Most Recent Articles Published on Neuromodulation

These articles are generated by an RSS Feed from Pubmed.  WCNeurotech are not responsible for the content of any external links which may be included in the feed.

The prospective evaluation of safety and success of a new method of introducing percutaneous paddle leads and complex arrays with an epidural access system.

Neuromodulation. 2012 Jan;15(1):21-30

Authors: Deer T, Bowman R, Schocket SM, Kim C, Ranson M, Amirdelfan K, Raso L

Abstract
Objectives:? Spinal cord stimulation (SCS) has become a mainstay in the continuum of care for patients suffering from chronic neuropathic pain of the trunk and limbs. Options for placing these devices have included a percutaneous method of using an epidural needle to place a cylindrical (percutaneous) lead to stimulate the spinal cord, or an open laminotomy method for placing a paddle lead at the location of the surgical decompression of the laminae. Both of these methods have been successful in a high percentage of patients, but neither have been ideal. Limitations of the percutaneous leads have been inefficiency of power delivery, inability to achieve desired depth of stimulation in the spinal cord, occasional lead migration and difficulty covering complex pain patterns. Limitations of the paddle lead have been the need for surgical laminotomy, inability to steer the lead once placed, limits on placement in the vicinity of the surgical decompression, and a perceived risk of increased bleeding and trauma to the tissue. These factors have led many minimally invasive spine specialists to seek new options for SCS. This paper presents the initial US experience with a newly approved device to place both paddle leads, and multi-lead arrays into the epidural space via a percutaneous Seldinger-guided approach through a single needle placement. We will both describe the technique and review the outcomes of some of the early cases. Materials and Methods:? After Investigational Review Board clearance, patients consented to data collection in a prospective fashion regarding the use of a new percutaneous epidural introducer (Epiducer, St. Jude Neurological, Minneapolis, MN, USA) to place paddle leads and complex lead arrays. The patients underwent education regarding expectations and risks of the procedure consistent with our normal preoperative period. Patients underwent preoperative anesthesia screening and proper testing as outlined by the Joint Commission on Hospital Accreditation, and were given the opportunity to ask questions concerning the procedure. Once the patient wished to move forward, they were consented using the approved case reporting form and followed during the course of their care. The initial cases were performed in West Virginia with subsequent cases following at the other centers involved in this analysis. The outcomes of this analysis focused on three areas: 1 The technical success in placing the percutaneous sheath. This included the ability to successfully complete: ?? epidural access with a 14-gauge Tuohy needle ?? ability to place a styleted guidewire ?? ability to introduce the introduction system over the wire into the epidural space ?? ability to remove the guidewire and introduction tip leaving the 10-gauge sheath intact 2 The ability to place the desired lead or leads into the epidural space via the percutaneous introduction sheath. 3 The presence of any major adverse event which were defined as: ?? nerve injury ?? paraplegia ?? worsening of baseline pain ?? epidural hematoma ?? epidural infection ?? dural tear ?? dural rent ?? retained device that could not be removed This information was carefully recorded for each implant, and summarized in this communication. Results:? During the initial 30 days of the evaluation period, 43 epidural introduction systems were attempted in 38 patients. In patients in whom more than one paddle lead was placed, the system required the reinsertion of the guidewire through the Epiducer, removal of the Epiducer, and rewiring over the guidewire. This is necessary because the diameter of a paddle lead does not allow two or three leads to be placed without rewiring the system. The success of placement was 42/43, with inability to access the epidural space in one patient in whom ligamentum flavum hypertrophy was present on the preoperative imaging study. In all patients, the system was placed at the L1-L2 level, or lower, based on the Food and Drug Administration labeling. The total numbers of leads placed were 75, with both paddle and percutaneous arrays implanted successfully. There were no adverse events during this prospective surveillance evaluation. Ten patients complained of soreness at the entry site and post-procedure stiffness. These complaints were treated with ice, rest, and analgesics and resolved without incident. Conclusion:? This paper describes the initial US cases of the placement of a paddle lead via a minimally invasive percutaneous method, as well as complex cylindrical arrays with a single needle entry to the epidural space. The device functioned successfully and presented a safe option for placing paddle leads and complex arrays.

PMID: 22296616 [PubMed - in process]

The conflict of safety versus access to new therapies: the FDA, clinical trial design, and neuromodulation.

Neuromodulation. 2012 Jan;15(1):1-4

Authors: Levy RM

PMID: 22296614 [PubMed - in process]

Transaxillary Subpectoral Implantation of Implantable Pulse Generator for Deep Brain Stimulation.

Neuromodulation. 2012 Feb 2;

Authors: Son BC, Han SH, Choi YS, Kim HS, Kim MC, Yang SH, Lee SW

Abstract
Objectives:? Deep brain stimulation (DBS) is an effective modality of treating cardinal motor symptoms of several movement disorders such as Parkinson's disease, essential tremor, and dystonia. Although hardware-related complications of DBS have been reported, the cosmetic satisfaction and discomfort associated with infraclavicular subcutaneous implantation of the pulse generator has not been described. The authors adopted a technique of transaxillary subpectoral implantable pulse generator (IPG) placement and investigated the difference in the discomfort, cosmetic satisfaction, mean operation time for IPG implantation, and severity of postoperative pain between infraclavicular subcutaneous placement and transaxillary subpectoral implantation of IPG. Materials and Methods:? 25 patients who underwent bilateral, infraclavicular subcutaneous IPG placement for DBS and 15 patients who had bilateral, transaxillary subpectoral IPG placement were investigated. Results:? The differences in cosmetic satisfaction and discomfort between the two groups were significant. The cosmetic satisfaction was higher and discomfort was less in the subpectoral IPG implantation group (p?=?0.002 and p?=?0.000). However, more time was needed for IPG implantation, and the postoperative pain was more severe after subpectoral IPG implantation (p?=?0.002 and p?=?0.000). There was no difference in cosmetic satisfaction according to sex (p?=?0.907). There was one transient intercostobrachial nerve injury in the subpectoral IPG implantation group and two infections which needed removal of one side of the DBS hardware in the infraclavicular IPG implantation group. Conclusions:? These results demonstrated that subpectoral transaxillary IPG implantation can provide better cosmetic satisfaction in patients undergoing DBS, with less discomfort and morbidity related to erosion and infection.

PMID: 22300254 [PubMed - as supplied by publisher]

A systematic review on reporting and assessment of adverse effects associated with transcranial direct current stimulation.

Int J Neuropsychopharmacol. 2011 Sep;14(8):1133-45

Authors: Brunoni AR, Amadera J, Berbel B, Volz MS, Rizzerio BG, Fregni F

Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive method of brain stimulation that has been intensively investigated in clinical and cognitive neuroscience. Although the general impression is that tDCS is a safe technique with mild and transient adverse effects (AEs), human data on safety and tolerability are largely provided from single-session studies in healthy volunteers. In addition the frequency of AEs and its relationship with clinical variables is unknown. With the aim of assessing tDCS safety in different conditions and study designs, we performed a systematic review and meta-analysis of tDCS clinical trials. We assessed Medline and other databases and reference lists from retrieved articles, searching for articles from 1998 (first trial with contemporary tDCS parameters) to August 2010. Animal studies, review articles and studies assessing other neuromodulatory techniques were excluded. According to our eligibility criteria, 209 studies (from 172 articles) were identified. One hundred and seventeen studies (56%) mentioned AEs in the report. Of these studies, 74 (63%) reported at least one AE and only eight studies quantified AEs systematically. In the subsample reporting AEs, the most common were, for active vs. sham tDCS group, itching (39.3% vs. 32.9%, p>0.05), tingling (22.2% vs. 18.3%, p>0.05), headache (14.8% vs. 16.2%, p>0.05), burning sensation (8.7% vs. 10%, p>0.05) and discomfort (10.4% vs. 13.4%, p>0.05). Meta-analytical techniques could be applied in only eight studies for itching, but no definite results could be obtained due to between-study heterogeneity and low number of studies. Our results suggested that some AEs such as itching and tingling were more frequent in the tDCS active group, although this was not statistically significant. Although results suggest that tDCS is associated with mild AEs only, we identified a selective reporting bias for reporting, assessing and publishing AEs of tDCS that hinders further conclusions. Based on our findings, we propose a revised adverse effects questionnaire to be applied in tDCS studies in order to improve systematic reporting of tDCS-related AEs.

PMID: 21320389 [PubMed - indexed for MEDLINE]

Deep brain stimulation for movement disorders.

Front Integr Neurosci. 2012;6:2

Authors: Pizzolato G, Mandat T

Abstract
Stereotactic technique and the introduction of deep brain stimulation (DBS) can be considered two milestones in the field of surgical neuromodulation. At present the role of DBS in the treatment of clinically and epidemiologically relevant movement disorders is widely accepted and DBS procedures are performed in many clinical centers worldwide. Here we review the current state of the art of DBS treatment for the most common movement disorders: Parkinson's disease, essential tremor, and dystonia. In this review, we give a brief description of the candidate patient selection criteria, the different anatomical targets for each of these condition, and the expected outcomes as well as possible side effects.

PMID: 22291623 [PubMed - in process]

Timing of posterior parahippocampal gyrus activity reveals multiple scene processing stages.

Hum Brain Mapp. 2012 Jan 30;

Authors: Bastin J, Committeri G, Kahane P, Galati G, Minotti L, Lachaux JP, Berthoz A

Abstract
Posterior parahippocampal gyrus (PPHG) is strongly involved during scene recognition and spatial cognition. How PPHG electrophysiological activity could underlie these functions, and whether they share similar timing mechanisms is unknown. We addressed this question in two intracerebral experiments which revealed that PPHG neural activity dissociated an early stimulus-driven effect (>200 and <500 ms) and a late task-related effect (>600 and <800 ms). Strongest PPHG gamma band (50-150 Hz) activities were found early when subjects passively viewed scenes (scene selectivity effect) and lately when they had to estimate the position of an object relative to the environment (allocentric effect). Based on single trial analyses, we were able to predict when patients viewed scenes (compared to other visual categories) and when they performed allocentric judgments (compared to other spatial judgments). The anatomical location corresponding to the strongest effects was in the depth of the collateral sulcus. Our findings directly affect current theories of visual scene processing and spatial orientation by providing new timing constraints and by demonstrating the existence of separable information processing stages in the functionally defined parahippocampal place area. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc.

PMID: 22287281 [PubMed - as supplied by publisher]

Identifying behavioral circuits in Drosophila melanogaster: moving targets in a flying insect.

Curr Opin Neurobiol. 2012 Jan 27;

Authors: Griffith LC

Abstract
Drosophila melanogaster has historically been the premier model system for understanding the molecular and genetic bases of complex behaviors. In the last decade technical advances, in the form of new genetic tools and electrophysiological and optical methods, have allowed investigators to begin to dissect the neuronal circuits that generate behavior in the adult. The blossoming of circuit analysis in this organism has also reinforced our appreciation of the inadequacy of wiring diagrams for specifying complex behavior. Neuromodulation and neuronal plasticity act to reconfigure circuits on both short and long time scales. These processes act on the connectome, providing context by integrating external and internal cues that are relevant for behavioral choices. New approaches in the fly are providing insight into these basic principles of circuit function.

PMID: 22285110 [PubMed - as supplied by publisher]

Effective Deep Brain Stimulation in Heroin Addiction: A Case Report with Complementary Intracranial Electroencephalogram.

Biol Psychiatry. 2012 Jan 24;

Authors: Valencia-Alfonso CE, Luigjes J, Smolders R, Cohen MX, Levar N, Mazaheri A, van den Munckhof P, Schuurman PR, van den Brink W, Denys D

PMID: 22281120 [PubMed - as supplied by publisher]

Serotonin Modulates Multiple Calcium Current Subtypes in Commissural Interneurons of the Neonatal Mouse.

J Neurophysiol. 2012 Jan 25;

Authors: Abbinanti MD, Harris-Warrick R

Abstract
Calcium currents are critical to the intrinsic properties of neurons and the networks that contain them. These currents make attractive targets for neuromodulation. Here, we examine the serotonergic modulation of specific calcium current subtypes in neonatal (P0-5) intersegmental commissural interneurons (CINs), members of the hindlimb locomotor Central Pattern Generator CPG in the mouse spinal cord. Previous work in our lab showed that serotonin (5-HT) excited CINs in part by reducing a calcium current and thus indirectly reducing the calcium-activated potassium current (Diaz-Rios et al. 2007). We have determined which calcium currents are targets of serotonin modulation. Utilizing whole-cell voltage clamp and toxins to specific calcium current subtypes, we found that N- and P/Q-type currents comprise over 60% of the overall calcium current. Blockade of each of these subtypes alone with either ?-conotoxin GVIA or ?-agatoxin TK was unable to occlude 5-HT's reduction of the calcium current. However, coapplication of both blockers together fully occluded 5-HT's reduction of the calcium current. Thus, 5-HT decreases both N- and P/Q-type calcium current to excite neonatal CINs.

PMID: 22279189 [PubMed - as supplied by publisher]

Echoes from childhood-imitation in Gilles de la Tourette Syndrome.

Mov Disord. 2012 Jan 25;

Authors: Finis J, Moczydlowski A, Pollok B, Biermann-Ruben K, Thomalla G, Heil M, Krause H, Jonas M, Schnitzler A, Münchau A

Abstract
BACKGROUND: Tourette syndrome patients are reported to show automatic imitation (echopraxia), but this has not yet been proven experimentally. METHODS: Video clips showing either tics of other Tourette patients or spontaneous movements of healthy subjects were presented to Tourette patients and healthy subjects. Participants' responses were assessed using blinded review of video recordings by 2 independent raters and related to stimuli presented. RESULTS: Both raters detected more echoes in patients. In a permutation analysis, no healthy subject had echoes above chance level. In contrast, 6 and 5 patients were classified as echoers according to rater 1 and rater 2, respectively, in 1 analysis, and 9 patients were so classified in a second analysis (according to rater 2 only). Concordance between raters was high. Patients echoed both following stimuli showing tics and following stimuli showing spontaneous movements. Most echoes were part of patients' individual tic repertoire. CONCLUSIONS: Echopraxia is a hallmark of Tourette syndrome. © 2012 Movement Disorder Society.

PMID: 22278950 [PubMed - as supplied by publisher]

A novel percutaneous technique to implant plate-type electrodes.

Minim Invasive Neurosurg. 2011 Oct;54(5-6):219-22

Authors: Logé D, De Coster O, Pollet W, Vancamp T

Abstract
In spinal cord stimulation (SCS) mainly 2 distinctive implantation techniques can be recognized: the percutaneous and surgical technique.A puncture is made with a blunt 14 gauge Tuohy needle. Once inside the epidural space the guide wire needs to be advanced in the epidural space, then the Tuohy needle is removed. The Epiducer is advanced under the guidance of lateral fluoroscopy, to confirm epidural entry. The S-series electrode is introduced through the sheet in the epidural space.We present a novel technique to introduce small profile paddle leads (S-SeriesTM: St. Jude Medical - Neuromodulation Division, Plano, TX) in the epidural space via a percutaneous approach using the EpiducerTM (St. Jude Medical - Neuromodulation Division, Plano, TX) lead delivery system.

PMID: 22278783 [PubMed - in process]

Mechanisms of neuromodulation by a nonhypophysiotropic GnRH system controlling motivation of reproductive behavior in the teleost brain.

J Reprod Dev. 2011;57(6):665-74

Authors: Abe H, Oka Y

Abstract
Fine tuning of the nervous system in response to intrinsic and extrinsic cues is necessary for successful reproductive behavior. Gonadotropin releasing hormone (GnRH) was originally identified as a hypophysiotropic hormone that facilitates the release of gonadotropins from the pituitary. Although later studies reported their presence, the nonhypophysiotropic GnRH systems, which consist of two groups located in the terminal nerve (TN) and the midbrain tegmentum, respectively, has long been overshadowed by the hypophysiotropic GnRH system. By taking advantage of the teleost brains in which all three GnRH systems are well developed, the anatomical and electrophysiological properties of all three groups of GnRH neurons have been studied. However, despite our increasing endocrinological knowledge, we know very little about the manner of information flow by nonhypophysiotropic neuromodulatory GnRH neurons in the brain. In this article, we will review recent advances in the studies of nonhypophysiotropic GnRH neurons from cellular to behavioral levels. We will first discuss general features of the information processing by peptides and then introduce our recent approaches toward the understanding of the excitation-secretion coupling mechanism of single GnRH neuron using our newly developed primary culture system of isolated TN-GnRH3 neurons. We also introduce autocrine/paracrine regulation of TN-GnRH3 neurons by NPFF peptides for synchronization among them. In addition, we highlight recent advances in the neuromodulatory action of GnRH peptide on the information processing of sensory neuronal circuits and reproductive behavior. These multidisciplinary approaches will greatly advance our understanding of the complex action of GnRH peptides in relation to the brain control of reproduction.

PMID: 22277963 [PubMed - in process]

A theory of rate coding control by intrinsic plasticity effects.

PLoS Comput Biol. 2012 Jan;8(1):e1002349

Authors: Naudé J, Paz JT, Berry H, Delord B

Abstract
Intrinsic plasticity (IP) is a ubiquitous activity-dependent process regulating neuronal excitability and a cellular correlate of behavioral learning and neuronal homeostasis. Because IP is induced rapidly and maintained long-term, it likely represents a major determinant of adaptive collective neuronal dynamics. However, assessing the exact impact of IP has remained elusive. Indeed, it is extremely difficult disentangling the complex non-linear interaction between IP effects, by which conductance changes alter neuronal activity, and IP rules, whereby activity modifies conductance via signaling pathways. Moreover, the two major IP effects on firing rate, threshold and gain modulation, remain unknown in their very mechanisms. Here, using extensive simulations and sensitivity analysis of Hodgkin-Huxley models, we show that threshold and gain modulation are accounted for by maximal conductance plasticity of conductance that situate in two separate domains of the parameter space corresponding to sub- and supra-threshold conductance (i.e. activating below or above the spike onset threshold potential). Analyzing equivalent integrate-and-fire models, we provide formal expressions of sensitivities relating to conductance parameters, unraveling unprecedented mechanisms governing IP effects. Our results generalize to the IP of other conductance parameters and allow strong inference for calcium-gated conductance, yielding a general picture that accounts for a large repertoire of experimental observations. The expressions we provide can be combined with IP rules in rate or spiking models, offering a general framework to systematically assess the computational consequences of IP of pharmacologically identified conductance with both fine grain description and mathematical tractability. We provide an example of such IP loop model addressing the important issue of the homeostatic regulation of spontaneous discharge. Because we do not formulate any assumptions on modification rules, the present theory is also relevant to other neural processes involving excitability changes, such as neuromodulation, development, aging and neural disorders.

PMID: 22275858 [PubMed - in process]

Design and Validation of a Fully Implantable, Chronic, Closed-Loop Neuromodulation Device With Concurrent Sensing and Stimulation.

IEEE Trans Neural Syst Rehabil Eng. 2012 Jan 23;

Authors: Stanslaski S, Afshar P, Cong P, Giftakis J, Stypulkowski P, Carlson D, Linde D, Ullestad D, Avestruz A, Denison T

Abstract
Chronically implantable, closed-loop neuromodulation devices with concurrent sensing and stimulation hold promise for better understanding the nervous system and improving therapies for neurological disease. Concurrent sensing and stimulation are needed to maximize usable neural data, minimize time delays for closed-loop actuation, and investigate the instantaneous response to stimulation. Current systems lack concurrent sensing and stimulation primarily because of stimulation interference to neural signals of interest. While careful design of high performance amplifiers has proved useful to reduce disturbances in the system, stimulation continues to contaminate neural sensing due to biological effects like tissue-electrode impedance mismatch and constraints on stimulation parameters needed to deliver therapy. In this work we describe systematic methods to mitigate the effect of stimulation through a combination of sensing hardware, stimulation parameter selection, and classification algorithms that counter residual stimulation disturbances. To validate these methods we implemented and tested a completely implantable system for over one year in a large animal model of epilepsy. The system proved capable of measuring and detecting seizure activity in the hippocampus both during and after stimulation. Furthermore, we demonstrate an embedded algorithm that actuates neural modulation in response to seizure detection during stimulation, validating the capability to detect bioelectrical markers in the presence of therapy and titrate it appropriately. The capability to detect neural states in the presence of stimulation and optimally titrate therapy is a key innovation required for generalizing closed-loop neural systems for multiple disease states.

PMID: 22275720 [PubMed - as supplied by publisher]

[Sacral neuromodulation in urology - development and current status].

Aktuelle Urol. 2012 Jan;43(1):39-48

Authors: Schwalenberg T, Stolzenburg JU, Kriegel C, Gonsior A

Abstract
Sacral neuromodulation (SNM) in urology is employed to treat refractory lower urinary tract dysfunction as well as chronic pelvic pain. Electrical stimulation of the sacral afferents (S2?-?S4) causes activation and conditioning of higher autonomic and somatic neural structures and thereby influences the efferents controlling the urinary bladder, the rectum and their related sphincter systems. It is therefore possible to treat overactivity as well as hypocontractility and functional bladder neck obstruction. SNM treatment is conducted biphasically. Initially, test electrodes are placed to evaluate changes in micturition and pain parameters. If, in this first phase - called peripheral nerve evaluation (PNE test) - sufficient improvements are observed, the patient progresses to phase two which involves implantation of the permanent electrodes and impulse generator system. In recent years, the "two stage approach" with initial implantation of the permanent electrodes has been favoured as it increases treatment success rates. Long-term success rates of SNM vary significantly in the literature (50?-?80?%) due to heterogeneous patient populations as well as improved surgical approaches. With the introduction of "tined lead electrodes" (2002), tissue damage is reduced to a minimum. Technical innovation, financial feasibility (reimbursed in Germany since 2004) and wider application, especially in otherwise therapy-refractory patients or complex dysfunctions of the pelvis, have established SNM as a potent treatment option in urology.

PMID: 22271337 [PubMed - in process]

Peripheral nerve stimulation for trigeminal neuropathic pain.

Pain Physician. 2012 Jan;15(1):27-33

Authors: Stidd DA, Wuollet AL, Bowden K, Price T, Patwardhan A, Barker S, Weinand ME, Annabi J, Annabi E

Abstract
Facial pain is a complex disease with a number of possible etiologies. Trigeminal neuropathic pain (TNP) is defined as pain caused by a lesion or disease of the trigeminal branch of the peripheral nervous system resulting in chronic facial pain over the distribution of the injured nerve. First line treatment of TNP includes management with anticonvulsant medication (carbamazepine, phenytoin, gabapentin, etc.), baclofen, and analgesics. TNP, however, can be a condition difficult to adequately treat with medical management alone. Patients with TNP can suffer from significant morbidity as a result of inadequate treatment or the side effects of pharmacologic therapy. TNP refractory to medical management can be considered for treatment with a growing number of invasive procedures. Peripheral nerve stimulation (PNS) is a minimally invasive option that has been shown to effectively treat medically intractable TNP. We present a case series of common causes of TNP successfully treated with PNS with up to a 2 year follow-up. Only one patient required implantation of new electrode leads secondary to electrode migration. The patients in this case series continue to have significant symptomatic relief, demonstrating PNS as an effective treatment option for intractable TNP. Though there are no randomized trials, peripheral neuromodulation has been shown to be an effective means of treating TNP refractory to medical management in a growing number of case series. PNS is a safe procedure that can be performed even on patients that are not optimal surgical candidates and should be considered for patients suffering from TNP that have failed medical management.

PMID: 22270735 [PubMed - in process]

Sensor-driven position-adaptive spinal cord stimulation for chronic pain.

Pain Physician. 2012 Jan;15(1):1-12

Authors: Schultz DM, Webster LR, Kosek P, Dar U, Tan Y, Sun M

Abstract
BACKGROUND: Variation in the intensity of neurostimulation due to body position is a practical problem for many patients implanted with spinal cord stimulation (SCS) systems because positional changes may result in overstimulation or understimulation that leads to frequent need for compensatory manual programming adjustments.
OBJECTIVES: The purpose of this study was to assess the safety and effectiveness of a novel type of SCS therapy designed to automatically adapt stimulation amplitude in response to changes in a patient's position or activity.The primary objective of the study was to demonstrate that automatic position adaptive SCS benefited patients in terms of pain relief and/or convenience compared with neurostimulation adjusted with conventional manual programming. Secondary objectives included assessment of worsened pain relief with automatic adjustment; change in pain score; and the number of manual programming adjustments with position-adaptive neurostimulation compared with manual programming.
STUDY DESIGN: Prospective, multicenter, open-label, randomized crossover study.
SETTING: Ten interventional pain management centers in the US.
METHODS: Patients were enrolled a minimum of one week after a successful SCS screening trial. They were then implanted with the RestoreSensor neurostimulation device (Medtronic, Inc., Minneapolis, MN) that could be programmed to either automatic position-adaptive stimulation (AdaptiveStim) or manual adjustment of stimulation parameters. After implant, all devices were programmed to conventional manual adjustment for a 4-week postoperative period. The patients were then randomized to either conventional manual programming adjustment or position-adaptive stimulation with crossover to the opposite treatment arm occurring at 6 weeks after randomization. The patients were followed for another 6 weeks after crossover. This study was conducted under an FDA-approved Investigational Device Exemption (IDE) and approval of the responsible Institutional Review Boards (IRBs) of the study centers.
RESULTS: Seventy-nine patients were enrolled in the study. In an intent-to-treat analysis, 86.5% of patients achieved the primary objective of improved pain relief with no loss of convenience or improved convenience with no loss of pain relief using automatic position-adaptive stimulation compared with using conventional manual programming adjustment alone. This was statistically significantly greater than the predefined minimum success rate of 25%, p < 0.001 (exact one-sided 97.5% lower confidence limit was 76.5%). Only 2.8% of patients reported worsened pain relief during position-adaptive stimulation compared with manual programming. There was a statistically significant reduction in the mean numeric pain rating scale score compared with baseline scores in both treatment arms. Additionally, position-adaptive stimulation demonstrated a statistically significant 41% reduction in the daily average number of programming button presses for amplitude adjustment compared with manual programming (18.2 per day versus 30.7 per day, P = 0.002). Functional improvements reported with position-adaptive stimulation included: improved comfort during position changes (80.3%); improved activity (69%); and improved sleep (47.9%). Adverse events associated with uncomfortable sensations from stimulation did not differ significantly between treatment arms. The incidence of device-related serious adverse events was 3.9%.
LIMITATIONS: Patients and physicians were not blinded to whether devices were programmed to automatic position-adaptive stimulation or manual adjustment. Responses to assessment questionnaires were based on patient recall.
CONCLUSIONS: The study demonstrated that automatic position-adaptive stimulation is safe and effective in providing benefits in terms of patient-reported improved pain relief and convenience compared with using manual programming adjustment alone. Clinical Trial: NCT01106404.

PMID: 22270733 [PubMed - in process]

[The future of invasive neuromodulation : New techniques and expanded indications.]

Urologe A. 2012 Jan 21;

Authors: van Ophoven A, Pannek J

Abstract
Due to the increasing popularity of neuromodulation, the number of indications and patient groups to which this technique is offered is also increasing. We evaluated the currently available data concerning neuromodulation in geriatric patients, children and patients with spinal cord injury and potential alternatives regarding neural targets and implantation techniques.The evidence of the use of neuromodulation in these patient groups is low. In geriatric patients, the use of neuromodulation seems to be justified. The few existing results concerning neuromulation in children are positive; however, there are no data about long term effects of neuromodulation on the growing organism. In patients with spinal cord injury, neuromodulation by microsurgical nerve anastomosis does not seem to be successful. According to the preliminary data of a single study, neuromodulation in acute spinal cord injury may prevent development of a neurogenic bladder dysfunction. The laparoscopic implantation of electrodes for neuromodulation unfolds new technical opportunities; however, until today there is no proof of the efficacy of this technique. Pudendal neuromodulation appears to be a meaningful addition to the therapeutic armamentarium for selected indications.The existing studies demonstrate the future opportunities of neuromodulation also in geriatric patients, children and patientens with spinal cord injuries. However, especially in the latter two groups, further studies concerning effectiveness and long term consequences are mandatory prior to offering these techniques to patients in everyday practise.

PMID: 22269995 [PubMed - as supplied by publisher]

[Sacral neuromodulation for neurogenic bladder dysfunction.]

Urologe A. 2012 Jan 25;

Authors: Kessler TM, Wöllner J, Kozomara M, Mordasini L, Mehnert U

Abstract
Sacral neuromodulation (SNM) represents a promising option for managing treatment-refractory neurogenic bladder dysfunction. It remains to be seen, however, which types of neurogenic bladder dysfunction and which underlying neurological disorders best respond to SNM. Constant improvements in SNM have been achieved and it is now a minimally invasive approach performed under local anesthesia which should be considered before undertaking larger reconstructive procedures. An electrode is implanted in the S3 or S4 sacral foramen and during a test phase lasting for days to weeks the patient keeps a bladder diary to determine whether SNM has provided a relevant benefit. If the results of the test phase are positive, a neuromodulator is implanted in the gluteal area (or more rarely in the abdominal wall).The mechanism of action of SNM has not been completely clarified, but the afferent nerves most likely play a key role. It appears that SNM produces a modulation of medullary reflexes and brain centers by peripheral afferents. The implanted neuromodulation system does not lead to limitation of the patient's activities. However, it should be noted that high-frequency diathermy and unipolar electrocauterization are contraindicated in patients with neuromodulators, that during extracorporeal shock wave lithotripsy the focal point should not be in the direct vicinity of the neuromodulator or the electrode, that ultrasound and radiotherapy in the region of the implanted components should be avoided, that the neuromodulation should be discontinued in pregnancy, and that MRI examinations should only be conducted when urgently indicated and the neuromodulator is turned off.

PMID: 22269992 [PubMed - as supplied by publisher]

A unique approach to severe constipation.

Urol Nurs. 2011 Nov-Dec;31(6):348-50

Authors: Atnip S, Schaffer JI

Abstract
Sacral neuromodulation used for urge urinary incontinence, urgency-frequency, and nonobstructive urinary retention, has incidentally been noted to normalize bowel function. This 48-year old female with severe constipation who had failed all conservative treatment measures returned to normal defecatory function after sacral neuromodulation under the supervision of a nurse practitioner.

PMID: 22263442 [PubMed - in process]

Effects of stimulation site and stimulation parameters on bladder inhibition by electrical nerve stimulation.

BJU Int. 2012 Jan 19;

Authors: Snellings AE, Grill WM

Abstract
What's known on the subject? and What does the study add? Electrical stimulation of the dorsal nerve of the penis, the compound pudendal nerve and the S1 sacral nerve have been used clinically to treat the symptoms of overactive bladder, but the relative efficacy of the three locations was unclear and the optimal stimulation parameters across locations had not been determined. In the present paper we quantified the effects of acute electrical stimulation location, frequency and amplitude on isovolumetric reflex bladder contractions and maximum cystometric capacity in anaesthetized male cats. Our results could influence the selection of anatomical targets for clinical neuromodulation and how neuromodulation devices are programmed. OBJECTIVE: ?? To quantify the effects of acute electrical stimulation frequency and amplitude at the dorsal nerve of the penis (DNP), pudendal nerve (PN) and S1 sacral nerve (S1) on isovolumetric reflex bladder contractions and maximum cystometric capacity in anaesthetized male cats. MATERIALS AND METHODS: ?? Experiments were conducted in 14 adult male cats anaesthetized with ?-chloralose. ?? The effects of stimulation on the pressure - time integral of reflex bladder contractions were evaluated using a randomized block design with the following factors randomized: stimulation intensity (0.8, 1, or 2× the threshold for evoking a reflex electromyogram response in the external anal sphincter [T]), frequency (2?Hz, 5?Hz, 7.5?Hz, 10?Hz, 15?Hz, 20?Hz, or 33?Hz) and location (PN, S1 or DNP). ?? The effects of stimulation (with parameters that produced maximum inhibition of isovolumetric bladder contractions) on cystometric capacity were evaluated using a randomized block design, with the order of stimulation location randomized and control trials interleaved with stimulation trials. RESULTS: ?? Inhibition of isovolumetric bladder contractions was significantly dependent on stimulation location, frequency, amplitude and the interactions between any two of these variables. ?? Stimulation of the DNP, at 5?Hz, 7.5?Hz or 10?Hz, and at 2T caused greater reductions in normalized bladder contraction area than any other location, frequency or amplitude tested. ?? Stimulation of the PN or S1 at 7.5?Hz or 10?Hz and 2T, or of the DNP at 5?Hz, 7.5?Hz or 10?Hz and 0.8T, 1T or 2T generated maximum inhibition of isovolumetric bladder contractions. ?? Cystometric capacity was significantly larger with stimulation (10?Hz, 1T-2T) than control. ?? There was no significant difference in cystometric capacity based upon stimulation location. CONCLUSIONS: ?? There was no significant difference in the maximum degree to which the respective optimum parameters inhibited bladder contractions or increased cystometric capacity by location. ?? The range of amplitudes and frequencies that caused maximum inhibition was larger for DNP stimulation than for PN or S1 stimulation. ?? These findings have implications on the selection of anatomical target and device programming for clinical neuromodulation for treatment of the symptoms of overactive bladder.

PMID: 22260212 [PubMed - as supplied by publisher]

Mild traumatic brain injury.

Eur J Neurol. 2012 Feb;19(2):191-198

Authors: Vos PE, Alekseenko Y, Battistin L, Ehler E, Gerstenbrand F, Muresanu DF, Potapov A, Stepan CA, Traubner P, Vecsei L, von Wild K

PMID: 22260187 [PubMed - as supplied by publisher]

Successful Treatment of Testicular Pain With Peripheral Nerve Stimulation of the Cutaneous Branch of the Ilioinguinal and Genital Branch of the Genitofemoral Nerves.

Neuromodulation. 2012 Jan 18;

Authors: Rosendal F, Moir L, de Pennington N, Green AL, Aziz TZ

Abstract
Objectives:? To assess the effect of peripheral nerve stimulation on neuropathic testicular pain. Material and Methods:? A 30-year-old man with a four-year history of chronic testicular pain following scrotal hydrocele surgery had two percutaneous leads implanted in his groin and low-frequency stimulation of the cutaneous branch of the ilioinguinal and genital branch of the genitofemoral nerves. Result:? At seven-month follow-up, the pain intensity had declined from 9/10 to 2/10 on the numeric rating scale. Conclusion:? We report the successful implantation of an ilioinguinal and genitofemoral nerve stimulator for sustained suppression of intractable neuropathic testicular pain.

PMID: 22257117 [PubMed - as supplied by publisher]

Approaches to optical neuromodulation from rodents to non-human primates by integrated optoelectronic devices.

Conf Proc IEEE Eng Med Biol Soc. 2011 Aug;2011:7525-8

Authors: Wang J, Ozden I, Diagne M, Wagner F, Borton D, Brush B, Agha N, Burwell R, Sheinberg D, Diester I, Deisseroth K, Nurmikko A

Abstract
Methods on rendering neurons in the central nervous system to be light responsive has led to a boom in using optical neuromodulation as a new approach for controlling brain states and understanding neural circuits. In addition to the developing versatility to "optogenetically" labeling of neural cells and their subtypes by microbiological methods, parallel efforts are under way to design and implement optoelectronic devices to achieve simultaneous optical neuromodulation and electrophysiological recording with high spatial and temporal resolution. Such new device-based technologies need to be developed for full exploitation of the promise of optogenetics. In this paper we present single- and multi-element optoelectronic devices developed in our laboratories. The single-unit element, namely the coaxial optrode, was utilized to characterize the neural responses in optogenetically modified rodent and primate models. Furthermore, the multi-element device, integrating the optrode with a 6×6 microelectrode array, was used to characterize the spatiotemporal spread of neural activity in response to single-site optical stimulation in freely moving rats. We suggest that the particular approaches we employed can lead to the emergence of methods where spatio-temporal optical modulation is integrated with real-time read out from neural populations.

PMID: 22256079 [PubMed - in process]

Emerging technology for advancing the treatment of epilepsy using a dynamic control framework.

Conf Proc IEEE Eng Med Biol Soc. 2011 Aug;2011:753-6

Authors: Stanslaski S, Giftakis J, Stypulkowski P, Carlson D, Afshar P, Cong P, Denison T

Abstract
We briefly describe a dynamic control system framework for neuromodulation for epilepsy, with an emphasis on its practical challenges and the preliminary validation of key prototype technologies in a chronic animal model. The current state of neuromodulation can be viewed as a classical dynamic control framework such that the nervous system is the classical "plant", the neural stimulator is the controller/actuator, clinical observation, patient diaries and/or measured bio-markers are the sensor, and clinical judgment applied to these sensor inputs forms the state estimator. Technology can potentially address two main factors contributing to the performance limitations of existing systems: "observability," the ability to observe the state of the system from output measurements, and "controllability," the ability to drive the system to a desired state. In addition to improving sensors and actuator performance, methods and tools to better understand disease state dynamics and state estimation are also critical for improving therapy outcomes. We describe our preliminary validation of key "observability" and "controllability" technology blocks using an implanted research tool in an epilepsy disease model. This model allows for testing the key emerging technologies in a representative neural network of therapeutic importance. In the future, we believe these technologies might enable both first principles understanding of neural network behavior for optimizing therapy design, and provide a practical pathway towards clinical translation.

PMID: 22254420 [PubMed - in process]

Advancing neuromodulation using a dynamic control framework.

Conf Proc IEEE Eng Med Biol Soc. 2011 Aug;2011:671-4

Authors: Afshar P, Wei X, Lazarewicz M, Gupta R, Molnar G, Denison T

Abstract
The current state of neuromodulation can be cast in a classical dynamic control framework such that the nervous system is the classical "plant", the neural stimulator is the controller, tools to collect clinical data are the sensors, and the physician's judgment is the state estimator. This framework characterizes the types of opportunities available to advance neuromodulation. In particular, technology can potentially address two dominant factors limiting the performance of the control system: "observability," the ability to observe the state of the system from output measurements, and "controllability," the ability to drive the system to a desired state using control actuation. Improving sensors and actuation methods are necessary to address these factors. Equally important is improving state estimation by understanding the neural processes underlying diseases. Development of enabling technology to utilize control theory principles facilitates investigations into improving intervention as well as research into the dynamic properties of the nervous system and mechanisms of action of therapies. In this paper, we provide an overview of the control system framework for neuromodulation, its practical challenges, and investigational devices applying this framework for limited applications. To help motivate future efforts, we describe our chronically implantable, low-power neural stimulation system, which integrates sensing, actuation, and state estimation. This research system has been implanted and used in an ovine to address novel research questions.

PMID: 22254398 [PubMed - in process]

Precise temporal association between cortical potentials evoked by motor imagination and afference induces cortical plasticity.

J Physiol. 2012 Jan 16;

Authors: Mrachacz-Kersting N, Kristensen SR, Niazi IK, Farina D

Abstract
In monkeys, the repeated activation of somatosensory afferents projecting onto the motor cortex (M1) has a pivotal role in motor skill learning. Here we investigate if sensory feedback that is artificially generated at specific times during imagination of a dorsiflexion task leads to reorganization of the human M1. The common peroneal nerve was stimulated to generate an afferent volley timed to arrive during specific phases of the cortical potential generated when a movement was imagined (50 repetitions). The change in the output of M1 was quantified by applying single transcranial magnetic stimuli to the area of M1 controlling the tibialis anterior muscle. The results demonstrated that the concomitance between the cognitive process of movement (motor imagination) and the ascending volley due to the peripheral nerve stimulation can lead to significant increases in cortical excitability. These increases were critically dependent on the timing between the peripherally generated afferent volley and the cortical potential generated during the imagined movement. Only if the afferent volley arrived during the peak negative deflection of the potential, were significant alterations in motor cortical output attained. These results are the first to demonstrate that an artificially generated signal (the peripheral afferent volley) can interact with a physiologically generated signal in humans leading to plastic changes within the M1, the final output stage for movement generation within the human brain. The results presented may have implications in systems for artificially inducing cortical plasticity in patients with motor impairments (neuromodulation).

PMID: 22250210 [PubMed - as supplied by publisher]

Vitamin D in the New Millennium.

Curr Osteoporos Rep. 2012 Jan 17;

Authors: Wimalawansa SJ

Abstract
The incidence of vitamin D deficiency is rising worldwide, yet in the vast majority of patients, the condition remains undiagnosed and untreated. Current evidence overwhelmingly indicates that supplemental doses greater than 800 IU/day have beneficial effects on the musculoskeletal system, improving skeletal homeostasis, thus leading to fewer falls and fractures. Evidence is also accumulating on the beneficial effects of vitamin D on extraskeletal systems, such as improving immune health, autoimmune disorders, cancer, neuromodulation, diabetes, and metabolic syndrome. The cause-effect relationship of vitamin D deficiency with increasing incidences of nonskeletal disorders is being investigated. Published reports support the definition of sufficiency, serum levels of 25-hydroxyvitamin D [25(OH)D] greater than 30 ng/mL (75 nmol/L). To achieve this, most people need vitamin D supplementation ranging from 600 to 2000 IU/day; consumption up to of 5000 international units (IU) per day of vitamin D is reported as safe. Although light-skinned individuals need 1000 IU/day of vitamin D, elderly and dark-skinned individuals are likely to need approximately 2000 IU/day to maintain serum 25(OH)D levels greater than 30 ng/mL. Other vulnerable patients, such as the obese, those who have undergone bariatric surgery, and those with gastrointestinal malabsorption syndromes, may require higher doses of vitamin D to maintain normal serum levels and be healthy.

PMID: 22249582 [PubMed - as supplied by publisher]

Prefrontal neuromodulation by nicotinic receptors for cognitive processes.

Psychopharmacology (Berl). 2012 Jan 18;

Authors: Dos Santos Coura R, Granon S

Abstract
RATIONALE: The prefrontal cortex (PFC) mediates executive functions, a set of control processes that optimize performance on cognitive tasks. It enables appropriate decision-making and mediates adapted behaviors, all processes impaired in psychiatric or degenerative disorders. Key players of normal functioning of the PFC are neurotransmitter (NT) systems arising from subcortical nuclei and targeting PFC subareas and, also, neuronal nicotinic acetylcholine receptors (nAChRs). These ion channels, located on multiple cell compartments in all brain areas, mediate direct cholinergic transmission and modulate the release of NTs that cross onto PFC neurons or interneurons. OBJECTIVE: We compiled current knowledge concerning the role of nAChRs in NT release, focusing on the PFC. We point out plausible mechanisms of interaction among PFC circuits implicated in executive functions and emphasized the role of ?2-containing nAChRs, the high-affinity receptors for acetylcholine (ACh). These receptors are more directly implicated in behavioral flexibility either when located on PFC neurons or in the monoaminergic or cholinergic systems targeting the PFC. RESULTS: We shed light on potentially crucial roles played by nAChRs in complex interactions between local and afferent NTs. We show how they could act on cognition via PFC networks. CONCLUSIONS: nAChRs are crucial for decision-making, during integration of emotional and motivational features, both mediated by different NT pathways in the PFC. We review the knowledge recently gained on cognitive functions in mice and our current understanding of PFC NT modulation. The combination of these data is expected to provide new hypotheses concerning the role of AChRs in cognitive processes.

PMID: 22249358 [PubMed - as supplied by publisher]

Reversible, hyperacute allodynia after evacuation of a cervical epidural hematoma.

J Pain Symptom Manage. 2012 Feb;43(2):e9-e11

Authors: Bonicalzi V, Graziano A, Roero C, Canavero S

PMID: 22248795 [PubMed - in process]

Page Last Updated : 23-11-2011