavum conchae and the auditory canal, nerve profiles were identified between the cartilage and the skin and out of the cartilage. The density of nerves and of myelinated nerve fibers was higher out of the cartilage and in the auditory canal with respect to the cavum conchae. Moreover, the nerves were more numerous in the superior and posterior-inferior than in the anterior-inferior segments of the auditory canal. The present study established a precise nerve map of the human cavum conchae and the cartilaginous segment of the auditory canal demonstrating regional differences in the pattern of innervation of the human outer ear. These results may provide additional neuroanatomical basis for the accurate design of auricular transcutaneous nerve stimulation devices.

  3. Electric stimulation and decimeter wave therapy improve the recovery of injured sciatic nerves

    PubMed Central

    Zhao, Feng; He, Wei; Zhang, Yingze; Tian, Dehu; Zhao, Hongfang; Yu, Kunlun; Bai, Jiangbo

    2013-01-01

    Drug treatment, electric stimulation and decimeter wave therapy have been shown to promote the repair and regeneration of the peripheral nerves at the injured site. This study prepared a Mackinnon's model of rat sciatic nerve compression. Electric stimulation was given immediately after neurolysis, and decimeter wave radiation was performed at 1 and 12 weeks post-operation. Histological observation revealed that intraoperative electric stimulation and decimeter wave therapy could improve the local blood circulation of repaired sites, alleviate hypoxia of compressed nerves, and lessen adhesion of compressed nerves, thereby decreasing the formation of new entrapments and enhancing compressed nerve regeneration through an improved microenvironment for regeneration. Immunohistochemical staining results revealed that intraoperative electric stimulation and decimeter wave could promote the expression of S-100 protein. Motor nerve conduction velocity and amplitude, the number and diameter of myelinated nerve fibers, and sciatic functional index were significantly increased in the treated rats. These results verified that intraoperative electric stimulation and decimeter wave therapy contributed to the regeneration and the recovery of the functions in the compressed nerves. PMID:25206506

  4. Bacterial colonization of stimulation electrode wires in patients undergoing temporary sacral nerve stimulation.

    PubMed

    Dudding, T; Vaizey, C

    2010-02-01

    In patients undergoing sacral nerve stimulation (SNS), a temporary percutaneous stimulation wire is often used to assess the clinical response to therapy prior to chronic stimulation. The aim of this study was to evaluate the incidence of bacterial colonization of screening wires and risk of clinical infection in patients undergoing prolonged temporary SNS screening. Data were collected prospectively on a consecutive series of patients undergoing temporary SNS for bowel dysfunction. Procedures were performed using a standardized percutaneous technique with a single shot of either co-amoxyclav 1.2 g or cefuroxime 1.5 g given intravenously on induction. Adherent polyurethane dressings were applied to secure the wire. At the end of the screening period the wire and dressings were removed, the skin entry site was cleaned using an alcohol wipe and the wire removed via an aseptic technique. The distal tip of the wire was then cut and sent for culture. Thirteen wires were removed at a median of 21 (range 16-29) days following insertion. There were no signs of local or systemic infection. Seven of the thirteen wires (54%) were found to have deep bacterial colonization. The commonest organisms isolated were staphylococcus species. There was no correlation between the length of time the lead had been implanted and the incidence of bacterial colonization. Bacterial colonization of the temporary stimulation wire is common but appears to be associated with a low risk of clinical infection. A single peri-operative dose of antibiotics does not appear to prevent colonization.

  5. Electrical Stimulation to Enhance Axon Regeneration After Peripheral Nerve Injuries in Animal Models and Humans.

    PubMed

    Gordon, Tessa

    2016-04-01

    Injured peripheral nerves regenerate their lost axons but functional recovery in humans is frequently disappointing. This is so particularly when injuries require regeneration over long distances and/or over long time periods. Fat replacement of chronically denervated muscles, a commonly accepted explanation, does not account for poor functional recovery. Rather, the basis for the poor nerve regeneration is the transient expression of growth-associated genes that accounts for declining regenerative capacity of neurons and the regenerative support of Schwann cells over time. Brief low-frequency electrical stimulation accelerates motor and sensory axon outgrowth across injury sites that, even after delayed surgical repair of injured nerves in animal models and patients, enhances nerve regeneration and target reinnervation. The stimulation elevates neuronal cyclic adenosine monophosphate and, in turn, the expression of neurotrophic factors and other growth-associated genes, including cytoskeletal proteins. Electrical stimulation of denervated muscles immediately after nerve transection and surgical repair also accelerates muscle reinnervation but, at this time, how the daily requirement of long-duration electrical pulses can be delivered to muscles remains a practical issue prior to translation to patients. Finally, the technique of inserting autologous nerve grafts that bridge between a donor nerve and an adjacent recipient denervated nerve stump significantly improves nerve regeneration after delayed nerve repair, the donor nerves sustaining the capacity of the denervated Schwann cells to support nerve regeneration. These reviewed methods to promote nerve regeneration and, in turn, to enhance functional recovery after nerve injury and surgical repair are sufficiently promising for early translation to the clinic.

  6. Safety analysis of vagal nerve stimulation for continuous nerve monitoring during thyroid surgery.

    PubMed

    Friedrich, Colin; Ulmer, Christoph; Rieber, Fabian; Kern, Eva; Kohler, Andrea; Schymik, Karolina; Thon, Klaus-Peter; Lamadé, Wolfram

    2012-09-01

    Intraoperative neuromonitoring (IONM) facilitates recurrent laryngeal nerve (RLN) identification, but various studies affirm virtually unchanged postoperative RLN palsy rates. Several authors meanwhile suggest continuous intraoperative neuromonitoring (CIONM) via vagal nerve stimulation (VNS) to improve RLN protection. However, knowledge of side effects of electrical VNS derives mainly from its therapeutic applications in the fields of neurology and psychiatry. The presented study was conducted to further evaluate the safety of CIONM and identify possible VNS related side effects. Prospective nonrandomized controlled trail. Forty patients scheduled for thyroid or parathyroid surgery were enrolled in the trail. The intervention group consisted of 22 patients receiving VNS for CIONM. Eighteen patients were operated on with routine IONM. To assess VNS-induced effects on the autonomic nervous system (ANS), heart rate variability analysis (HRVA) was applied. Serum cytokine levels of tumor necrosis factor (TNF)-α were monitored to evaluate immunomodulatory effects of VNS. HRVA revealed significantly increased vagal activity during CIONM. This parasympathetic predominance was not countered by the sympathetic nervous system. Despite a significant increase of vagal tone, no hemodynamic events occurred; in fact, no significant changes in median heart rate or in median arterial blood pressure were detected. Even though anti-inflammatory effects of VNS have been reported, no attenuation of cytokine release of TNF-α was measured. VNS for CIONM resulted in increased vagal activity assessable via HRVA. The increased parasympathetic tone affected neither hemodynamics nor levels of the proinflammatory cytokine TNF-α. VNS for CIONM appears safe with the applied settings. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  7. Frequency dependent changes in mechanosensitivity of rat knee joint afferents after antidromic saphenous nerve stimulation.

    PubMed

    Just, S; Heppelmann, B

    2002-01-01

    The aim of the present study was to examine the effect of electrical saphenous nerve stimulation (14 V, 1-10 Hz) on the mechanosensitivity of rat knee joint afferents. The responses to passive joint rotations at defined torque were recorded from slowly conducting knee joint afferent nerve fibres (0.6-20.0 m/s). After repeated nerve stimulation with 1 Hz, the mechanosensitivity of about 79% of the units was significantly affected. The effects were most prominent at a torque close to the mechanical threshold. In about 46% of the examined nerve fibres a significant increase was obtained, whereas about 33% reduced their mechanosensitivity. The sensitisation was prevented by an application of 5 microM phentolamine, an alpha-adrenergic receptor blocker, together with a neuropeptide Y receptor blocker. An inhibition of N-type Ca(2+) channels by an application of 1 microM omega-conotoxin GVIA caused comparable changes of the mechanosensitivity during the electrical stimulation. Electrical nerve stimulation with higher frequencies resulted in a further reduction of the mean response to joint rotations. After stimulation with 10 Hz, there was a nearly complete loss of mechanosensitivity.In conclusion, antidromic electrical nerve stimulation leads to a frequency dependent transient decrease of the mechanosensitivity. A sensitisation was only obtained at 1 Hz, but this effect may be based on the influence of sympathetic nerve fibres.

  8. Effects of cardiac sympathetic nerve stimulation on regional coronary blood flow

    SciTech Connect

    Haws, C.W.; Green, L.S.; Burgess, M.J.; Abildskov, J.A.

    1987-02-01

    The purpose of this study was to examine the effects of cardiac sympathetic nerve stimulation on regional coronary blood flow following ..beta..-blockade. In 17 anesthetized dogs treated with propranolol (2 mg/kg iv) regional myocardial perfusion was measured (radio labelled microspheres) during control and during stimulation of the ventrolateral, ventromedial, or recurrent cardiac nerve. Ventrolateral nerve stimulation produced 25.5 +/- 3.4 and 23.5 +/- 3.1% (mean +/- SE) decreases in coronary blood flow in the posterior and lateral quadrants of the left ventricle. Ventromedial nerve stimulation produced 18.6 +/- 2.8, 15.4 +/- 2.8, and 10.1 +/- 3.2% decreases in flow in the anterior, septal, and lateral left ventricle, respectively. Recurrent cardiac nerve stimulation produced 16.4 +/- 2.1, 15.6 +/- 2.2, and 13.6 +/- 2.5% decreases in flow in the anterior and septal left ventricle and right ventricle, respectively. Ventrolateral nerve stimulation resulted in a small but significant increase in the endocardial-to-epicardial blood flow ratio in the posterolateral left ventricle. The authors conclude that the cardiac sympathetic nerves have selective regional effects on myocardial perfusion that could contribute to fine regulation of flow in the normal heart and could have beneficial or adverse effects in the setting of coronary stenosis or occlusion.

  9. Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults.

    PubMed

    Gibson, William; Wand, Benedict M; O'Connell, Neil E

    2017-09-14

    Neuropathic pain, which is due to nerve disease or damage, represents a significant burden on people and society. It can be particularly unpleasant and achieving adequate symptom control can be difficult. Non-pharmacological methods of treatment are often employed by people with neuropathic pain and may include transcutaneous electrical nerve stimulation (TENS). This review supersedes one Cochrane Review 'Transcutaneous electrical nerve stimulation (TENS) for chronic pain' (Nnoaham 2014) and one withdrawn protocol 'Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults' (Claydon 2014). This review replaces the original protocol for neuropathic pain that was withdrawn. To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. We searched CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, Web of Science, PEDro, LILACS (up to September 2016) and various clinical trials registries. We also searched bibliographies of included studies for further relevant studies. We included randomised controlled trials where TENS was evaluated in the treatment of central or peripheral neuropathic pain. We included studies if they investigated the following: TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. Two review authors independently screened all database search results and identified papers requiring full-text assessment. Subsequently, two review authors independently applied inclusion/exclusion criteria to these studies. The same review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using GRADE. We included 15 studies with 724 participants. We found a

  10. Transverse Magnetic Waves in Myelinated Nerves

    DTIC Science & Technology

    2007-11-02

    IN MYELINATED NERVES M. Mª Villapecellín-Cid1, L. Mª Roa2, and J. Reina-Tosina1 1Área de Teoría de la Señal y Comunicaciones , E.S. de Ingeniería...y Comunicaciones , E.S. de Ingeniería, University of Seville, Seville, Spain Performing Organization Report Number Sponsoring/Monitoring Agency Name(s

  11. Optic Nerve Assessment Using 7-Tesla Magnetic Resonance Imaging

    PubMed Central

    Singh, Arun D.; Platt, Sean M.; Lystad, Lisa; Lowe, Mark; Oh, Sehong; Jones, Stephen E.; Alzahrani, Yahya; Plesec, Thomas

    2016-01-01

    Purpose The purpose of this study was to correlate high-resolution magnetic resonance imaging (MRI) and histologic findings in a case of juxtapapillary choroidal melanoma with clinical evidence of optic nerve invasion. Methods With institutional review board approval, an enucleated globe with choroidal melanoma and optic nerve invasion was imaged using a 7-tesla MRI followed by histopathologic evaluation. Results Optical coherence tomography, B-scan ultrasonography, and 1.5-tesla MRI of the orbit (1-mm sections) could not detect optic disc invasion. Ex vivo, 7-tesla MRI detected optic nerve invasion, which correlated with histopathologic features. Conclusions Our case demonstrates the potential to document the existence of optic nerve invasion in the presence of an intraocular tumor, a feature that has a major bearing on decision making, particularly for consideration of enucleation. PMID:27239461

  12. Optic Nerve Assessment Using 7-Tesla Magnetic Resonance Imaging.

    PubMed

    Singh, Arun D; Platt, Sean M; Lystad, Lisa; Lowe, Mark; Oh, Sehong; Jones, Stephen E; Alzahrani, Yahya; Plesec, Thomas

    2016-04-01

    The purpose of this study was to correlate high-resolution magnetic resonance imaging (MRI) and histologic findings in a case of juxtapapillary choroidal melanoma with clinical evidence of optic nerve invasion. With institutional review board approval, an enucleated globe with choroidal melanoma and optic nerve invasion was imaged using a 7-tesla MRI followed by histopathologic evaluation. Optical coherence tomography, B-scan ultrasonography, and 1.5-tesla MRI of the orbit (1-mm sections) could not detect optic disc invasion. Ex vivo, 7-tesla MRI detected optic nerve invasion, which correlated with histopathologic features. Our case demonstrates the potential to document the existence of optic nerve invasion in the presence of an intraocular tumor, a feature that has a major bearing on decision making, particularly for consideration of enucleation.

  13. Magnetic stimulation of the human brain and peripheral nervous system: an introduction and the results of an initial clinical evaluation.

    PubMed

    Barker, A T; Freeston, I L; Jalinous, R; Jarratt, J A

    1987-01-01

    This report describes a novel method of stimulating the motor cortex and deep peripheral nerves in humans. The technique, developed in the Department of Medical Physics of Sheffield University, uses a large pulse of magnetic field to induce currents within the body and is painless. The basic principles of magnetic stimulation are described, and the technique is compared with conventional electrical stimulation. Safety aspects are discussed with reference to established clinical electrical and magnetic procedures. The results of the first clinical study using magnetic stimulation are described and show clear central motor pathway slowing in multiple sclerosis patients.

  14. Vagal nerve stimulation without dissecting the carotid sheath during intraoperative neuromonitoring of the recurrent laryngeal nerve in thyroid surgery.

    PubMed

    Wu, Che-Wei; Dionigi, Gianlorenzo; Chen, Hui-Chun; Chen, Hsiu-Ya; Lee, Ka-Wo; Lu, I-Cheng; Chang, Pi-Ying; Hsiao, Pi-Jung; Ho, Kuen-Yao; Chiang, Feng-Yu

    2013-10-01

    Vagal nerve stimulation (VNS) has been recommended as a routine procedure during intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN). However, many surgeons have been discouraged from performing VNS because of the need for opening the carotid sheath. The purpose of this study was to investigate the feasibility and reliability of VNS without carotid sheath dissection. Two hundred twenty patients with 376 nerves at risk were enrolled in this study. VNS without nerve exposure during IONM was applied by simply pressing a ball-tip stimulator on the space between the carotid artery and jugular vein. VNS without nerve exposure was feasible in all cases and did not result in any morbidity. All VNS signals were successfully obtained within 30 minutes of the start of the operation and all showed a clear and reliable laryngeal electromyography (EMG) response that was similar to that from the conventional method in which nerve exposure for VNS is applied. VNS without dissecting the carotid sheath is feasible and reliable, rendering it a simple, safe, and surgeon-friendly procedure during IONM. Copyright © 2013 Wiley Periodicals, Inc.

  15. Adverse outcomes associated with nerve stimulator-guided and ultrasound-guided peripheral nerve blocks by supervised trainees: update of a single-site database.

    PubMed

    Orebaugh, Steven L; Kentor, Michael L; Williams, Brian A

    2012-01-01

    We previously published a retrospective review of complications related to peripheral nerve blocks performed by supervised trainees, from our quality assurance and billing data, guided by either ultrasound, with nerve stimulator confirmation, or landmark-based nerve stimulator techniques. This report updates our results, for the period from May 2008 through December 2011, representing ongoing transition to near-complete combined ultrasound/nerve stimulator guidance in a block-oriented, outpatient orthopedic anesthesia practice. We queried our deidentified departmental quality improvement electronic database for adverse outcomes associated with peripheral nerve blocks. Billing records were also deidentified and used to provide the denominator of total number of blocks using each technique of neurolocation. The types of blocks considered in this analysis were interscalene, axillary, femoral, sciatic, and popliteal-sciatic blocks. Nerve block complications based on each type of guidance were then compared for the entire recent 30-month time period, as well as for the 6-year period of this report. There were 9062 blocks performed by ultrasound/nerve stimulator, and 5436 by nerve stimulator alone over the entire 72-month period. Nerve injuries lasting longer than 1 year were rare, but similar in frequency with both nerve guidance techniques. The incidence of local anesthetic systemic toxicity was found to be higher with landmark-nerve stimulator technique than with use of ultrasound-guided nerve blocks (6/5436 vs 0/9069, P = 0.0061). We report a large series of combined ultrasound/nerve stimulator nerve blocks by supervised trainees without major local anesthetic systemic toxicity. While lacking the compelling evidence of randomized controlled trials, this observational database nonetheless allows increased confidence in the safety of using combined ultrasound/nerve stimulator in the setting of anesthesiologists-in-training.

  16. Numerical dosimetry of transcranial magnetic stimulation coils

    NASA Astrophysics Data System (ADS)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of stimulating neurons by means of electromagnetic induction. TMS can be used to map brain function and shows promise for the diagnosis and treatment of neurological and psychiatric disorders. Calculation of fields induced in the brain are necessary to accurately identify stimulated neural tissue during TMS. This allows the development of novel TMS coil designs capable of stimulating deeper brain regions and increasing the localization of stimulation that can be achieved. We have performed numerical calculations of magnetic and electric field with high-resolution anatomically realistic human head models to find these stimulated brain regions for a variety of proposed TMS coil designs. The realistic head models contain heterogeneous tissue structures and electrical conductivities, yielding superior results to those obtained from the simplified homogeneous head models that are commonly employed. The attenuation of electric field as a function of depth in the brain and the localization of stimulating field have been methodically investigated. In addition to providing a quantitative comparison of different TMS coil designs the variation of induced field between subjects has been investigated. We also show the differences in induced fields between adult, adolescent and child head models to preemptively identify potential safety issues in the application of pediatric TMS.

  17. Periodical assessment of electrophysiological recovery following sciatic nerve crush via surface stimulation in rats.

    PubMed

    Wang, Yaxian; Wang, Hongkui; Mi, Daguo; Gu, Xiaosong; Hu, Wen

    2015-03-01

    When evaluating peripheral nerve regeneration, electrophysiological test is recognized as an optimal assessment, which is a quantitative, objective, and direct evidence reflecting function as compared to morphological examinations. In murine models of nerve regeneration, however, it remains a challenge to record compound muscle action potentials (CMAPs) periodically and non-invasively, i.e., with no insult to the nerve. In the present study, we recorded CMAPs in the gastrocnemius muscle weekly until 8 weeks after sciatic nerve crush by stimulating the nerve in a surface manner, and the electric stimuli were delivered to the skin between ischial tuberosity and major trochanter using bipolar hook electrodes. The CMAPs were reproducibly recorded in this way from 3 weeks post-injury, and both amplitude and latency were well correlated to post-operative time. Furthermore, a strong positive correlation was observed between CMAP amplitude and sciatic function index (SFI), a well-recognized assessment for sciatic nerve function. CMAP recordings by direct nerve stimulation at 8 weeks post-injury showed no significant difference in amplitude compared to surface stimulation, but the peak latency was relatively longer than the latter. This study indicated that non-invasive surface stimulation-based periodical recording of CMAPs was a practical electrophysiological approach to monitor the progression of peripheral nerve regeneration in murine models.

  18. Nociception specific supraorbital nerve stimulation may prevent cluster headache attacks: serendipity in a blink reflex study.

    PubMed

    Haane, Danielle Y P; Koehler, Peter J

    2014-10-01

    In cluster headache, neuromodulation is offered when patients are refractory to pharmacological prophylaxis. Non-invasive peripheral neuromodulatory approaches are of interest. We will focus on these and particularly on nociception specific, transcutaneous supraorbital nerve stimulation. In a study using the nociception specific blink reflex, we made a serendipitous discovery, notably the potential prophylactic effect of bilateral, time contingent, nociception specific, transcutaneous stimulation of the supraorbital nerve. We report on a case series of seven cluster headache patients, in whom attacks seemed to disappear during repeated stimulation of the supraorbital nerves. Three patients stopped experiencing attacks since study participation. Bilateral, time contingent, nociception specific, transcutaneous supraorbital nerve stimulation may have a prophylactic effect in episodic and chronic cluster headache. Given its limited side effects and its non-invasive nature, further studies to investigate this potential peripheral neuromodulatory approach for both episodic and chronic cluster headache are warranted. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  19. Spectral and spatial dependence of
diffuse optical signals in response to
peripheral nerve stimulation

    PubMed Central

    Chen, Debbie K.; Erb, M. Kelley; Tong, Yunjie; Yu, Yang; Sassaroli, Angelo; Bergethon, Peter R.; Fantini, Sergio

    2010-01-01

    Using non-invasive, near-infrared spectroscopy we have previously reported optical signals measured at or around peripheral nerves in response to their stimulation. Such optical signals featured amplitudes on the order of 0.1% and peaked about 100 ms after peripheral nerve stimulation in human subjects. Here, we report a study of the spatial and spectral dependence of the optical signals induced by stimulation of the human median and sural nerves, and observe that these optical signals are: (1) unlikely due to either dilation or constriction of blood vessels, (2) not associated with capillary bed hemoglobin, (3) likely due to blood vessel(s) displacement, and (4) unlikely due to fiber-skin optical coupling effects. We conclude that the most probable origin of the optical response to peripheral nerve stimulation is from displacement of blood vessels within the optically probed volume, as a result of muscle twitch in adjacent areas. PMID:21258519

  20. Vagus Nerve Stimulation for Electrographic Status Epilepticus in Slow-Wave Sleep.

    PubMed

    Carosella, Christopher M; Greiner, Hansel M; Byars, Anna W; Arthur, Todd M; Leach, James L; Turner, Michele; Holland, Katherine D; Mangano, Francesco T; Arya, Ravindra

    2016-07-01

    Electrographic status epilepticus in slow sleep or continuous spike and waves during slow-wave sleep is an epileptic encephalopathy characterized by seizures, neurocognitive regression, and significant activation of epileptiform discharges during nonrapid eye movement sleep. There is no consensus on the diagnostic criteria and evidence-based optimal treatment algorithm for children with electrographic status epilepticus in slow sleep. We describe a 12-year-old girl with drug-resistant electrographic status epilepticus in slow wave sleep that was successfully treated with vagus nerve stimulation. Her clinical presentation, presurgical evaluation, decision-making, and course after vagus nerve stimulator implantation are described in detail. After vagus nerve stimulator implantation, the girl remained seizure free for more than a year, resolved the electrographic status epilepticus in slow sleep pattern on electroencephalography, and exhibited significant cognitive improvement. Vagus nerve stimulation may be considered for electrographic status epilepticus in slow sleep. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Transcutaneous Electrical Nerve Stimulation Improves Exercise Tolerance in Healthy Subjects.

    PubMed

    Tomasi, F P; Chiappa, G; Maldaner da Silva, V; Lucena da Silva, M; Lima, A S C G B; Arena, R; Bottaro, M; Cipriano, G

    2015-07-01

    Transcutaneous electrical nerve stimulation (TENS) increases peripheral blood flow by attenuation of the muscle metaboreflex, improving oxygen supply to working muscles. We tested the hypothesis that application of TENS at ganglion improves exercise performance. 11 subjects underwent constant-work rate tests (CWR) to the limit of tolerance (Tlim) while receiving TENS or placebo. Oxygen uptake (V.O2), carbon dioxide (V.CO2), minute ventilation (V.E), ventilatory equivalent (V.E/V.CO2), heart rate (HR) and oxygen pulse (V.O2/HR) were analyzed at isotime separated by percentile and Tlim. V.O2 was lower and V.CO2 was higher at 100% of isotime during TENS, while there were no differences in V.E and V.E/V.CO2. HR was lower during exercise with TENS, and V.O2/HR increased at peak exercise (17.96±1.9 vs. 20.38±1 ml/min/bpm, P<0.05). TENS increased mechanical efficiency at isotime and Tlim (4.10±0.50 vs. 3.39±0.52%, P<0.05 and 3.95±0.67 vs. 3.77±0.45%, P<0.05) and exercise tolerance compared to P-TENS (390±41 vs. 321±41 s; P<0.05). Our data shows that the application of TENS can potentially increase exercise tolerance and oxygen supply in healthy subjects.

  2. Postinjury Vagal Nerve Stimulation Protects Against Intestinal Epithelial Barrier Breakdown

    PubMed Central

    Krzyzaniak, Michael; Peterson, Carrie; Loomis, William; Hageny, Ann-Marie; Wolf, Paul; Reys, Luiz; Putnam, James; Eliceiri, Brian; Baird, Andrew; Bansal, Vishal; Coimbra, Raul

    2014-01-01

    Background Vagal nerve stimulation (VNS) can have a marked anti-inflammatory effect. We have previously shown that preinjury VNS prevented intestinal barrier breakdown and preserved epithelial tight junction protein expression. However, a pretreatment model has little clinical relevance for the care of the trauma patient. Therefore, we postulated that VNS conducted postinjury would also have a similar protective effect on maintaining gut epithelial barrier integrity. Methods Male balb/c mice were subjected to a 30% total body surface area, full-thickness steam burn followed by right cervical VNS at 15, 30, 60, 90, 120, and 150 minutes postinjury. Intestinal barrier dysfunction was quantified by permeability to 4 kDa fluorescein isothiocyanate-Dextran, histologic evaluation, gut tumor necrosis factor-alpha (TNF-α) enzyme-linked immunosorbent assay, and expression of tight junction proteins (myosin light chain kinase, occludin, and ZO-1) using immunoblot and immunoflourescence. Results Histologic examination documented intestinal villi appearance similar to sham if cervical VNS was performed within 90 minutes of burn insult. VNS done after injury decreased intestinal permeability to fluorescein isothiocyanate-Dextran when VNS was ≤90 minutes after injury. Burn injury caused a marked increase in intestinal TNF-α levels. VNS-treated animals had TNF-α levels similar to sham when VNS was performed within 90 minutes of injury. Tight junction protein expression was maintained at near sham values if VNS was performed within 90 minutes of burn, whereas expression was significantly altered in burn. Conclusion Postinjury VNS prevents gut epithelial breakdown when performed within 90 minutes of thermal injury. This could represent a therapeutic window and clinically relevant strategy to prevent systemic inflammatory response distant organ injury after trauma. PMID:21610431

  3. The inhibitory effects of pudendal nerve stimulation on bladder overactivity in spinal cord injury dogs: is early stimulation necessary?

    PubMed

    Chen, Guoqing; Liao, Limin; Dong, Qian; Ju, Yanhe

    2012-01-01

    To determine the inhibitory effects of pudendal nerve stimulation (5 Hz) on bladder overactivity at early and late stages of spinal cord injury in dogs. The study was performed in eight dogs with chronic spinal cord transection at the T9-T10 level. Group 1 (four dogs) underwent electrical stimulation of pudendal nerve one month after spinal cord transection. Group 2 (four dogs) underwent stimulation six months after spinal cord transection. The bladders were removed for histological examination of fibrosis after the stimulation. The bladder capacity and the compliance were significantly increased (p < 0.05) by pudendal nerve stimulation in group 1, but not in group 2. The nonvoiding contractions were inhibited in both groups by electrical stimulation. Collagen fiber was increased, while elastic fiber was significantly decreased (p < 0.05) in group 2 when compared with group 1. Pudendal nerve stimulation can increase the bladder capacity and compliance only during the early period before the bladder wall becomes fibrosit and can inhibit the nonvoiding contraction during two stages. © 2012 International Neuromodulation Society.

  4. Left phrenic nerve anatomy relative to the coronary venous system: Implications for phrenic nerve stimulation during cardiac resynchronization therapy.

    PubMed

    Spencer, Julianne H; Goff, Ryan P; Iaizzo, Paul A

    2015-07-01

    The objective of this study was to quantitatively characterize anatomy of the human phrenic nerve in relation to the coronary venous system, to reduce undesired phrenic nerve stimulation during left-sided lead implantations. We obtained CT scans while injecting contrast into coronary veins of 15 perfusion-fixed human heart-lung blocs. A radiopaque wire was glued to the phrenic nerve under CT, then we created three-dimensional models of anatomy and measured anatomical parameters. The left phrenic nerve typically coursed over the basal region of the anterior interventricular vein, mid region of left marginal veins, and apical region of inferior and middle cardiac veins. There was large variation associated with the average angle between nerve and veins. Average angle across all coronary sinus tributaries was fairly consistent (101.3°-111.1°). The phrenic nerve coursed closest to the middle cardiac vein and left marginal veins. The phrenic nerve overlapped a left marginal vein in >50% of specimens.

  5. Treating obstructive sleep apnea with hypoglossal nerve stimulation.

    PubMed

    Eastwood, Peter R; Barnes, Maree; Walsh, Jennifer H; Maddison, Kathleen J; Hee, Geoffrey; Schwartz, Alan R; Smith, Philip L; Malhotra, Atul; McEvoy, R Douglas; Wheatley, John R; O'Donoghue, Fergal J; Rochford, Peter D; Churchward, Tom; Campbell, Matthew C; Palme, Carsten E; Robinson, Sam; Goding, George S; Eckert, Danny J; Jordan, Amy S; Catcheside, Peter G; Tyler, Louise; Antic, Nick A; Worsnop, Christopher J; Kezirian, Eric J; Hillman, David R

    2011-11-01

    Reduced upper airway muscle activity during sleep is fundamental to obstructive sleep apnea (OSA) pathogenesis. Hypoglossal nerve stimulation (HGNS) counteracts this problem, with potential to reduce OSA severity. To examine safety and efficacy of a novel HGNS system (HGNS, Apnex Medical, Inc.) in treating OSA. Twenty-one patients, 67% male, age (mean ± SD) 53.6 ± 9.2 years, with moderate to severe OSA and unable to tolerate continuous positive airway pressure (CPAP). Each participant underwent surgical implantation of the HGNS system in a prospective single-arm interventional trial. OSA severity was defined by apnea-hypopnea index (AHI) during in-laboratory polysomnography (PSG) at baseline and 3 and 6 months post-implant. Therapy compliance was assessed by nightly hours of use. Symptoms were assessed using the Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Calgary Sleep Apnea Quality of Life Index (SAQLI), and the Beck Depression Inventory (BDI). HGNS was used on 89% ± 15% of nights (n = 21). On these nights, it was used for 5.8 ± 1.6 h per night. Nineteen of 21 participants had baseline and 6-month PSGs. There was a significant improvement (all P < 0.05) from baseline to 6 months in: AHI (43.1 ± 17.5 to 19.5 ± 16.7), ESS (12.1 ± 4.7 to 8.1 ± 4.4), FOSQ (14.4 ± 2.0 to 16.7 ± 2.2), SAQLI (3.2 ± 1.0 to 4.9 ± 1.3), and BDI (15.8 ± 9.0 to 9.7 ± 7.6). Two serious device-related adverse events occurred: an infection requiring device removal and a stimulation lead cuff dislodgement requiring replacement. HGNS demonstrated favorable safety, efficacy, and compliance. Participants experienced a significant decrease in OSA severity and OSA-associated symptoms. NAME: Australian Clinical Study of the Apnex Medical HGNS System to Treat Obstructive Sleep Apnea. NCT01186926. URL: http://clinicaltrials.gov/ct2/show/NCT01186926.

  6. Transcutaneous electrical nerve stimulation (TENS) for pain management in labour

    PubMed Central

    Dowswell, Therese; Bedwell, Carol; Lavender, Tina; Neilson, James P

    2014-01-01

    Background Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity. During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain. TENS machines are frequently operated by women, which may increase a sense of control in labour. Objectives To assess the effects of TENS on pain in labour. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (30 April 2011) and reference lists of retrieved papers. Selection criteria Randomised controlled trials comparing women receiving TENS for pain management in labour versus routine care, alternative non-pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines. Data collection and analysis Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies. Main results Seventeen trials with 1466 women contribute data to the review. Thirteen examined TENS applied to the back, two to acupuncture points, and two to the cranium. Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (average risk ratio 0.41, 95% confidence interval 0.31 to 0.54; measured in two studies). The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain. There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No

  7. Transcutaneous electrical nerve stimulation (TENS) for fibromyalgia in adults.

    PubMed

    Johnson, Mark I; Claydon, Leica S; Herbison, G Peter; Jones, Gareth; Paley, Carole A

    2017-10-09

    Fibromyalgia is characterised by persistent, widespread pain; sleep problems; and fatigue. Transcutaneous electrical nerve stimulation (TENS) is the delivery of pulsed electrical currents across the intact surface of the skin to stimulate peripheral nerves and is used extensively to manage painful conditions. TENS is inexpensive, safe, and can be self-administered. TENS reduces pain during movement in some people so it may be a useful adjunct to assist participation in exercise and activities of daily living. To date, there has been only one systematic review in 2012 which included TENS, amongst other treatments, for fibromyalgia, and the authors concluded that TENS was not effective. To assess the analgesic efficacy and adverse events of TENS alone or added to usual care (including exercise) compared with placebo (sham) TENS; no treatment; exercise alone; or other treatment including medication, electroacupuncture, warmth therapy, or hydrotherapy for fibromyalgia in adults. We searched the following electronic databases up to 18 January 2017: CENTRAL (CRSO); MEDLINE (Ovid); Embase (Ovid); CINAHL (EBSCO); PsycINFO (Ovid); LILACS; PEDRO; Web of Science (ISI); AMED (Ovid); and SPORTDiscus (EBSCO). We also searched three trial registries. There were no language restrictions. We included randomised controlled trials (RCTs) or quasi-randomised trials of TENS treatment for pain associated with fibromyalgia in adults. We included cross-over and parallel-group trial designs. We included studies that evaluated TENS administered using non-invasive techniques at intensities that produced perceptible TENS sensations during stimulation at either the site of pain or over nerve bundles proximal (or near) to the site of pain. We included TENS administered as a sole treatment or TENS in combination with other treatments, and TENS given as a single treatment or as a course of treatments. Two review authors independently determined study eligibility by assessing each record and

  8. Does Pulsed Magnetic Field Therapy Influence Nerve Regeneration in the Median Nerve Model of the Rat?

    PubMed Central

    Beck-Broichsitter, Benedicta E.; Lamia, Androniki; Fregnan, Federica; Smeets, Ralf; Becker, Stephan T.; Sinis, Nektarios

    2014-01-01

    The aim of this study was to evaluate the impact of pulsed magnetic field therapy on peripheral nerve regeneration after median nerve injury and primary coaptation in the rat. Both median nerves were surgically exposed and denervated in 24 female Wistar rats. A microsurgical coaptation was performed on the right side, whereas on the left side a spontaneous healing was prevented. The study group underwent a daily pulsed magnetic field therapy; the other group served as a control group. The grasping force was recorded 2 weeks after the surgical intervention for a period of 12 weeks. The right median nerve was excised and histologically examined. The histomorphometric data and the functional assessments were analyzed by t-test statistics and one-way ANOVA. One-way ANOVA indicated a statistically significant influence of group affiliation and grasping force (P = 0.0078). Grasping strength was higher on a significant level in the experimental group compared to the control group permanently from the 9th week to the end of the study. T-test statistics revealed a significantly higher weight of the flexor digitorum sublimis muscle (P = 0.0385) in the experimental group. The histological evaluation did not reveal any statistically significant differences concerning the histomorphometric parameters. Our results suggest that the pulsed magnetic field therapy has a positive influence on the functional aspects of neural regeneration. More studies are needed to precisely evaluate and optimize the intensity and duration of the application. PMID:25143937

  9. Risk of Encountering Dorsal Scapular and Long Thoracic Nerves during Ultrasound-guided Interscalene Brachial Plexus Block with Nerve Stimulator

    PubMed Central

    Kim, Yeon Dong; Yu, Jae Yong; Shim, Junho; Heo, Hyun Joo

    2016-01-01

    Background Recently, ultrasound has been commonly used. Ultrasound-guided interscalene brachial plexus block (IBPB) by posterior approach is more commonly used because anterior approach has been reported to have the risk of phrenic nerve injury. However, posterior approach also has the risk of causing nerve injury because there are risks of encountering dorsal scapular nerve (DSN) and long thoracic nerve (LTN). Therefore, the aim of this study was to evaluate the risk of encountering DSN and LTN during ultrasound-guided IBPB by posterior approach. Methods A total of 70 patients who were scheduled for shoulder surgery were enrolled in this study. After deciding insertion site with ultrasound, awake ultrasound-guided IBPB with nerve stimulator by posterior approach was performed. Incidence of muscle twitches (rhomboids, levator scapulae, and serratus anterior muscles) and current intensity immediately before muscle twitches disappeared were recorded. Results Of the total 70 cases, DSN was encountered in 44 cases (62.8%) and LTN was encountered in 15 cases (21.4%). Both nerves were encountered in 10 cases (14.3%). Neither was encountered in 21 cases (30.4%). The average current measured immediately before the disappearance of muscle twitches was 0.44 mA and 0.50 mA at DSN and LTN, respectively. Conclusions Physicians should be cautious on the risk of injury related to the anatomical structures of nerves, including DSN and LTN, during ultrasound-guided IBPB by posterior approach. Nerve stimulator could be another option for a safer intervention. Moreover, if there is a motor response, it is recommended to select another way to secure better safety. PMID:27413483

  10. Electrical stimulation promotes regeneration of defective peripheral nerves after delayed repair intervals lasting under one month.

    PubMed

    Xu, Chungui; Kou, Yuhui; Zhang, Peixun; Han, Na; Yin, Xiaofeng; Deng, Jiuxu; Chen, Bo; Jiang, Baoguo

    2014-01-01

    Electrical stimulation (ES) has been proven to be an effective means of enhancing the speed and accuracy of nerve regeneration. However, these results were recorded when the procedure was performed almost immediately after nerve injury. In clinical settings, most patients cannot be treated immediately. Some patients with serious trauma or contaminated wounds need to wait for nerve repair surgery. Delays in nerve repair have been shown to be associated with poorer results than immediate surgery. It is not clear whether electrical stimulation still has any effect on nerve regeneration after enough time has elapsed. A delayed nerve repair model in which the rats received delayed nerve repair after 1 day, 1 week, 1 month, and 2 months was designed. At each point in time, the nerve stumps of half the rats were bridged with an absorbable conduit and the rats were given 1 h of weak electrical stimulation. The other half was not treated. In order to analyze the morphological and molecular differences among these groups, 6 ES rats and 6 sham ES rats per point in time were killed 5 days after surgery. The other rats in each group were allowed to recover for 6 weeks before the final functional test and tissue observation. The amounts of myelinated fibers in the distal nerve stumps decreased as the delay in repair increased for both ES rats and sham ES rats. In the 1-day-delay and 1-week-delay groups, there were more fibers in ES rats than in sham ES rats. And the compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) results were better for ES rats in these two groups. In order to analyze the mechanisms underlying these differences, Masson staining was performed on the distal nerves and quantitative PCR on the spinal cords. Results showed that, after delays in repair of 1 month and 2 months, there was more collagen tissue hyperplasia in the distal nerve in all rats. The brain-derived neurotrophic factor (BDNF) and trkB expression levels in the

  11. Electrical Stimulation Promotes Regeneration of Defective Peripheral Nerves after Delayed Repair Intervals Lasting under One Month

    PubMed Central

    Zhang, Peixun; Han, Na; Yin, Xiaofeng; Deng, Jiuxu; Chen, Bo; Jiang, Baoguo

    2014-01-01

    Background Electrical stimulation (ES) has been proven to be an effective means of enhancing the speed and accuracy of nerve regeneration. However, these results were recorded when the procedure was performed almost immediately after nerve injury. In clinical settings, most patients cannot be treated immediately. Some patients with serious trauma or contaminated wounds need to wait for nerve repair surgery. Delays in nerve repair have been shown to be associated with poorer results than immediate surgery. It is not clear whether electrical stimulation still has any effect on nerve regeneration after enough time has elapsed. Methods A delayed nerve repair model in which the rats received delayed nerve repair after 1 day, 1 week, 1 month, and 2 months was designed. At each point in time, the nerve stumps of half the rats were bridged with an absorbable conduit and the rats were given 1 h of weak electrical stimulation. The other half was not treated. In order to analyze the morphological and molecular differences among these groups, 6 ES rats and 6 sham ES rats per point in time were killed 5 days after surgery. The other rats in each group were allowed to recover for 6 weeks before the final functional test and tissue observation. Results The amounts of myelinated fibers in the distal nerve stumps decreased as the delay in repair increased for both ES rats and sham ES rats. In the 1-day-delay and 1-week-delay groups, there were more fibers in ES rats than in sham ES rats. And the compound muscle action potential (CMAP) and motor nerve conduction velocity (MNCV) results were better for ES rats in these two groups. In order to analyze the mechanisms underlying these differences, Masson staining was performed on the distal nerves and quantitative PCR on the spinal cords. Results showed that, after delays in repair of 1 month and 2 months, there was more collagen tissue hyperplasia in the distal nerve in all rats. The brain-derived neurotrophic factor (BDNF) and trk

  12. [Transcranial magnetic stimulation used in psychiatry].

    PubMed

    Bouché, Christophe; Marigaux, Sandrine; Pattedoie, Nicolas

    2015-11-01

    Repetitive transcranial magnetic stimulation is a non-invasive treatment technique, using electromagnetism properties. It has been used for around twenty years in neurology (treatment of neuropathic pain, certain abnormal movements, Parkinson's disease), and in psychiatry (obsessive compulsive disorder, hallucinations, mood disorders, etc.). The presence and support of a nurse during the sessions is essential.

  13. Magnetic Stimulation Studies of Foveal Representation

    ERIC Educational Resources Information Center

    Lavidor, Michal; Walsh, Vincent

    2004-01-01

    The right and left visual fields each project to the contralateral cerebral hemispheres, but the extent of the functional overlap of the two hemifields along the vertical meridian is still under debate. After presenting the spatial, temporal, and functional specifications of Transcranial Magnetic Stimulation (TMS), we show that TMS is particularly…

  14. Magnetic stimulation of the cauda equina in the spinal canal with a flat, large round coil.

    PubMed

    Matsumoto, Hideyuki; Octaviana, Fitri; Terao, Yasuo; Hanajima, Ritsuko; Yugeta, Akihiro; Hamada, Masashi; Inomata-Terada, Satomi; Nakatani-Enomoto, Setsu; Tsuji, Shoji; Ugawa, Yoshikazu

    2009-09-15

    Magnetic round coil stimulation over the spinal enlargement activates the spinal nerves at the neuro-foramina level. However, activation of the cauda equina in the spinal canal has never been described in the literature. This study, for which 40 healthy subjects were recruited, activated the cauda equina using a round 20-cm-diameter coil designated as a Magnetic Augmented Translumbosacral Stimulation (MATS) coil. Magnetic stimulation placing the edge of the coil over the L1 and L3 spinous processes elicited compound muscle action potentials (CMAPs) from the abductor hallucis muscle. The CMAPs were compared with those elicited through high-voltage electrical stimulation. The CMAP latencies to L1 level MATS coil stimulation were not significantly different from those evoked by electrical stimulation at the same level. The CMAP latencies to L3 level MATS coil stimulation were varied in each subject. In fact, the L1 level MATS coil stimulation is considered to activate the cauda equina at the root exit site from the conus medullaris; the L3 level MATS coil stimulation activates some mid-part of the cauda equina or the distal cauda equina by spreading current. The MATS coil facilitates evaluation of spinal nerve conduction in the cauda equina.

  15. Vagus nerve stimulation for complex partial seizures: surgical technique, safety, and efficacy.

    PubMed

    Landy, H J; Ramsay, R E; Slater, J; Casiano, R R; Morgan, R

    1993-01-01

    Electrical stimulation of the vagus nerve has shown efficacy in controlling seizures in experimental models, and early clinical trials have suggested possible benefit in humans. Eleven patients with complex partial seizures were subjected to implantation of vagus nerve stimulators. Electrode contacts embedded in silicone rubber spirals were placed on the left vagus nerve in the low cervical area. A transcutaneously programmable stimulator module was placed in an infraclavicular subcutaneous pocket and connected to the electrode. One patient required replacement of the system due to electrode fracture. Another patient developed delayed ipsilateral vocal-cord paralysis; the technique was then modified to allow more tolerance for postoperative nerve edema. A third patient showed asymptomatic vocal-cord paresis on immediate postoperative laryngoscopy. Vagus nerve stimulation produces transient vocal-cord dysfunction while the current is on. Nine patients were randomly assigned to receive either high- or low-current stimulation, and seizure frequency was recorded. The high-current stimulation group showed a median reduction in seizure frequency of 27.7% compared to the preimplantation baseline, while the low-current stimulation group showed a median increase of 6.3%. This difference approached statistical significance. The entire population then received maximally tolerable stimulation. The high-current stimulation group showed a further 14.3% reduction, while the low-current stimulation group showed a 25.4% reduction compared to the blinded period. The efficacy of vagus nerve stimulation seemed to depend on stimulus parameters, and a cumulative effect was evident. These results are encouraging, and further study of this modality as an adjunct treatment for epilepsy is warranted.

  16. A randomized controlled trial of chronic vagus nerve stimulation for treatment of medically intractable seizures. The Vagus Nerve Stimulation Study Group.

    PubMed

    1995-02-01

    Preliminary reports have suggested that chronic, intermittent stimulation of the vagus nerve (VNS) is an alternative treatment for patients with medically refractory seizures. We performed a multicenter, randomized, controlled trial to evaluate the efficacy and safety of adjunctive VNS in patients with poorly controlled partial seizures. An implanted, programmable pacemaker-like device was connected to two stimulating electrodes wrapped around the left vagus nerve. One hundred fourteen patients were randomized to receive 14 weeks of high-level stimulation (presumed therapeutic dose) or low-level stimulation (presumed subtherapeutic dose) using a blinded, parallel study design. Seizure frequency was compared with a 12-week baseline. Mean reduction in seizure frequency was 24.5% for the "high" stimulation group versus 6.1% for the "low" stimulation group (p = 0.01). Thirty-one percent of patients receiving high stimulation had a seizure frequency reduction of > or = 50%, versus 13% of patients in the low group (p = 0.02). Treatment emergent side effects were largely limited to a transient hoarseness occurring during the stimulation train. One patient with no previous history of cardiac disease experienced a myocardial infarction during the third month of vagal stimulation. VNS may be an effective alternative treatment for patients who have failed antiepileptic drug therapy and are not optimal candidates for epilepsy surgery.

  17. Electrical stimulation of the starfish's radial nerve in vitro induces the release of a gonadotrophin.

    PubMed

    DeSantis, M; Cloud, J G

    1984-09-01

    In starfish a neuropeptide responsible for the induction of ovulation and the reinitiation of meiotic maturation in fully grown oocytes appears to be released from the radial nerves at the time of spawning. The objectives of this investigation were to determine if the radial nerve would release this gonadotrophin when electrically stimulated in vitro and to locate other possible sources of this factor. Electrical stimulation of radial nerves isolated from the starfish, Pycnopodia helianthoides, resulted in the release of the gonadotrophin. Significant amounts of this neuropeptide were detected neither in other tissues of the starfish nor in mammalian nervous tissue.

  18. A micro-scale printable nanoclip for electrical stimulation and recording in small nerves

    NASA Astrophysics Data System (ADS)

    Lissandrello, Charles A.; Gillis, Winthrop F.; Shen, Jun; Pearre, Ben W.; Vitale, Flavia; Pasquali, Matteo; Holinski, Bradley J.; Chew, Daniel J.; White, Alice E.; Gardner, Timothy J.

    2017-06-01

    Objective. The vision of bioelectronic medicine is to treat disease by modulating the signaling of visceral nerves near various end organs. In small animal models, the nerves of interest can have small diameters and limited surgical access. New high-resolution methods for building nerve interfaces are desirable. In this study, we present a novel nerve interface and demonstrate its use for stimulation and recording in small nerves. Approach. We design and fabricate micro-scale electrode-laden nanoclips capable of interfacing with nerves as small as 50 µm in diameter. The nanoclips are fabricated using a direct laser writing technique with a resolution of 200 nm. The resolution of the printing process allows for incorporation of a number of innovations such as trapdoors to secure the device to the nerve, and quick-release mounts that facilitate keyhole surgery, obviating the need for forceps. The nanoclip can be built around various electrode materials; here we use carbon nanotube fibers for minimally invasive tethering. Main results. We present data from stimulation-evoked responses of the tracheal syringeal (hypoglossal) nerve of the zebra finch, as well as quantification of nerve functionality at various time points post implant, demonstrating that the nanoclip is compatible with healthy nerve activity over sub-chronic timescales. Significance. Our nerve interface addresses key challenges in interfacing with small nerves in the peripheral nervous system. Its small size, ability to remain on the nerve over sub-chronic timescales, and ease of implantation, make it a promising tool for future use in the treatment of disease.

  19. A micro-scale printable nanoclip for electrical stimulation and recording in small nerves.

    PubMed

    Lissandrello, Charles A; Gillis, Winthrop F; Shen, Jun; Pearre, Ben W; Vitale, Flavia; Pasquali, Matteo; Holinski, Bradley J; Chew, Daniel J; White, Alice E; Gardner, Timothy J

    2017-06-01

    The vision of bioelectronic medicine is to treat disease by modulating the signaling of visceral nerves near various end organs. In small animal models, the nerves of interest can have small diameters and limited surgical access. New high-resolution methods for building nerve interfaces are desirable. In this study, we present a novel nerve interface and demonstrate its use for stimulation and recording in small nerves. We design and fabricate micro-scale electrode-laden nanoclips capable of interfacing with nerves as small as 50 µm in diameter. The nanoclips are fabricated using a direct laser writing technique with a resolution of 200 nm. The resolution of the printing process allows for incorporation of a number of innovations such as trapdoors to secure the device to the nerve, and quick-release mounts that facilitate keyhole surgery, obviating the need for forceps. The nanoclip can be built around various electrode materials; here we use carbon nanotube fibers for minimally invasive tethering. We present data from stimulation-evoked responses of the tracheal syringeal (hypoglossal) nerve of the zebra finch, as well as quantification of nerve functionality at various time points post implant, demonstrating that the nanoclip is compatible with healthy nerve activity over sub-chronic timescales. Our nerve interface addresses key challenges in interfacing with small nerves in the peripheral nervous system. Its small size, ability to remain on the nerve over sub-chronic timescales, and ease of implantation, make it a promising tool for future use in the treatment of disease.

  20. Transcranial magnetic stimulation reduces nociceptive threshold in rats.

    PubMed

    Ambriz-Tututi, Mónica; Sánchez-González, Violeta; Drucker-Colín, René

    2012-05-01

    Transcranial magnetic stimulation (TMS) is a procedure that uses magnetic fields to stimulate or inhibit nerve cells in the brain noninvasively. TMS induces an electromagnetic current in the underlying cortical neurons. Varying frequencies and intensities of TMS increase or decrease excitability in the cortical area directly targeted. It has been suggested that TMS has potential in the treatment of some neurological disorders such as Parkinson's disease, stroke, and depression. Initial case reports and open label trials reported by several groups support the use of TMS in pain treatment. In the present study, we evaluated the effect of TMS on the nociceptive threshold in the rat. The parameters used were a frequency of 60 Hz and an intensity of 2 and 6 mT for 2 hr twice per day. After 5 days of TMS treatment, rats were evaluated for mechanical, chemical, and cold stimulation. We observed a significant reduction in the nociceptive threshold in TMS-treated rats but not in sham-treated rats in all behavioral tests evaluated. When TMS treatment was stopped, a slow recovery to normal mechanic threshold was observed. Interestingly, i.c.v. MK-801 or CNQX administration reverted the TMS-induced pronociception. The results suggest that high-frequency TMS can alter the nociceptive threshold and produce allodynia in the rats; results suggest the involvement of NMDA and AMPA/KA receptors on TMS-induced allodynia in the rat.

  1. Reduction of pentylenetetrazole-induced seizure activity in awake rats by seizure-triggered trigeminal nerve stimulation.

    PubMed

    Fanselow, E E; Reid, A P; Nicolelis, M A

    2000-11-01

    Stimulation of the vagus nerve has become an effective method for desynchronizing the highly coherent neural activity typically associated with epileptic seizures. This technique has been used in several animal models of seizures as well as in humans suffering from epilepsy. However, application of this technique has been limited to unilateral stimulation of the vagus nerve, typically delivered according to a fixed duty cycle, independently of whether ongoing seizure activity is present. Here, we report that stimulation of another cranial nerve, the trigeminal nerve, can also cause cortical and thalamic desynchronization, resulting in a reduction of seizure activity in awake rats. Furthermore, we demonstrate that providing this stimulation only when seizure activity begins results in more effective and safer seizure reduction per second of stimulation than with previous methods. Seizure activity induced by intraperitoneal injection of pentylenetetrazole was recorded from microwire electrodes in the thalamus and cortex of awake rats while the infraorbital branch of the trigeminal nerve was stimulated via a chronically implanted nerve cuff electrode. Continuous unilateral stimulation of the trigeminal nerve reduced electrographic seizure activity by up to 78%, and bilateral trigeminal stimulation was even more effective. Using a device that automatically detects seizure activity in real time on the basis of multichannel field potential signals, we demonstrated that seizure-triggered stimulation was more effective than the stimulation protocol involving a fixed duty cycle, in terms of the percent seizure reduction per second of stimulation. In contrast to vagus nerve stimulation studies, no substantial cardiovascular side effects were observed by unilateral or bilateral stimulation of the trigeminal nerve. These findings suggest that trigeminal nerve stimulation is safe in awake rats and should be evaluated as a therapy for human seizures. Furthermore, the results

  2. Temperature-controlled optical stimulation of the rat prostate cavernous nerves.

    PubMed

    Tozburun, Serhat; Hutchens, Thomas C; McClain, Michael A; Lagoda, Gwen A; Burnett, Arthur L; Fried, Nathaniel M

    2013-06-01

    Optical nerve stimulation (ONS) may be useful as a diagnostic tool for intraoperative identification and preservation of the prostate cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. Successful ONS requires elevating the nerve temperature to within a narrow range (~42 to 47°C) for nerve activation without thermal damage to the nerve. This preliminary study explores a prototype temperature-controlled optical nerve stimulation (TC-ONS) system for maintaining a constant (±1°C) nerve temperature during short-term ONS of the rat prostate CNs. A 150-mW, 1455-nm diode laser was operated in continuous-wave mode, with and without temperature control, during stimulation of the rat CNs for 15 to 30 s through a fiber optic probe with a 1-mm-diameter spot. A microcontroller opened and closed an in-line mechanical shutter in response to an infrared sensor, with a predetermined temperature set point. With TC-ONS, higher laser power settings were used to rapidly and safely elevate the CNs to a temperature necessary for a fast intracavernous pressure response, while also preventing excessive temperatures that would otherwise cause thermal damage to the nerve. With further development, TC-ONS may provide a rapid, stable, and safe method for intraoperative identification and preservation of the prostate CNs.

  3. Temperature-controlled optical stimulation of the rat prostate cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Hutchens, Thomas C.; McClain, Michael A.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2013-06-01

    Optical nerve stimulation (ONS) may be useful as a diagnostic tool for intraoperative identification and preservation of the prostate cavernous nerves (CN), responsible for erectile function, during prostate cancer surgery. Successful ONS requires elevating the nerve temperature to within a narrow range (˜42 to 47°C) for nerve activation without thermal damage to the nerve. This preliminary study explores a prototype temperature-controlled optical nerve stimulation (TC-ONS) system for maintaining a constant (±1°C) nerve temperature during short-term ONS of the rat prostate CNs. A 150-mW, 1455-nm diode laser was operated in continuous-wave mode, with and without temperature control, during stimulation of the rat CNs for 15 to 30 s through a fiber optic probe with a 1-mm-diameter spot. A microcontroller opened and closed an in-line mechanical shutter in response to an infrared sensor, with a predetermined temperature set point. With TC-ONS, higher laser power settings were used to rapidly and safely elevate the CNs to a temperature necessary for a fast intracavernous pressure response, while also preventing excessive temperatures that would otherwise cause thermal damage to the nerve. With further development, TC-ONS may provide a rapid, stable, and safe method for intraoperative identification and preservation of the prostate CNs.

  4. Efficacy of Electrical Pudendal Nerve Stimulation versus Transvaginal Electrical Stimulation in Treating Female Idiopathic Urgency Urinary Incontinence.

    PubMed

    Wang, Siyou; Lv, Jianwei; Feng, Xiaoming; Lv, Tingting

    2017-06-01

    We compared the efficacy of electrical pudendal nerve stimulation vs transvaginal electrical stimulation to treat female idiopathic urgency urinary incontinence. A total of 120 female patients with idiopathic urgency urinary incontinence refractory to medication were randomized at a ratio of 2:1 to group 1 of 80 patients and group 2 of 40. Groups 1 and 2 were treated with electrical pudendal nerve stimulation and transvaginal electrical stimulation, respectively. To perform electrical pudendal nerve stimulation long acupuncture needles were deeply inserted into 4 sacrococcygeal points and electrified to stimulate pudendal nerves. Outcome measures were the 24-hour pad test and a questionnaire to measure the severity of symptoms and quality of life in women with urgency urinary incontinence. The median severity of symptoms and quality of life score on the urgency urinary incontinence questionnaire (urgency urinary incontinence total score) was 13 (range 7 to 18.75) in group 1 and 11 (range 8 to 16) in group 2 before treatment, which decreased to 2 (range 0 to 6.75) in group 1 and 6.5 (range 3.25 to 10.75) in group 2 (both p <0.01) after the completion of treatment. At the end of treatment in group 1 complete symptom resolution was noted in 34 patients (42.5%), with a 50% or greater symptom improvement rate in 70.1%. In group 2 complete symptom resolution was noted in 1 patient (2.5%) with a 50% or greater symptom improvement rate in 45.0%. The posttreatment urgency urinary incontinence total score was lower and the therapeutic effect was better in group 1 than in group 2 (both p <0.01). Electrical pudendal nerve stimulation is more effective than transvaginal electrical stimulation in treating drug refractory, female idiopathic urgency urinary incontinence. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  5. Model study of combined electrical and near-infrared neural stimulation on the bullfrog sciatic nerve.

    PubMed

    You, Mengxian; Mou, Zongxia

    2017-07-01

    This paper implemented a model study of combined electrical and near-infrared (808 nm) neural stimulation (NINS) on the bullfrog sciatic nerve. The model includes a COMSOL model to calculate the electric-field distribution of the surrounding area of the nerve, a Monte Carlo model to simulate light transport and absorption in the bullfrog sciatic nerve during NINS, and a NEURON model to simulate the neural electrophysiology changes under electrical stimulus and laser irradiation. The optical thermal effect is considered the main mechanism during NINS. Therefore, thermal change during laser irradiation was calculated by the Monte Carlo method, and the temperature distribution was then transferred to the NEURON model to stimulate the sciatic nerve. The effects on thermal response by adjusting the laser spot size, energy of the beam, and the absorption coefficient of the nerve are analyzed. The effect of the ambient temperature on the electrical stimulation or laser stimulation and the interaction between laser irradiation and electrical stimulation are also studied. The results indicate that the needed stimulus threshold for neural activation or inhibition is reduced by laser irradiation. Additionally, the needed laser energy for blocking the action potential is reduced by electrical stimulus. Both electrical and laser stimulation are affected by the ambient temperature. These results provide references for subsequent animal experiments and could be of great help to future basic and applied studies of infrared neural stimulation (INS).

  6. Stimulation of phrenic nerve activity by an acetylcholine releasing drug: 4-aminopyridine.

    PubMed

    Folgering, H; Rutten, J; Agoston, S

    1979-03-16

    The effect of the acetylcholine releaser 4-aminopyridine on ventilation was studied by recording and quantifying the efferent phrenic nerve activity in 40 paralysed and vagotomized cats; with arterial Po2, PCO2 and pH kept constant. 4-Aminopyridine, given intravenously or in the vertebral artery, stimulates the phrenic nerve activity in a dose dependent manner. The stimulatory effects of 4-aminopyridine on the phrenic nerve activity could be abolished completely by administration of high doses of atropine. We conclude that 4-aminopyridine, which is used clinically for the reversal of a neuromuscular block, stimulates the phrenic nerve activity. Since the role of cholinergic mechanisms in the central chemoreception has been well established, the effect on the phrenic nerve activity is most probably by an increased release of acetylcholine at the site of the central chemoreceptors.

  7. Removal of Vagus Nerve Stimulator Leads and Reuse of Same Site for Reimplantation: Technique and Experience.

    PubMed

    Kumar, Ramesh; Winston, Ken R; Folzenlogen, Zach

    2016-07-01

    This report describes the authors' experience and technique in removing vagus nerve stimulator leads, including coils, and reuse of the same site on the vagus nerve for implantation of new coils. The charts of all patients who underwent complete removal by the authors of vagus nerve stimulator leads between 1 September 2001 and 1 July 2015 were retrospectively reviewed. Thirty patients underwent 31 surgeries for removal of vagus nerve stimulator leads. Complete removal, including proximal coils around the vagus nerve, was achieved in all cases. Reimplantation was performed immediately at the same location in 24 patients, delayed in 1 patient, and never replaced in 6. Long-term vocal cord paralysis followed 2 of 9 surgeries performed with sharp dissection and followed one of 22 surgeries in which dissection was performed with monopolar microneedle electrocautery. Vagus nerve stimulator coils can be removed from the vagus nerve, via monopolar microneedle electrocautery, and the same site reused for immediate reimplantation with relative safety. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Irritation Induced Bladder Overactivity Is Suppressed by Tibial Nerve Stimulation in Cats

    PubMed Central

    Tai, Changfeng; Chen, Mang; Shen, Bing; Wang, Jicheng; Roppolo, James R.; de Groat, William C.

    2011-01-01

    Purpose To investigate the effects of tibial nerve stimulation on bladder overactivity induced by acetic acid (AA) irritation. Material and Methods Cystometry was performed in 10 α-chloralose anesthetized female cats by infusing saline or AA through a urethral catheter that was secured by a ligature around the urethra. Intravesical infusion of 0.25% AA was used to irritate the bladder and induce bladder overactivity. Multiple cystometrograms (CMGs) were performed before, during, and after tibial nerve stimulation to determine the inhibitory effect on the micturition reflex. Results Infusion of 0.25% AA irritated the bladder, induced bladder overactivity, and significantly reduced the bladder capacity to about 20% of the control capacity measured during saline infusion. Tibial nerve stimulation at either low (5 Hz) or high (30 Hz) frequency significantly increased bladder capacity to about 40% of the saline control capacity when it was applied during AA infusion CMG. The amplitude of bladder contractions was smaller during AA irritation than during saline distention due to a significantly smaller bladder capacity. Tibial nerve stimulation at 5 Hz not only increased bladder capacity but also increased the amplitude of bladder contractions. Conclusion Activation of somatic afferents in the tibial nerve of cats can partially reverse the bladder overactivity induced by intravesical administration of a chemical irritant that activates C-fiber afferent nerves. These data are consistent with clinical studies showing that tibial nerve neuromodulation is effective in treating overactive bladder symptoms. PMID:21600604

  9. Irritation induced bladder overactivity is suppressed by tibial nerve stimulation in cats.

    PubMed

    Tai, Changfeng; Chen, Mang; Shen, Bing; Wang, Jicheng; Roppolo, James R; de Groat, William C

    2011-07-01

    We investigated the effects of tibial nerve stimulation on bladder overactivity induced by acetic acid irritation. Cystometry was performed in 10 α-chloralose anesthetized female cats by infusing saline or acetic acid through a urethral catheter that was secured by a ligature around the urethra. Intravesical infusion of 0.25% acetic acid was used to irritate the bladder and induce bladder overactivity. Multiple cystometrograms were done before, during and after tibial nerve stimulation to determine the inhibitory effect on the micturition reflex. Infusion of 0.25% acetic acid irritated the bladder, induced bladder overactivity and significantly decreased bladder capacity to about 20% of control capacity measured during saline infusion. Tibial nerve stimulation at low (5 Hz) or high (30 Hz) frequency significantly increased bladder capacity to about 40% of saline control capacity when it was applied during acetic acid infusion cystometrogram. Bladder contraction amplitude was smaller during acetic acid irritation than during saline distention due to significantly smaller bladder capacity. Tibial nerve stimulation at 5 Hz increased bladder capacity and bladder contraction amplitude. Activation of somatic afferents in the tibial nerve of cats can partially reverse the bladder overactivity induced by intravesical administration of a chemical irritant that activates C-fiber afferent nerves. These data are consistent with clinical studies showing that tibial nerve neuromodulation is effective treatment for overactive bladder symptoms. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  10. Repetitive common peroneal nerve stimulation increases ankle dorsiflexor motor evoked potentials in incomplete spinal cord lesions.

    PubMed

    Thompson, Aiko K; Lapallo, Brandon; Duffield, Michael; Abel, Briana M; Pomerantz, Ferne

    2011-04-01

    Plasticity of corticospinal tract (CST) activity likely plays a key role in motor function recovery after central nervous system (CNS) lesions. In non-injured adults, 30 min of repetitive common peroneal nerve stimulation (rCPnS) increases CST excitability by 40-50% and the effect persists for at least 30 min. The present study evaluated with transcranial magnetic stimulation (TMS) the changes in CST excitability after 30 min of rCPnS in people with foot drop due to incomplete SCI. Suprathreshold rCPnS (25 Hz, alternating 1 s on 1 s off stimulation cycle) was given for two 15-min periods, while the subject sat at rest with ankle and knee joints fixed. Before, between, and after the periods of stimulation, the tibialis anterior (TA) motor evoked potentials (MEPs) to TMS were measured at a TMS intensity that originally produced a half-maximum MEP (typically 10-20% above threshold) while the sitting subject provided 25-30% maximum voluntary TA contraction. In 10 subjects with SCI, the peak-to-peak TA MEP increased by 14 ± 3% after rCPnS and the peak increase (+21 ± 7%) occurred 15 min after the cessation of rCPnS. The TA H-reflex, measured in separate experiments in 7 subjects, did not increase after rCPnS. The results indicate that rCPnS can increase CST excitability for the TA in people with incomplete SCI, although its effects appear smaller and shorter lasting than those found in non-injured control subjects. Such short-term plasticity in the CST excitability induced by rCPnS may contribute to long-term therapeutic effects of functional electrical stimulation previously reported in people with CNS lesions.

  11. Electrical potentials from the eye and optic nerve of Strombus: effects of electrical stimulation of the optic nerve.

    PubMed

    Gillary, H L

    1977-02-01

    1. Photic stimulation of the mature eye of Strombus can evoke in the optic nerve 'on' activity in numerous small afferent fibres and repetitive 'off' bursts of afferent impulses in a smaller number of larger fibres. 2. Synchronous invasion of the eye by electrically evoked impulses in small optic nerve fibres (apparently the 'on' afferents, antidromically activated) can evoke a burst of impulses in the larger 'off' fibres which propagate away from the eye. Invasion of the eye via one branch of optic nerve can evoke an answering burst in another branch. 3. Such electrically evoked bursts are similar to light-evoked 'off' bursts with respect to their impulse composition, their ability to be inhibited by illumination of the eye, and their susceptibility to MgCl2 anaesthesia. 4. Invasion of the eye by a train of repetitive electrically evoked impulses in the absence of photic stimulation can give rise to repetitive 'off' bursts as well as concomitant oscillatory potentials in the eye which are similar to those normally evoked by cessation of a photic stimulus. 5. The electrically evoked 'off' bursts appear to be caused by an excitatory rebound following the cessation of inhibitory synaptic input from photoreceptors which can be antidromically activated by electrical stimulation of the optic nerve. 6. The experimental results suggest that the rhythmic discharge of the 'off' fibres evoked by the cessation of a photic stimulus is mediated by the abrupt decrease of inhibitory synaptic input from the receptors.

  12. A single trial of transcutaneous electrical nerve stimulation reduces chronic neuropathic pain following median nerve injury in rats.

    PubMed

    Cho, Hwi-Young; Suh, Hye Rim; Han, Hee Chul

    2014-01-01

    Neuropathic pain is a devastating chronic condition and is often induced in the upper limb following nerve injury or damage. Various drugs or surgical methods have been used to manage neuropathic pain; however, these are frequently accompanied by undesirable side effects. Transcutaneous electrical nerve stimulation (TENS) is a safe and non-invasive intervention that has been used to alleviate different types of pain in the clinic, but it is unclear whether TENS can improve chronic neuropathic pain in the upper limb. Thus, the aim of this study was to investigate the effects of a single trial of TENS on chronic neuropathic pain following median nerve injury. Male rats weighing 200-250 g received median nerve-ligation of the right forearm, while the control group received only skin-incision without nerve-ligation. Neuropathic pain-behaviors, including mechanical, cold, and thermal allodynia, were measured for 4 weeks. After the development of chronic neuropathic pain, TENS (100 Hz, 200 µs, sub-motor threshold) or placebo-TENS (sham stimulation) was applied for 20 min to the ipsilateral or contralateral side. Neuropathic pain behavior was assessed before and after intervention. Median nerve-ligation significantly induced and maintained neuropathic pain in the ipsilateral side. TENS application to the ipsilateral side effectively attenuated the three forms of chronic neuropathic pain in the ipsilateral side compared to sham-treated rats (peripheral and central effects), while TENS application to contralateral side only reduced mechanical allodynia in the ipsilateral side (central effect). Our findings demonstrate that TENS can alleviate chronic neuropathic pain following median nerve injury.

  13. Does Sacral Nerve Stimulation Improve Continence Through Enhanced Sensitivity of the Anal Canal? A Pilot Study.

    PubMed

    Haas, S; Brock, C; Krogh, K; Gram, M; Lundby, L; Drewes, A M; Laurberg, S

    2016-11-01

    It has been suggested that the effects of sacral nerve stimulation against fecal incontinence involve neuromodulation at spinal or supraspinal levels. This study aims to investigate the afferent sensory pathways from the anorectum before and during sacral nerve stimulation. This is an explorative study. Fifteen women with idiopathic fecal incontinence (mean age, 58 ± 12.2 years) were selected. Cortical evoked potentials were recorded during repeated rapid balloon distension of the rectum and the anal canal both before and during temporary sacral nerve stimulation. Stimuli applied were individualized according to the subjective urge to defecate. The main outcomes measured were 1) stimulus intensity, 2) latencies and amplitudes of cortical evoked potentials, and 3) spectral content in predefined frequency bands of cortical evoked potentials. The median Wexner fecal incontinence score improved from 15.5 ± 3.6 before to 6.7 ± 5 during sacral nerve stimulation (p < 0.001). Sacral nerve stimulation did not affect the threshold for urge to defecate during rectal distension (p = 0.64) but reduced the threshold from stimulation of the anal canal by 50% (p = 0.03). No statistically significant differences were found in latencies, amplitudes, or spectral analysis. This is a pilot study of limited size. In patients with idiopathic fecal incontinence, sacral nerve stimulation reduced the threshold for urge to defecate elicited from the anal canal, whereas supraspinal responses remained unaltered. This may suggest that sacral nerve stimulation, at least in part, acts via somatic afferent fibers enhancing anal sensation.

  14. Stimulating the lip motor cortex with transcranial magnetic stimulation.

    PubMed

    Möttönen, Riikka; Rogers, Jack; Watkins, Kate E

    2014-06-14

    Transcranial magnetic stimulation (TMS) has proven to be a useful tool in investigating the role of the articulatory motor cortex in speech perception. Researchers have used single-pulse and repetitive TMS to stimulate the lip representation in the motor cortex. The excitability of the lip motor representation can be investigated by applying single TMS pulses over this cortical area and recording TMS-induced motor evoked potentials (MEPs) via electrodes attached to the lip muscles (electromyography; EMG). Larger MEPs reflect increased cortical excitability. Studies have shown that excitability increases during listening to speech as well as during viewing speech-related movements. TMS can be used also to disrupt the lip motor representation. A 15-min train of low-frequency sub-threshold repetitive stimulation has been shown to suppress motor excitability for a further 15-20 min. This TMS-induced disruption of the motor lip representation impairs subsequent performance in demanding speech perception tasks and modulates auditory-cortex responses to speech sounds. These findings are consistent with the suggestion that the motor cortex contributes to speech perception. This article describes how to localize the lip representation in the motor cortex and how to define the appropriate stimulation intensity for carrying out both single-pulse and repetitive TMS experiments.

  15. Chronic migraine headache prevention with noninvasive vagus nerve stimulation

    PubMed Central

    Calhoun, Anne H.; Lipton, Richard B.; Grosberg, Brian M.; Cady, Roger K.; Dorlas, Stefanie; Simmons, Kristy A.; Mullin, Chris; Liebler, Eric J.; Goadsby, Peter J.; Saper, Joel R.

    2016-01-01

    Objective: To evaluate the feasibility, safety, and tolerability of noninvasive vagus nerve stimulation (nVNS) for the prevention of chronic migraine (CM) attacks. Methods: In this first prospective, multicenter, double-blind, sham-controlled pilot study of nVNS in CM prophylaxis, adults with CM (≥15 headache d/mo) entered the baseline phase (1 month) and were subsequently randomized to nVNS or sham treatment (2 months) before receiving open-label nVNS treatment (6 months). The primary endpoints were safety and tolerability. Efficacy endpoints in the intent-to-treat population included change in the number of headache days per 28 days and acute medication use. Results: Fifty-nine participants (mean age, 39.2 years; mean headache frequency, 21.5 d/mo) were enrolled. During the randomized phase, tolerability was similar for nVNS (n = 30) and sham treatment (n = 29). Most adverse events were mild/moderate and transient. Mean changes in the number of headache days were −1.4 (nVNS) and −0.2 (sham) (Δ = 1.2; p = 0.56). Twenty-seven participants completed the open-label phase. For the 15 completers initially assigned to nVNS, the mean change from baseline in headache days after 8 months of treatment was −7.9 (95% confidence interval −11.9 to −3.8; p < 0.01). Conclusions: Therapy with nVNS was well-tolerated with no safety issues. Persistent prophylactic use may reduce the number of headache days in CM; larger sham-controlled studies are needed. ClinicalTrials.gov identifier: NCT01667250. Classification of evidence: This study provides Class II evidence that for patients with CM, nVNS is safe, is well-tolerated, and did not significantly change the number of headache days. This pilot study lacked the precision to exclude important safety issues or benefits of nVNS. PMID:27412146

  16. Pregabalin and transcutaneous electrical nerve stimulation for postherpetic neuralgia treatment.

    PubMed

    Barbarisi, Manlio; Pace, Maria Caterina; Passavanti, Maria Beatrice; Maisto, Massimo; Mazzariello, Luigi; Pota, Vincenzo; Aurilio, Caterina

    2010-09-01

    Postherpetic neuralgia (PHN) is responsible for one of the most common types of neuropathic pain, described as a burning pain that shakes, hits, and tightens and includes allodynia and paresthesia. To evaluate the efficacy of Pregabalin when used during transcutaneous electric nerve stimulation (TENS) in patients with PHN and to analyze any changes in physical activity and sleep quality. Patients aged 50 to 80 years were included in this randomized study. We enrolled 15 male (average age 65+/-8.6 y) and 15 female patients (average age 64+/-8.2 y). The male patients had a history of neuropathic pain lasting 15.6+/-8.8 months whereas the female patients had a history of neuropathic pain lasting about 14.9+/-8.6 months. We began with 1 week of patient screening followed by a week of Pregabalin titration. Then, we established the dose of Pregabalin for each patient to obtain visual analog scale (VAS) of less than 60 mm. The eligible patients were randomly divided into 2 groups receiving Pregabalin + TENS or Pregabalin+TENS placebo for the following 4 weeks. Patients underwent 8 outpatient visits during which they completed VAS, SF-McGill Pain Questionnaire, and sleep interference questionnaire. The resulting data showed that Pregabalin administration associated with TENS reduced pain in patients with PHN. At the end of the treatment, all the observed groups presented a reduction of mean VAS. The group treated with Pregabalin 300 (P300)+TENS had a reduction of pain of 30% and the group treated with Pregabalin 600 (P600)+TENS had a reduction of pain of 40%. The comparison between group P300+TENS versus group P300+TENS placebo showed a statistically significant reduction of VAS (P300+TENS 25+/-0.67 vs. P300+TENS placebo 39+/-1.19 P<0.02). Moreover, the comparison between group P600+TENS versus group P600+TENS placebo has shown a statistically significant reduction of VAS (P600+TENS 23+/-0.78 vs. P600+TENS placebo 32+/-0.81 P<0.02). At the end of the study, all groups

  17. Transcutaneous electric nerve stimulation (TENS) for cancer pain in adults.

    PubMed

    Robb, Karen A; Bennett, Michael I; Johnson, Mark I; Simpson, Karen J; Oxberry, Stephen G

    2008-07-16

    Cancer-related pain is complex and multi-dimensional but the mainstay of cancer pain management has predominately used a biomedical approach. There is a need for non-pharmacological and innovative approaches. Transcutaneous Electric Nerve Stimulation (TENS) may have a role for a significant number of patients but the effectiveness of TENS is currently unknown. The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. We searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED and PEDRO databases (11/04/08). Only randomised controlled trials (RCTS) investigating the use of TENS for the management of cancer-related pain in adults were included. The search strategy identified 37 possible published studies which were divided between two pairs of review authors that decided on study selection. A study eligibility form was used to screen each abstract and where study eligibility could not be determined from the abstract, the full paper was obtained and assessed by one pair of review authors. A standardised data extraction sheet was used to collect information on the studies and the quality of the studies was assessed independently by two review authors using the validated five-point Oxford Quality Scale. Final scores were discussed and agreed between all four review authors. The small sample sizes and differences in patient study populations of the two included studies prevented meta-analysis. Only two RCTs met the eligibility criteria (64 participants). These studies were heterogenous with respect to study population, sample size, study design, methodological quality, mode of TENS, treatment duration, method of administration and outcome measures used. In one RCT, there were no significant differences between TENS and placebo in women with chronic pain secondary to breast cancer treatment. In the other RCT, there were no significant differences between acupuncture-type TENS and sham in palliative care

  18. Optical and electrical stimulation of the rat prostate cavernous nerves: priming and fatigue studies

    NASA Astrophysics Data System (ADS)

    Kaouk, Ghallia S.; Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2015-02-01

    Optical nerve stimulation (ONS) is being explored as an alternative to electrical nerve stimulation (ENS) for use as an intra-operative diagnostic method for identification and preservation of prostate cavernous nerves (CNs) during radical prostatectomy. Nerve priming and fatigue studies were performed to further characterize CNs and provide insight into the different ONS and ENS mechanisms. ONS studies were conducted using a 1455-nm diode laser, coupled to fiber optic probe, and delivering a collimated, 1-mm-diameter laser spot on CNs. For nerve priming studies, laser power was escalated in 5 mW increments (15 - 60 mW) with each stimulation lasting 15 s, until a strong ICP response was observed, and then power was similarly de-escalated. For ONS fatigue studies, a constant laser power was delivered for a period of 10 min. ENS studies were conducted for comparison, with standard parameters (4 V, 5 ms, 16 Hz) for fatigue studies (10 min. duration), but incrementally increasing/decreasing voltage (0.1 - 4.0 V) for priming studies with 15 s stimulations. ONS threshold was approximately 20% higher during initial escalating laser power steps (6.4 W/cm2) than in subsequently de-escalating laser power steps (5.1 W/cm2), demonstrating a nerve priming effect. Evidence of nerve priming during ENS was not observed. For nerve fatigue studies, ONS of CNs showed a peak ICP response at about 60 s, followed by a gradual decay in ICP, while ENS maintained a strong, but cyclical ICP. Nerve priming may allow repetitive ONS of CNs at lower and hence safer laser power settings. Both nerve priming and fatigue studies revealed different mechanisms for ONS and ENS.

  19. Intrafascicular stimulation of monkey arm nerves evokes coordinated grasp and sensory responses

    PubMed Central

    Ledbetter, Noah M.; Ethier, Christian; Oby, Emily R.; Hiatt, Scott D.; Wilder, Andrew M.; Ko, Jason H.; Agnew, Sonya P.; Miller, Lee E.

    2013-01-01

    High-count microelectrode arrays implanted in peripheral nerves could restore motor function after spinal cord injury or sensory function after limb loss. In this study, we implanted Utah Slanted Electrode Arrays (USEAs) intrafascicularly at the elbow or shoulder in arm nerves of rhesus monkeys (n = 4) under isoflurane anesthesia. Input-output curves indicated that pulse-width-modulated single-electrode stimulation in each arm nerve could recruit single muscles with little or no recruitment of other muscles. Stimulus trains evoked specific, natural, hand movements, which could be combined via multielectrode stimulation to elicit coordinated power or pinch grasp. Stimulation also elicited short-latency evoked potentials (EPs) in primary somatosensory cortex, which might be used to provide sensory feedback from a prosthetic limb. These results demonstrate a high-resolution, high-channel-count interface to the peripheral nervous system for restoring hand function after neural injury or disruption or for examining nerve structure. PMID:23076108

  20. Release of relaxin-like gonad-stimulating substance from starfish radial nerves by lonomycin.

    PubMed

    Mita, Masatoshi

    2013-07-01

    In starfish, the peptide hormone gonad-stimulating substance (GSS) secreted from nervous tissue stimulates oocyte maturation to induce 1-methyladenine (1-MeAde) production by ovarian follicle cells. Recently, GSS was purified from radial nerves of the starfish Asterina pectinifera and identified as a relaxin-like peptide. This study examines the mechanism of GSS secretion from radial nerves. When radial nerves isolated from A. pectinifera were incubated in artificial seawater containing ionomycin as a calcium ionophore, GSS release increased in a dose-dependent manner; 50% activity of GSS release was obtained with approximately 10 µM ionomycin. Another calcium ionophore, A23187, also stimulated GSS release from radial nerves. In contrast, membrane permeable cyclic AMP and cyclic GMP analogs failed to induce GSS release. These results suggest that GSS secretion is induced by intracellular Ca(2+) as a second messenger.

  1. Responsiveness of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency.

    PubMed

    He, Shuman; Shahsavarani, Bahar S; McFayden, Tyler C; Wang, Haibo; Gill, Katherine E; Xu, Lei; Chao, Xiuhua; Luo, Jianfen; Wang, Ruijie; He, Nancy

    2017-07-01

    This study aimed to (1) investigate the responsiveness of the cochlear nerve (CN) to a single biphasic-electrical pulse in implanted children with cochlear nerve deficiency (CND) and (2) compare their results with those measured in implanted children with normal-size CNs. Participants included 23 children with CND (CND1 to CND23) and 18 children with normal-size CNs (S1 to S18). All subjects except for CND1 used Cochlear Nucleus cochlear implants with contour electrode arrays in their test ears. CND1 was implanted with a Cochlear Nucleus Freedom cochlear implant with a straight electrode array in the test ear. For each subject, the CN input/output (I/O) function and the refractory recovery function were measured using electrophysiological measures of the electrically evoked compound action potential (eCAP) at multiple electrode sites across the electrode array. Dependent variables included eCAP threshold, the maximum eCAP amplitude, slope of the I/O function, and time-constants of the refractory recovery function. Slopes of I/O functions were estimated using statistical modeling with a sigmoidal function. Recovery time-constants, including measures of the absolute refractory period and the relative refractory period, were estimated using statistical modeling with an exponential decay function. Generalized linear mixed-effect models were used to evaluate the effects of electrode site on the dependent variables measured in children with CND and to compare results of these dependent variables between subject groups. The eCAP was recorded at all test electrodes in children with normal-size CNs. In contrast, the eCAP could not be recorded at any electrode site in 4 children with CND. For all other children with CND, the percentage of electrodes with measurable eCAPs decreased as the stimulating site moved in a basal-to-apical direction. For children with CND, the stimulating site had a significant effect on the slope of the I/O functions and the relative refractory

  2. Regenerated Sciatic Nerve Axons Stimulated through a Chronically Implanted Macro-Sieve Electrode

    PubMed Central

    MacEwan, Matthew R.; Zellmer, Erik R.; Wheeler, Jesse J.; Burton, Harold; Moran, Daniel W.

    2016-01-01

    Sieve electrodes provide a chronic interface for stimulating peripheral nerve axons. Yet, successful utilization requires robust axonal regeneration through the implanted electrode. The present study determined the effect of large transit zones in enhancing axonal regeneration and revealed an intimate neural interface with an implanted sieve electrode. Fabrication of the polyimide sieve electrodes employed sacrificial photolithography. The manufactured macro-sieve electrode (MSE) contained nine large transit zones with areas of ~0.285 mm2 surrounded by eight Pt-Ir metallized electrode sites. Prior to implantation, saline, or glial derived neurotropic factor (GDNF) was injected into nerve guidance silicone-conduits with or without a MSE. The MSE assembly or a nerve guidance conduit was implanted between transected ends of the sciatic nerve in adult male Lewis rats. At 3 months post-operation, fiber counts were similar through both implant types. Likewise, stimulation of nerves regenerated through a MSE or an open silicone conduit evoked comparable muscle forces. These results showed that nerve regeneration was comparable through MSE transit zones and an open conduit. GDNF had a minimal positive effect on the quality and morphology of fibers regenerating through the MSE; thus, the MSE may reduce reliance on GDNF to augment axonal regeneration. Selective stimulation of several individual muscles was achieved through monopolar stimulation of individual electrodes sites suggesting that the MSE might be an optimal platform for functional neuromuscular stimulation. PMID:28008303

  3. Dilation of the oropharynx via selective stimulation of the hypoglossal nerve

    NASA Astrophysics Data System (ADS)

    Huang, Jingtao; Sahin, Mesut; Durand, Dominique M.

    2005-12-01

    The functional effects of selective hypoglossal nerve (HG) stimulation with a multi-contact peripheral nerve electrode were assessed using images of the upper airways and the tongue in anesthetized beagles. A biphasic pulse train of 50 Hz frequency and 2 s duration was applied through each one of the tripolar contact sets of the nerve electrode while the pharyngeal images were acquired into a computer. The stimulation current was limited to 20% above the activation threshold for maximum selectivity. The images showed that various contact sets could generate several different activation patterns of the tongue muscles resulting in medial and/or lateral dilation and closing of the airways at the tongue root. Some of these patterns translated into an increase in the oropharyngeal size while others did not have any effect. The pharyngeal sizes were not statistically different during stimulation either between the two different positions of the head (30° and 60°), or when the lateral contacts were compared with the medial ones. The contacts that had the least effect generated an average of 53 ± 15% pharyngeal dilation relative to the best contacts, indicating that the results are marginally sensitive to the contact position around the HG nerve trunk. These results suggest that selective HG nerve stimulation can be a useful technique to produce multiple tongue activation patterns that can dilate the pharynx. This may in turn increase the size of the patient population who can benefit from HG nerve stimulation as a treatment method for obstructive sleep apnea.

  4. Regenerated Sciatic Nerve Axons Stimulated through a Chronically Implanted Macro-Sieve Electrode.

    PubMed

    MacEwan, Matthew R; Zellmer, Erik R; Wheeler, Jesse J; Burton, Harold; Moran, Daniel W

    2016-01-01

    Sieve electrodes provide a chronic interface for stimulating peripheral nerve axons. Yet, successful utilization requires robust axonal regeneration through the implanted electrode. The present study determined the effect of large transit zones in enhancing axonal regeneration and revealed an intimate neural interface with an implanted sieve electrode. Fabrication of the polyimide sieve electrodes employed sacrificial photolithography. The manufactured macro-sieve electrode (MSE) contained nine large transit zones with areas of ~0.285 mm(2) surrounded by eight Pt-Ir metallized electrode sites. Prior to implantation, saline, or glial derived neurotropic factor (GDNF) was injected into nerve guidance silicone-conduits with or without a MSE. The MSE assembly or a nerve guidance conduit was implanted between transected ends of the sciatic nerve in adult male Lewis rats. At 3 months post-operation, fiber counts were similar through both implant types. Likewise, stimulation of nerves regenerated through a MSE or an open silicone conduit evoked comparable muscle forces. These results showed that nerve regeneration was comparable through MSE transit zones and an open conduit. GDNF had a minimal positive effect on the quality and morphology of fibers regenerating through the MSE; thus, the MSE may reduce reliance on GDNF to augment axonal regeneration. Selective stimulation of several individual muscles was achieved through monopolar stimulation of individual electrodes sites suggesting that the MSE might be an optimal platform for functional neuromuscular stimulation.

  5. Six years of experience with sacral nerve stimulation for fecal incontinence.

    PubMed

    Michelsen, Hanne B; Thompson-Fawcett, Mark; Lundby, Lilli; Krogh, Klaus; Laurberg, Søren; Buntzen, Steen

    2010-04-01

    Sacral nerve stimulation is one of many new surgical modalities for fecal incontinence. Short-term results from sacral nerve stimulation have been more encouraging than those from other modalities. The aim of this study was to report the outcome of percutaneous nerve evaluation tests and sacral nerve stimulation for the treatment of fecal incontinence from a single center covering a period of 6 years since the procedure was introduced. All of the candidates for a percutaneous nerve evaluation test and sacral nerve stimulation seen at our anal physiology unit between March 2001 and March 2007 were included in the study. A total of 177 patients with fecal incontinence (160 females), median age 59.5 (range, 27-88) years, underwent a percutaneous nerve evaluation test. Of these patients, 142 (80%) had a positive test, including 21 of 25 (84%) patients who required a repeat percutaneous nerve evaluation test. Because of a functional failure, 16 patients underwent a revision of the permanent electrode, 7 of whom (44%) were satisfied with the functional result after the revision. Of 126 patients, 15 (12%) have undergone an explantation, with an infection rate of only 1.6%. Overall, after a median follow-up of 24 (range, 3-72) months, the median Wexner incontinence score decreased from 16 (range, 6-20) to 10 (range, 0-20) (P < .0001). In the 10 patients who underwent at least 6 years of treatment, the effect was sustained, as the median Wexner incontinence score decreased from 20 (range, 12-20) to 7 (range, 2-11) (P < .0001). Sacral nerve stimulation is a simple, safe, and minimally invasive technique with low morbidity and excellent results, which appear to be maintained for the first 6 years after the procedure. For patients who underwent the treatment, median Wexner incontinence score decreased significantly after a median follow-up of 24 (range, 3-72) months. Twelve percent were explanted. The infection rate was 1.6%.

  6. Transcranial magnetic stimulation assisted by neuronavigation of magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Viesca, N. Angeline; Alcauter, S. Sarael; Barrios, A. Fernando; González, O. Jorge J.; Márquez, F. Jorge A.

    2012-10-01

    Technological advance has improved the way scientists and doctors can learn about the brain and treat different disorders. A non-invasive method used for this is Transcranial Magnetic Stimulation (TMS) based on neuron excitation by electromagnetic induction. Combining this method with functional Magnetic Resonance Images (fMRI), it is intended to improve the localization technique of cortical brain structures by designing an extracranial localization system, based on Alcauter et al. work.

  7. In vitro electrophoresis and in vivo electrophysiology of peripheral nerve using DC field stimulation

    PubMed Central

    Madison, Roger D.; Robinson, Grant A.; Krarup, Christian; Moldovan, Mihai; Li, Qiang; Wilson, Wilkie A.

    2014-01-01

    Background Given the movement of molecules within tissue that occurrs naturally by endogenous electric fields, we examined the possibility of using a low-voltage DC field to move charged substances in rodent peripheral nerve in vitro. New Method Labeled sugar- and protein-based markers were applied to a rodent peroneal nerve and then a 5–10 V/cm field was used to move the molecules within the extra- and intraneural compartments. Physiological and anatomical nerve properties were also assessed using the same stimulation in vivo. Results We demonstrate in vitro that charged and labeled compounds are capable of moving in a DC field along a nerve, and that the same field applied in vivo changes the excitability of the nerve, but without damage. Conclusions The results suggest that low-voltage electrophoresis could be used to move charged molecules, perhaps therapeutically, safely along peripheral nerves. PMID:24485870

  8. Semiconditional electrical stimulation of pudendal nerve afferents stimulation to manage neurogenic detrusor overactivity in patients with spinal cord injury.

    PubMed

    Lee, Young-Hee; Kim, Jung Moon; Im, Hyung Tae; Lee, Kye-Wook; Kim, Sung Hoon; Hur, Dong Min

    2011-10-01

    To evaluate the effect of semiconditional electrical stimulation of the pudendal nerve afferents for the neurogenic detrusor overactivity in patients with spinal cord injury. Forty patients (36 males, 4 males) with spinal cord injury who had urinary incontinence and frequency, as well as felt bladder contraction with bladder filling sense or autonomic dysreflexic symptom participated in this study. Patients with neurogenic detrusor overactivity were subdivided into complete injury and incomplete injury groups by ASIA classification and subdivided into tetraplegia and paraplegia groups by neurologic level of injury. Bladder function, such as bladder volumes infused to the bladder until the first occurrence of neurogenic detrusor overactivity (V(ini)) and the last contraction suppressed by electrical stimulation (V(max)) was measured by water cystometry (CMG) and compared with the results of each subgroup. Among the 40 subjects, 35 patients showed neurogenic detrusor overactivity in the CMG study. Among these 35 patients, detrusor overactivity was suppressed effectively by pudendal nerve afferent electrical stimulation in 32 patients. The infusion volume until the occurrence of the first reflex contraction (V(ini)) was 99.4±80.3 ml. The volume of saline infused to the bladder until the last contraction suppressed by semiconditional pudendal nerve stimulation (V(max)) was 274.3±93.2 ml, which was significantly greater than V(ini). In patients with good response to the pudendal nerve afferent stimulation, the bladder volume significantly increased by stimulation in all the patients. In this study, semiconditional electrical stimulation on the dorsal penile afferent nerve could effectively inhibit neurogenic detrusor overactivity and increase bladder volume in patients with spinal cord injury.

  9. Designing and Constructing a Magnetic Stimulator: Theoretical and Practical Considerations

    DTIC Science & Technology

    2001-10-25

    13, No 2,1991. [9] J. Cadwell , “Optimizing magnetic stimulator design”, Magnetic Motor Stimulation: Basic Principles and Clinical Experience (EEG Suppl. 43) 1991 Elsevier Science Publishers, B.V.

  10. Stimulating the neurotrophic and angiogenic properties of human adipose-derived stem cells enhances nerve repair.

    PubMed

    Kingham, Paul J; Kolar, Mallappa K; Novikova, Liudmila N; Novikov, Lev N; Wiberg, Mikael

    2014-04-01

    In future, adipose-derived stem cells (ASC) might be used to treat neurological disorders. In this study, the neurotrophic and angiogenic properties of human ASC were evaluated, and their effects in a peripheral nerve injury model were determined. In vitro growth factor stimulation of the cells resulted in increased secretion of brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), vascular endothelial growth factor-A (VEGF-A), and angiopoietin-1 proteins. Conditioned medium from stimulated cells increased neurite outgrowth of dorsal root ganglia (DRG) neurons. Similarly, stimulated cells showed an enhanced ability to induce capillary-like tube formation in an in vitro angiogenesis assay. ASC were seeded into a fibrin conduit that was used to bridge a 10 mm rat nerve gap. After 2 weeks, the animals treated with control or stimulated ASC showed an enhanced axon regeneration distance. Stimulated cells evoked more total axon growth. Analysis of regeneration and apoptosis-related gene expression showed that both ASC and stimulated ASC enhanced GAP-43 and activating transcription factor 3 (ATF-3) expression in the spinal cord and reduced c-jun expression in the DRG. Caspase-3 expression in the DRG was reduced by stimulated ASC. Both ASC and stimulated ASC also increased the vascularity of the fibrin nerve conduits. Thus, ASC produce functional neurotrophic and angiogenic factors, creating a more desirable microenvironment for nerve regeneration.

  11. Wireless peripheral nerve stimulation increases pain threshold in two neuropathic rat models.

    PubMed

    Rosellini, Will; Casavant, Reema; Engineer, Navzer; Beall, Patrick; Pierce, David; Jain, Ravi; Dougherty, Patrick M

    2012-06-01

    Neurostimulation approaches including spinal cord and peripheral nerve stimulation are typically used to treat intractable chronic pain in individuals who are refractory to pain medications. Our earlier studies have shown that a voltage controlled capacitive discharge (VCCD) method of stimulation of nerve activation is able to selectively recruit activity in large myelinated nerve fibers. In this study, we were able to wirelessly activate the sciatic nerve using the VCCD waveform. The purpose of this study was to determine whether this waveform can effectively improve two of the most troublesome pain symptoms experienced by patients with chronic neuropathic pain mechanical and cold hyperalgesia. Neuropathic mechanical hyperalgesia was reproduced using the Spinal Nerve Ligation (SNL) rat model whereas cold allodynia was reproduced using the Chronic Constriction Injury (CCI) model in male rats. Von Frey and cold plate tests were used to evaluate paw withdrawal threshold and latency to withdrawal before and after stimulation in experimental and control rats. Paw withdrawal threshold increased significantly compared to post-lesion baseline after VCCD stimulation in SNL rats. We also observed a significant improvement in cold allodynia in the active implant CCI rats after stimulation. These results suggest that the VCCD stimulation using a wireless microstimulator may be effective in the treatment of neuropathic pain. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Vagal nerve stimulation protects against burn-induced intestinal injury through activation of enteric glia cells

    PubMed Central

    Costantini, Todd W.; Bansal, Vishal; Krzyzaniak, Michael; Putnam, James G.; Peterson, Carrie Y.; Loomis, William H.; Wolf, Paul; Baird, Andrew; Eliceiri, Brian P.

    2010-01-01

    The enteric nervous system may have an important role in modulating gastrointestinal barrier response to disease through activation of enteric glia cells. In vitro studies have shown that enteric glia activation improves intestinal epithelial barrier function by altering the expression of tight junction proteins. We hypothesized that severe injury would increase expression of glial fibrillary acidic protein (GFAP), a marker of enteric glial activation. We also sought to define the effects of vagal nerve stimulation on enteric glia activation and intestinal barrier function using a model of systemic injury and local gut mucosal involvement. Mice with 30% total body surface area steam burn were used as model of severe injury. Vagal nerve stimulation was performed to assess the role of parasympathetic signaling on enteric glia activation. In vivo intestinal permeability was measured to assess barrier function. Intestine was collected to investigate changes in histology; GFAP expression was assessed by quantitative PCR, by confocal microscopy, and in GFAP-luciferase transgenic mice. Stimulation of the vagus nerve prevented injury-induced intestinal barrier injury. Intestinal GFAP expression increased at early time points following burn and returned to baseline by 24 h after injury. Vagal nerve stimulation prior to injury increased GFAP expression to a greater degree than burn alone. Gastrointestinal bioluminescence was imaged in GFAP-luciferase transgenic animals following either severe burn or vagal stimulation and confirmed the increased expression of intestinal GFAP. Injection of S-nitrosoglutathione, a signaling molecule released by activated enteric glia cells, following burn exerts protective effects similar to vagal nerve stimulation. Intestinal expression of GFAP increases following severe burn injury. Stimulation of the vagus nerve increases enteric glia activation, which is associated with improved intestinal barrier function. The vagus nerve may mediate the

  13. Corpus callosotomy for childhood-onset drug-resistant epilepsy unresponsive to vagus nerve stimulation.

    PubMed

    Arya, Ravindra; Greiner, Hansel M; Horn, Paul S; Turner, Michele; Holland, Katherine D; Mangano, Francesco T

    2014-12-01

    Corpus callosotomy and vagus nerve stimulation are common palliative options for people with drug-resistant epilepsy when resective epilepsy surgery is not feasible. Because most of the published corpus callosotomy experience comes from a period before vagus nerve stimulation was approved and widely used, there is a paucity of data about efficacy of corpus callosotomy in patients with inadequate response to vagus nerve stimulation. We report seven patients who had complete corpus callosotomy after an inadequate response to vagus nerve stimulation. At the time of surgery, these patients had failed a median of six antiseizure medications, three patients also had failed a trial of ketogenic diet, and all the patients had a vagus nerve stimulation implanted for a mean duration of 2.5 years with maximal tolerated settings. There was a decrease in total daily seizure frequency of 34.7% (± 94.7; median, 71.4%; interquartile range, 55.3) after corpus callosotomy at a mean follow-up of 2.6 years (± 1.4). One patient achieved complete seizure freedom and five patients had ≥ 50% reduction in seizure frequency. Six patients continued to have partial-onset seizures though the frequency was decreased. Drop attacks and tonic seizures stopped in all the patients. Seizure outcomes after corpus callosotomy in our series are most likely a result of complex dynamic interaction between the natural history of epilepsy, the effect of the surgery, ongoing vagus nerve stimulation modulation, and modification in antiseizure drugs. Our study supports the clinical decision to try corpus callosotomy in patients having nonlateralizing drug-resistant epilepsy with inadequate response to vagus nerve stimulation. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. The effect of electronic repositioning on left ventricular pacing and phrenic nerve stimulation.

    PubMed

    Champagne, Jean; Healey, Jeffrey S; Krahn, Andrew D; Philippon, Francois; Gurevitz, Osnat; Swearingen, Anne; Glikson, Michael

    2011-03-01

    Cardiac resynchronization therapy (CRT) improves survival and reduces heart failure symptoms. However, phrenic nerve stimulation and high pacing thresholds are common problems that limit CRT effectiveness. Current technology allows reprogramming of left ventricular (LV) pacing vectors, permitting 'electronic repositioning' to overcome both phrenic nerve stimulation and high pacing output without the need for re-operation. Patients underwent prospective evaluation of a CRT system implantation with a bipolar LV. Optimal LV threshold and avoidance of phrenic nerve stimulation were determined at baseline and at 6 months. A subset of 48 patients underwent more detailed evaluation of pacing threshold and phrenic nerve stimulation at baseline and at 6 months. Between 2004 and 2007, 228 patients underwent CRT implantation (64 CRT pacemakers, 164 CRT defibrillators). At baseline, electronic reprogramming to determine an alternate configuration compared with standard LVtip to LVring found a ≥ 1.0 V reduction in pacing threshold in 80 patients (35%). Of the 17 patients who had an LVtip to LVring configuration and high pacing threshold (>5.0 V), 16 could be reduced by >1.0 V (94%) and 11 could be reduced by >2.0 V through electronic repositioning alone without repositioning the lead (65%). At implant, there were 48 patients with phrenic nerve stimulation at less than maximum pacing output (21%) using the standard LVtip to LVring configuration. In 37 cases (77%), there was at least one other configuration with no phrenic nerve stimulation, which prevented the need for lead revision. Electronic repositioning is an important tool in the management of CRT patients which may help to lower thresholds, avoid phrenic nerve stimulation, and prevent unnecessary re-operations for LV lead repositioning.

  15. Transcranial magnetic stimulation and aphasia rehabilitation.

    PubMed

    Naeser, Margaret A; Martin, Paula I; Ho, Michael; Treglia, Ethan; Kaplan, Elina; Bashir, Shahid; Pascual-Leone, Alvaro

    2012-01-01

    Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005. In part 1, we review the rationale for applying slow, 1-Hz, rTMS to the undamaged right hemisphere in chronic nonfluent aphasia patients after a left hemisphere stroke; and we present a transcranial magnetic stimulation (TMS) protocol used with these patients that is associated with long-term, improved naming post-TMS. In part 2, we present results from a case study with chronic nonfluent aphasia where TMS treatments were followed immediately by speech therapy (constraint-induced language therapy). In part 3, some possible mechanisms associated with improvement after a series of TMS treatments in stroke patients with aphasia are discussed. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  16. Battery-powered implantable nerve stimulator for chronic activation of two skeletal muscles using multichannel techniques.

    PubMed

    Lanmüller, H; Sauermann, S; Unger, E; Schnetz, G; Mayr, W; Bijak, M; Rafolt, D; Girsch, W

    1999-05-01

    Chronic activation of skeletal muscle is used clinically in representative numbers for diaphragm pacing to restore breathing and for dynamic graciloplasty to achieve fecal continence. The 3 different stimulation techniques currently used for electrophrenic respiration (EPR) all apply high frequency powered implants. It was our goal to make these stimulation methods applicable for EPR by a battery-powered nerve stimulator that would maximize the patient's freedom of movement. Additionally, the system should allow the implementation of multichannel techniques and alternating stimulation of 2 skeletal muscles as a further improvement in graciloplasty. Generally, the developed implantable nerve stimulator can be used for simultaneous and alternating activation of 2 skeletal muscles. Stimulation of the motor nerve is achieved by either single channel or multichannel methods. Carousel stimulation and sequential stimulation can be used for graciloplasty as well as for EPR. For EPR we calculated an operating time of the implant battery of 4.1 years based on the clinically used stimulation parameters with carousel stimulation. The multichannel pulse generator is hermetically sealed in a titanium case sized 65 x 17 mm (diameter x height) and weighs 88 g.

  17. Is the vagus nerve stimulation a way to decrease body weight in humans?

    PubMed

    Bugajski, Andrzej; Gil, Krzysztof

    2012-01-01

    Obesity and its complications constitute an important health problem in growing number of people. Behavioral and pharmacological treatment is not much effective and surgical treatment carries too many threats. Promising method to be used is pharmacological or electric manipulation of vagus nerves. Regulation of food intake and energy utilization is a complex process regulated by centers in hypothalamus and brainstem which are receiving information from the peripheral via afferent neural pathways and sending peripherally adequate instructions by efferent neural pathways. In these signals conduction an important role plays vagus nerve. Additionally central nervous system stays under influence of endocrine, paracrine and neuroendocrine signals taking part in these regulations, functioning directly onto the centre or on the afferent neural endings. 80-90% fibers of vagus nerve are afferent fibers, so their action is mainly afferent, but possible contribution of the efferent fibers cannot be excluded. Efferent stimulation induces motility and secretion in the intestinal tract. Afferent unmyelinated C-type fibres of the vagus nerve are more sensitive and easily electrically stimulated. Information from vagus nerve is transmitted to nucleus tractus solitarius, which has projections to nucleus arcuate of the medio-basal hypothalamus, involved in the control of feeding behavior. It is suggested, that interaction onto the vagus nerve (stimulation or blocking) can be an alternative for other ways of obesity treatment. Through the manipulation of the vagus nerve activity the goal is achieved by influence on central nervous system regulating the energy homeostasis.

  18. 21 CFR 882.5805 - Repetitive transcranial magnetic stimulation system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Repetitive transcranial magnetic stimulation....5805 Repetitive transcranial magnetic stimulation system. (a) Identification. A repetitive transcranial magnetic stimulation system is an external device that delivers transcranial repetitive pulsed...

  19. 21 CFR 882.5805 - Repetitive transcranial magnetic stimulation system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Repetitive transcranial magnetic stimulation....5805 Repetitive transcranial magnetic stimulation system. (a) Identification. A repetitive transcranial magnetic stimulation system is an external device that delivers transcranial repetitive pulsed...

  20. 21 CFR 882.5805 - Repetitive transcranial magnetic stimulation system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Repetitive transcranial magnetic stimulation....5805 Repetitive transcranial magnetic stimulation system. (a) Identification. A repetitive transcranial magnetic stimulation system is an external device that delivers transcranial repetitive pulsed...

  1. Right-sided vagus nerve stimulation in humans: an effective therapy?

    PubMed

    Spuck, Sebastian; Nowak, Georg; Renneberg, Axel; Tronnier, Volker; Sperner, Jürgen

    2008-12-01

    Vagus nerve stimulation (VNS) is an additive treatment option for refractory epilepsy. The electrode is placed on the cervical trunk of the left vagus nerve. In patients who are not suitable for left-sided vagus nerve stimulation (L-VNS) right-sided vagus nerve stimulation (R-VNS) may be as effective. In animal models epilepsy is sufficiently suppressed by R-VNS. In a 16 years old boy suffering from medically refractory psychomotoric seizures with secondary generalisation, L-VNS reduced the frequency of generalized seizures. A deep wound infection required the removal of the system eight weeks later. Cicatrisation did not allow preparation of the left vagus nerve, therefore we implanted R-VNS with sufficient seizure suppression. However, compared to L-VNS, the effect occurred months later and cardiac symptoms were induced by stimulation of the right vagus nerve. R-VNS seems to be an effective and alternative therapy in selected patients responding to L-VNS where a left-sided reimplantation is not possible. Placement and adjustment of the device should be performed under ECG control. Further studies are necessary to compare the efficacy of L-VNS and R-VNS.

  2. Electrochemical and Electrophysiological Performance of Platinum Electrodes Within the Ninety-Nine-Electrode Stimulating Nerve Cuff.

    PubMed

    Pečlin, Polona; Mehle, Andraž; Karpe, Blaž; Rozman, Janez

    2015-10-01

    The trend in neural prostheses using selective nerve stimulation for electrical stimulation therapies is headed toward single-part systems having a large number of working electrodes (WEs), each of which selectively stimulate neural tissue or record neural response (NR). The present article reviews the electrochemical and electrophysiological performance of platinum WE within a ninety-nine-electrode spiral cuff for selective nerve stimulation and recording of peripheral nerves, with a focus on the vagus nerve (VN). The electrochemical properties of the WE were studied in vitro using the electrochemical impedance spectroscopy (EIS) technique. The equivalent circuit model (ECM) of the interface between the WE and neural tissue was extracted from the EIS data and simulated in the time domain using a preset current stimulus. Electrophysiological performance of in-space and fiber-type highly selective vagus nerve stimulation (VNS) was tested using an isolated segment of a porcine VN and carotid artery as a reference. A quasitrapezoidal current-controlled pulse (stimulus) was applied to the VN or arterial segment using an appointed group of three electrodes (triplet). The triplet and stimulus were configured to predominantly stimulate B-fibers and minimize the stimulation of A-fibers. The EIS results revealed capacitive charge transfer predominance, which is a highly desirable property. Electrophysiological performance testing indicated the potential existence of certain parameters and waveforms of the stimulus for which the contribution of the A-fibers to the NR decreased slightly and that of the B-fibers increased slightly. Findings show that the design of the stimulating electrodes, based on the EIS and ECM results, could act as a useful tool for nerve cuff development. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  3. Vagus Nerve Stimulation (VNS) and Treatment of Depression: To the Brainstem and Beyond

    PubMed Central

    Cristancho, Pilar; Peshek, Andrew D.

    2006-01-01

    Neuromodulation appears to be emerging gradually as a new therapeutic field in psychiatric treatment. It encompasses neuropsychiatric medical devices, such as vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS), deep brain stimulation (DBS), and electroconvulsive therapy (ECT). As a therapeutic approach to affective disorders, neuromodulation shifts the focus from the monoamine synapse to neural circuitry of the brain, which is dysregulated in depression. This neural circuitry has been elaborated on over the course of 15 years of neuroimaging research in mood disorders and is now believed to encompass disturbances in a frontolimbic network. These include reduced metabolism and blood flow in the prefrontal cortex and anterior cingulate and pathologically increased activity in the subgenual cingulate and amygdala. VNS is an implanted device that has established efficacy in pharmaco-resistant epilepsy. It was approved by the FDA for the treatment of severe, recurrent unipolar and bipolar depression in July of 2005. VNS adopts a bottom-up approach to modulating the neural circuitry of depression by stimulating vagal afferent fibers in the neck, which carry impulses to the brain stem to target there the locus ceruleus and dorsal raphe nucleus. Now that VNS has moved beyond the experimental phase and into the clinic, psychiatrists are faced with deciding who is an appropriate patient for this surgical implant and how to integrate VNS into existing treatment in order to optimize both efficacy and safety. This review of VNS will assess the efficacy and safety data that led to the FDA approval. We will also review for the busy clinician how VNS is likely to translate into clinical practice as a treatment option for patients in need who are suffering from severe depression. PMID:21103178

  4. Sacral Nerve Stimulation for Pediatric Lower Urinary Tract Dysfunction: Development of a Standardized Pathway with Objective Urodynamic Outcomes.

    PubMed

    Schober, Megan S; Sulkowski, Jason P; Lu, Peter L; Minneci, Peter C; Deans, Katherine J; Teich, Steven; Alpert, Seth A

    2015-12-01

    We propose that sacral nerve stimulation is a valid adjunctive therapy for refractory pediatric lower urinary tract dysfunction, and that prospective collection of preoperative and postoperative validated questionnaires and urodynamic data in a standardized fashion is beneficial in characterizing patient response. Patients were candidates for sacral nerve stimulation if they had refractory voiding dysfunction and standard treatments had failed. Preoperative evaluation included urodynamic studies, spinal magnetic resonance imaging, and validated bladder and bowel related questionnaires. Children were stratified into 2 groups, ie overactive bladder with or without incontinence (group 1) and detrusor underactivity/urinary retention requiring clean intermittent catheterization (group 2). A staged procedure was used with initial test lead placement, followed by permanent device insertion 2 weeks later if patients demonstrated symptom improvement with test lead. Postoperatively children were followed with questionnaires and at least 1 urodynamic study. A total of 26 children underwent sacral nerve stimulation. Mean patient age was 10.8 years and median followup was 1.2 years. There were 23 patients in group 1 and 4 in group 2 (1 patient was included in both groups). In group 1 voiding dysfunction scores improved significantly, and urodynamic studies revealed a significant decrease in mean number of uninhibited contractions and maximum detrusor pressure during the filling phase. In group 2 there was significant improvement in mean post-void residual. Sacral nerve stimulation is a treatment option that may produce significant improvement in objective and subjective measures of bladder function in children with refractory lower urinary tract dysfunction. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  5. Thirty minutes of low intensity electrical stimulation promotes nerve regeneration after sciatic nerve crush injury in a rat model.

    PubMed

    Alrashdan, Mohammad S; Park, Jong-Chul; Sung, Mi-Ae; Yoo, Sang Bae; Jahng, Jeong Won; Lee, Tae Hyung; Kim, Sung-June; Lee, Jong-Ho

    2010-06-01

    We investigated whether electrical stimulation (ES) applied directly for 30 minutes after crushing injury to the sciatic nerves of rats could improve nerve regeneration. Two groups of animals were used in this study (n = 20 each): the ES group received 30 minutes of low intensity ES (20 Hz pulse rate, 2 uA amplitude) immediately after a standard crush injury, while the control group received no stimulation after injury. Both groups were followed up for three weeks. The sciatic function index (SFI) was calculated weekly. Mean conduction velocity (MCV) and peak voltage (PV) were calculated, and the sensory neurons in L4 and L5 dorsal root ganglia (DRG) were traced with Fluorogold in retrograde fashion and quantified at the end of the follow up period. Histomorphometric studies were also carried out in both groups. The ES group showed improved functional and sensory recovery compared to the control group three weeks after injury. SFI, MCV and the number of retrogradely labeled sensory neurons were significantly higher in the ES group. Additionally, axon counts, myelin thicknesses and G-ratio values were also higher in the ES group. Quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) showed an elevated expression of brain derived neurotrophic factor (BDNF) in DRG sensory neurons of the ES group five days post-injury. Here, we present the first evidence that the application of ES for 30 minutes immediately following crush injury is effective to promote nerve regeneration in a rat sciatic nerve model.

  6. Transcutaneous electric nerve stimulation (TENS) for cancer pain in adults.

    PubMed

    Hurlow, Adam; Bennett, Michael I; Robb, Karen A; Johnson, Mark I; Simpson, Karen H; Oxberry, Stephen G

    2012-03-14

    Cancer-related pain is complex and multi-dimensional but the mainstay of cancer pain management has predominantly used a biomedical approach. There is a need for non-pharmacological and innovative approaches. Transcutaneous Electric Nerve Stimulation (TENS) may have a role in pain management but the effectiveness of TENS is currently unknown. This is an update of the original review published in Issue 3, 2008. The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. The initial review searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED and PEDRO databases in April 2008. We performed an updated search of CENTRAL, MEDLINE, EMBASE, CINAHL and PEDRO databases in November 2011. We included only randomised controlled trials (RCTS) investigating the use of TENS for the management of cancer-related pain in adults. The search strategy identified a further two studies for possible inclusion. One of the review authors screened each abstract using a study eligibility tool. Where eligibility could not be determined, a second author assessed the full paper. One author used a standardised data extraction sheet to collect information on the studies and independently assess the quality of the studies using the validated five-point Oxford Quality Scale. The small sample sizes and differences in patient study populations of the three included studies (two from the original review and a third included in this update) prevented meta-analysis. For the original review the search strategy identified 37 possible published studies; we divided these between two pairs of review authors who decided on study selection; all four review authors discussed and agreed final scores. Only one additional RCT met the eligibility criteria (24 participants) for this updated review. Although this was a feasibility study, not designed to investigate intervention effect, it suggested that TENS may improve bone pain on movement in a

  7. The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy.

    PubMed

    Park, C; Choi, J B; Lee, Y-S; Chang, H-S; Shin, C S; Kim, S; Han, D W

    2015-04-01

    Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy.

  8. Dosimetry of typical transcranial magnetic stimulation devices

    NASA Astrophysics Data System (ADS)

    Lu, Mai; Ueno, Shoogo

    2010-05-01

    The therapeutic staff using transcranial magnetic stimulation (TMS) devices could be exposed to magnetic pulses. In this paper, dependence of induced currents in real human man model on different coil shapes, distance between the coil and man model as well as the rotation of the coil in space have been investigated by employing impedance method. It was found that the figure-of-eight coil has less leakage magnetic field and low current density induced in the body compared with the round coil. The TMS power supply cables play an important role in the induced current density in human body. The induced current density in TMS operator decreased as the coil rotates from parallel position to perpendicular position. Our present study shows that TMS operator should stand at least 110 cm apart from the coil.

  9. A 3D Computational Model of Transcutaneous Electrical Nerve Stimulation for Estimating Aβ Tactile Nerve Fiber Excitability

    PubMed Central

    Zhu, Kaihua; Li, Liming; Wei, Xuyong; Sui, Xiaohong

    2017-01-01

    Tactile sensory feedback plays an important role in our daily life. Transcutaneous electrical nerve stimulation (TENS) is widely accepted to produce artificial tactile sensation. To explore the underlying mechanism of tactile sensation under TENS, this paper presented a novel 3D TENS computational model including an active Aβ tactile nerve fiber (TNF) model and a forearm finite element model with the fine-layered skin structure. The conduction velocity vs. fiber diameter and strength-duration relationships in this combined TENS model matched well with experimental data. Based on this validated TENS model, threshold current variation were further investigated under different stimulating electrode sizes with varied fiber diameters. The computational results showed that the threshold current intensity increased with electrode size, and larger nerve fibers were recruited at lower current intensities. These results were comparable to our psychophysical experimental data from six healthy subjects. This novel 3D TENS model would further guide the floorplan of the surface electrodes, and the stimulating paradigms for tactile sensory feedback. PMID:28559787

  10. Transcranial magnetic stimulation of the cerebellum.

    PubMed

    Minks, Eduard; Kopickova, Marie; Marecek, Radek; Streitova, Hana; Bares, Martin

    2010-06-01

    The cerebellum is a very complex structure with many motor/non-motor functions and direct and indirect connections with almost the entire central nervous system. Transcranial magnetic stimulation (TMS) is a non-invasive electrophysiological method for studying, diagnosing, and treating disorders of the nervous system. The aim of the present review is to summarise the research and potential clinical uses of cerebellar TMS. PubMed literature search using the key words "cerebellum TMS". TMS of the cerebellum is used in two types of protocols. The first type involves the separate stimulation of the cerebellum while tracking its clinical or electrophysiological influence on motor and non-motor functions. The second involves stimulation of the cerebellum as a conditioning stimulus before stimulating the motor cortex, to monitor the electrophysiological impact of cerebellar stimulation on the motor cortex. Most studies are performed on small groups of healthy volunteers; isolated studies are performed on patients with neurological disorders (spinocerebellar ataxia, migraine, dystonia, Miller Fisher syndrome). It has been shown that cerebellar TMS is able to influence motor systems, memory, and perception of time, and there is evidence of its electrophysiological effects in the frontal cortex. Published studies suggest that cerebellar TMS is currently only important in research. There is not yet any clear or reliable evidence of the therapeutic effects of cerebellar TMS. However, its use as a treatment method can be anticipated.

  11. Intraoperative cavernous nerve stimulation and Laser-Doppler flowmetry during radical prostatectomy.

    PubMed

    Axelson, Hans W; Johansson, Eva; Bill-Axelson, Anna

    2013-11-01

    Erectile dysfunction is a common side effect following radical prostatectomy mainly due to damage of the pelvic autonomic nerve fibers (cavernous nerves). Intraoperative electrical stimulation of the cavernous nerves while measuring changes in penile girth has previously been shown to provide the surgeon with feedback of nerve integrity. To test the feasibility of recording changes in glans penis blood flow by Laser Doppler flowmetry from cavernous nerve stimulation. Fifteen patients with localized prostate cancer undergoing radical prostatectomy had electrical stimulation of the proximal and distal parts of the neurovascular bundles after prostate removal. The stimulation consisted of 30-40 seconds biphasic constant current (10-30 mA) with 0.5 millisecond pulse duration. Stimulus induced changes in penile blood flow was recorded from a Laser Doppler probe attached to the glans penis. Changes in penile girth were simultaneously recorded from a mercury-in rubber strain gauge. Erectile function was evaluated three months after surgery. Ten patients had stimulus induced increase in Laser Doppler flow unilaterally (N=7) or bilaterally (N=3). Out of 10 patients, 6 reported some preserved erectile function postoperatively at 3 months follow-up (indicating 6 true and 4 false positives). Three patients had no Doppler response from stimulation and had no postoperative erectile function postoperatively (indicating three true negatives). Two patients were excluded from the study due to bad signal quality in the Laser Doppler signal. In the majority of patients, stimulation produced increase in penile girth sensed by the strain gauge. This preliminary report provides evidence that Laser Doppler Flowmetry is able to detect increased penile blood flow from intraoperative electrical stimulation of the neurovascular bundles. However, further improvement in the recording technique is required. Laser Doppler Flowmetry may also be feasible to confirm autonomic nerve sparing in women

  12. Sacral Nerve Stimulation Can Be an Effective Treatment for Low Anterior Resection Syndrome.

    PubMed

    Eftaiha, Saleh M; Balachandran, Banujan; Marecik, Slawomir J; Mellgren, Anders; Nordenstam, Johan; Melich, George; Prasad, Leela M; Park, John J

    2017-05-06

    Sacral nerve stimulation has become a preferred method for the treatment of faecal incontinence in patients who fail conservative (non-operative) therapy. In previous small studies, sacral nerve stimulation has demonstrated improvement of faecal incontinence and quality of life in a majority of patients with low anterior resection syndrome. We evaluated the efficacy of sacral nerve stimulation in the treatment of low anterior resection syndrome, using a recently developed and validated low anterior resection syndrome instrument to quantify symptoms. A retrospective review of consecutive patients undergoing sacral nerve stimulation for the treatment of low anterior resection syndrome was performed. Procedures took place in the Division of Colon and Rectal Surgery at two academic tertiary medical centers. Pre and post treatment Cleveland Clinic Incontinence Scores and Low Anterior Resection Syndrome Scores were assessed. Twelve patients (50% men) suffering from low anterior resection syndrome with a mean age of 67.8 (±10.8) years underwent sacral nerve test stimulation. Ten patients (83%) proceeded to permanent implantation. Median time from anterior resection to stimulator implant was 16 (range, 5-108) months. At a median follow-up of 19.5 (range, 4-42) months, there were significant improvements in Cleveland Clinic Incontinence Scores and the Low Anterior Resection Syndrome Scores (p<0.001). Sacral nerve stimulation improved symptoms in patients suffering from low anterior resection syndrome and may therefore be a viable treatment option. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Implantable microcoils for intracortical magnetic stimulation

    PubMed Central

    Lee, Seung Woo; Fallegger, Florian; Casse, Bernard D. F.; Fried, Shelley I.

    2016-01-01

    Neural prostheses that stimulate the neocortex have the potential to treat a wide range of neurological disorders. However, the efficacy of electrode-based implants remains limited, with persistent challenges that include an inability to create precise patterns of neural activity as well as difficulties in maintaining response consistency over time. These problems arise from fundamental limitations of electrodes as well as their susceptibility to implantation and have proven difficult to overcome. Magnetic stimulation can address many of these limitations, but coils small enough to be implanted into the cortex were not thought strong enough to activate neurons. We describe a new microcoil design and demonstrate its effectiveness for both activating cortical neurons and driving behavioral responses. The stimulation of cortical pyramidal neurons in brain slices in vitro was reliable and could be confined to spatially narrow regions (<60 μm). The spatially asymmetric fields arising from the coil helped to avoid the simultaneous activation of passing axons. In vivo implantation was safe and resulted in consistent and predictable behavioral responses. The high permeability of magnetic fields to biological substances may yield another important advantage because it suggests that encapsulation and other adverse effects of implantation will not diminish coil performance over time, as happens to electrodes. These findings suggest that a coil-based implant might be a useful alternative to existing electrode-based devices. The enhanced selectivity of microcoil-based magnetic stimulation will be especially useful for visual prostheses as well as for many brain-computer interface applications that require precise activation of the cortex. PMID:27957537

  14. Management of phrenic nerve stimulation caused by epicardial pacemaker leads in children.

    PubMed

    Wells, Winfield J; Batra, Anjan S

    2003-11-01

    To find a suitable site with good sensing and low pacing thresholds, it may be necessary to place an epicardial pacemaker lead in close proximity to the phrenic nerve. To prevent phrenic stimulation, a silastic patch can be sewn over the area of the pacing electrode to shield it from the nerve. This simple technique prevents diaphragm contraction and has not interfered with long-term pacemaker lead function.

  15. Dynamic Article: Percutaneous Nerve Evaluation Versus Staged Sacral Nerve Stimulation for Fecal Incontinence.

    PubMed

    Rice, Teresa C; Quezada, Yarini; Rafferty, Janice F; Paquette, Ian M

    2016-10-01

    Sacral neuromodulation using a 2-staged approach is an established therapy for fecal incontinence. Office-based percutaneous nerve evaluation is a less-invasive alternative to the stage 1 procedure but is seldom used in the evaluation of patients with fecal incontinence. The aim of this study was to determine the clinical success of percutaneous nerve evaluation versus a staged approach. This was a retrospective review of a prospectively maintained, single-institution database of patients treated with sacral neuromodulation for fecal incontinence. This study was conducted at a single academic medical center. Eighty-six consecutive patients were treated with sacral neuromodulation for fecal incontinence. Percutaneous nerve evaluation was compared with a staged approach. The primary outcome measured was the proportion of patients progressing to complete implantation based on >50% improvement in Wexner score during the testing phase. Percutaneous nerve evaluation was performed in 45 patients, whereas 41 underwent a staged approach. The mean baseline Wexner score did not differ between testing groups. Success was similar between the staged approach and percutaneous nerve evaluation (90.2% versus 82.2%; p = 0.36). The mean 3-month Wexner score was not significantly different between testing methods (4.4 versus 4.1; p = 0.74). However, infection was more likely to occur after the staged approach (10.5% versus 0.0%; p < 0.05). This study was limited by its retrospective nature and potential for selection bias. Percutaneous nerve evaluation offers a viable alternative to a staged approach in the evaluation of patients for sacral neuromodulation in the setting of fecal incontinence. Not only are success rates similar, but percutaneous nerve evaluation also has the benefit of limiting patients to 1 operating room visit and has lower rates of infection as compared with the traditional staged approach for sacral neuromodulation.

  16. Use of vagal nerve stimulation as a treatment for refractory epilepsy in dogs.

    PubMed

    Muñana, Karen R; Vitek, Susanne M; Tarver, W Brent; Saito, Miyoko; Skeen, Todd M; Sharp, Nicholas J H; Olby, Natasha J; Haglund, Michael M

    2002-10-01

    To evaluate safety and efficacy of vagal nerve stimulation in dogs with refractory epilepsy. Placebo-controlled, double-masked, crossover study. 10 dogs with poorly controlled seizures. A programmable pacemaker-like device designed to deliver intermittent stimulation to the left cervical trunk of the vagus was surgically implanted in each dog. Dogs were assigned randomly to two 13-week test periods, 1 with nerve stimulation and 1 without nerve stimulation. Owners recorded data on seizure frequency, duration, and intensity, as well as adverse effects. No significant difference in seizure frequency, duration, or severity was detected between overall 13-week treatment and control periods. During the final 4 weeks of the treatment period, a significant decrease in mean seizure frequency (34.4%) was detected, compared with the control period. Complications included transient bradycardia, asystole, and apnea during intraoperative device testing, and seroma formation, subcutaneous migration of the generator, and transient Horner's syndrome during the 14-day period between surgery and suture removal. No adverse effects of stimulation were detected, and most owners were satisfied with the treatment. Vagal nerve stimulation is a potentially safe approach to seizure control that appears to be efficacious in certain dogs and should be considered a possible treatment option when antiepileptic medications are ineffective.

  17. Intraoperative pelvic nerve stimulation performed under continuous electromyography of the internal anal sphincter.

    PubMed

    Kneist, Werner; Kauff, Daniel W; Rahimi Nedjat, Roman K; Rink, Andreas D; Heimann, Axel; Somerlik, Karin; Koch, Klaus P; Doerge, Thomas; Lang, Hauke

    2010-11-01

    The aim of this animal study was to investigate the effect of intraoperative pelvic nerve stimulation on internal anal sphincter electromyographic signals in order to evaluate its possible use for neuromonitoring during nerve-sparing pelvic surgery. Eight pigs underwent low anterior rectal resection. The intersphincteric space was exposed, and the internal (IAS) and external anal sphincter (EAS) were identified. Electromyography of both sphincters was performed with bipolar needle electrodes. Intermittent bipolar electric stimulation of the inferior hypogastric plexus and the pelvic splanchnic nerves was carried out bilaterally. The recorded signals were analyzed in its frequency spectrum. In all animals, electromyographic recordings of IAS and EAS were successful. Intraoperative nerve stimulation resulted in a sudden amplitude increase in the time-based electromyographic signals of IAS (1.0 (0.5-9.0) μV vs. 4.0 (1.0-113.0) μV) and EAS (p < 0.001). The frequency spectrum of IAS in the resting state ranged from 0.15 to 5 Hz with highest activity in median at 0.77 Hz (46 cycles/min). Pelvic nerve stimulation resulted in an extended spectrum ranging from 0.15 to 20 Hz. EAS signals showed higher frequencies mainly in a range of 50 to 350 Hz. However, after muscle relaxation with pancuronium bromide, only the low frequency spectrum of the IAS signals was still present. Intraoperative verification of IAS function by stimulation of pelvic autonomic nerves is possible. The IAS electromyographic response could be used to monitor pelvic autonomic nerve preservation.

  18. The "vagal ansa": a source of complication in vagus nerve stimulation.

    PubMed

    Gopalakrishnan, Chittur Viswanathan; Kestle, John R W; Connolly, Mary B

    2015-05-01

    A 16-year-old boy underwent vagus nerve stimulation for treatment-resistant multifocal epilepsy. During intraoperative system diagnostics, vigorous contraction of the ipsilateral sternomastoid muscle was observed. On re-exploration, a thin nerve fiber passing from the vagus to the sternomastoid was found hooked up in the upper electrode. Detailed inspection revealed an abnormal course of the superior root of the ansa cervicalis, which descended down as a single nerve trunk with the vagus and separated to join the inferior root. The authors discuss the variation in the course of the ansa cervicalis and how this could be a reason for postoperative neck muscle contractions.

  19. The effect of partial superficial parotidectomy on amplitude, latency and threshold of facial nerve stimulation.

    PubMed

    Ozturk, Kerem; Akyildiz, Serdar; Gode, Sercan; Turhal, Goksel; Gursan, Gulce; Kirazli, Tayfun

    2016-06-01

    The aim of this study is to assess the effect of partial superficial parotidectomy and facial nerve dissection to electrophysiologic parameters of intraoperative facial nerve monitoring such as nerve stimulation threshold, stimulus amplitude and latency. Twenty-five patients who underwent partial superficial parotidectomy for benign parotid gland mass were included in the study. After the identification of the facial nerve main trunk, minimum stimulation threshold, latencies and amplitudes of the orbicularis oculi (electrode 1) and orbicularis oris (electrode 2) electrodes at 0.50 milliamperes (mA) were recorded. All of the recordings were repeated after the completion of parotidectomy. Median nerve dissection duration was calculated and size of the tumors was measured during macroscopic pathology. The median minimum nerve stimulation threshold was 0.15 mA [interquartile range (IQR) = 0.05] before and 0.15 mA (IQR = 0.08) after the parotidectomy (p = 0.02). Median nerve dissection duration was 49 min (IQR = 38). Median amplitude and latency in electrode 1 before and after the facial nerve dissection were 322 millivolts (mV) (IQR = 330), 370 mV (IQR = 370) (p = 0.02), 3 milliseconds (ms) (IQR = 1) and 4 ms (IQR = 2) (p = 0.05), respectively. Median amplitude and latency in electrode 2 before and after the facial nerve dissection were 396 mV (IQR = 275), 365 mV (IQR = 836) (p = 0.86), 3 ms (IQR = 1.5) and 4 ms (IQR = 1.5) (p = 0.17), respectively. Minimal nerve stimulation threshold and amplitude of electrode 1 were affected by facial nerve dissection among the electrophysiologic parameters (p = 0.02 and p = 0.02). Of the electrophysiological parameters only the latency of electrode 2 was significantly correlated with tumor size (p = 0.03). Besides, none of the parameters were predictive for a possible postoperative facial nerve dysfunction regarding superficial partial parotidectomy.

  20. Near-infrared signals associated with electrical stimulation of peripheral nerves

    PubMed Central

    Fantini, Sergio; Chen, Debbie K.; Martin, Jeffrey M.; Sassaroli, Angelo; Bergethon, Peter R.

    2011-01-01

    We report our studies on the optical signals measured non-invasively on electrically stimulated peripheral nerves. The stimulation consists of the delivery of 0.1 ms current pulses, below the threshold for triggering any visible motion, to a peripheral nerve in human subjects (we have studied the sural nerve and the median nerve). In response to electrical stimulation, we observe an optical signal that peaks at about 100 ms post-stimulus, on a much longer time scale than the few milliseconds duration of the electrical response, or sensory nerve action potential (SNAP). While the 100 ms optical signal we measured is not a direct optical signature of neural activation, it is nevertheless indicative of a mediated response to neural activation. We argue that this may provide information useful for understanding the origin of the fast optical signal (also on a 100 ms time scale) that has been measured non-invasively in the brain in response to cerebral activation. Furthermore, the optical response to peripheral nerve activation may be developed into a diagnostic tool for peripheral neuropathies, as suggested by the delayed optical signals (average peak time: 230 ms) measured in patients with diabetic neuropathy with respect to normal subjects (average peak time: 160 ms). PMID:22399834

  1. Near-infrared signals associated with electrical stimulation of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Fantini, Sergio; Chen, Debbie K.; Martin, Jeffrey M.; Sassaroli, Angelo; Bergethon, Peter R.

    2009-02-01

    We report our studies on the optical signals measured non-invasively on electrically stimulated peripheral nerves. The stimulation consists of the delivery of 0.1 ms current pulses, below the threshold for triggering any visible motion, to a peripheral nerve in human subjects (we have studied the sural nerve and the median nerve). In response to electrical stimulation, we observe an optical signal that peaks at about 100 ms post-stimulus, on a much longer time scale than the few milliseconds duration of the electrical response, or sensory nerve action potential (SNAP). While the 100 ms optical signal we measured is not a direct optical signature of neural activation, it is nevertheless indicative of a mediated response to neural activation. We argue that this may provide information useful for understanding the origin of the fast optical signal (also on a 100 ms time scale) that has been measured non-invasively in the brain in response to cerebral activation. Furthermore, the optical response to peripheral nerve activation may be developed into a diagnostic tool for peripheral neuropathies, as suggested by the delayed optical signals (average peak time: 230 ms) measured in patients with diabetic neuropathy with respect to normal subjects (average peak time: 160 ms).

  2. [ELECTRIC STIMULATION OF VAGUS NERVE MODULATES A PROPAGATION OF OXYGEN EPILEPSY IN RABBITS].

    PubMed

    Zhilyaev, S Yu; Moskvin, A N; Platonova, T F; Demchenko, I T

    2015-11-01

    The activation of autonomic afferents (achieved through the vagus nerve (VN) electrical stimulation) on CNS O2 toxicity and cardiovascular function was investigated. In conscious rabbits at 5 ATA 02, prodromal signs of CNS O2 toxicity and convulsion latency were determined with and without vagus nerve (VN) stimulation. EEG, ECG and respiration were also recorded. In rabbits at 5 ATA, sympathetic overdrive and specific patterns on the EEG (synchronization of slow-waves), ECG (tachycardia) and respiration (respiratory minute volume increase) preceded motor convulsions. Vagus nerve stimulation increased parasympathetic component of autonomic drive and significantly delayed prodromal signs of oxygen toxicity and convulsion latency. Autonomic afferent input to the brain is a novel target for preventing CNS toxicity in HBO2.

  3. Increased extracellular concentrations of norepinephrine in cortex and hippocampus following vagus nerve stimulation in the rat.

    PubMed

    Roosevelt, Rodney W; Smith, Douglas C; Clough, Richard W; Jensen, Robert A; Browning, Ronald A

    2006-11-13

    The vagus nerve is an important source of afferent information about visceral states and it provides input to the locus coeruleus (LC), the major source of norepinephrine (NE) in the brain. It has been suggested that the effects of electrical stimulation of the vagus nerve on learning and memory, mood, seizure suppression, and recovery of function following brain damage are mediated, in part, by the release of brain NE. The hypothesis that left vagus nerve stimulation (VNS) at the cervical level results in increased extracellular NE concentrations in the cortex and hippocampus was tested at four stimulus intensities: 0.0, 0.25, 0.5, and 1.0 mA. Stimulation at 0.0 and 0.25 mA had no effect on NE concentrations, while the 0.5 mA stimulation increased NE concentrations significantly in the hippocampus (23%), but not the cortex. However, 1.0 mA stimulation significantly increased NE concentrations in both the cortex (39%) and hippocampus (28%) bilaterally. The increases in NE were transient and confined to the stimulation periods. VNS did not alter NE concentrations in either structure during the inter-stimulation baseline periods. No differences were observed between NE levels in the initial baseline and the post-stimulation baselines. These findings support the hypothesis that VNS increases extracellular NE concentrations in both the hippocampus and cortex.

  4. Receptive-field changes induced by peripheral nerve stimulation in SI of adult cats.

    PubMed

    Recanzone, G H; Allard, T T; Jenkins, W M; Merzenich, M M

    1990-05-01

    1. Receptive fields (RFs) of neurons in the primary somatosensory (SI) cortex were defined before, during, and after electrical stimulation of myelinated fibers in the dorsal cutaneous branch of the ulnar nerve in adult pentobarbital sodium-anesthetized cats. 2. This stimulation resulted in an approximately threefold increase of SI multiunit RF sizes. Substantial changes were first recorded within 1-2 h of stimulation. RFs typically enlarged continuously over a several-hour stimulation period, then stabilized. 3. RF-area increases were observed within both the forepaw and hindpaw representational zones in the SI cortex contralateral to the stimulated forepaw nerve. RF sizes did not increase in the ipsilateral SI body surface representation or in sham-stimulation control animals. 4. Preliminary studies indicate that stimulation-induced changes can be halted and often reversed by the intravenous administration of the opiate antagonist naloxone. 5. These observations suggest a global naloxone-sensitive modulatory system that operates on large-diameter afferent inputs in the cat somatosensory system. The increases in RF size occur under nerve-stimulation conditions similar to those that result in the generation of widespread analgesia (Chung et al. 1984a,b; Gamble and Milne 1986; Toda and Ichioka 1978).

  5. Increased Extracellular Concentrations of Norepinephrine in Cortex and Hippocampus Following Vagus Nerve Stimulation in the Rat.

    PubMed Central

    Roosevelt, Rodney W.; Smith, Douglas C.; Clough, Richard W.; Jensen, Robert A.; Browning, Ronald A.

    2006-01-01

    The vagus nerve is an important source of afferent information about visceral states and it provides input to the locus coeruleus (LC), the major source of norepinephrine (NE) in the brain. It has been suggested that the effects of electrical stimulation of the vagus nerve on learning and memory, mood, seizure suppression, and recovery of function following brain damage are mediated, in part, by the release of brain NE. The hypothesis that left vagus nerve stimulation (VNS) at the cervical level results in increased extracellular NE concentrations in the cortex and hippocampus was tested at four stimulus intensities 0.0, 0.25, 0.5, and 1.0 mA. Stimulation at 0.0 and 0.25 mA had no effect on NE concentrations, while the 0.5 mA stimulation increased NE concentrations significantly in the hippocampus (23%), but not the cortex. However, 1.0 mA stimulation significantly increased NE concentrations in both the cortex (39%) and hippocampus (28%) bilaterally. The increases in NE were transient and confined to the stimulation periods. VNS did not alter NE concentrations in either structure during the inter-stimulation baseline periods. No differences were observed between NE levels in the initial baseline and the post-stimulation baselines. These findings support the hypothesis that VNS increases extracellular NE concentrations in both the hippocampus and cortex. PMID:16962076

  6. Portable stimulator design aimed at differentiating facial nerves from normal tissues.

    PubMed

    Kara, S; Kemaloğlu, S; Sener, F; Okandan, M; Erkan, M A

    2004-04-01

    Facial nerves are very prone to risk of being cut away in the facial surgeries. In order to differentiate the normal tissues from the nerves during the surgeries, facial stimulator is very essential. These stimulators are particularly useful in triggering action potentials in the facial muscle tissue. In the case of any damage to these nerves, paralysis is unavoidable. Second use of the stimulator would be to diagnose how severe the facial problems are. Third use, which is a noninvasive application, is the employment of facial stimulator to treat and diagnose facial problems that arose from temperature differences, cuts or strain. The stimulation is achieved through DC voltage pulses that conform to user-specified amplitude, pulse duration and pulse intervals. These variables are set according to the age, sex, and physiological conditions of the patient. Peripheral Interface Controller is used to derive different pulse patterns. The current specifications of our stimulator are a range of 0.1-20 V pulse amplitude, 0.1-2 msec pulse duration, and 0.05-1 sec pulse interval. The main benefits of our stimulator are its graphic display that shows the form of pulse, its compact size, and operation on a battery power supply and adaptability to convert to other stimulation applications.

  7. Application of conductive polymers, scaffolds and electrical stimulation for nerve tissue engineering.

    PubMed

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein; Kiani, Sahar; Al-Deyab, Salem S; Ramakrishna, Seeram

    2011-04-01

    Among the numerous attempts to integrate tissue engineering concepts into strategies to repair nearly all parts of the body, neuronal repair stands out. This is partially due to the complexity of the nervous anatomical system, its functioning and the inefficiency of conventional repair approaches, which are based on single components of either biomaterials or cells alone. Electrical stimulation has been shown to enhance the nerve regeneration process and this consequently makes the use of electrically conductive polymers very attractive for the construction of scaffolds for nerve tissue engineering. In this review, by taking into consideration the electrical properties of nerve cells and the effect of electrical stimulation on nerve cells, we discuss the most commonly utilized conductive polymers, polypyrrole (PPy) and polyaniline (PANI), along with their design and modifications, thus making them suitable scaffolds for nerve tissue engineering. Other electrospun, composite, conductive scaffolds, such as PANI/gelatin and PPy/poly(ε-caprolactone), with or without electrical stimulation, are also discussed. Different procedures of electrical stimulation which have been used in tissue engineering, with examples on their specific applications in tissue engineering, are also discussed.

  8. Intraoperative identification of the facial nerve by needle electromyography stimulation with a burr

    PubMed Central

    KHAMGUSHKEEVA, N.N.; ANIKIN, I.A.; KORNEYENKOV, A.A.

    2016-01-01

    The purpose of this research is to improve the safety of surgery for patients with a pathology of the middle and inner ear by preventing damage to the facial nerve by conducting intraoperative monitoring of the facial nerve by needle electromyography with continuous stimulation with a burr. Patients and Methods The clinical part of the prospective study was carried out on 48 patients that were diagnosed with suppurative otitis media. After the surgery with intraoperative monitoring, the facial nerve with an intact bone wall was stimulated electrically in the potentially dangerous places of damage. Minimum (threshold) stimulation (mA) of the facial nerve with a threshold event of 100 μV was used to register EMG events. The anatomical part of the study was carried out on 30 unformalinized cadaver temporal bones from adult bodies. The statistical analysis of obtained data was carried out with parametric methods (Student’s t-test), non-parametric correlation (Spearman’s method) and regression analysis. Results It was found that 1 mA of threshold amperage corresponded to 0.8 mm thickness of the bone wall of the facial canal. Values of transosseous threshold stimulation in potentially dangerous sections of the injury to the facial nerve were obtained. Conclusion These data lower the risk of paresis (paralysis) of the facial muscles during otologic surgery. PMID:27142821

  9. The role of cutaneous inputs during magnetic transcranial stimulation.

    PubMed

    Rossini, P M; Tecchio, F; Sabato, A; Finazzi-Agrò, A; Pasqualetti, P; Rossi, S

    1996-10-01

    Latency and amplitude characteristics of motor evoked potentials (MEPs) from abductor digiti minimi (ADM) and first dorsal interosseus (FDI) muscles were evaluated in 7 healthy volunteers via magnetic transcranial stimulation of the hemiscalp overlying contralateral motor areas. MEPs in complete relaxation and during contraction were recorded in two different experimental conditions: before and following anesthesia of median (sensory + motor) and radial (sensory) nerve fibers at wrist. This procedure induced a complete loss of skin sensation from dorsal and palmar aspects of the hand area "enveloping" the FDI muscle. On the other hand, the skin overlying the ADM muscle, as well as the strength of ulnar nerve supplied muscles were spared. This selective sensory deprivation lead to the following short-term changes: the physiological latency "jump" toward shorter values in contracted MEPs vs. relaxation was partially lost in the FDI (3.0 +/- 1.4 ms in basal condition, 1.8 +/- 1.1 ms after anesthesia, P = 0.028), while it was still clearly evident in the ADM (3.7 +/- 0.9 ms and 3.3 +/- 1.0 ms, respectively). Moreover, minor amplitude changes of MEPs during active contraction in the two muscles were detected: MEPs recorded from the FDI muscle were less potentiated during voluntary contraction than those recorded from the ADM muscle. The role of the cutaneous input in governing latency/amplitude characteristics of MEPs is discussed.

  10. Design of a compact laparoscopic probe for optical stimulation of the cavernous nerves

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Fried, Nathaniel M.

    2009-02-01

    The cavernous nerves are responsible for erectile function and course along the prostate surface, varying in size and location among patients, making preservation of sexual function challenging after prostate cancer surgery. Electrical stimulation has proven inconsistent and unreliable in identifying these nerves and evaluating nerve function. Optical stimulation of the rat cavernous nerves has recently been reported as a alternative to electrical stimulation, with potential advantages including noncontact stimulation and improved spatial selectivity. This study describes the design of a compact laparoscopic probe for future clinical use in optical nerve stimulation. The 10-Fr (3.4-mm-OD) prototype laparoscopic probe includes an aspheric lens for collimation of the laser beam with a 0.8- mm-diameter spot, coupled with a 200-μm-core optical fiber. A 45° gold-coated rod mirror in the probe tip provides side-firing delivery of the laser radiation. The probe handle houses a miniature linear motorized stage for lateral scanning of the probe tip over a 25-mm line along the prostate surface. A 5.5-W Thulium fiber laser with tunable wavelength range of 1850-1880 nm was tested with the probe. The probe fits through a standard 5-mm-ID laparoscopic port and is capable of delivering pulse energies up to 8 mJ (1.6 J/cm2) at a 2.5-ms pulse duration, well above the threshold (~ 0.35 J/cm2) for optical stimulation of the cavernous nerves.

  11. Enhanced nerve-stimulated muscarinic and neurokinin contractions of ileum from streptozotocin guinea-pigs.

    PubMed

    Cellini, J; Pommier, R; Porter, R; LePard, K J

    2012-10-01

    Diabetes mellitus can lead to neuropathy of enteric neurons, resulting in abnormal gut motility. These studies investigated voltage-dependent contributions of muscarinic M₃ receptor activation by acetylcholine and neurokinin NK₁ receptor activation by neurokinins to nerve-stimulated contractions of longitudinal ileal strips from STZ guinea-pigs, a type 1 diabetic model with insulin deficiency, but mild hyperglycaemia. Contractions to bethanechol, substance P methyl ester, and nerve stimulation were greater in diabetic as compared to control ileum. The muscarinic M₃ receptor antagonist 4-DAMP at lower voltages and the neurokinin NK₁ receptor antagonist SR140333 at higher voltages, but not the neurokinin NK₁ receptor antagonist CP-96,345, were more effective at inhibiting nerve-stimulated immediate peak contractions and total areas of contraction of ileum from diabetic as compared to control animals. For diabetic ileum, voltage-dependent increases in the areas of nerve-stimulated contraction were observed in the presence of 4-DAMP and CP-96,345 but not SR140333. At low voltages only, nerve-stimulated release of acetylcholine was greater from diabetic as compared to control ileum. Fluorescence intensity of tachykinin-like immunoreactivity was increased in ileal myenteric ganglia from diabetic as compared to control animals. In diabetic guinea-pigs, stronger ileal nerve-stimulated contractions reflected increased release of acetylcholine at lower voltages and tachykinins at higher voltages, as well as increased sensitivity of smooth muscle M₃ and NK₁ receptors to acetylcholine and tachykinins. Hypoinsulinaemia may be a primary contributor to intestinal motility dysfunction in type 1 diabetes mellitus.

  12. Long-term efficacy and safety of sacral nerve stimulation for fecal incontinence.

    PubMed

    Mellgren, Anders; Wexner, Steven D; Coller, John A; Devroede, Ghislain; Lerew, Darin R; Madoff, Robert D; Hull, Tracy

    2011-09-01

    Sacral nerve stimulation is effective in the treatment of urinary incontinence and is currently under Food and Drug Administration review in the United States for fecal incontinence. Previous reports have focused primarily on short-term results of sacral nerve stimulation for fecal incontinence. The present study reports the long-term effectiveness and safety of sacral nerve stimulation for fecal incontinence in a large prospective multicenter study. Patients with fecal incontinent episodes more than twice per week were offered participation in this multicentered prospective trial. Patients showing ≥ 50% improvement during test stimulation were offered chronic implantation of the InterStim Therapy system (Medtronic; Minneapolis, MN). The aims of the current report were to provide 3-year follow-up data on patients from that study who underwent sacral nerve stimulation and were monitored under the rigors of an Food and Drug Administration-approved investigational protocol. One hundred thirty-three patients underwent test stimulation with a 90% success rate, of whom 120 (110 females) with a mean age of 60.5 years and a mean duration of fecal incontinence of 7 years received chronic implantation. Mean length of follow-up was 3.1 (range, 0.2-6.1) years, with 83 patients completing all or part of the 3-year follow-up assessment. At 3 years follow-up, 86% of patients (P < .0001) reported ≥ 50% reduction in the number of incontinent episodes per week compared with baseline and the number of incontinent episodes per week decreased from a mean of 9.4 at baseline to 1.7. Perfect continence was achieved in 40% of subjects. The therapy also improved the fecal incontinence severity index. Sacral nerve stimulation had a positive impact on the quality of life, as evidenced by significant improvements in all 4 scales of the Fecal Incontinence Quality of Life instrument at 12, 24, and 36 months of follow-up. The most common device- or therapy-related adverse events through the

  13. A microcontroller-based implantable nerve stimulator used for rats.

    PubMed

    Sha, Hong; Zheng, Zheng; Wang, Yan; Ren, Chaoshi

    2005-01-01

    A microcontroller-based stimulator that can be flexible programmed after it has been implanted into a rat was studied. Programmability enables implanted stimulators to generate customized, complex protocols for experiments. After implantation, a coded light pulse train that contains information of specific identification will unlock a certain stimulator. If a command that changing the parameters is received, the microcontroller will update its flash memory after it affirms the commands. The whole size of it is only 1.6 cubic centimeters, and it can work for a month. The devices have been successfully used in animal behavior experiments, especially on rats.

  14. [Treatment of congenital facial paralysis with crossed innervation of facial nerve and electric field stimulation].

    PubMed

    Ysunza-Rivera, A; Iñigo-Muñoz, F; Drucker-Colín, R; Ortiz-Monasterio, F; Pesqueira, T

    1992-04-01

    Congenital facial palsy is a devastating deformity. At present time there are no reports of the early treatment of this disorder. The treatment may be to supply contralateral auto reinnervation to the affected muscles through a sural-facial nerve graft enhanced by electric field stimulation. The purpose of this paper is to report 5 cases of congenital facial palsy treated by a crossed sural-facial nerve graft, enhanced by electric field stimulation. One year after surgery, clinical and electrodiagnostic examinations indicate appropriate reinnervation activity in all the patients.

  15. Origin of subcortical somatosensory evoked potentials in response to posterior tibial nerve stimulation in humans.

    PubMed

    Urasaki, E; Wada, S; Yokota, A; Tokimura, T; Yasukouchi, H

    1993-06-01

    To identify the origin of short latency somatosensory evoked potentials (SSEPs) to posterior tibial nerve stimulation, direct recordings were made from the cervical cord, the ventricular system and the frontal subcortex during 8 neurosurgical operations. The origin of each component of SSEPs was also studied in 7 selected patients with various lesions in the central nervous system. In addition, SSEPs to median nerve stimulation were investigated in 4 of 8 surgical cases and all 7 cases of the lesion study group. Bilateral posterior tibial nerve stimulation in 10 normal subjects showed spinal N28 on the skin of the posterior neck and far-field P30 and N33 components followed by a cortical P38 component at the scalp. Direct recordings made to the mid-brain through the medulla oblongata showed a negative potential with gradually increasing latency. The peak of the negativity in the vicinity of the dorsal column nucleus showed almost the same latency as that of the scalp far-field P30, and positivity with a stationary peak was found above the dorsal column nucleus. Above the mid-pons, there was a stationary negativity with no latency shift, showing the same peak latency as that of scalp N33. The spatiotemporal distributions of P30 and N33 to posterior tibial nerve stimulation were analogous to those of P14 and N18 by median nerve stimulation. Transesophageal and direct cervical cord recordings showed that the spinal N13 phase to median nerve stimulation was reversed between the dorsal and ventral sides of the cervical cord. No such reversal occurred for the spinal N28 potential. Clinical lesion studies showed that changes in P30 and P14, and in N33 and N18 correlated with one another: that is, 1) prolongation of latency of N33 was also observed for N18; 2) absence of P30 was paralleled by the absence of P14. These data suggest that spinal N28 originates from ascending activity such as a dorsal column volley, and scalp P30 comes from activity near the dorsal column

  16. Efferents and afferents in an intact muscle nerve: background activity and effects of sural nerve stimulation in the cat.

    PubMed

    Bessou, P; Joffroy, M; Pagès, B

    1981-11-01

    1. The background activity was observed in gamma and alpha efferent fibres and in group I and II fibres innervating the muscle gastrocnemius lateralis or medialis. The reflex effects of ipsilateral and contralateral sural nerve stimulations on the muscle efferents were analysed together with their consequences upon the afferents of the same muscle. The observations were made in the decerebrated cat without opening the neural loops between the muscle and the spinal cord.2. The multi-unit discharges of each category of fibres were obtained, on line, by an original electronic device (Joffroy, 1975, 1980) that sorted the action potentials from the whole electrical activity of a small branch of gastrocnemius lateralis or medialis nerve according to the direction and velocity of propagation of the potentials.3. The small nerve may be regarded as a representative sample of different functional groups of fibres conducting faster than 12 m.sec(-1) and supplying gastrocnemius muscles.4. Some gamma efferents were always tonically firing except when a transient flaccid state developed. Usually the alpha efferents were silent, probably because the muscle was fixed close to the minimal physiological length.5. Separate and selective stimulations of Abeta, Adelta and C fibres of ipsilateral and contralateral sural nerve showed that each group could induce the excitation of gamma neurones. The reciprocal inhibition period of alpha efferents during a flexor reflex was only once accompanied by a small decrease in gamma-firing.6. The reflex increase of over-all frequency of gamma efferents resulted from an increased firing rate of tonic gamma neurones and from the recruitment of gamma neurones previously silent. When the gamma efferents in the small nerve naturally occurred in two subgroups, the slower-conducting subgroup (mainly composed of tonic gamma axons) was activated before the faster-conducting subgroup (mostly composed by gamma axons with no background discharge). Some rare

  17. Effects of acute selective pudendal nerve electrical stimulation after simulated childbirth injury

    PubMed Central

    Gill, Bradley C.; Dissaranan, Charuspong; Zutshi, Massarat; Balog, Brian M.; Lin, Danli; Damaser, Margot S.

    2013-01-01

    During childbirth, a combinatorial injury occurs and can result in stress urinary incontinence (SUI). Simulated childbirth injury, consisting of vaginal distension (VD) and pudendal nerve crush (PNC), results in slowed recovery of continence, as well as decreased expression of brain-derived neurotrophic factor (BDNF), a regenerative cytokine. Electrical stimulation has been shown to upregulate BDNF in motor neurons and facilitate axon regrowth through the increase of βII-tubulin expression after injury. In this study, female rats underwent selective pudendal nerve motor branch (PNMB) stimulation after simulated childbirth injury or sham injury to determine whether such stimulation affects bladder and anal function after injury and whether the stimulation increases BDNF expression in Onuf's nucleus after injury. Rats received 4 h of VD followed by bilateral PNC and 1 h of subthreshold electrical stimulation of the left PNMB and sham stimulation of the right PNMB. Rats underwent filling cystometry and anal pressure recording before, during, and after the stimulation. Bladder and anal contractile function were partially disrupted after injury. PNMB stimulation temporarily inhibited bladder contraction after injury. Two days and 1 wk after injury, BDNF expression in Onuf's nucleus of the stimulated side was significantly increased compared with the sham-stimulated side, whereas βII-tubulin expression in Onuf's nucleus of the stimulated side was significantly increased only 1 wk after injury. Acute electrical stimulation of the pudendal nerve proximal to the crush site upregulates BDNF and βII-tubulin in Onuf's nucleus after simulated childbirth injury, which could be a potential preventive option for SUI after childbirth injury. PMID:23152293

  18. Effects of acute selective pudendal nerve electrical stimulation after simulated childbirth injury.

    PubMed

    Jiang, Hai-Hong; Gill, Bradley C; Dissaranan, Charuspong; Zutshi, Massarat; Balog, Brian M; Lin, Danli; Damaser, Margot S

    2013-02-01

    During childbirth, a combinatorial injury occurs and can result in stress urinary incontinence (SUI). Simulated childbirth injury, consisting of vaginal distension (VD) and pudendal nerve crush (PNC), results in slowed recovery of continence, as well as decreased expression of brain-derived neurotrophic factor (BDNF), a regenerative cytokine. Electrical stimulation has been shown to upregulate BDNF in motor neurons and facilitate axon regrowth through the increase of β(II)-tubulin expression after injury. In this study, female rats underwent selective pudendal nerve motor branch (PNMB) stimulation after simulated childbirth injury or sham injury to determine whether such stimulation affects bladder and anal function after injury and whether the stimulation increases BDNF expression in Onuf's nucleus after injury. Rats received 4 h of VD followed by bilateral PNC and 1 h of subthreshold electrical stimulation of the left PNMB and sham stimulation of the right PNMB. Rats underwent filling cystometry and anal pressure recording before, during, and after the stimulation. Bladder and anal contractile function were partially disrupted after injury. PNMB stimulation temporarily inhibited bladder contraction after injury. Two days and 1 wk after injury, BDNF expression in Onuf's nucleus of the stimulated side was significantly increased compared with the sham-stimulated side, whereas β(II)-tubulin expression in Onuf's nucleus of the stimulated side was significantly increased only 1 wk after injury. Acute electrical stimulation of the pudendal nerve proximal to the crush site upregulates BDNF and β(II)-tubulin in Onuf's nucleus after simulated childbirth injury, which could be a potential preventive option for SUI after childbirth injury.

  19. Cortical plasticity induced by different degrees of peripheral nerve injuries: a rat functional magnetic resonance imaging study under 9.4 Tesla

    PubMed Central

    2013-01-01

    Background Major peripheral nerve injuries not only result in local deficits but may also cause distal atrophy of target muscles or permanent loss of sensation. Likewise, these injuries have been shown to instigate long-lasting central cortical reorganization. Methods Cortical plasticity changes induced after various types of major peripheral nerve injury using an electrical stimulation technique to the rat upper extremity and functional magnetic resonance imaging (fMRI) were examined. Studies were completed out immediately after injury (acute stage) and at two weeks (subacute stage) to evaluate time affect on plasticity. Results After right-side median nerve transection, cortical representation of activation of the right-side ulnar nerve expanded intra-hemispherically into the cortical region that had been occupied by the median nerve representation After unilateral transection of both median and ulnar nerves, cortical representation of activation of the radial nerve on the same side of the body also demonstrated intra-hemispheric expansion. However, simultaneous electrical stimulation of the contralateral uninjured median and ulnar nerves resulted in a representation that had expanded both intra- and inter-hemispherically into the cortical region previously occupied by the two transected nerve representations. Conclusions After major peripheral nerve injury, an adjacent nerve, with similar function to the injured nerve, may become significantly over-activated in the cortex when stimulated. This results in intra-hemispheric cortical expansion as the only component of cortical plasticity. When all nerves responsible for a certain function are injured, the same nerves on the contralateral side of the body are affected and become significantly over-activated during a task. Both intra- and inter-hemispheric cortical expansion exist, while the latter dominates cortical plasticity. PMID:23659705

  20. The effect of acidaemia on the response to stimulation of the autonomic nerves to the heart

    PubMed Central

    Linden, R. J.; Norman, J.

    1969-01-01

    1. The effects are described of an acidaemia produced either by an inhalation of carbon dioxide or by an infusion of hydrochloric acid on the response of the heart to stimulation of the ansae subclaviae and right vagus nerve in anaesthetized dogs. 2. The results show that during an acidaemia (pH 6·95) of up to 2 hr duration the response to stimulation of the right vagus nerve was enhanced and that the inotropic response to stimulation of sympathetic nerves was not changed; the chronotropic response was depressed during acidaemia only at the low end of the range of responses, from 0 to 40 beats/min. The importance of preventing acidaemia when investigating reflex heart rate responses is discussed. 3. It is suggested that in the intact animal with an innervated heart the response of the heart to stimulation of the sympathetic nerves is unaltered in acidaemia and that the reported effects of changed cardiovascular response during acidaemia may in part be explained by the enhanced response to vagal stimulation and an altered response of the peripheral vessels. PMID:5761973

  1. Posterior tibial nerve stimulation for treating neurologic bladder in women: a randomized clinical trial.

    PubMed

    Eftekhar, Tahereh; Teimoory, Nastaran; Miri, Elahe; Nikfallah, Abolghasem; Naeimi, Mahsa; Ghajarzadeh, Mahsa

    2014-01-01

    Overactive bladder (OAB) is a disabling disorder. Treatment of cases with OAB includes behavioral, pharmacological, surgical interventions and peripheral electrical stimulation. The goal of this study was to determine effects of posterior tibial nerve stimulation on sexual function and pelvic disorders in women with Overactive bladder (OAB). Fifty women were randomly assigned to PTNS (posterior tibial nerve stimulation) plus tolterodine or tolterodine alone treatment. Tolterodine group received 4 mg tolterodine daily for three months while the other group received this treatment plus percutaneous tibial nerve stimulation for 12 consequence weeks. Two in PTNS group and 8 in the control group withdrew from the study. Age, education level, and occupation status were not significantly different between two groups. Mean total FSFI and its subscales were not significantly different before and after treatment between two groups. Urine leakage associated with a feeling of urgency and loss of stool or gas from the rectum beyond patient's control became significantly different after treatment between two groups. Posterior tibial nerve stimulation could help urinary problems in women with a neurologic bladder.

  2. Glial hyperpolarization upon nerve root stimulation in the leech Hirudo medicinalis.

    PubMed

    Schmidt, J; Prinz, P; Deitmer, J W

    1999-07-01

    Hyperpolarizing responses in neuropil glial cells evoked by nerve root stimulation were studied in the central nervous system of the leech Hirudo medicinalis using intracellular recording and extracellular stimulation techniques. From a mean resting potential of -60.5 +/- 1.0, the glial membrane was hyperpolarized by -8.6 +/- 0.8 mV, via stimulation of the dorsal posterior nerve root in an isolated ganglion. Nerve root stimulation evoked biphasic or depolarizing responses in glial cells with resting potentials around -70 mV (Rose CR, Deitmer JW. J. Neurophysiol. 73:125-131, 1995). The hyperpolarizing response was reduced by the ionotropic glutamate receptor antagonist CNQX (50 microM) to 58% of its initial amplitude. In 15 mM Ca2+/15 mM Mg(2+)-saline the hyperpolarization was reduced by 44%. The hyperpolarization that persisted in high-divalent cation saline was not affected by CNQX. Bath-applied glutamate (500 microM) and kainate (2 microM) elicited glial hyperpolarizations that were sensitive to CNQX and 10 mM Mg2+/1 mM Ca(2+)-saline. The 5-HT-antagonist methysergide did not affect the hyperpolarizations evoked by nerve root stimulation. The results show that in the leech glial membrane responses to neuronal activity include not only depolarizations, as shown previously, but also hyperpolarizations, which are mediated by direct and indirect neuron-glial communication pathways. In the indirect pathway, glutamate is a transmitter between neurons.

  3. Vagus nerve stimulation therapy for partial-onset seizures: a randomized active-control trial.

    PubMed

    Handforth, A; DeGiorgio, C M; Schachter, S C; Uthman, B M; Naritoku, D K; Tecoma, E S; Henry, T R; Collins, S D; Vaughn, B V; Gilmartin, R C; Labar, D R; Morris, G L; Salinsky, M C; Osorio, I; Ristanovic, R K; Labiner, D M; Jones, J C; Murphy, J V; Ney, G C; Wheless, J W

    1998-07-01

    The purpose of this multicenter, add-on, double-blind, randomized, active-control study was to compare the efficacy and safety of presumably therapeutic (high) vagus nerve stimulation with less (low) stimulation. Chronic intermittent left vagus nerve stimulation has been shown in animal models and in preliminary clinical trials to suppress the occurrence of seizures. Patients had at least six partial-onset seizures over 30 days involving complex partial or secondarily generalized seizures. Concurrent antiepileptic drugs were unaltered. After a 3-month baseline, patients were surgically implanted with stimulating leads coiled around the left vagus nerve and connected to an infraclavicular subcutaneous programmable pacemaker-like generator. After randomization, device initiation, and a 2-week ramp-up period, patients were assessed for seizure counts and safety over 3 months. The primary efficacy variable was the percentage change in total seizure frequency compared with baseline. Patients receiving high stimulation (94 patients, ages 13 to 54 years) had an average 28% reduction in total seizure frequency compared with a 15% reduction in the low stimulation group (102 patients, ages 15 to 60 year; p = 0.04). The high-stimulation group also had greater improvements on global evaluation scores, as rated by a blinded interviewer and the patient. High stimulation was associated with more voice alteration and dyspnea. No changes in physiologic indicators of gastric, cardiac, or pulmonary functions occurred. Vagus nerve stimulation is an effective and safe adjunctive treatment for patients with refractory partial-onset seizures. It represents the advent of a new, nonpharmacologic treatment for epilepsy.

  4. A Study on Duration of Effect of Transcutaneous Electrical Nerve Stimulation Therapy on Whole Saliva Flow.

    PubMed

    Bhasin, Neha; Reddy, Sreedevi; Nagarajappa, Anil Kumar; Kakkad, Ankur

    2015-06-01

    Saliva is a complex fluid, whose important role is to maintain the well being of oral cavity. Salivary gland hypofunction or hyposalivation is the condition of having reduced saliva production which leads to the subjective complaint of oral dryness termed xerostomia.(7) Management of xerostomia includes palliative therapy using topical agents or systemic therapy. Electrostimulation to produce saliva was studied in the past and showed moderate promise but never became part of mainstream therapy. Hence, this study was undertaken to evaluate the effect of transcutaneous electrical nerve stimulation (TENS) on whole salivary flow rate in healthy adults and to evaluate how long this effect of TENS lasts on salivary flow. One hundred healthy adult subjects were divided into five age groups with each group containing 20 subjects equally divided into males and females in each group. Unstimulated saliva was collected using a graduated test tube fitted with funnel and quantity was measured. Transcutaneous electrical nerve stimulation unit was activated and stimulated saliva was collected. Saliva was again collected 30 minutes and 24 hours post stimulation. The mean unstimulated whole saliva flow rate for all subjects (n = 100) was 2.60 ml/5 min. During stimulation, it increased to 3.60 ± 0.39 ml/5 min. There was 38.46% increase in salivary flow. Ninety six out of 100 responded positively to TENS therapy. Salivary flow remained increased 30 minutes and 24 hours post stimulation with the values being 3.23 ± 0.41 ml/5 min and 2.69 ± 0.39 ml/5 min respectively. Repeated measures One way analysis of variance (ANOVA) test showed that the difference between these values were statistically significant. Transcutaneous electrical nerve stimulation therapy was effective for stimulation of whole saliva in normal, healthy subjects and its effect retained till 30 minutes and a little up to 24 hours. Transcutaneous electrical nerve stimulation may work best synergistically with other

  5. Cerebral magnetic fields to lingual stimulation.

    PubMed

    Karhu, J; Hari, R; Lu, S T; Paetau, R; Rif, J

    1991-01-01

    We recorded cerebral magnetic fields to electric stimulation of the tongue in 7 healthy adults. The two main deflections of the response peaked around 55 msec (P55m) and 140 msec (N140m). During both of them the magnetic field pattern, determined with a 7- or 24-channel SQUID magnetometer, suggested a dipolar current source. The topography of P55m can be explained by a tangential dipole at the first somatosensory cortex (SI) in the posterior wall of the central sulcus. The equivalent source of N140m is, on average, about 1 cm lateral to the source of P55m. The reported method allows non-invasive determination of the cortical tongue representation area.

  6. Blood pressure control with selective vagal nerve stimulation and minimal side effects

    NASA Astrophysics Data System (ADS)

    Plachta, Dennis T. T.; Gierthmuehlen, Mortimer; Cota, Oscar; Espinosa, Nayeli; Boeser, Fabian; Herrera, Taliana C.; Stieglitz, Thomas; Zentner, Joseph

    2014-06-01

    Objective. Hypertension is the largest threat to patient health and a burden to health care systems. Despite various options, 30% of patients do not respond sufficiently to medical treatment. Mechanoreceptors in the aortic arch relay blood pressure (BP) levels through vagal nerve (VN) fibers to the brainstem and trigger the baroreflex, lowering the BP. Selective electrical stimulation of these nerve fibers reduced BP in rats. However, there is no technique described to localize and stimulate these fibers inside the VN without inadvertent stimulation of non-baroreceptive fibers causing side effects like bradycardia and bradypnea. Approach. We present a novel method for selective VN stimulation to reduce BP without the aforementioned side effects. Baroreceptor compound activity of rat VN (n = 5) was localized using a multichannel cuff electrode, true tripolar recording and a coherent averaging algorithm triggered by BP or electrocardiogram. Main results. Tripolar stimulation over electrodes near the barofibers reduced the BP without triggering significant bradycardia and bradypnea. The BP drop was adjusted to 60% of the initial value by varying the stimulation pulse width and duration, and lasted up to five times longer than the stimulation. Significance. The presented method is robust to impedance changes, independent of the electrode's relative position, does not compromise the nerve and can run on implantable, ultra-low power signal processors.

  7. Hypoalgesia in response to transcutaneous electrical nerve stimulation (TENS) depends on stimulation intensity.

    PubMed

    Moran, Fidelma; Leonard, Tracey; Hawthorne, Stephanie; Hughes, Ciara M; McCrum-Gardner, Evie; Johnson, Mark I; Rakel, Barbara A; Sluka, Kathleen A; Walsh, Deirdre M

    2011-08-01

    Transcutaneous electrical nerve stimulation (TENS) is an electrophysical modality used for pain management. This study investigated the dose response of different TENS intensities on experimentally induced pressure pain. One hundred and thirty TENS naïve healthy individuals (18-64 years old; 65 males, 65 females) were randomly allocated to 5 groups (n = 26 per group): Strong Non Painful TENS; Sensory Threshold TENS; Below Sensory Threshold TENS; No Current Placebo TENS; and Transient Placebo TENS. Active TENS (80 Hz) was applied to the forearm for 30 minutes. Transient Placebo TENS was applied for 42 seconds after which the current amplitude automatically reset to 0 mA. Pressure pain thresholds (PPT) were recorded from 2 points on the hand and forearm before and after TENS to measure hypoalgesia. There were significant differences between groups at both the hand and forearm (ANOVA; P = .005 and .002). At 30 minutes, there was a significant hypoalgesic effect in the Strong Non Painful TENS group compared to: Below Sensory Threshold TENS, No Current Placebo TENS and Transient Placebo TENS groups (P < .0001) at the forearm; Transient Placebo TENS and No Current Placebo TENS groups at the hand (P = .001). There was no significant difference between Strong Non Painful TENS and Sensory Threshold TENS groups. The area under the curve for the changes in PPT significantly correlated with the current amplitude (r(2) = .33, P = .003). These data therefore show that there is a dose-response effect of TENS with the largest effect occurring with the highest current amplitudes. This study shows a dose response for the intensity of TENS for pain relief with the strongest intensities showing the greatest effect; thus, we suggest that TENS intensity should be titrated to achieve the strongest possible intensity to achieve maximum pain relief. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  8. Studies on magnetism and bioelectromagnetics for 45 years: from magnetic analog memory to human brain stimulation and imaging.

    PubMed

    Ueno, Shoogo

    2012-01-01

    Forty-five years of studies on magnetism and bioelectromagnetics, in our laboratory, are presented. This article is prepared for the d'Arsonval Award Lecture. After a short introduction of our early work on magnetic analog memory, we review and discuss the following topics: (1) Magnetic nerve stimulation and localized transcranial magnetic stimulation (TMS) of the human brain by figure-eight coils; (2) Measurements of weak magnetic fields generated from the brain by superconducting quantum interference device (SQUID) systems, called magnetoencephalography (MEG), and its application in functional brain studies; (3) New methods of magnetic resonance imaging (MRI) for the imaging of impedance of the brain, called impedance MRI, and the imaging of neuronal current activities in the brain, called current MRI; (4) Cancer therapy and other medical treatments by pulsed magnetic fields; (5) Effects of static magnetic fields and magnetic control of cell orientation and cell growth; and (6) Effects of radio frequency magnetic fields and control of iron ion release and uptake from and into ferritins, iron cage proteins. These bioelectromagnetic studies have opened new horizons in magnetism and medicine, in particular for brain research and treatment of ailments such as depression, Parkinson's, and Alzheimer's diseases.

  9. The immediate effectiveness of electrical nerve stimulation and electrical muscle stimulation on myofascial trigger points.

    PubMed

    Hsueh, T C; Cheng, P T; Kuan, T S; Hong, C Z

    1997-01-01

    This study is designed to investigate the immediate effectiveness of electrotherapy on myofascial trigger points of upper trapezius muscle. Sixty patients (25 males and 35 females) who had myofascial trigger points in one side of the upper trapezius muscles were studied. The involved upper trapezius muscles were treated with three different methods according to a random assignment: group A muscles (n = 18) were given placebo treatment (control group); group B muscles (n = 20) were treated with electrical nerve stimulation (ENS) therapy; and group C muscles (n = 22) were given electrical muscle stimulation (EMS) therapy. The effectiveness of treatment was assessed by conducting three measurements on each muscle before and immediately after treatment: subjective pain intensity [(PI) with a visual analog scale], pressure pain threshold [(PT) with algometry], and range of motion [(ROM) with a goniometer] of upper trapezius muscle (lateral bending of cervical spine to the opposite side). When the effectiveness of treatment was compared with that of the placebo group (group A), there was significant improvement in PI and PT in group B (P < 0.01) but not in group C (P > 0.05). The improvement of ROM was significantly more in group C (P < 0.01) as compared with that in group A or group B. When each group was divided into two additional subgroups based on the initial PI, it was found that ENS could reduce PI and increase PT significantly (P < 0.05), but did not significantly (P > 0.05) improve ROM, as compared with the placebo group for both subgroups. EMS could significantly (P < 0.05) improve ROM, but not PT, better than the placebo groups, for either subgroup. It could reduce PI significantly more (P < 0.05) than placebo controls only for the subgroup with mild to moderate pain, but not with severe pain. For pain relief, ENS was significantly better (P < 0.05) than EMS; but for the improvement of ROM, EMS was significantly better (P < 0.05) than ENS. It is concluded that

  10. Effect of low frequency transcutaneous magnetic stimulation on sensory and motor transmission.

    PubMed

    Leung, Albert; Shukla, Shivshil; Lee, Jacquelyn; Metzger-Smith, Valerie; He, Yifan; Chen, Jeffrey; Golshan, Shahrokh

    2015-09-01

    Peripheral nerve injury diminishes fast conducting large myelinated afferent fibers transmission but enhances smaller pain transmitting fibers firing. This aberrant afferent neuronal behavior contributes to development of chronic post-traumatic peripheral neuropathic pain (PTP-NP). Non-invasive dynamic magnetic flux stimulation has been implicated in treating PTP-NP, a condition currently not adequately addressed by other therapies including transcutaneous electrical nerve stimulation (TENS). The current study assessed the effect of low frequency transcutaneous magnetic stimulation (LFTMS) on peripheral sensory thresholds, nerve conduction properties, and TENS induced fast afferent slowing effect as measured by motor and sensory conduction studies in the ulnar nerve. Results indicated sham LFTMS with TENS (Sham + TENS) significantly (P = 0.02 and 0.007, respectively) reduces sensory conduction velocity (CV) and increases sensory onset latency (OL), and motor peak latency (PL) whereas, real LFTMS with TENS (Real + TENS) reverses effects of TENS on sensory CV and OL, and significantly (P = 0.036) increases the sensory PL. LFTMS alone significantly (P < 0.05) elevates sensory PL and onset-to-peak latency. LFTMS appears to reverse TENS slowing effect on fast conducting fibers and casts a selective peripheral modulatory effect on slow conducting pain afferent fibers.

  11. Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve

    PubMed Central

    Kent, Alexander R; Grill, Warren M

    2013-01-01

    Objective Electrical stimulation of the pudendal nerve (PN) is being developed as a means to restore bladder function in persons with spinal cord injury. A single nerve cuff electrode placed on the proximal PN trunk may enable selective stimulation of distinct fascicles to maintain continence or evoke micturition. The objective of this study was to design a nerve cuff that enabled selective stimulation of the PN. Approach We evaluated the performance of both flat interface nerve electrode (FINE) cuff and round cuff designs, with a range of FINE cuff heights and number of contacts, as well as multiple contact orientations. This analysis was performed using a computational model, in which the nerve and fascicle cross-sectional positions from five human PN trunks were systematically reshaped within the nerve cuff. These cross-sections were used to create finite element models, with electric potentials calculated and applied to a cable model of a myelinated axon to evaluate stimulation selectivity for different PN targets. Subsequently, the model was coupled to a genetic algorithm (GA) to identify solutions that used multiple contact activation to maximize selectivity and minimize total stimulation voltage. Main results Simulations did not identify any significant differences in selectivity between FINE and round cuffs, although the latter required smaller stimulation voltages for target activation due to preserved localization of targeted fascicle groups. Further, it was found that a 10 contact nerve cuff generated sufficient selectivity for all PN targets, with the degree of selectivity dependent on the relative position of the target within the nerve. The GA identified solutions that increased fitness by 0.7–45.5% over single contact activation by decreasing stimulation of non-targeted fascicles. Significance This study suggests that using an optimal nerve cuff design and multiple contact activation could enable selective stimulation of the human PN trunk for

  12. Model-based analysis and design of nerve cuff electrodes for restoring bladder function by selective stimulation of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Kent, Alexander R.; Grill, Warren M.

    2013-06-01

    Objective. Electrical stimulation of the pudendal nerve (PN) is being developed as a means to restore bladder function in persons with spinal cord injury. A single nerve cuff electrode placed on the proximal PN trunk may enable selective stimulation of distinct fascicles to maintain continence or evoke micturition. The objective of this study was to design a nerve cuff that enabled selective stimulation of the PN. Approach. We evaluated the performance of both flat interface nerve electrode (FINE) cuff and round cuff designs, with a range of FINE cuff heights and number of contacts, as well as multiple contact orientations. This analysis was performed using a computational model, in which the nerve and fascicle cross-sectional positions from five human PN trunks were systematically reshaped within the nerve cuff. These cross-sections were used to create finite element models, with electric potentials calculated and applied to a cable model of a myelinated axon to evaluate stimulation selectivity for different PN targets. Subsequently, the model was coupled to a genetic algorithm (GA) to identify solutions that used multiple contact activation to maximize selectivity and minimize total stimulation voltage. Main results. Simulations did not identify any significant differences in selectivity between FINE and round cuffs, although the latter required smaller stimulation voltages for target activation due to preserved localization of targeted fascicle groups. Further, it was found that a ten contact nerve cuff generated sufficient selectivity for all PN targets, with the degree of selectivity dependent on the relative position of the target within the nerve. The GA identified solutions that increased fitness by 0.7-45.5% over single contact activation by decreasing stimulation of non-targeted fascicles. Significance. This study suggests that using an optimal nerve cuff design and multiple contact activation could enable selective stimulation of the human PN trunk for

  13. Transcutaneous vagus nerve stimulation (t-VNS) in pharmacoresistant epilepsies: a proof of concept trial.

    PubMed

    Stefan, Hermann; Kreiselmeyer, Gernot; Kerling, Frank; Kurzbuch, Katrin; Rauch, Christophe; Heers, Marcel; Kasper, Burkhard S; Hammen, Thilo; Rzonsa, Martina; Pauli, Elisabeth; Ellrich, Jens; Graf, Wolfgang; Hopfengärtner, Rüdiger

    2012-07-01

    To elucidate, in a pilot-study, whether noninvasive transcutaneous vagus nerve stimulation (t-VNS) is a safe and tolerable alternative treatment option in pharmacoresistant epilepsy. t-VNS was applied to 10 patients with pharmacoresistant epilepsies. Stimulation via the auricular branch of the vagus nerve of the left tragus was delivered three times per day for 9 months. Subjective documentation of stimulation effects was obtained from patients' seizure diaries. For a more reliable assessment of seizure frequency, we carried out prolonged outpatient video-electroencephalography (EEG) monitoring. In addition, computerized testing of cognitive, affective, and emotional functions was performed. Three patients aborted the study. Of the remaining seven patients, an overall reduction of seizure frequency was observed in five patients after 9 months of t-VNS. The noninvasive t-VNS stimulation is a safe and well-tolerated method for relatively long periods, and might be an alternative treatment option for patients with epilepsy.

  14. A constant current peripheral nerve stimulator (Neurostim T4). Description, and evaluation in volunteers.

    PubMed

    Pollmaecher, T; Steiert, H; Buzello, W

    1986-12-01

    A pocket-size, battery-powered peripheral nerve stimulator featuring a calibrated constant current floating output (max. 80 mA) was evaluated in unanaesthetized volunteers. Modes of stimulation included continuous 1 Hz, continuous train-of-four every 15 s, and on-demand tetanus (50 Hz per 5 s). Within the limits of 0-250 V, voltage adjusted automatically for 0.2-ms monophasic square pulses. Between 20 and 80 mA, the dial error of current intensity was less than +/- 5%. Maximum allowable resistance for the generation of 40-mA pulses was 5 k omega--that is five times the average tissue impedance as measured in 15 volunteers. With surface electrodes, the current intensity required for maximal indirect muscle stimulation in another 50 individuals was 38 +/- 23 mA (mean +/- SD). With up to 80 mA stimulus current, supramaximal nerve stimulation was obtained in 94% of the volunteers.

  15. Vagus nerve stimulation: Surgical technique of implantation and revision and related morbidity.

    PubMed

    Giordano, Flavio; Zicca, Anna; Barba, Carmen; Guerrini, Renzo; Genitori, Lorenzo

    2017-04-01

    Indications for vagus nerve stimulation (VNS) therapy include focal, multifocal epilepsy, drop attacks (tonic/atonic seizures), Lennox-Gastaut syndrome, tuberous sclerosis complex (TSC)-related multifocal epilepsy, and unsuccessful resective surgery. Surgical outcome is about 50-60% for seizures control, and may also improve mood, cognition, and memory. On this basis, VNS has also been proposed for the treatment of major depression and Alzheimer's' disease. The vagus nerve stimulator must be implanted with blunt technique on the left side to avoid cardiac side effects through the classic approach for anterior cervical discectomy. The actual device is composed of a wire with three helical contacts (two active contacts, one anchoring) and a one-pin battery. VNS is usually started 2 weeks after implantation with recommended settings of stimulation (1.0-2.0 mA; 500 μs pulse width; 20-30 Hz; 30 s ON, 5 min OFF). The complications of VNS therapy are early (related to surgery) and late (related to the device and to stimulation of the vagus nerve). Early complications include the following: intraoperative bradycardia and asystole during lead impedance testing, peritracheal hematoma, infections (3-8%), and vagus nerve injury followed by hoarseness, dyspnea, and dysphagia because of left vocal cord paralysis. Delayed morbidity due to the device includes late infections or problems in wound healing; other more rare events are due to late injury of the nerve. Late complications due to nerve stimulation include delayed arrhythmias, laryngopharyngeal dysfunction (hoarseness, dyspnea, and coughing), obstructive sleep apnea, stimulation of phrenic nerve, tonsillar pain mimicking glossopharyngeal neuralgia, and vocal cord damage during prolonged endotracheal intubation. The laryngopharyngeal dysfunction occurs in about 66% of patients and is usually transitory and due to the stimulation of the inferior (recurrent) laryngeal nerve. A true late paralysis of the left vocal cord

  16. Effects of Asymmetric Superior Laryngeal Nerve Stimulation on Glottic Posture, Acoustics, Vibration

    PubMed Central

    Chhetri, Dinesh K.; Neubauer, Juergen; Bergeron, Jennifer L.; Sofer, Elazar; Peng, Kevin A.; Jamal, Nausheen

    2013-01-01

    Objectives Evaluate the effects of asymmetric superior laryngeal nerve stimulation on the vibratory phase, laryngeal posture, and acoustics. Study Design Basic science study using an in vivo canine model. Methods The superior laryngeal nerves were symmetrically and asymmetrically stimulated over eight activation levels to mimic laryngeal asymmetries representing various levels of superior laryngeal nerve paresis and paralysis conditions. Glottal posture change, vocal fold speed, and vibration of these 64 distinct laryngeal activation conditions were evaluated by high speed video and concurrent acoustic and aerodynamic recordings. Assessments were made at phonation onset. Results Vibratory phase was symmetric in all symmetric activation conditions but consistent phase asymmetry towards the vocal fold with higher superior laryngeal nerve activation was observed. Superior laryngeal nerve paresis and paralysis conditions had reduced vocal fold strain and fundamental frequency. Superior laryngeal nerve activation increased vocal fold closure speed, but this effect was more pronounced for the ipsilateral vocal fold. Increasing asymmetry led to aperiodic and chaotic vibration. Conclusions This study directly links vocal fold tension asymmetry with vibratory phase asymmetry; in particular the side with greater tension leads in the opening phase. The clinical observations of vocal fold lag, reduced vocal range, and aperiodic voice in superior laryngeal paresis and paralysis is also supported. PMID:23712542

  17. Fascicular nerve stimulation and recording using a novel double-aisle regenerative electrode

    NASA Astrophysics Data System (ADS)

    Delgado-Martínez, I.; Righi, M.; Santos, D.; Cutrone, A.; Bossi, S.; D'Amico, S.; Del Valle, J.; Micera, S.; Navarro, X.

    2017-08-01

    Objective. As artificial prostheses become more refined, they are most often used as a therapeutic option for hand amputation. By contrast to extra- or intraneural interfaces, regenerative nerve electrodes are designed to enable electrical interfaces with regrowing axonal bundles of injured nerves, aiming to achieve high selectivity for recording and stimulation. However, most of the developed designs pose an obstacle to the regrowth mechanisms due to low transparency and cause impairment to the nerve regeneration. Approach. Here we present the double-aisle electrode, a new type of highly transparent, non-obstructive regenerative electrode. Using a double-side thin-film polyimide planar multi-contact electrode, two nerve fascicles can regenerate without physical impairment through two electrically isolated aisles. Main results. We show that this electrode can be used to selectively record and stimulate fascicles, acutely as well as chronically, and allow regeneration in nerve gaps of several millimeters without impairment. Significance. This multi-aisle regenerative electrode may be suitable for neuroprosthetic applications, such as prostheses, for the restoration of hand function after amputation or severe nerve injuries.

  18. Effects of asymmetric superior laryngeal nerve stimulation on glottic posture, acoustics, vibration.

    PubMed

    Chhetri, Dinesh K; Neubauer, Juergen; Bergeron, Jennifer L; Sofer, Elazar; Peng, Kevin A; Jamal, Nausheen

    2013-12-01

    Evaluate the effects of asymmetric superior laryngeal nerve stimulation on the vibratory phase, laryngeal posture, and acoustics. Basic science study using an in vivo canine model. The superior laryngeal nerves were symmetrically and asymmetrically stimulated over eight activation levels to mimic laryngeal asymmetries representing various levels of superior laryngeal nerve paresis and paralysis conditions. Glottal posture change, vocal fold speed, and vibration of these 64 distinct laryngeal-activation conditions were evaluated by high speed video and concurrent acoustic and aerodynamic recordings. Assessments were made at phonation onset. Vibratory phase was symmetric in all symmetric activation conditions, but consistent phase asymmetry toward the vocal fold with higher superior laryngeal-nerve activation was observed. Superior laryngeal nerve paresis and paralysis conditions had reduced vocal fold strain and fundamental frequency. Superior laryngeal nerve activation increased vocal fold closure speed, but this effect was more pronounced for the ipsilateral vocal fold. Increasing asymmetry led to aperiodic and chaotic vibration. This study directly links vocal-fold tension asymmetry with vibratory phase asymmetry, in particular the side with greater tension leads in the opening phase. The clinical observations of vocal fold lag, reduced vocal range, and aperiodic voice in superior laryngeal paresis and paralysis is also supported. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  19. Assessing the Firing Properties of the Electrically Stimulated Auditory Nerve Using a Convolution Model.

    PubMed

    Strahl, Stefan B; Ramekers, Dyan; Nagelkerke, Marjolijn M B; Schwarz, Konrad E; Spitzer, Philipp; Klis, Sjaak F L; Grolman, Wilko; Versnel, Huib

    2016-01-01

    The electrically evoked compound action potential (eCAP) is a routinely performed measure of the auditory nerve in cochlear implant users. Using a convolution model of the eCAP, additional information about the neural firing properties can be obtained, which may provide relevant information about the health of the auditory nerve. In this study, guinea pigs with various degrees of nerve degeneration were used to directly relate firing properties to nerve histology. The same convolution model was applied on human eCAPs to examine similarities and ultimately to examine its clinical applicability. For most eCAPs, the estimated nerve firing probability was bimodal and could be parameterised by two Gaussian distributions with an average latency difference of 0.4 ms. The ratio of the scaling factors of the late and early component increased with neural degeneration in the guinea pig. This ratio decreased with stimulation intensity in humans. The latency of the early component decreased with neural degeneration in the guinea pig. Indirectly, this was observed in humans as well, assuming that the cochlear base exhibits more neural degeneration than the apex. Differences between guinea pigs and humans were observed, among other parameters, in the width of the early component: very robust in guinea pig, and dependent on stimulation intensity and cochlear region in humans. We conclude that the deconvolution of the eCAP is a valuable addition to existing analyses, in particular as it reveals two separate firing components in the auditory nerve.

  20. Conduction block induced by high frequency AC stimulation in unmyelinated nerves.

    PubMed

    Joseph, Laveeta; Haeffele, Benjamin D; Butera, Robert J

    2007-01-01

    The potential neurophysiological applications of high frequency AC stimulation (HFAC) in blocking conduction has led to a series of experimental and modeling studies analyzing the effect of HFAC conduction block on mixed nerves. However, many of these computational studies have been based on axon models that are perhaps not valid for the nerves under study. The isolated response of unmyelinated nerves to HFAC has also not been previously studied. In this study, 5-50 kHz sinusoidal HFAC stimulation waveforms were used to reversibly block conduction through the unmyelinated nerve fibers of Aplysia. Unlike myelinated nerves, the minimum HFAC amplitude for blocking conduction in these nerves showed a non-monotonic behavior with frequency. The Hodgkin-Huxley model did not accurately predict the experimentally observed trends but modifying the model to incorporate a frequency-dependent membrane capacitance resulted in a significant change in the high frequency response of the model while still preserving the standard characteristics of action potential propagation.

  1. Electrically conductive biodegradable polymer composite for nerve regeneration: electricity-stimulated neurite outgrowth and axon regeneration.

    PubMed

    Zhang, Ze; Rouabhia, Mahmoud; Wang, Zhaoxu; Roberge, Christophe; Shi, Guixin; Roche, Phillippe; Li, Jiangming; Dao, Lê H

    2007-01-01

    Normal and electrically stimulated PC12 cell cultures and the implantation of nerve guidance channels were performed to evaluate newly developed electrically conductive biodegradable polymer composites. Polypyrrole (PPy) doped by butane sulfonic acid showed a significantly higher number of viable cells compared with PPy doped by polystyrenesulfonate after a 6-day culture. The PC12 cells were left to proliferate for 6 days, and the PPy-coated membranes, showing less initial cell adherence, recorded the same proliferation rate as did the noncoated membranes. Direct current electricity at various intensities was applied to the PC12 cell-cultured conductive membranes. After 7 days, the greatest number of neurites appeared on the membranes with a current intensity approximating 1.7-8.4 microA/cm. Nerve guidance channels made of conductive biodegradable composite were implanted into rats to replace 8 mm of sciatic nerve. The implants were harvested after 2 months and analyzed with immunohistochemistry and transmission electron microscopy. The regenerated nerve tissue displayed myelinated axons and Schwann cells that were similar to those in the native nerve. Electrical stimulation applied through the electrically conductive biodegradable polymers therefore enhanced neurite outgrowth in a current-dependent fashion. The conductive polymers also supported sciatic nerve regeneration in rats.

  2. Can we predict the response in the treatment of epilepsy with vagus nerve stimulation?

    PubMed

    Arcos, A; Romero, L; Gelabert, M; Prieto, A; Pardo, J; Osorio, X Rodriguez; Arráez, M A

    2014-10-01

    Despite the introduction of new antiepileptic drugs and advances in the surgical treatment of epilepsy, an important group of patients still remains uncontrolled by any of these methods. The relatively recent introduction of vagus nerve stimulation is yet another possible treatment for refractory epilepsy. This safe, simple, and adjustable technique reduces the number of seizures and multiple publications support its increasing efficacy and effectiveness, with few adverse effects. The goal of our study is to determine the efficacy of this procedure and the factors predicting a response, particularly in the presence of a temporal lobe discharge on the video electroencephalogram (video-EEG) and magnetic resonance imaging (MRI) lesions. We undertook a retrospective study of all the patients with refractory epilepsy who underwent implantation of a vagus nerve stimulator between 2003 and 2009, and with a minimum follow-up of 6 months. The statistical analysis was done with SPSS for Windows. The stimulator was implanted in 40 patients, of whom 38 had a minimum follow-up of 6 months. In one patient, the device had to be removed due to infection, so the series comprised 37 patients. These were divided into different groups, according to the epidemiologic, clinical, radiologic, and electroencephalographic data. In addition, an analysis of the response was performed. The efficacy of the procedure was established according to the reduction in the mean seizure frequency. The baseline value of these seizures was 80.97 ± 143.59, falling to 37 ± 82.51 at the last revision. The response rate (reduction in seizures ≥ 50 %) at 6 months was 51.4 %, with 62.2 % of the patients showing this reduction at the last evaluation. Significant differences in the response were seen for the variables: baseline frequency of seizures, temporal lobe discharge on VideoEEG and MRI lesions. The mean time to response was 10 months in patients with lower rate of seizures versus 25 months of those

  3. An implantable electrical stimulator used for peripheral nerve rehabilitation in rats

    PubMed Central

    RUI, BIYU; GUO, SHANGCHUN; ZENG, BINGFANG; WANG, JINGWU; CHEN, XIN

    2013-01-01

    This study evaluated an implantable electrical stimulator using a sciatic nerve injury animal model, and ethological, electrophysiological and histological assessments. Forty Sprague-Dawley rats were used in the study, and were subjected to crushing of the right sciatic nerve with a micro-vessel clamp. Electrical stimulators were implanted in twenty of the rats (the implantation group), while the remaining twenty rats were assigned to the control group. At three and six weeks following the surgery, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MCV) were demonstrated to be significantly higher in the implantation group compared with the control group (P<0.05). Histological analysis, using hematoxylin and eosin (H&E) staining, showed the typical pathological atrophy, and an assessment of the nerve that had been crushed revealed distal axonal breakdown in the control group. These results suggest that the implantable electrical stimulator was effective, and was suitable for implantation in a Sprague-Dawley rat model. PMID:23935712

  4. Improvement of depression following transcranial magnetic stimulation.

    PubMed

    George, M S; Nahas, Z; Kozel, F A; Goldman, J; Molloy, M; Oliver, N

    1999-12-01

    Psychiatry as a field was transformed by the discovery and introduction of electroconvulsive therapy (ECT) as a treatment in the early part of this century. ECT demonstrated that depression was a disease of the brain and that it could be treated with a direct brain intervention. Psychiatry's evolution continued in 1958 with the discovery of the antidepressant activity of the monoamine oxidase inhibitors. Interestingly, although the area of neuropsychopharmacology has continued to advance, the realm of physical somatic interventions in psychiatry has lagged behind. With perhaps the exception of light therapy, there were no advances in somatic interventions in psychiatry. However, in 1985, Barker et al. developed a brief high intensity electromagnet capable of depolarizing cortical neurons, called transcranial magnetic stimulation (TMS). There has been much interest in the past 10 years in whether TMS might have antidepressant actions, similar to ECT but without causing a seizure and with no apparent cognitive side effects. This review examines the basic principles underlying TMS, and describes how TMS differs from electrical stimulation and the other uses of magnets.

  5. Radiofrequency energy ablation in a child with an implanted vagus nerve stimulator.

    PubMed

    Radolec, Mackenzy M; Beerman, Lee B; Arora, Gaurav

    2015-10-01

    An 8-year-old girl with supraventricular tachycardia and an implanted vagus nerve stimulator underwent radiofrequency ablation of her supraventricular tachycardia substrate. No known literature exists addressing the potential interaction of these two technologies, although there are reported cases of interaction between radiofrequency and other implanted stimulating devices such as pacemakers. The procedure was performed successfully without observed interaction, and the patient's family reported no significant change in frequency of seizure control.

  6. Pulsed 808-nm infrared laser stimulation of the auditory nerve in guinea pig cochlea.

    PubMed

    Xia, Nan; Wu, Xiao Y; Wang, Xing; Mou, Zong X; Wang, Man Q; Gu, Xin; Zheng, Xiao L; Hou, Wen S

    2014-01-01

    Pulsed near-infrared radiation has been proposed as an alternative stimulus for auditory nerve stimulation and could be potentially used in the design of cochlear implant. Although the infrared with high absorption coefficient of water (i.e., wavelength ranged from 1.8 to 2.2 μm) has been widely investigated, the lymph in the cochlea absorbs most of the infrared energies, and only a small part can arrive at the target auditory nerves. The present study is aimed to test whether the short-wavelength near-infrared irradiation with lower absorption coefficients can penetrate the lymph fluid to stimulate the auditory nerves. An 808-nm near-infrared laser was chosen to stimulate the auditory nerve in the guinea pig cochlea. The infrared pulse was delivered by an optical fiber that was surgically inserted near the round window membrane and oriented toward the spiral ganglion cells in the basal turn of the cochlea. The 2-Hz infrared pulses were used to stimulate the cochlea before and after the deafness with different pulse durations (100-1,000 μs). Optically evoked compound action potentials (oCAPs) were recorded during the infrared radiation. We successfully recorded oCAPs from both normal hearing animals and deafened animals. The oCAP amplitude increased with the infrared radiation energy. The preliminary experiment suggests that the near-infrared with lower absorption coefficients can effectively pass through the lymph filled in the cochlea and stimulate the auditory nerve. Further studies will optimize the deafness animal model and determine the optimal stimulation parameters.

  7. Clinical application of repetitive transcranial magnetic stimulation in stroke rehabilitation☆

    PubMed Central

    Shin, Joonho; Yang, EunJoo; Cho, KyeHee; Barcenas, Carmelo L; Kim, Woo Jin; Min, Yusun; Paik, Nam-Jong

    2012-01-01

    Proper stimulation to affected cerebral hemisphere would promote the functional recovery of patients with stroke. Effects of repetitive transcranial magnetic stimulation on cortical excitability can be can be altered by the stimulation frequency, intensity and duration. There has been no consistent recognition regarding the best stimulation frequency and intensity. This study reviews the intervention effects of repetitive transcranial stimulation on motor impairment, dysphagia, visuospatial neglect and aphasia, and summarizes the stimulation frequency, intensity and area for repetitive transcranial magnetic stimulation to yield the best therapeutic effects. PMID:25745455

  8. Enhanced vascular permeability in rat skin induced by sensory nerve stimulation: evaluation of the time course and appropriate stimulation parameters.

    PubMed

    Carmichael, N M E; Dostrovsky, J O; Charlton, M P

    2008-05-15

    Activation of nociceptors causes them to secrete neuropeptides. The binding of these peptides to receptors on blood vessels causes vasodilation and increased vascular permeability that allows loss of proteins and fluid (plasma extravasation, PE); this contributes to inflammation. This study defines the relationship between electrical activation of nociceptors and PE and evaluates the time course of this response in the skin of rats. We measured the time course and extent of PE by digital imaging of changes in skin reflectance caused by leakage of Evans Blue (EB) dye infused in the circulatory system before stimulation. Stimulation of the exclusively sensory saphenous nerve caused the skin to become dark blue within 2 min due to accumulation of EB. While PE is usually measured after 5-15 min of electrical stimulation, we found that stimulation for only 1 min at 4 Hz produced maximum PE. This response was dependent on the number of electrical stimuli at least for 4 Hz and 8 Hz stimulation rates. Since accumulation of EB in the skin is only slowly reversible, to determine the duration of enhanced vascular permeability we administered EB at various times after electrical stimulation of the saphenous nerve. PE was only observed when EB was infused within 5 min of electrical stimulation but could still be observed 50 min after capsaicin (1%, 25 microl) injection into the hind paw. These findings indicate that enhanced vascular permeability evoked by electrical stimulation persists only briefly after release of neuropeptides from nociceptors in the skin. Therefore, treatment of inflammation by blockade of neuropeptide release and receptors may be more effective than treatments aimed at epithelial gaps. We propose, in models of stimulation-induced inflammation, the use of a short stimulus train.

  9. Transcranial magnetic stimulation after spinal cord injury.

    PubMed

    Awad, Basem I; Carmody, Margaret A; Zhang, Xiaoming; Lin, Vernon W; Steinmetz, Michael P

    2015-02-01

    To review the basic principles and techniques of transcranial magnetic stimulation (TMS) and provide information and evidence regarding its applications in spinal cord injury clinical rehabilitation. A review of the available current and historical literature regarding TMS was conducted, and a discussion of its potential use in spinal cord injury rehabilitation is presented. TMS provides reliable information about the functional integrity and conduction properties of the corticospinal tracts and motor control in the diagnostic and prognostic assessment of various neurological disorders. It allows one to follow the evolution of motor control and to evaluate the effects of different therapeutic procedures. Motor-evoked potentials can be useful in follow-up evaluation of motor function during treatment and rehabilitation, specifically in patients with spinal cord injury and stroke. Although studies regarding somatomotor functional recovery after spinal cord injury have shown promise, more trials are required to provide strong and substantial evidence. TMS is a promising noninvasive tool for the treatment of spasticity, neuropathic pain, and somatomotor deficit after spinal cord injury. Further investigation is needed to demonstrate whether different protocols and applications of stimulation, as well as alternative cortical sites of stimulation, may induce more pronounced and beneficial clinical effects. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. The sweet taste in the calf. II. Glossopharyngeal nerve responses to taste stimulation of the tongue.

    PubMed

    Hård af Segerstad, C H; Hellekant, G

    1989-05-01

    Recordings were obtained from the glossopharyngeal nerve in 1-5-week-old calves during stimulation of the circumvallate tongue area with NaCl, quinine hydrochloride, citric acid, and the sweet compounds: acesulfam-K, aspartame, fructose, galactose, glucose, glycine, lactose, maltose, monellin, Na-saccharin, sucrose, thaumatin, and xylitol. All compounds except aspartame, monellin and thaumatin gave a nerve response. Glycine, followed by Na-saccharin, elicited the largest responses. Sucrose gave the largest response among the disaccharides, while there was no significant difference between the monosaccharides. Expressed as percent of the NaCl responses, the responses to glycine, sucrose, xylitol, fructose, galactose, glucose, lactose and maltose were considerably larger in the glossopharyngeal nerve than in the chorda tympani nerve. This can be taken as an indication that the posterior region of the tongue serves as the major receptive area for sweet in cattle.

  11. Transcutaneous Vagus Nerve Stimulation: A Promising Method for Treatment of Autism Spectrum Disorders.

    PubMed

    Jin, Yu; Kong, Jian

    2016-01