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Sample records for electrical brain stimulation

  1. Deep Brain Electrical Stimulation in Epilepsy

    NASA Astrophysics Data System (ADS)

    Rocha, Luisa L.

    2008-11-01

    The deep brain electrical stimulation has been used for the treatment of neurological disorders such as Parkinson's disease, chronic pain, depression and epilepsy. Studies carried out in human brain indicate that the application of high frequency electrical stimulation (HFS) at 130 Hz in limbic structures of patients with intractable temporal lobe epilepsy abolished clinical seizures and significantly decreased the number of interictal spikes at focus. The anticonvulsant effects of HFS seem to be more effective in patients with less severe epilepsy, an effect associated with a high GABA tissue content and a low rate of cell loss. In addition, experiments using models of epilepsy indicate that HFS (pulses of 60 μs width at 130 Hz at subthreshold current intensity) of specific brain areas avoids the acquisition of generalized seizures and enhances the postictal seizure suppression. HFS is also able to modify the status epilepticus. It is concluded that the effects of HFS may be a good strategy to reduce or avoid the epileptic activity.

  2. Electrical engram: how deep brain stimulation affects memory.

    PubMed

    Lee, Hweeling; Fell, Jürgen; Axmacher, Nikolai

    2013-11-01

    Deep brain stimulation (DBS) is a surgical procedure involving implantation of a pacemaker that sends electric impulses to specific brain regions. DBS has been applied in patients with Parkinson's disease, depression, and obsessive-compulsive disorder (among others), and more recently in patients with Alzheimer's disease to improve memory functions. Current DBS approaches are based on the concept that high-frequency stimulation inhibits or excites specific brain regions. However, because DBS entails the application of repetitive electrical stimuli, it primarily exerts an effect on extracellular field-potential oscillations similar to those recorded with electroencephalography. Here, we suggest a new perspective on how DBS may ameliorate memory dysfunction: it may enhance normal electrophysiological patterns underlying long-term memory processes within the medial temporal lobe. PMID:24126128

  3. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks. PMID:24967698

  4. Giovanni Aldini: from animal electricity to human brain stimulation.

    PubMed

    Parent, André

    2004-11-01

    Two hundred years ago, Giovanni Aldini published a highly influential book that reported experiments in which the principles of Luigi Galvani (animal electricity) and Alessandro Volta (bimetallic electricity) were used together for the first time. Aldini was born in Bologna in 1762 and graduated in physics at the University of his native town in 1782. As nephew and assistant of Galvani, he actively participated in a series of crucial experiments with frog's muscles that led to the idea that electricity was the long-sought vital force coursing from brain to muscles. Aldini became professor of experimental physics at the University of Bologna in 1798. He traveled extensively throughout Europe, spending much time defending the concept of his discreet uncle against the incessant attacks of Volta, who did not believe in animal electricity. Aldini used Volta's bimetallic pile to apply electric current to dismembered bodies of animals and humans; these spectacular galvanic reanimation experiments made a strong and enduring impression on his contemporaries. Aldini also treated patients with personality disorders and reported complete rehabilitation following transcranial administration of electric current. Aldini's work laid the ground for the development of various forms of electrotherapy that were heavily used later in the 19th century. Even today, deep brain stimulation, a procedure currently employed to relieve patients with motor or behavioral disorders, owes much to Aldini and galvanism. In recognition of his merits, Aldini was made a knight of the Iron Crown and a councillor of state at Milan, where he died in 1834. PMID:15595271

  5. Visualizing Simulated Electrical Fields from Electroencephalography and Transcranial Electric Brain Stimulation: A Comparative Evaluation

    PubMed Central

    Eichelbaum, Sebastian; Dannhauer, Moritz; Hlawitschka, Mario; Brooks, Dana; Knösche, Thomas R.; Scheuermann, Gerik

    2014-01-01

    Electrical activity of neuronal populations is a crucial aspect of brain activity. This activity is not measured directly but recorded as electrical potential changes using head surface electrodes (electroencephalogram - EEG). Head surface electrodes can also be deployed to inject electrical currents in order to modulate brain activity (transcranial electric stimulation techniques) for therapeutic and neuroscientific purposes. In electroencephalography and noninvasive electric brain stimulation, electrical fields mediate between electrical signal sources and regions of interest (ROI). These fields can be very complicated in structure, and are influenced in a complex way by the conductivity profile of the human head. Visualization techniques play a central role to grasp the nature of those fields because such techniques allow for an effective conveyance of complex data and enable quick qualitative and quantitative assessments. The examination of volume conduction effects of particular head model parameterizations (e.g., skull thickness and layering), of brain anomalies (e.g., holes in the skull, tumors), location and extent of active brain areas (e.g., high concentrations of current densities) and around current injecting electrodes can be investigated using visualization. Here, we evaluate a number of widely used visualization techniques, based on either the potential distribution or on the current-flow. In particular, we focus on the extractability of quantitative and qualitative information from the obtained images, their effective integration of anatomical context information, and their interaction. We present illustrative examples from clinically and neuroscientifically relevant cases and discuss the pros and cons of the various visualization techniques. PMID:24821532

  6. [Interest of EEG recording during direct electrical stimulation for brain mapping function in surgery].

    PubMed

    Trebuchon, A; Guye, M; Tcherniack, V; Tramoni, E; Bruder, N; Metellus, P

    2012-06-01

    Brain tumor surgery is at risk when lesions are located in eloquent areas. The interindividual anatomo-functional variability of the central nervous system implies that brain surgery within eloquent regions may induce neurological sequelae. Brain mapping using intraoperative direct electrical stimulation in awake patients has been for long validated as the standard for functional brain mapping. Direct electrical stimulation inducing a local transient electrical and functional disorganization is considered positive if the task performed by the patient is disturbed. The brain area stimulated is then considered as essential for the function tested. However, the exactitude of the information provided by this technique is cautious because the actual impact of cortical direct electrical stimulation is not known. Indeed, the possibility of false negative (insufficient intensity of the stimulation due to the heterogeneity of excitability threshold of different cortical areas) or false positive (current spread, interregional signal propagation responsible for remote effects, which make difficult the interpretation of positive or negative behavioural effects) constitute a limitation of this technique. To improve the sensitivity and specificity of this technique, we used an electrocorticographic recording system allowing a real time visualization of the local. We provide here evidence that direct cortical stimulation combined with electrocorticographic recording could be useful to detect remote after discharge and to adjust stimulation parameters. In addition this technique offers new perspective to better assess connectivity of cerebral networks. PMID:22683402

  7. Manganese-enhanced MR imaging of brain activation evoked by noxious peripheral electrical stimulation.

    PubMed

    Cha, Myeounghoon; Lee, Kyuhong; Lee, Chulhyun; Cho, Jee-Hyun; Cheong, Chaejoon; Sohn, Jin-Hun; Lee, Bae Hwan

    2016-02-01

    As imaging technology develops, magnetic resonance imaging (MRI) has furthered our understanding of brain function by clarifying the anatomical structure and generating functional imaging data related to information processing in pain conditions. Recent studies have reported that manganese (Mn(2+))-enhanced MRI (MEMRI) provides valuable information about the functions of the central nervous system. The aim of this study was to identify specific brain regions activated during noxious electric stimulation using high-resolution MEMRI. Male Sprague Dawley rats were divided into three groups: naïve, sham electrical stimulation, and noxious electric stimulation. Under urethane with α-chloralose mixture anesthesia, a catheter was placed in the external carotid artery to administrate 20% mannitol and manganese chloride (25mM MnCl2). Noxious electric stimulation (2Hz, 10V) was applied to the hind paw with a needle electrode. Stimulation-induced neuronal activation was detected using 4.7-T MRI. In response to noxious electrical stimulation, remarkable Mn(2+)-enhanced signals were observed in the agranular insular cortex, auditory cortex, primary somatosensory cortex of the hind limb, and granular and dysgranular insular cortex, which correspond to sensory tactile electric stimulus to the hindpaws. These results indicate that the combination of MEMRI with activity-induced Mn(2+)-dependent contrast can delineate functional areas in the rat brain. PMID:26733299

  8. Deep brain stimulation

    MedlinePlus

    ... the brain The neurostimulator, which puts out the electric current. The stimulator is similar to a heart pacemaker . It is usually placed under the skin near the collarbone, but may be ... pulses travel from the neurostimulator, along the extension ...

  9. Invasive and transcranial photoacoustic imaging of the vascular response to brain electrical stimulation

    NASA Astrophysics Data System (ADS)

    Tsytsarev, Vassiliy; Yao, Junjie; Hu, Song; Li, Li; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2010-02-01

    Advances in the brain functional imaging greatly facilitated the understanding of neurovascular coupling. For monitoring of the microvascular response to the brain electrical stimulation in vivo we used optical-resolution photoacoustic microscopy (OR-PAM) through the cranial openings as well as transcranially. Both types of the vascular response, vasoconstriction and vasodilatation, were clearly observed with good spatial and temporal resolution. Obtained results confirm one of the primary points of the neurovascular coupling theory that blood vessels could present vasoconstriction or vasodilatation in response to electrical stimulation, depending on the balance between inhibition and excitation of the different parts of the elements of the neurovascular coupling system.

  10. Influence of air ions on brain activity induced by electrical stimulation in the rat

    NASA Astrophysics Data System (ADS)

    Olivereau, J. M.; Lambert, J. F.; Truong-Ngoc, A.

    1981-03-01

    The brain induced activity was studied in 18 rats wearing chronically skull implanted electrodes. The stimulating factor was various electrical stimulations of the mesencephalic reticular activating formation, given during the slow wave state of sleep. The results of 300 stimulations were measured by amplitude and frequency changes in the EEG simultaneously recorded. Animals previously exposed to positive air ions (3 weeks 80,000 ions/ml) exhibited lowered excitability of the reticulocortical system. Significantly higher stimulations were necessary to induce arousal. Negative air ions induced more intricate effects: brain excitability was lowered when tested with weak stimulations, but normal when evaluated with medium high level stimilations. Sleep seems first more stable but as stimulation increases, arousal is soon as effective as in controls. These results are in agreement with others findings in behavioral fields and partly explains them.

  11. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation.

    PubMed

    Pais-Vieira, Miguel; Yadav, Amol P; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A L

    2016-01-01

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders. PMID:27605389

  12. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation

    PubMed Central

    Pais-Vieira, Miguel; Yadav, Amol P.; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A. L.

    2016-01-01

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders. PMID:27605389

  13. A reliable method for intracranial electrode implantation and chronic electrical stimulation in the mouse brain

    PubMed Central

    2013-01-01

    Background Electrical stimulation of brain structures has been widely used in rodent models for kindling or modeling deep brain stimulation used clinically. This requires surgical implantation of intracranial electrodes and subsequent chronic stimulation in individual animals for several weeks. Anchoring screws and dental acrylic have long been used to secure implanted intracranial electrodes in rats. However, such an approach is limited when carried out in mouse models as the thin mouse skull may not be strong enough to accommodate the anchoring screws. We describe here a screw-free, glue-based method for implanting bipolar stimulating electrodes in the mouse brain and validate this method in a mouse model of hippocampal electrical kindling. Methods Male C57 black mice (initial ages of 6–8 months) were used in the present experiments. Bipolar electrodes were implanted bilaterally in the hippocampal CA3 area for electrical stimulation and electroencephalographic recordings. The electrodes were secured onto the skull via glue and dental acrylic but without anchoring screws. A daily stimulation protocol was used to induce electrographic discharges and motor seizures. The locations of implanted electrodes were verified by hippocampal electrographic activities and later histological assessments. Results Using the glue-based implantation method, we implanted bilateral bipolar electrodes in 25 mice. Electrographic discharges and motor seizures were successfully induced via hippocampal electrical kindling. Importantly, no animal encountered infection in the implanted area or a loss of implanted electrodes after 4–6 months of repetitive stimulation/recording. Conclusion We suggest that the glue-based, screw-free method is reliable for chronic brain stimulation and high-quality electroencephalographic recordings in mice. The technical aspects described this study may help future studies in mouse models. PMID:23914984

  14. Repeated electrical stimulation of reward-related brain regions affects cocaine but not "natural" reinforcement.

    PubMed

    Levy, Dino; Shabat-Simon, Maytal; Shalev, Uri; Barnea-Ygael, Noam; Cooper, Ayelet; Zangen, Abraham

    2007-12-19

    Drug addiction is associated with long-lasting neuronal adaptations including alterations in dopamine and glutamate receptors in the brain reward system. Treatment strategies for cocaine addiction and especially the prevention of craving and relapse are limited, and their effectiveness is still questionable. We hypothesized that repeated stimulation of the brain reward system can induce localized neuronal adaptations that may either potentiate or reduce addictive behaviors. The present study was designed to test how repeated interference with the brain reward system using localized electrical stimulation of the medial forebrain bundle at the lateral hypothalamus (LH) or the prefrontal cortex (PFC) affects cocaine addiction-associated behaviors and some of the neuronal adaptations induced by repeated exposure to cocaine. Repeated high-frequency stimulation in either site influenced cocaine, but not sucrose reward-related behaviors. Stimulation of the LH reduced cue-induced seeking behavior, whereas stimulation of the PFC reduced both cocaine-seeking behavior and the motivation for its consumption. The behavioral findings were accompanied by glutamate receptor subtype alterations in the nucleus accumbens and the ventral tegmental area, both key structures of the reward system. It is therefore suggested that repeated electrical stimulation of the PFC can become a novel strategy for treating addiction. PMID:18094257

  15. Effect of Epidural Electrical Stimulation and Repetitive Transcranial Magnetic Stimulation in Rats With Diffuse Traumatic Brain Injury

    PubMed Central

    Yoon, Yong-Soon; Cho, Kang Hee; Kim, Eun-Sil; Lee, Mi-Sook

    2015-01-01

    Objective To evaluate the effects of epidural electrical stimulation (EES) and repetitive transcranial magnetic stimulation (rTMS) on motor recovery and brain activity in a rat model of diffuse traumatic brain injury (TBI) compared to the control group. Methods Thirty rats weighing 270-285 g with diffuse TBI with 45 kg/cm2 using a weight-drop model were assigned to one of three groups: the EES group (ES) (anodal electrical stimulation at 50 Hz), the rTMS group (MS) (magnetic stimulation at 10 Hz, 3-second stimulation with 6-second intervals, 4,000 total stimulations per day), and the sham-treated control group (sham) (no stimulation). They were pre-trained to perform a single-pellet reaching task (SPRT) and a rotarod test (RRT) for 14 days. Diffuse TBI was then induced and an electrode was implanted over the dominant motor cortex. The changes in SPRT success rate, RRT performance time rate and the expression of c-Fos after two weeks of EES or rTMS were tracked. Results SPRT improved significantly from day 8 to day 12 in the ES group and from day 4 to day 14 in the MS group (p<0.05) compared to the sham group. RRT improved significantly from day 6 to day 11 in ES and from day 4 to day 9 in MS compared to the sham group. The ES and MS groups showed increased expression of c-Fos in the cerebral cortex compared to the sham group. Conclusion ES or MS in a rat model of diffuse TBI can be used to enhance motor recovery and brain activity. PMID:26161348

  16. Methodological Dimensions of Transcranial Brain Stimulation with the Electrical Current in Human

    PubMed Central

    Rostami, Maryam; Golesorkhi, Mehrshad; Ekhtiari, Hamed

    2013-01-01

    Transcranial current stimulation (TCS) is a neuromodulation method in which the patient is exposed to a mild electric current (direct or alternating) at 1-2 mA, resulting in an increase or a decrease in the brain excitability. This modification in neural activities can be used as a method for functional human brain mapping with causal inferences. This method might also facilitate the treatments of many neuropsychiatric disorders based on its inexpensive, simple, safe, noninvasive, painless, semi-focal excitatory and inhibitory effects. Given this, a comparison amongst different brain stimulation modalities has been made to determine the potential advantages of the TCS method. In addition, considerable methodological details on using TCS in basic and clinical neuroscience studies in human subjects have been introduced. Technical characteristics of TCS devices and their related accessories with regard to safety concerns have also been well articulated. Finally, some TCS application opportunities have been emphasized, including its potential use in the near future. PMID:25337348

  17. [Methods of brain stimulation based on weak electric current--future tool for the clinician?].

    PubMed

    Kotilainen, Tuukka; Lehto, Soili M

    2016-01-01

    Methods of brain stimulation based on a weak electric current are non-invasive neuromodulation techniques. They include transcranial direct current, alternating current and random noise stimulation. These methods modify the membrane potential of neurons without triggering the action potential, and have been successfully utilized to influence cognition and regulation of emotions in healthy experimental subjects. In clinical studies, indications of the efficacy of these techniques have been obtained in the treatment of depression, schizophrenia, memory disorders and pain as well as in stroke rehabilitation. It is hoped that these techniques will become established as part of the care and rehabilitation of psychiatric and neurologic patients in the future. PMID:27017784

  18. Long-lasting hyperpolarization underlies seizure reduction by low frequency deep brain electrical stimulation

    PubMed Central

    Toprani, Sheela; Durand, Dominique M

    2013-01-01

    Mesial temporal lobe epilepsy (MTLE) is a common medically refractory neurological disease. Deep brain electrical stimulation (DBS) of grey matter has been used for MTLE with limited success. However, stimulation of a white matter tract connecting the hippocampi, the ventral hippocampal commissure (VHC), with low frequencies that simulate interictal discharges has shown promising results, with seizure reduction greater than 98% in bilateral hippocampi during stimulation and greater than 50% seizure reduction in bilateral hippocampi after treatment. A major hurdle to the implementation and optimization of this treatment is that the mechanisms of seizure reduction by low frequency electrical stimulation (LFS) are not known. The goal of this study is to understand how commissural fibre tract stimulation reduces bilateral hippocampal epileptic activity in an in vitro slice preparation containing bilateral hippocampi connected by the VHC. It is our hypothesis that electrical stimuli induce hyperpolarization lasting hundreds of milliseconds following each pulse which reduces spontaneous epileptic activity during each inter-stimulus interval (ISI). Stimulus-induced long-lasting-hyperpolarization (LLH) can be mediated by GABAB inhibitory post-synaptic potentials (IPSPs) or slow after-hyperpolarization (sAHP). To test the role of LLH in effective bilateral seizure reduction by fibre tract stimulation, we measured stimulus-induced hyperpolarization during LFS of the VHC using electrophysiology techniques. Antagonism of the GABAB IPSP and/or sAHP diminished stimulus-induced hyperpolarization concurrently with LFS efficacy (greater than 50% reduction). Blocking both the GABAB IPSP and sAHP simultaneously eliminated the effect of electrical stimulation on seizure reduction entirely. These data show that LFS of the VHC is an effective protocol for bilateral hippocampal seizure reduction and that its efficacy relies on the induction of long-lasting hyperpolarization mediated

  19. Differential responsiveness of the right parahippocampal region to electrical stimulation in fixed human brains: Implications for historical surgical stimulation studies?

    PubMed

    Rouleau, Nicolas; Persinger, Michael A

    2016-07-01

    If structure dictates function within the living human brain, then the persistence of specific responses to weak electric currents in fixed, deceased brains could reflect "hardwired" properties. Different key structures from the left and right hemispheres of brains that had been fixed for over 20years with ethanol-formalin-acetic acid were stimulated with either 1-Hz, 7-Hz, 10-Hz, 20-Hz, or 30-Hz, sine-wave, square-wave, or pulsed currents while needle-recorded quantitative electroencephalographic responses were obtained. Differential responses occurred only within the right hippocampus and parahippocampal gyrus. The right hippocampus displayed frequency-independent increases in gamma power relative to the left hemispheric homologue. The parahippocampal region responded exclusively to 7-Hz pulsed currents with wideband (8-30Hz) power. These profiles are consistent with dynamic connections associated with memory and consciousness and may partially explain the interactions resultant of pulse type and hemisphere for experiential elicitations during the golden age of surgical stimulations. The results also indicate that there may be an essential "hardwiring" within the human brain that is maintained for decades when it is fixed appropriately. PMID:27208828

  20. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens.

    PubMed

    Albaugh, Daniel L; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  1. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    PubMed Central

    Albaugh, Daniel L.; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  2. The Morphological and Molecular Changes of Brain Cells Exposed to Direct Current Electric Field Stimulation

    PubMed Central

    Pelletier, Simon J.; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin

    2015-01-01

    Background: The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Methods: Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. Results: In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. Conclusion: We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. PMID:25522422

  3. Resuscitation therapy for traumatic brain injury-induced coma in rats: mechanisms of median nerve electrical stimulation

    PubMed Central

    Feng, Zhen; Zhong, Ying-jun; Wang, Liang; Wei, Tian-qi

    2015-01-01

    In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually increased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our findings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the prefrontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation. PMID:26170820

  4. Electrical stimulation of the human brain: perceptual and behavioral phenomena reported in the old and new literature.

    PubMed

    Selimbeyoglu, Aslihan; Parvizi, Josef

    2010-01-01

    In this review, we summarize the subjective experiential phenomena and behavioral changes that are caused by electrical stimulation of the cerebral cortex or subcortical nuclei in awake and conscious human subjects. Our comprehensive review contains a detailed summary of the data obtained from electrical brain stimulation (EBS) in humans in the last 100 years. Findings from the EBS studies may provide an additional layer of information about the neural correlates of cognition and behavior in healthy human subjects, or the neuroanatomy of illusions and hallucinations in patients with psychosis and the brain symptomatogenic zones in patients with epilepsy. We discuss some fundamental concepts, issues, and remaining questions that have defined the field of EBS, and review the current state of knowledge about the mechanism of action of EBS suggesting that the modulation of activity within a localized, but distributed, neuroanatomical network might explain the perceptual and behavioral phenomena that are reported during focal electrical stimulation of the human brain. PMID:20577584

  5. Electrical stimulation of the brain and the development of cortical visual prostheses: An historical perspective.

    PubMed

    Lewis, Philip M; Rosenfeld, Jeffrey V

    2016-01-01

    Rapid advances are occurring in neural engineering, bionics and the brain-computer interface. These milestones have been underpinned by staggering advances in micro-electronics, computing, and wireless technology in the last three decades. Several cortically-based visual prosthetic devices are currently being developed, but pioneering advances with early implants were achieved by Brindley followed by Dobelle in the 1960s and 1970s. We have reviewed these discoveries within the historical context of the medical uses of electricity including attempts to cure blindness, the discovery of the visual cortex, and opportunities for cortex stimulation experiments during neurosurgery. Further advances were made possible with improvements in electrode design, greater understanding of cortical electrophysiology and miniaturisation of electronic components. Human trials of a new generation of prototype cortical visual prostheses for the blind are imminent. This article is part of a Special Issue entitled Hold Item. PMID:26348986

  6. Functional asymmetry between the left and right human fusiform gyrus explored through electrical brain stimulation.

    PubMed

    Rangarajan, Vinitha; Parvizi, Josef

    2016-03-01

    The ventral temporal cortex (VTC) contains several areas with selective responses to words, numbers, faces, and objects as demonstrated by numerous human and primate imaging and electrophysiological studies. Our recent work using electrocorticography (ECoG) confirmed the presence of face-selective neuronal populations in the human fusiform gyrus (FG) in patients implanted with intracranial electrodes in either the left or right hemisphere. Electrical brain stimulation (EBS) disrupted the conscious perception of faces only when it was delivered in the right, but not left, FG. In contrast to our previous findings, here we report both negative and positive EBS effects in right and left FG, respectively. The presence of right hemisphere language dominance in the first, and strong left-handedness and poor language processing performance in the second case, provide indirect clues about the functional architecture of the human VTC in relation to hemispheric asymmetries in language processing and handedness. PMID:26277460

  7. Brain stimulation in migraine.

    PubMed

    Brighina, Filippo; Cosentino, Giuseppe; Fierro, Brigida

    2013-01-01

    Migraine is a very prevalent disease with great individual disability and socioeconomic burden. Despite intensive research effort in recent years, the etiopathogenesis of the disease remains to be elucidated. Recently, much importance has been given to mechanisms underlying the cortical excitability that has been suggested to be dysfunctional in migraine. In recent years, noninvasive brain stimulation techniques based on magnetic fields (transcranial magnetic stimulation, TMS) and on direct electrical currents (transcranial direct current stimulation, tDCS) have been shown to be safe and effective tools to explore the issue of cortical excitability, activation, and plasticity in migraine. Moreover, TMS, repetitive TMS (rTMS), and tDCS, thanks to their ability to interfere with and/or modulate cortical activity inducing plastic, persistent effects, have been also explored as potential therapeutic approaches, opening an interesting perspective for noninvasive neurostimulation for both symptomatic and preventive treatment of migraine and other types of headache. In this chapter we critically review evidence regarding the role of noninvasive brain stimulation in the pathophysiology and treatment of migraine, delineating the advantages and limits of these techniques together with potential development and future application. PMID:24112926

  8. Analyzing the tradeoff between electrical complexity and accuracy in patient-specific computational models of deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Howell, Bryan; McIntyre, Cameron C.

    2016-06-01

    Objective. Deep brain stimulation (DBS) is an adjunctive therapy that is effective in treating movement disorders and shows promise for treating psychiatric disorders. Computational models of DBS have begun to be utilized as tools to optimize the therapy. Despite advancements in the anatomical accuracy of these models, there is still uncertainty as to what level of electrical complexity is adequate for modeling the electric field in the brain and the subsequent neural response to the stimulation. Approach. We used magnetic resonance images to create an image-based computational model of subthalamic DBS. The complexity of the volume conductor model was increased by incrementally including heterogeneity, anisotropy, and dielectric dispersion in the electrical properties of the brain. We quantified changes in the load of the electrode, the electric potential distribution, and stimulation thresholds of descending corticofugal (DCF) axon models. Main results. Incorporation of heterogeneity altered the electric potentials and subsequent stimulation thresholds, but to a lesser degree than incorporation of anisotropy. Additionally, the results were sensitive to the choice of method for defining anisotropy, with stimulation thresholds of DCF axons changing by as much as 190%. Typical approaches for defining anisotropy underestimate the expected load of the stimulation electrode, which led to underestimation of the extent of stimulation. More accurate predictions of the electrode load were achieved with alternative approaches for defining anisotropy. The effects of dielectric dispersion were small compared to the effects of heterogeneity and anisotropy. Significance. The results of this study help delineate the level of detail that is required to accurately model electric fields generated by DBS electrodes.

  9. Exogenously induced brain activation regulates neuronal activity by top-down modulation: conceptualized model for electrical brain stimulation.

    PubMed

    Spezia Adachi, Lauren Naomi; Quevedo, Alexandre Silva; de Souza, Andressa; Scarabelot, Vanessa Leal; Rozisky, Joanna Ripoll; de Oliveira, Carla; Marques Filho, Paulo Ricardo; Medeiros, Liciane Fernandes; Fregni, Felipe; Caumo, Wolnei; Torres, Iraci L S

    2015-05-01

    Physiological and exogenous factors are able to adjust sensory processing by modulating activity at different levels of the nervous system hierarchy. Accordingly, transcranial direct current stimulation (tDCS) may use top-down mechanisms to control the access for incoming information along the neuroaxis. To test the hypothesis that brain activation induced by tCDS is able to initiate top-down modulation and that chronic stress disrupts this effect, 60-day-old male Wistar rats (n = 78) were divided into control; control + tDCS; control + sham-tDCS; stress; stress + tDCS; and stress + sham-tDCS. Chronic stress was induced using a restraint stress model for 11 weeks, and then, the treatment was applied over 8 days. BDNF levels were used to assess neuronal activity at spinal cord, brainstem, and hippocampus. Mechanical pain threshold was assessed by von Frey test immediately and 24 h after the last tDCS-intervention. tDCS was able to decrease BDNF levels in the structures involved in the descending systems (spinal cord and brainstem) only in unstressed animals. The treatment was able to reverse the stress-induced allodynia and to increase the pain threshold in unstressed animals. Furthermore, there was an inverse relation between pain sensitivity and spinal cord BDNF levels. Accordingly, we propose the addition of descending systems in the current brain electrical modulation model. PMID:25665871

  10. Transcranial electrical brain stimulation modulates neuronal tuning curves in perception of numerosity and duration

    PubMed Central

    Javadi, Amir Homayoun; Brunec, Iva K.; Walsh, Vincent; Penny, Will D.; Spiers, Hugo J.

    2014-01-01

    Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method with many putative applications and reported to effectively modulate behaviour. However, its effects have yet to be considered at a computational level. To address this we modelled the tuning curves underlying the behavioural effects of stimulation in a perceptual task. Participants judged which of the two serially presented images contained more items (numerosity judgement task) or was presented longer (duration judgement task). During presentation of the second image their posterior parietal cortices (PPCs) were stimulated bilaterally with opposite polarities for 1.6 s. We also examined the impact of three stimulation conditions on behaviour: anodal right-PPC and cathodal left-PPC (rA-lC), reverse order (lA-rC) and no-stimulation condition. Behavioural results showed that participants were more accurate in numerosity and duration judgement tasks when they were stimulated with lA-rC and rA-lC stimulation conditions respectively. Simultaneously, a decrease in performance on numerosity and duration judgement tasks was observed when the stimulation condition favoured the other task. Thus, our results revealed a double-dissociation of laterality and task. Importantly, we were able to model the effects of stimulation on behaviour. Our computational modelling showed that participants' superior performance was attributable to a narrower tuning curve — smaller standard deviation of detection noise. We believe that this approach may prove useful in understanding the impact of brain stimulation on other cognitive domains. PMID:25130301

  11. Brain-controlled functional electrical stimulation for lower-limb motor recovery in stroke survivors.

    PubMed

    McCrimmon, Colin M; King, Christine E; Wang, Po T; Cramer, Steven C; Nenadic, Zoran; Do, An H

    2014-01-01

    Despite the prevalence of stroke-induced gait impairment due to foot drop, current rehabilitative practices to improve gait function are limited, and orthoses can be uncomfortable and do not provide long-lasting benefits. Therefore, novel modalities that may facilitate lasting neurological and functional improvements, such as brain-computer interfaces (BCIs), have been explored. In this article, we assess the feasibility of BCI-controlled functional electrical stimulation (FES) as a novel physiotherapy for post-stroke foot drop. Three chronic stroke survivors with foot drop received three, 1-hour sessions of therapy during 1 week. All subjects were able to purposefully operate the BCI-FES system in real time. Furthermore, the salient electroencephalographic (EEG) features used for classification by the data-driven methodology were determined to be physiologically relevant. Over the course of this short therapy, the subjects' dorsiflexion active range of motion (AROM) improved by 3°, 4°, and 8°, respectively. These results indicate that chronic stroke survivors can operate the BCI-FES system, and that BCI-FES intervention may promote functional improvements. PMID:25570191

  12. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms

    PubMed Central

    Lim, L W; Prickaerts, J; Huguet, G; Kadar, E; Hartung, H; Sharp, T; Temel, Y

    2015-01-01

    Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and ventral tegmental area) on a variety of depressive-like behaviors using rat models. In the naive animal study, we found that HFS of the Cg, vmPFC, NAc core and LHb reduced anxiety levels and increased motivation for food. In the chronic unpredictable stress model, there was a robust depressive-like behavioral phenotype. Moreover, vmPFC HFS, in a comparison of all stimulated targets, produced the most profound antidepressant effects with enhanced hedonia, reduced anxiety and decreased forced-swim immobility. In the following set of electrophysiological and histochemical experiments designed to unravel some of the underlying mechanisms, we found that vmPFC HFS evoked a specific modulation of the serotonergic neurons in the dorsal raphe nucleus (DRN), which have long been linked to mood. Finally, using a neuronal mapping approach by means of c-Fos expression, we found that vmPFC HFS modulated a brain circuit linked to the DRN and known to be involved in affect. In conclusion, HFS of the vmPFC produced the most potent antidepressant effects in naive rats and rats subjected to stress by mechanisms also including the DRN. PMID:25826110

  13. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms.

    PubMed

    Lim, L W; Prickaerts, J; Huguet, G; Kadar, E; Hartung, H; Sharp, T; Temel, Y

    2015-01-01

    Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and ventral tegmental area) on a variety of depressive-like behaviors using rat models. In the naive animal study, we found that HFS of the Cg, vmPFC, NAc core and LHb reduced anxiety levels and increased motivation for food. In the chronic unpredictable stress model, there was a robust depressive-like behavioral phenotype. Moreover, vmPFC HFS, in a comparison of all stimulated targets, produced the most profound antidepressant effects with enhanced hedonia, reduced anxiety and decreased forced-swim immobility. In the following set of electrophysiological and histochemical experiments designed to unravel some of the underlying mechanisms, we found that vmPFC HFS evoked a specific modulation of the serotonergic neurons in the dorsal raphe nucleus (DRN), which have long been linked to mood. Finally, using a neuronal mapping approach by means of c-Fos expression, we found that vmPFC HFS modulated a brain circuit linked to the DRN and known to be involved in affect. In conclusion, HFS of the vmPFC produced the most potent antidepressant effects in naive rats and rats subjected to stress by mechanisms also including the DRN. PMID:25826110

  14. Not all brains are created equal: the relevance of individual differences in responsiveness to transcranial electrical stimulation

    PubMed Central

    Krause, Beatrix; Cohen Kadosh, Roi

    2014-01-01

    A current issue in the research of augmentation of brain functions using transcranial electrical stimulation (tES) is the diversity and inconsistency in outcome results. Similar studies often report different results, depending on the parameters and tasks used. Such inconsistencies have led to significant doubts about the efficacy of the method in the broader scientific community, despite its promising potential for patient recovery and treatment. Evidence on the large variability in individual cortical excitability and response to tES suggests that stimulation may affect individuals differently, depending on the subject’s age, gender, brain state, hormonal levels, and pre-existing regional excitability. Certain factors might even lead to the reversal of polarity-dependent effects, and therefore have crucial implications for neurorehabilitation and cognitive enhancement. Research paradigms may have to be refined in the future to avoid the confounding effects of such factors. PMID:24605090

  15. Deep brain stimulation: new techniques.

    PubMed

    Hariz, Marwan

    2014-01-01

    The technology of the hardware used in deep brain stimulation (DBS), and the mode of delivering the stimulation have not significantly evolved since the start of the modern era of DBS 25 years ago. However, new technology is now being developed along several avenues. New features of the implantable pulse generator (IPG) allow fractionation of the electric current into variable proportions between different contacts of the multi-polar lead. Another design consists in leads that allow selective current steering from directionally placed electrode contacts that would deliver the stimulation in a specific direction or even create a directional shaped electric field that would conform to the anatomy of the brain target aimed at, avoiding adjacent structures, and thus avoiding side effects. Closed loop adaptive stimulation technologies are being developed, allowing a tracking of the pathological local field potential of the brain target, and delivering automatically the stimulation to suppress the pathological activity as soon as it is detected and for as long as needed. This feature may contribute to a DBS therapy "on demand", instead of continuously. Finally, advances in imaging technology are providing "new" brain targets, and increasingly allowing DBS to be performed accurately while avoiding the risks of microelectrode recording. PMID:24262179

  16. Effects of brain-computer interface-based functional electrical stimulation on brain activation in stroke patients: a pilot randomized controlled trial

    PubMed Central

    Chung, EunJung; Kim, Jung-Hee; Park, Dae-Sung; Lee, Byoung-Hee

    2015-01-01

    [Purpose] This study sought to determine the effects of brain-computer interface-based functional electrical stimulation (BCI-FES) on brain activation in patients with stroke. [Subjects] The subjects were randomized to in a BCI-FES group (n=5) and a functional electrical stimulation (FES) group (n=5). [Methods] Patients in the BCI-FES group received ankle dorsiflexion training with FES for 30 minutes per day, 5 times under the brain-computer interface-based program. The FES group received ankle dorsiflexion training with FES for the same amount of time. [Results] The BCI-FES group demonstrated significant differences in the frontopolar regions 1 and 2 attention indexes, and frontopolar 1 activation index. The FES group demonstrated no significant differences. There were significant differences in the frontopolar 1 region activation index between the two groups after the interventions. [Conclusion] The results of this study suggest that BCI-FES training may be more effective in stimulating brain activation than only FES training in patients recovering from stroke. PMID:25931680

  17. Thirty minute transcutaneous electric acupoint stimulation modulates resting state brain activities: a perfusion and BOLD fMRI study.

    PubMed

    Jiang, Yin; Hao, Ying; Zhang, Yue; Liu, Jing; Wang, Xiaoying; Han, Jisheng; Fang, Jing; Zhang, Jue; Cui, Cailian

    2012-05-31

    Increasing neuroimaging studies have focused on the sustained after effects of acupuncture, especially for the changes of brain activities in rest. However, short-period stimuli have mostly been chosen in these works. The present study aimed to investigate how the resting state brain activities in healthy subjects were modulated by relatively long-period (30 min) acupuncture, a widely used modality in clinical practice. Transcutaneous electric acupoint stimulation (TEAS) or intermittent minimal TEAS (MTEAS) were given for 30 min to 40 subjects. Functional MRI (fMRI) data were collected including the pre-stimulation resting state and the post-stimulation resting state, using dual-echo arterial spin labeling (ASL) techniques, representing both cerebral blood flow (CBF) signals and blood oxygen-dependent level (BOLD) signals simultaneously. Following 30 min TEAS, but not MTEAS, the mean global CBF decreased, and a significant decrease of regional CBF was observed in SI, insula, STG, MOG and IFG. Functional connectivity analysis showed more secure and spatially extended connectivity of both the DMN and SMN after 30 min TEAS. Our results implied that modulation of the regional brain activities and network connectivity induced by thirty minute TEAS may associate with the acupuncture-related therapeutic effects. Furthermore, the resting state regional CBF quantified by ASL perfusion fMRI may serve as a potential biomarker in future acupuncture studies. PMID:22541167

  18. TMS-EEG: A window into the neurophysiological effects of transcranial electrical stimulation in non-motor brain regions.

    PubMed

    Hill, Aron T; Rogasch, Nigel C; Fitzgerald, Paul B; Hoy, Kate E

    2016-05-01

    Transcranial electrical stimulation (tES) techniques are able to induce changes in cortical excitability and plasticity through the administration of weak currents to the brain and are currently being used to manipulate a vast array of cognitive processes. Despite the widespread use of tES technologies within both research and remedial settings, their precise neurophysiological mechanisms of action are not well established outside of the motor cortex. The expanding use of tES within non-motor brain regions highlights the growing need for a more comprehensive understanding of the effects of stimulation across a diversity of cortical locations. The combination of transcranial magnetic stimulation with electroencephalography (TMS-EEG) provides a method of directly probing both local and widespread changes in brain neurophysiology, through the recording of TMS-evoked potentials and cortical oscillations. In this review we explore TMS-EEG as a tool for examining the impact of tES on cortical function and argue that multimodal approaches which combine tES with TMS-EEG could lead to a deeper understanding of the mechanisms which underlie tES-induced cognitive modulation. PMID:26959337

  19. Acupuncture-Related Modulation of Pain-Associated Brain Networks During Electrical Pain Stimulation: A Functional Magnetic Resonance Imaging Study

    PubMed Central

    Choi, Kyung-Eun; Gizewski, Elke R.; Wen, Ming; Rampp, Thomas; Gasser, Thomas; Dobos, Gustav J.; Forsting, Michael; Musial, Frauke

    2014-01-01

    Abstract Objective: Findings of existing functional MRI (fMRI) studies on the neural mechanisms that mediate effects of acupuncture analgesia are inconsistent. This study analyzes the effects of manual acupuncture on pain ratings and brain activation in response to experimental, electrical pain stimuli. Design: Fourteen healthy volunteers were examined by using a 1.5-T MRI scanner. The intensity of pain stimuli was adjusted to individual pain ratings on a numeric rating scale. Baseline fMRI was performed during electrical pain stimulation in a blocked design. For the second session, manual acupuncture with repeated stimulation was performed on contralateral acupoints—large intestine 4, liver 3, and stomach 36—before imaging. After imaging, subjective pain ratings and ratings of the de qi sensation were assessed. Results: Compared with baseline, volunteers showed modulated brain activity under pain conditions in the cingulate gyrus, insula, primary somatosensory cortex, and prefrontal areas after the acupuncture session. In accordance with the literature, anterior insular and prefrontal activity seemed to be correlated with acupuncture treatment. Conclusion: This study supports the existence of analgesic acupuncture effects that outlast the needling period. Pain-associated brain areas were modulated in direct response to a preceding acupuncture treatment. PMID:25389905

  20. The Effect of Variation in Permittivity of Different Tissues on Induced Electric Field in the Brain during Transcranial Magnetic Stimulation

    NASA Astrophysics Data System (ADS)

    Hadimani, Ravi; Porzig, Konstantin; Crowther, Lawrence; Brauer, Hartmut; Toepfer, Hannes; Jiles, David; Department of Electrical and Computer Engineering, Iowa State University Team; Department of Advanced Electromagnetics, Ilmenau University of Technology Team

    2013-03-01

    Estimation of electric field in the brain during Transcranial Magnetic Stimulation (TMS) requires knowledge of the electric property of brain tissue. Grey and white matters have unusually high relative permittivities of ~ 106 at low frequencies. However, relative permittivity of cerebrospinal fluid is ~ 102. With such a variation it is necessary to consider the effect of boundaries. A model consisting of 2 hemispheres was used in the model with the properties of one hemisphere kept constant at σ1 = 0.1Sm-1 and ɛr 1 = 10 while the properties of the second hemisphere were changed kept at σ2 = 0.1Sm-1 to 2Sm-1 and ɛr 2 = 102 to 105. A 70 mm diameter double coil was used as the source of the magnetic field. The amplitude of the current in the coil was 5488 A at a frequency of 2.9 kHz. The results show that the electric field, E induced during magnetic stimulation is independent of the relative permittivity, ɛr and varies with the conductivity. Thus the variation in E, calculated with homogeneous and heterogeneous head models was due to variation in conductivity of the tissues and not due to variation in permittivities.

  1. Integrated device for optical stimulation and spatiotemporal electrical recording of neural activity in light-sensitized brain tissue

    PubMed Central

    Zhang, Jiayi; Laiwalla, Farah; Kim, Jennifer A; Urabe, Hayato; Van Wagenen, Rick; Song, Yoon-Kyu; Connors, Barry W; Zhang, Feng; Deisseroth, Karl; Nurmikko, Arto V

    2010-01-01

    Neural stimulation with high spatial and temporal precision is desirable both for studying the real-time dynamics of neural networks and for prospective clinical treatment of neurological diseases. Optical stimulation of genetically targeted neurons expressing the light sensitive channel protein Channelrhodopsin (ChR2) has recently been reported as a means for millisecond temporal control of neuronal spiking activities with cell-type selectivity. This offers the prospect of enabling local delivery of optical stimulation and the simultaneous monitoring of the neural activity by electrophysiological means, both in the vicinity of and distant to the stimulation site. We report here a novel dual-modality hybrid device, which consists of a tapered coaxial optical waveguide (‘optrode’) integrated into a 100 element intra-cortical multi-electrode recording array. We first demonstrate the dual optical delivery and electrical recording capability of the single optrode in in vitro preparations of mouse retina, photo-stimulating the native retinal photoreceptors while recording light-responsive activities from ganglion cells. The dual-modality array device was then used in ChR2 transfected mouse brain slices. Specifically, epileptiform events were reliably optically triggered by the optrode and their spatiotemporal patterns were simultaneously recorded by the multi-electrode array. PMID:19721185

  2. Integrated device for optical stimulation and spatiotemporal electrical recording of neural activity in light-sensitized brain tissue

    NASA Astrophysics Data System (ADS)

    Zhang, Jiayi; Laiwalla, Farah; Kim, Jennifer A.; Urabe, Hayato; Van Wagenen, Rick; Song, Yoon-Kyu; Connors, Barry W.; Zhang, Feng; Deisseroth, Karl; Nurmikko, Arto V.

    2009-10-01

    Neural stimulation with high spatial and temporal precision is desirable both for studying the real-time dynamics of neural networks and for prospective clinical treatment of neurological diseases. Optical stimulation of genetically targeted neurons expressing the light sensitive channel protein Channelrhodopsin (ChR2) has recently been reported as a means for millisecond temporal control of neuronal spiking activities with cell-type selectivity. This offers the prospect of enabling local delivery of optical stimulation and the simultaneous monitoring of the neural activity by electrophysiological means, both in the vicinity of and distant to the stimulation site. We report here a novel dual-modality hybrid device, which consists of a tapered coaxial optical waveguide ('optrode') integrated into a 100 element intra-cortical multi-electrode recording array. We first demonstrate the dual optical delivery and electrical recording capability of the single optrode in in vitro preparations of mouse retina, photo-stimulating the native retinal photoreceptors while recording light-responsive activities from ganglion cells. The dual-modality array device was then used in ChR2 transfected mouse brain slices. Specifically, epileptiform events were reliably optically triggered by the optrode and their spatiotemporal patterns were simultaneously recorded by the multi-electrode array.

  3. Opiate withdrawal behavior after focal brain stimulation.

    PubMed

    Williams, D A; Thorn, B E

    1984-11-01

    Electrical stimulation of the brainstem abolishes pain, while continued stimulation induces tolerance to the analgesic effect. Analgesic drugs producing tolerance also induce physical dependence, suggesting that the phenomenon of tolerance is associated with addiction. There is evidence that the neural mechanism for stimulation-produced analgesia is related to the release of opiate substances within the brain. We therefore propose that repeated or protracted brain stimulation elicits dependence upon the endorphins released by electrical stimulation of the neurons themselves. To investigate this possibility, rats were given repetitive bursts of analgesic electrical brain stimulation for two hours. Immediately thereafter, they were injected with the opiate antagonist, naloxone. Behaviors associated with low grade opiate withdrawal were observed. These data suggest that prolonged analgesic stimulation can result in naloxone-precipitated behaviors similar to the behaviors exhibited during opiate withdrawal. PMID:6542676

  4. Electrical brain stimulation improves cognitive performance by modulating functional connectivity and task-specific activation.

    PubMed

    Meinzer, Marcus; Antonenko, Daria; Lindenberg, Robert; Hetzer, Stefan; Ulm, Lena; Avirame, Keren; Flaisch, Tobias; Flöel, Agnes

    2012-02-01

    Excitatory anodal transcranial direct current stimulation (atDCS) can improve human cognitive functions, but neural underpinnings of its mode of action remain elusive. In a cross-over placebo ("sham") controlled study we used functional magnetic resonance imaging (fMRI) to investigate neurofunctional correlates of improved language functions induced by atDCS over a core language area, the left inferior frontal gyrus (IFG). Intrascanner transcranial direct current stimulation-induced changes in overt semantic word generation assessed behavioral modulation; task-related and task-independent (resting-state) fMRI characterized language network changes. Improved word-retrieval during atDCS was paralleled by selectively reduced task-related activation in the left ventral IFG, an area specifically implicated in semantic retrieval processes. Under atDCS, resting-state fMRI revealed increased connectivity of the left IFG and additional major hubs overlapping with the language network. In conclusion, atDCS modulates endogenous low-frequency oscillations in a distributed set of functionally connected brain areas, possibly inducing more efficient processing in critical task-relevant areas and improved behavioral performance. PMID:22302824

  5. Deep Brain Stimulation

    PubMed Central

    Perlmutter, Joel S.; Mink, Jonathan W.

    2015-01-01

    Deep brain stimulation (DBS) has provided remarkable benefits for people with a variety of neurologic conditions. Stimulation of the ventral intermediate nucleus of the thalamus can dramatically relieve tremor associated with essential tremor or Parkinson disease (PD). Similarly, stimulation of the subthalamic nucleus or the internal segment of the globus pallidus can substantially reduce bradykinesia, rigidity, tremor, and gait difficulties in people with PD. Multiple groups are attempting to extend this mode of treatment to other conditions. Yet, the precise mechanism of action of DBS remains uncertain. Such studies have importance that extends beyond clinical therapeutics. Investigations of the mechanisms of action of DBS have the potential to clarify fundamental issues such as the functional anatomy of selected brain circuits and the relationship between activity in those circuits and behavior. Although we review relevant clinical issues, we emphasize the importance of current and future investigations on these topics. PMID:16776585

  6. Learned EEG-based brain self-regulation of motor-related oscillations during application of transcranial electric brain stimulation: feasibility and limitations

    PubMed Central

    Soekadar, Surjo R.; Witkowski, Matthias; Cossio, Eliana G.; Birbaumer, Niels; Cohen, Leonardo G.

    2014-01-01

    Objective: Transcranial direct current stimulation (tDCS) improves motor learning and can affect emotional processing and attention. However, it is unclear whether learned electroencephalography (EEG)-based brain-machine interface (BMI) control during tDCS is feasible, how application of transcranial electric currents during BMI control would interfere with feature-extraction of physiological brain signals and how it affects brain control performance. Here we tested this combination and evaluated stimulation-dependent artifacts across different EEG frequencies and stability of motor imagery-based BMI control. Approach: Ten healthy volunteers were invited to two BMI-sessions, each comprising two 60-trial blocks. During the trials, learned desynchronization of mu-rhythms (8–15 Hz) associated with motor imagery (MI) recorded over C4 was translated into online cursor movements on a computer screen. During block 2, either sham (session A) or anodal tDCS (session B) was applied at 1 mA with the stimulation electrode placed 1 cm anterior of C4. Main results: tDCS was associated with a significant signal power increase in the lower frequencies most evident in the signal spectrum of the EEG channel closest to the stimulation electrode. Stimulation-dependent signal power increase exhibited a decay of 12 dB per decade, leaving frequencies above 9 Hz unaffected. Analysis of BMI control performance did not indicate a difference between blocks and tDCS conditions. Conclusion: Application of tDCS during learned EEG-based self-regulation of brain oscillations above 9 Hz is feasible and safe, and might improve applicability of BMI systems. PMID:24672456

  7. Transcranial brain stimulation: closing the loop between brain and stimulation

    PubMed Central

    Karabanov, Anke; Thielscher, Axel; Siebner, Hartwig Roman

    2016-01-01

    Purpose of review To discuss recent strategies for boosting the efficacy of noninvasive transcranial brain stimulation to improve human brain function. Recent findings Recent research exposed substantial intra- and inter-individual variability in response to plasticity-inducing transcranial brain stimulation. Trait-related and state-related determinants contribute to this variability, challenging the standard approach to apply stimulation in a rigid, one-size-fits-all fashion. Several strategies have been identified to reduce variability and maximize the plasticity-inducing effects of noninvasive transcranial brain stimulation. Priming interventions or paired associative stimulation can be used to ‘standardize’ the brain-state and hereby, homogenize the group response to stimulation. Neuroanatomical and neurochemical profiling based on magnetic resonance imaging and spectroscopy can capture trait-related and state-related variability. Fluctuations in brain-states can be traced online with functional brain imaging and inform the timing or other settings of transcranial brain stimulation. State-informed open-loop stimulation is aligned to the expression of a predefined brain state, according to prespecified rules. In contrast, adaptive closed-loop stimulation dynamically adjusts stimulation settings based on the occurrence of stimulation-induced state changes. Summary Approaches that take into account trait-related and state-related determinants of stimulation-induced plasticity bear considerable potential to establish noninvasive transcranial brain stimulation as interventional therapeutic tool. PMID:27224087

  8. Age-related deficits in voluntary control over saccadic eye movements: consideration of electrical brain stimulation as a therapeutic strategy.

    PubMed

    Chen, Po Ling; Machado, Liana

    2016-05-01

    Sudden changes in our visual environment trigger reflexive eye movements, so automatically they often go unnoticed. Consequently, voluntary control over reflexive eye movements entails considerable effort. In relation to frontal-lobe deterioration, adult aging adversely impacts voluntary saccadic eye movement control in particular, which compromises effective performance of daily activities. Here, we review the nature of age-related changes in saccadic control, focusing primarily on the antisaccade task because of its assessment of 2 key age-sensitive control functions: reflexive saccade inhibition and voluntary saccade generation. With an ultimate view toward facilitating development of therapeutic strategies, we systematically review the neuroanatomy underpinning voluntary control over saccadic eye movements and natural mechanisms that kick in to compensate for age-related declines. We then explore the potential of noninvasive electrical brain stimulation to counteract aging deficits. Based on evidence that anodal transcranial direct current stimulation can confer a range of benefits specifically relevant to aging brains, we put forward this neuromodulation technique as a therapeutic strategy for improving voluntary saccadic eye movement control in older adults. PMID:27103518

  9. NONINVASIVE BRAIN STIMULATION IN TRAUMATIC BRAIN INJURY

    PubMed Central

    Demirtas-Tatlidede, Asli; Vahabzadeh-Hagh, Andrew M.; Bernabeu, Montserrat; Tormos, Jose M.; Pascual-Leone, Alvaro

    2012-01-01

    Brain stimulation techniques have evolved in the last few decades with more novel methods capable of painless, noninvasive brain stimulation. While the number of clinical trials employing noninvasive brain stimulation continues to increase in a variety of medication-resistant neurological and psychiatric diseases, studies evaluating their diagnostic and therapeutic potential in traumatic brain injury (TBI) are largely lacking. This review introduces different techniques of noninvasive brain stimulation, which may find potential use in TBI. We cover transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), low-level laser therapy (LLLT) and transcranial doppler sonography (TCD) techniques. We provide a brief overview of studies to date, discuss possible mechanisms of action, and raise a number of considerations when thinking about translating these methods to clinical use. PMID:21691215

  10. Current Status of Research on Providing Sight to the Blind by Electrical Stimulation of the Brain

    ERIC Educational Resources Information Center

    Dobelle, William H.

    1977-01-01

    Described is a prosthesis that connects a television camera and associated circuitry to the visual centers of the brain to restore a limited amount of visual sensation to totally blind persons. (Author/MH)

  11. Can transcranial electrical stimulation improve learning difficulties in atypical brain development? A future possibility for cognitive training☆

    PubMed Central

    Krause, Beatrix; Cohen Kadosh, Roi

    2013-01-01

    Learning difficulties in atypical brain development represent serious obstacles to an individual's future achievements and can have broad societal consequences. Cognitive training can improve learning impairments only to a certain degree. Recent evidence from normal and clinical adult populations suggests that transcranial electrical stimulation (TES), a portable, painless, inexpensive, and relatively safe neuroenhancement tool, applied in conjunction with cognitive training can enhance cognitive intervention outcomes. This includes, for instance, numerical processing, language skills and response inhibition deficits commonly associated with profound learning difficulties and attention-deficit hyperactivity disorder (ADHD). The current review introduces the functional principles, current applications and promising results, and potential pitfalls of TES. Unfortunately, research in child populations is limited at present. We suggest that TES has considerable promise as a tool for increasing neuroplasticity in atypically developing children and may be an effective adjunct to cognitive training in clinical settings if it proves safe. The efficacy and both short- and long-term effects of TES on the developing brain need to be critically assessed before it can be recommended for clinical settings. PMID:23770059

  12. Can transcranial electrical stimulation improve learning difficulties in atypical brain development? A future possibility for cognitive training.

    PubMed

    Krause, Beatrix; Cohen Kadosh, Roi

    2013-10-01

    Learning difficulties in atypical brain development represent serious obstacles to an individual's future achievements and can have broad societal consequences. Cognitive training can improve learning impairments only to a certain degree. Recent evidence from normal and clinical adult populations suggests that transcranial electrical stimulation (TES), a portable, painless, inexpensive, and relatively safe neuroenhancement tool, applied in conjunction with cognitive training can enhance cognitive intervention outcomes. This includes, for instance, numerical processing, language skills and response inhibition deficits commonly associated with profound learning difficulties and attention-deficit hyperactivity disorder (ADHD). The current review introduces the functional principles, current applications and promising results, and potential pitfalls of TES. Unfortunately, research in child populations is limited at present. We suggest that TES has considerable promise as a tool for increasing neuroplasticity in atypically developing children and may be an effective adjunct to cognitive training in clinical settings if it proves safe. The efficacy and both short- and long-term effects of TES on the developing brain need to be critically assessed before it can be recommended for clinical settings. PMID:23770059

  13. Deep Brain Stimulation for Obesity

    PubMed Central

    Sussman, Eric S; Zhang, Michael; Pendharkar, Arjun V; Azagury, Dan E; Bohon, Cara; Halpern, Casey H

    2015-01-01

    Obesity is now the third leading cause of preventable death in the US, accounting for 216,000 deaths annually and nearly 100 billion dollars in health care costs. Despite advancements in bariatric surgery, substantial weight regain and recurrence of the associated metabolic syndrome still occurs in almost 20-35% of patients over the long-term, necessitating the development of novel therapies. Our continually expanding knowledge of the neuroanatomic and neuropsychiatric underpinnings of obesity has led to increased interest in neuromodulation as a new treatment for obesity refractory to current medical, behavioral, and surgical therapies. Recent clinical trials of deep brain stimulation (DBS) in chronic cluster headache, Alzheimer’s disease, and depression and obsessive-compulsive disorder have demonstrated the safety and efficacy of targeting the hypothalamus and reward circuitry of the brain with electrical stimulation, and thus provide the basis for a neuromodulatory approach to treatment-refractory obesity. In this study, we review the literature implicating these targets for DBS in the neural circuitry of obesity. We will also briefly review ethical considerations for such an intervention, and discuss genetic secondary-obesity syndromes that may also benefit from DBS. In short, we hope to provide the scientific foundation to justify trials of DBS for the treatment of obesity targeting these specific regions of the brain. PMID:26180683

  14. Frequency Band-Specific Electrical Brain Stimulation Modulates Cognitive Control Processes

    PubMed Central

    van Driel, Joram; Sligte, Ilja G.; Linders, Jara; Elport, Daniel; Cohen, Michael X

    2015-01-01

    A large body of findings has tied midfrontal theta-band (4–8 Hz) oscillatory activity to adaptive control mechanisms during response conflict. Thus far, this evidence has been correlational. To evaluate whether theta oscillations are causally involved in conflict processing, we applied transcranial alternating current stimulation (tACS) in the theta band to a midfrontal scalp region, while human subjects performed a spatial response conflict task. Conflict was introduced by incongruency between the location of the target stimulus and the required response hand. As a control condition, we used alpha-band (8–12 Hz) tACS over the same location. The exact stimulation frequencies were determined empirically for each subject based on a pre-stimulation EEG session. Behavioral results showed general conflict effects of slower response times (RT) and lower accuracy for high conflict trials compared to low conflict trials. Importantly, this conflict effect was reduced specifically during theta tACS, which was driven by slower response times on low conflict trials. These results show how theta tACS can modulate adaptive cognitive control processes, which is in accordance with the view of midfrontal theta oscillations as an active mechanism for cognitive control. PMID:26405801

  15. Pathways of Translation: Deep Brain Stimulation

    PubMed Central

    Gionfriddo, Michael R.; Greenberg, Alexandra J.; Wahegaonkar, Abhijeet L.; Lee, Kendall H.

    2014-01-01

    Electrical stimulation of the brain has a 2000 year history. Deep brain stimulation (DBS), one form of neurostimulation, is a functional neurosurgical approach in which a high frequency electric current stimulates targeted brain structures for therapeutic benefit. It is an effective treatment for certain neuropathologic movement disorders and an emerging therapy for psychiatric conditions and epilepsy. Its translational journey did not follow the typical bench-to-bedside path, but rather reversed the process. The shift from ancient and medieval folkloric remedy to accepted medical practice began with independent discoveries about electricity during the 17th century and was fostered by technological advances of the 20th. In this article we review that journey and discuss how the quest to expand its applications and continue to improve outcomes is taking DBS from the bedside back to the bench. PMID:24330698

  16. Stimulant mechanisms of cathinones - effects of mephedrone and other cathinones on basal and electrically evoked dopamine efflux in rat accumbens brain slices.

    PubMed

    Opacka-Juffry, Jolanta; Pinnell, Thomas; Patel, Nisha; Bevan, Melissa; Meintel, Meghan; Davidson, Colin

    2014-10-01

    Mephedrone, an erstwhile "legal high", and some non-abused cathinones (ethcathinone, diethylpropion and bupropion) were tested for stimulant effects in vitro, through assessing their abilities to increase basal and electrically evoked dopamine efflux in rat accumbens brain slices, and compared with cocaine and amphetamine. We also tested mephedrone against cocaine in a dopamine transporter binding study. Dopamine efflux was electrically evoked and recorded using voltammetry in the rat accumbens core. We constructed concentration response curves for these cathinones for effects on basal dopamine levels; peak efflux after local electrical stimulation and the time-constant of the dopamine decay phase, an index of dopamine reuptake. We also examined competition between mephedrone or cocaine and [(125)I]RTI121 at the dopamine transporter. Mephedrone was less potent than cocaine at displacing [(125)I]RTI121. Mephedrone and amphetamine increased basal levels of dopamine in the absence of electrical stimulation. Cocaine, bupropion, diethylpropion and ethcathinone all increased the peak dopamine efflux after electrical stimulation and slowed dopamine reuptake. Cocaine was more potent than bupropion and ethcathinone, while diethylpropion was least potent. Notably, cocaine had the fastest onset of action. These data suggest that, with respect to dopamine efflux, mephedrone is more similar to amphetamine than cocaine. These findings also show that cocaine was more potent than bupropion and ethcathinone while diethylpropion was least potent. Mephedrone's binding to the dopamine transporter is consistent with stimulant effects but its potency was lower than that of cocaine. These findings confirm and further characterize stimulant properties of mephedrone and other cathinones in adolescent rat brain. PMID:24795175

  17. A Study on the Effect of Electrical Stimulation as a User Stimuli for Motor Imagery Classification in Brain-Machine Interface

    PubMed Central

    Bhattacharyya, Saugat; Clerc, Maureen; Hayashibe, Mitsuhiro

    2016-01-01

    Functional Electrical Stimulation (FES) provides a neuroprosthetic interface to non-recovered muscle groups by stimulating the affected region of the human body. FES in combination with Brain-machine interfacing (BMI) has a wide scope in rehabilitation because this system directly links the cerebral motor intention of the users with its corresponding peripheral muscle activations. In this paper, we examine the effect of FES on the electroencephalography (EEG) during motor imagery (left- and right-hand movement) training of the users. Results suggest a significant improvement in the classification accuracy when the subject was induced with FES stimuli as compared to the standard visual one. PMID:27478573

  18. Brain Stimulation for Torsion Dystonia

    PubMed Central

    Fox, Michael D.; Alterman, Ron L.

    2016-01-01

    Dystonia is a heterogeneous neurological disorder characterized by abnormal muscle contractions for which standard medical therapy is often inadequate. For such patients, therapeutic brain stimulation is becoming increasingly utilized. Here we review the evidence and effect sizes for treating different types of dystonia with different types of brain stimulation. Strong (level B) evidence supports the use of deep brain stimulation (DBS) for the treatment of primary generalized or segmental dystonia, especially DYT-1, as well as for patients with cervical dystonia. Large effect sizes have also been reported for DBS treatment of tardive dystonia, writer’s cramp, cranial dystonia, myoclonus dystonia, and off-state dystonia associated with Parkinson’s disease. Lesser benefit is generally seen in dystonia secondary to structural brain damage. Other brain stimulation techniques including epidural cortical stimulation and noninvasive brain stimulation have been investigated, but generally report smaller effect sizes in a more limited number of patients. Recent advances relevant to patient selection, surgical approach, DBS programming, and mechanism of action are discussed. PMID:25894231

  19. Physiological and modeling evidence for focal transcranial electrical brain stimulation in humans: A basis for high-definition tDCS

    PubMed Central

    Edwards, Dylan; Cortes, Mar; Datta, Abhishek; Minhas, Preet; Wassermann, Eric M.; Bikson, Marom

    2015-01-01

    Transcranial Direct Current Stimulation (tDCS) is a non-invasive, low-cost, well-tolerated technique producing lasting modulation of cortical excitability. Behavioral and therapeutic outcomes of tDCS are linked to the targeted brain regions, but there is little evidence that current reaches the brain as intended. We aimed to: (1) validate a computational model for estimating cortical electric fields in human transcranial stimulation, and (2) assess the magnitude and spread of cortical electric field with a novel High-Definition tDCS (HD-tDCS) scalp montage using a 4×1-Ring electrode configuration. In three healthy adults, Transcranial Electrical Stimulation (TES) over primary motor cortex (M1) was delivered using the 4×1 montage (4× cathode, surrounding a single central anode; montage radius ~3 cm) with sufficient intensity to elicit a discrete muscle twitch in the hand. The estimated current distribution in M1 was calculated using the individualized MRI-based model, and compared with the observed motor response across subjects. The response magnitude was quantified with stimulation over motor cortex as well as anterior and posterior to motor cortex. In each case the model data were consistent with the motor response across subjects. The estimated cortical electric fields with the 4×1 montage were compared (area, magnitude, direction) for TES and tDCS in each subject. We provide direct evidence in humans that TES with a 4×1-Ring configuration can activate motor cortex and that current does not substantially spread outside the stimulation area. Computational models predict that both TES and tDCS waveforms using the 4×1-Ring configuration generate electric fields in cortex with comparable gross current distribution, and preferentially directed normal (inward) currents. The agreement of modeling and experimental data for both current delivery and focality support the use of the HD-tDCS 4×1-Ring montage for cortically targeted neuromodulation. PMID:23370061

  20. 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.

  1. Wireless magnetothermal deep brain stimulation.

    PubMed

    Chen, Ritchie; Romero, Gabriela; Christiansen, Michael G; Mohr, Alan; Anikeeva, Polina

    2015-03-27

    Wireless deep brain stimulation of well-defined neuronal populations could facilitate the study of intact brain circuits and the treatment of neurological disorders. Here, we demonstrate minimally invasive and remote neural excitation through the activation of the heat-sensitive capsaicin receptor TRPV1 by magnetic nanoparticles. When exposed to alternating magnetic fields, the nanoparticles dissipate heat generated by hysteresis, triggering widespread and reversible firing of TRPV1(+) neurons. Wireless magnetothermal stimulation in the ventral tegmental area of mice evoked excitation in subpopulations of neurons in the targeted brain region and in structures receiving excitatory projections. The nanoparticles persisted in the brain for over a month, allowing for chronic stimulation without the need for implants and connectors. PMID:25765068

  2. Multivariate autoregressive models with exogenous inputs for intracerebral responses to direct electrical stimulation of the human brain

    PubMed Central

    Chang, Jui-Yang; Pigorini, Andrea; Massimini, Marcello; Tononi, Giulio; Nobili, Lino; Van Veen, Barry D.

    2012-01-01

    A multivariate autoregressive (MVAR) model with exogenous inputs (MVARX) is developed for describing the cortical interactions excited by direct electrical current stimulation of the cortex. Current stimulation is challenging to model because it excites neurons in multiple locations both near and distant to the stimulation site. The approach presented here models these effects using an exogenous input that is passed through a bank of filters, one for each channel. The filtered input and a random input excite a MVAR system describing the interactions between cortical activity at the recording sites. The exogenous input filter coefficients, the autoregressive coefficients, and random input characteristics are estimated from the measured activity due to current stimulation. The effectiveness of the approach is demonstrated using intracranial recordings from three surgical epilepsy patients. We evaluate models for wakefulness and NREM sleep in these patients with two stimulation levels in one patient and two stimulation sites in another resulting in a total of 10 datasets. Excellent agreement between measured and model-predicted evoked responses is obtained across all datasets. Furthermore, one-step prediction is used to show that the model also describes dynamics in pre-stimulus and evoked recordings. We also compare integrated information—a measure of intracortical communication thought to reflect the capacity for consciousness—associated with the network model in wakefulness and sleep. As predicted, higher information integration is found in wakefulness than in sleep for all five cases. PMID:23226122

  3. Electrical stimulation: a societal perspective.

    PubMed

    Gater, D R; McDowell, S M; Abbas, J J

    2000-01-01

    Societal perspective on functional electrical stimulation is colored by media influence, popular thought, and political climate as much as by the science that supports it. The purpose of this article is to examine how these influences facilitate or inhibit the application of electrical stimulation in today's world and to describe the challenges facing the use of electrical stimulation in the future. Emphasis will be placed on perceived need, cost, and available resources and how these factors must be addressed to utilize functional electrical stimulation successfully in society. PMID:11067581

  4. Brain stimulation in posttraumatic stress disorder

    PubMed Central

    Novakovic, Vladan; Sher, Leo; Lapidus, Kyle A.B.; Mindes, Janet; A.Golier, Julia; Yehuda, Rachel

    2011-01-01

    Posttraumatic stress disorder (PTSD) is a complex, heterogeneous disorder that develops following trauma and often includes perceptual, cognitive, affective, physiological, and psychological features. PTSD is characterized by hyperarousal, intrusive thoughts, exaggerated startle response, flashbacks, nightmares, sleep disturbances, emotional numbness, and persistent avoidance of trauma-associated stimuli. The efficacy of available treatments for PTSD may result in part from relief of associated depressive and anxiety-related symptoms in addition to treatment of core symptoms that derive from reexperiencing, numbing, and hyperarousal. Diverse, heterogeneous mechanisms of action and the ability to act broadly or very locally may enable brain stimulation devices to address PTSD core symptoms in more targeted ways. To achieve this goal, specific theoretical bases derived from novel, well-designed research protocols will be necessary. Brain stimulation devices include both long-used and new electrical and magnetic devices. Electroconvulsive therapy (ECT) and Cranial electrotherapy stimulation (CES) have both been in use for decades; transcranial magnetic stimulation (TMS), magnetic seizure therapy (MST), deep brain stimulation (DBS), transcranial Direct Current Stimulation (tDCS), and vagus nerve stimulation (VNS) have been developed recently, over approximately the past twenty years. The efficacy of brain stimulation has been demonstrated as a treatment for psychiatric and neurological disorders such as anxiety (CES), depression (ECT, CES, rTMS, VNS, DBS), obsessive-compulsive disorder (OCD) (DBS), essential tremor, dystonia (DBS), epilepsy (DBS, VNS), Parkinson Disease (DBS), pain (CES), and insomnia (CES). To date, limited data on brain stimulation for PTSD offer only modest guidance. ECT has shown some efficacy in reducing comorbid depression in PTSD patients but has not been demonstrated to improve most core PTSD symptoms. CES and VNS have shown some efficacy in

  5. Electrical stimulation in exercise training

    NASA Technical Reports Server (NTRS)

    Kroll, Walter

    1994-01-01

    Electrical stimulation has a long history of use in medicine dating back to 46 A.D. when the Roman physician Largus found the electrical discharge of torpedo fishes useful in the treatment of pain produced by headache and gout. A rival Greek physician, Dioscorides, discounted the value of the torpedo fish for headache relief but did recommend its use in the treatment of hemorrhoids. In 1745, the Leyden jar and various sized electrostatic generators were used to treat angina pectoris, epilepsy, hemiplegia, kidney stones, and sciatica. Benjamin Franklin used an electrical device to treat successfully a young woman suffering from convulsive fits. In the late 1800's battery powered hydroelectric baths were used to treat chronic inflammation of the uterus while electrified athletic supporters were advertised for the treatment of male problems. Fortunately, such an amusing early history of the simple beginnings of electrical stimulation did not prevent eventual development of a variety of useful therapeutic and rehabilitative applications of electrical stimulation. Over the centuries electrical stimulation has survived as a modality in the treatment of various medical disorders with its primary application being in the rehabilitation area. Recently, a surge of new interest in electrical stimulation has been kindled by the work of a Russian sport scientist who reported remarkable muscle strength and endurance improvements in elite athletes. Yakov Kots reported his research on electric stimulation and strength improvements in 1977 at a Canadian-Soviet Exchange Symposium held at Concordia University in Montreal. Since then an explosion of new studies has been seen in both sport science and in medicine. Based upon the reported works of Kots and the present surge of new investigations, one could be misled as to the origin of electrical stimulation as a technique to increase muscle strength. As a matter of fact, electric stimulation has been used as a technique to improve

  6. Lower Extremity Functional Electrical Stimulation During Inpatient Rehabilitation: A Pilot Study Investigating Gait and Muscle Activity in Persons With Stroke or Brain Injury

    PubMed Central

    Lairamore, Chad I.; Garrison, Mark K.; Bourgeon, Laetitia; Mennemeier, Mark

    2015-01-01

    The purpose of this study was to investigate the therapeutic effect of functional electrical stimulation for improving gait and tibialis anterior (TA) muscle activity in individuals with stroke or brain injury who were enrolled in an inpatient rehabilitation program. Twenty-six individuals, 2-33 days post injury, were randomly assigned to an experimental group or control group. No significant differences were observed between groups at the conclusion of the study as both groups achieved similar improvements in gait speed, TA muscle activity, and FIM™ locomotion scores. This single site study found a low dose of gait training sessions with single channel FES did not augment gait nor EMG activity beyond gait training with sham stimulation. PMID:25153616

  7. Deep brain stimulation for movement disorders.

    PubMed

    Larson, Paul S

    2014-07-01

    Deep brain stimulation (DBS) is an implanted electrical device that modulates specific targets in the brain resulting in symptomatic improvement in a particular neurologic disease, most commonly a movement disorder. It is preferred over previously used lesioning procedures due to its reversibility, adjustability, and ability to be used bilaterally with a good safety profile. Risks of DBS include intracranial bleeding, infection, malposition, and hardware issues, such migration, disconnection, or malfunction, but the risk of each of these complications is low--generally ≤ 5% at experienced, large-volume centers. It has been used widely in essential tremor, Parkinson's disease, and dystonia when medical treatment becomes ineffective, intolerable owing to side effects, or causes motor complications. Brain targets implanted include the thalamus (most commonly for essential tremor), subthalamic nucleus (most commonly for Parkinson's disease), and globus pallidus (Parkinson's disease and dystonia), although new targets are currently being explored. Future developments include brain electrodes that can steer current directionally and systems capable of "closed loop" stimulation, with systems that can record and interpret regional brain activity and modify stimulation parameters in a clinically meaningful way. New, image-guided implantation techniques may have advantages over traditional DBS surgery. PMID:24833244

  8. Deep Brain Stimulation Tested for Early Alzheimer's

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_160137.html Deep Brain Stimulation Tested for Early Alzheimer's Although treatment seems ... 2016 THURSDAY, July 28, 2016 (HealthDay News) -- Deep brain stimulation appears safe for people with early Alzheimer's ...

  9. Perceived intensity of somatosensory cortical electrical stimulation

    PubMed Central

    Blair, Hugh T.; Blaisdell, Aaron P.; Judy, Jack W.

    2010-01-01

    Artificial sensations can be produced by direct brain stimulation of sensory areas through implanted microelectrodes, but the perceptual psychophysics of such artificial sensations are not well understood. Based on prior work in cortical stimulation, we hypothesized that perceived intensity of electrical stimulation may be explained by the population response of the neurons affected by the stimulus train. To explore this hypothesis, we modeled perceived intensity of a stimulation pulse train with a leaky neural integrator. We then conducted a series of two-alternative forced choice behavioral experiments in which we systematically tested the ability of rats to discriminate frequency, amplitude, and duration of electrical pulse trains delivered to the whisker barrel somatosensory cortex. We found that the model was able to predict the performance of the animals, supporting the notion that perceived intensity can be largely accounted for by spatiotemporal integration of the action potentials evoked by the stimulus train. PMID:20440610

  10. Deep Brain Stimulation: Expanding Applications

    PubMed Central

    TEKRIWAL, Anand; BALTUCH, Gordon

    2015-01-01

    For over two decades, deep brain stimulation (DBS) has shown significant efficacy in treatment for refractory cases of dyskinesia, specifically in cases of Parkinson's disease and dystonia. DBS offers potential alleviation from symptoms through a well-tolerated procedure that allows personalized modulation of targeted neuroanatomical regions and related circuitries. For clinicians contending with how to provide patients with meaningful alleviation from often debilitating intractable disorders, DBSs titratability and reversibility make it an attractive treatment option for indications ranging from traumatic brain injury to progressive epileptic supra-synchrony. The expansion of our collective knowledge of pathologic brain circuitries, as well as advances in imaging capabilities, electrophysiology techniques, and material sciences have contributed to the expanding application of DBS. This review will examine the potential efficacy of DBS for neurologic and psychiatric disorders currently under clinical investigation and will summarize findings from recent animal models. PMID:26466888

  11. Brain stimulation using electromagnetic sources: theoretical aspects.

    PubMed Central

    Heller, L; van Hulsteyn, D B

    1992-01-01

    We prove that, at the frequencies generally proposed for extracranial stimulation of the brain, it is not possible, using any superposition of external current sources, to produce a three-dimensional local maximum of the electric field strength inside the brain. The maximum always occurs on a boundary where the conductivity jumps in value. Nevertheless, it may be possible to achieve greater two-dimensional focusing and shaping of the electric field than is currently available. Towards this goal we have used the reciprocity theorem to present a uniform treatment of the electric field inside a conducting medium produced by a variety of sources: an external magnetic dipole (current loop), an external electric dipole (linear antenna), and surface and depth electrodes. This formulation makes use of the lead fields from magneto- and electroencephalography. For the special case of a system with spherically symmetric conductivity, we derive a simple analytic formula for the electric field due to an external magnetic dipole. This formula is independent of the conductivity profile and therefore embraces spherical models with any number of shells. This explains the "insensitivity" to the skull's conductivity that has been described in numerical studies. We also present analytic formulas for the electric field due to an electric dipole, and also surface and depth electrodes, for the case of a sphere of constant conductivity. PMID:1420862

  12. Closed-Loop Control of Epilepsy by Transcranial Electrical Stimulation

    PubMed Central

    Berényi, Antal; Belluscio, Mariano; Mao, Dun; Buzsáki, György

    2016-01-01

    Many neurological and psychiatric diseases are associated with clinically detectable, altered brain dynamics. The aberrant brain activity, in principle, can be restored through electrical stimulation. In epilepsies, abnormal patterns emerge intermittently, and therefore, a closed-loop feedback brain control that leaves other aspects of brain functions unaffected is desirable. Here, we demonstrate that seizure-triggered, feedback transcranial electrical stimulation (TES) can dramatically reduce spike-and-wave episodes in a rodent model of generalized epilepsy. Closed-loop TES can be an effective clinical tool to reduce pathological brain patterns in drug-resistant patients. PMID:22879515

  13. Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injury-induced coma: orexin-A-mediated N-methyl-D-aspartate receptor subunit NR1 upregulation

    PubMed Central

    Feng, Zhen; Du, Qing

    2016-01-01

    Electrical stimulation of the median nerve is a noninvasive technique that facilitates awakening from coma. In rats with traumatic brain injury-induced coma, median nerve stimulation markedly enhances prefrontal cortex expression of orexin-A and its receptor, orexin receptor 1. To further understand the mechanism underlying wakefulness mediated by electrical stimulation of the median nerve, we evaluated its effects on the expression of the N-methyl-D-aspartate receptor subunit NR1 in the prefrontal cortex in rat models of traumatic brain injury-induced coma, using immunohistochemistry and western blot assays. In rats with traumatic brain injury, NR1 expression increased with time after injury. Rats that underwent electrical stimulation of the median nerve (30 Hz, 0.5 ms, 1.0 mA for 15 minutes) showed elevated NR1 expression and greater recovery of consciousness than those without stimulation. These effects were reduced by intracerebroventricular injection of the orexin receptor 1 antagonist SB334867. Our results indicate that electrical stimulation of the median nerve promotes recovery from traumatic brain injury-induced coma by increasing prefrontal cortex NR1 expression via an orexin-A-mediated pathway. PMID:27482224

  14. Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injury-induced coma: orexin-A-mediated N-methyl-D-aspartate receptor subunit NR1 upregulation.

    PubMed

    Feng, Zhen; Du, Qing

    2016-06-01

    Electrical stimulation of the median nerve is a noninvasive technique that facilitates awakening from coma. In rats with traumatic brain injury-induced coma, median nerve stimulation markedly enhances prefrontal cortex expression of orexin-A and its receptor, orexin receptor 1. To further understand the mechanism underlying wakefulness mediated by electrical stimulation of the median nerve, we evaluated its effects on the expression of the N-methyl-D-aspartate receptor subunit NR1 in the prefrontal cortex in rat models of traumatic brain injury-induced coma, using immunohistochemistry and western blot assays. In rats with traumatic brain injury, NR1 expression increased with time after injury. Rats that underwent electrical stimulation of the median nerve (30 Hz, 0.5 ms, 1.0 mA for 15 minutes) showed elevated NR1 expression and greater recovery of consciousness than those without stimulation. These effects were reduced by intracerebroventricular injection of the orexin receptor 1 antagonist SB334867. Our results indicate that electrical stimulation of the median nerve promotes recovery from traumatic brain injury-induced coma by increasing prefrontal cortex NR1 expression via an orexin-A-mediated pathway. PMID:27482224

  15. 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. PMID:25797650

  16. The Fos expression in rat brain following electrical stimulation of dura mater surrounding the superior sagittal sinus changed with the pre-treatment of rizatriptan benzoate.

    PubMed

    Wang, Xiaolin; Yu, Shengyuan; Dong, Zhao; Jiang, Lei

    2011-01-01

    Fos expression in the brain was systematically investigated by means of immunohistochemical staining after electrical stimulation of the dura mater surrounding the superior sagittal sinus in conscious rats. Fos-like immunoreactive neurons are distributed mainly in the upper cervical spinal cord, spinal trigeminal nucleus caudal part, raphe magnus nucleus, periaqueductal gray, ventromedial hypothalamic nucleus, and mediodorsal thalamus nucleus. With the pre-treatment of intraperitoneal injection of rizatriptan benzoate, the number of Fos-like immunoreactive neurons decreased in the spinal trigeminal nucleus caudal part and raphe magnus nucleus, increased in the periaqueductal gray, and remained unchanged in the ventromedial hypothalamic nucleus and mediodorsal thalamus nucleus. These results provide morphological evidence that the nuclei described above are involved in the development and maintenance of the trigeminovascular headache. PMID:20934408

  17. Evoked Electromyographically Controlled Electrical Stimulation

    PubMed Central

    Hayashibe, Mitsuhiro

    2016-01-01

    Time-variant muscle responses under electrical stimulation (ES) are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications. Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES) are also well known source of time-varying characteristics coming from muscle response under ES. Therefore, it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favor of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG) signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm. PMID:27471448

  18. Theory of feedback controlled brain stimulations for Parkinson's disease

    NASA Astrophysics Data System (ADS)

    Sanzeni, A.; Celani, A.; Tiana, G.; Vergassola, M.

    2016-01-01

    Limb tremor and other debilitating symptoms caused by the neurodegenerative Parkinson's disease are currently treated by administering drugs and by fixed-frequency deep brain stimulation. The latter interferes directly with the brain dynamics by delivering electrical impulses to neurons in the subthalamic nucleus. While deep brain stimulation has shown therapeutic benefits in many instances, its mechanism is still unclear. Since its understanding could lead to improved protocols of stimulation and feedback control, we have studied a mathematical model of the many-body neural network dynamics controlling the dynamics of the basal ganglia. On the basis of the results obtained from the model, we propose a new procedure of active stimulation, that depends on the feedback of the network and that respects the constraints imposed by existing technology. We show by numerical simulations that the new protocol outperforms the standard ones for deep brain stimulation and we suggest future experiments that could further improve the feedback procedure.

  19. Deep brain stimulation: new directions.

    PubMed

    Ostergard, T; Miller, J P

    2014-12-01

    The role of deep brain stimulation (DBS) in the treatment of movement disorders is well established, but there has recently been a proliferation of additional indications that have been shown to be amenable to this technology. The combination of innovative approaches to neural interface technology with novel target identification based on previously discovered clinical effects of lesioning procedures has led to a fundamental paradigm for new directions in the application of DBS. The historical use of neurosurgical lesioning procedures in the treatment of psychiatric diseases such as obsessive compulsive disorder provided an initial opportunity to expand the use of DBS. The list is rapidly expanding and now includes major depressive disorder, Tourette's syndrome, addiction disorders, and eating disorders. Keen observations by neurosurgeons using these devices have lead to the incidental discovery of treatments for diseases without previous neurosurgical treatments. These discoveries are breaking new ground in the treatment of disorders of cognition, headache syndromes, disorders of consciousness, and epilepsy. Two features of DBS make it well-suited for treatment of disorders of nervous system function. First, the reversible, non-lesional nature of DBS allows for investigation of new targets without the morbidity of permanent side effects. Second, the programmable nature of DBS allows practitioners to alter stimulation patterns to minimize side effects and potentially improve efficacy through reprogramming. More importantly, proper scientific evaluation of new targets is aided by the ability to turn stimulation on and off with evaluators blinded to the stimulation status. Knowledge of these emerging therapies is important for practitioners, as there are many situations where a single target can effectively treat the symptoms of more than one disease. The intersection of advances in neuromodulation, neurophysiology, neuroimaging, and functional neuroanatomy has

  20. Origin and Evolution of Deep Brain Stimulation

    PubMed Central

    Sironi, Vittorio A.

    2011-01-01

    This paper briefly describes how the electrical stimulation, used since antiquity to modulate the nervous system, has been a fundamental tool of neurophysiologic investigation in the second half of the eighteenth century and was subsequently used by the early twentieth century, even for therapeutic purposes. In mid-twentieth century the advent of stereotactic procedures has allowed the drift from lesional to stimulating technique of deep nuclei of the brain for therapeutic purposes. In this way, deep brain stimulation (DBS) was born, that, over the last two decades, has led to positive results for the treatment of medically refractory Parkinson’s disease, essential tremor, and dystonia. In recent years, the indications for therapeutic use of DBS have been extended to epilepsy, Tourette’s syndrome, psychiatric diseases (depression, obsessive–compulsive disorder), some kinds of headache, eating disorders, and the minimally conscious state. The potentials of the DBS for therapeutic use are fascinating, but there are still many unresolved technical and ethical problems, concerning the identification of the targets for each disease, the selection of the patients and the evaluation of the results. PMID:21887135

  1. Brain stimulation and inhibitory control.

    PubMed

    Juan, Chi-Hung; Muggleton, Neil G

    2012-04-01

    Inhibitory control mechanisms are important in a range of behaviours to prevent execution of motor acts which, having been planned, are no longer necessary or appropriate. Examples of this can be seen in a range of sports, such as cricket and baseball, where the choice between execution and inhibition of a bat swing must be made in a very brief time window. Deficits in inhibitory control have been associated with problems in behavioural regulation in impulsive violence as well as a range of clinical disorders. The roles of various areas, including the frontal eye fields (FEF), the pre-supplementary motor area (pre-SMA) and the inferior frontal gyrus, in inhibitory control have been investigated using an inhibitory control task and both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). Typically effects on response inhibition but no effects on response generation have been seen. The contributions of these areas to performance seem to differ with, for example, pre-SMA being involved when the task is relatively novel whereas this is not the case for FEF. The findings from brain stimulation studies offer both insight into which areas are necessary for effective inhibitory control and recent extension of findings for the role of the inferior frontal gyrus illustrate how the specific functions by which these areas contribute may be further clarified. Future work, including making use of the temporal specificity of TMS and combination of TMS/tDCS with other neuroimaging techniques, may further clarify the nature and functions played by the network of areas involved in inhibitory control. PMID:22494830

  2. Tolerance to repeated rewarding electrical stimulation of the parabrachial complex.

    PubMed

    Hurtado, María M; Puerto, Amadeo

    2016-10-01

    The parabrachial complex has been related to various rewarding behavioral processes. As previously shown, electrical stimulation of the lateral parabrachial external (LPBe) subnucleus induces opiate-dependent concurrent place preference. In this study, two groups of animals (and their respective controls) were subjected to sessions of rewarding brain stimulation daily or on alternate days. The rats stimulated every other day maintained a consistent preference for the place associated with the brain stimulation. However, as also found in the Insular Cortex, there was a progressive decay in the initial place preference of animals receiving daily stimulation. These data suggest that the rewarding effects induced by electrical stimulation of LPBe subnucleus may be subject to tolerance. These findings are discussed with respect to other anatomical areas showing reward decay and to the reinforcing effects induced by various electrical and chemical rewarding agents. PMID:27283973

  3. [MRI compatibility of deep brain stimulator].

    PubMed

    Zhang, Yujing

    2013-07-01

    Deep brain stimulation (DBS) therapy develops rapidly in clinical application. The structures of deep brain stimulator and magnetic resonance imaging (MRI) equipment are introduced, the interactions are analyzed, and the two compatible problems of radio frequency (RF) heating and imaging artifact are summarized in this paper. PMID:24195387

  4. Localization of the central rhythm generator involved in spontaneous consummatory licking in rats: functional ablation and electrical brain stimulation studies.

    PubMed Central

    Brozek, G; Zhuravin, I A; Megirian, D; Bures, J

    1996-01-01

    Localization of the central rhythm generator (CRG) of spontaneous consummatory licking was studied in freely moving rats by microinjection of tetrodotoxin (TTX) into the pontine reticular formation. Maximum suppression of spontaneous water consumption was elicited by TTX (1 ng) blockade of the oral part of the nucleus reticularis gigantocellularis (NRG), whereas TTX injections into more caudal or rostral locations caused significantly weaker disruption of drinking. To verify the assumption that TTX blocked the proper CRG of licking rather than some relay in its output, spontaneously drinking thirsty rats were intracranially stimulated via electrodes chronically implanted into the oral part of the NRG. Lick-synchronized stimulation (a 100-ms train of 0.1-ms-wide rectangular pulses at 100 Hz and 25-150 microA) applied during continuous licking (after eight regular consecutive licks) caused a phase shift of licks emitted after stimulus delivery. The results suggest that the stimulation has reset the CRG of licking without changing its frequency. The reset-inducing threshold current was lowest during the tongue retraction and highest during the tongue protrusion period of the lick cycle. It is concluded that the CRG of licking is located in the oral part of NRG. PMID:8622936

  5. Brain stimulation: Neuromodulation as a potential treatment for motor recovery following traumatic brain injury.

    PubMed

    Clayton, E; Kinley-Cooper, S K; Weber, R A; Adkins, D L

    2016-06-01

    There is growing evidence that electrical and magnetic brain stimulation can improve motor function and motor learning following brain damage. Rodent and primate studies have strongly demonstrated that combining cortical stimulation (CS) with skilled motor rehabilitative training enhances functional motor recovery following stroke. Brain stimulation following traumatic brain injury (TBI) is less well studied, but early pre-clinical and human pilot studies suggest that it is a promising treatment for TBI-induced motor impairments as well. This review will first discuss the evidence supporting brain stimulation efficacy derived from the stroke research field as proof of principle and then will review the few studies exploring neuromodulation in experimental TBI studies. This article is part of a Special Issue entitled SI:Brain injury and recovery. PMID:26855256

  6. Neuromuscular Electrical Stimulation for Skeletal Muscle Function

    PubMed Central

    Doucet, Barbara M.; Lam, Amy; Griffin, Lisa

    2012-01-01

    Lack of neural innervation due to neurological damage renders muscle unable to produce force. Use of electrical stimulation is a medium in which investigators have tried to find a way to restore movement and the ability to perform activities of daily living. Different methods of applying electrical current to modify neuromuscular activity are electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical stimulation (FES). This review covers the aspects of electrical stimulation used for rehabilitation and functional purposes. Discussed are the various parameters of electrical stimulation, including frequency, pulse width/duration, duty cycle, intensity/amplitude, ramp time, pulse pattern, program duration, program frequency, and muscle group activated, and how they affect fatigue in the stimulated muscle. PMID:22737049

  7. Functional electrical stimulation and spinal cord injury.

    PubMed

    Ho, Chester H; Triolo, Ronald J; Elias, Anastasia L; Kilgore, Kevin L; DiMarco, Anthony F; Bogie, Kath; Vette, Albert H; Audu, Musa L; Kobetic, Rudi; Chang, Sarah R; Chan, K Ming; Dukelow, Sean; Bourbeau, Dennis J; Brose, Steven W; Gustafson, Kenneth J; Kiss, Zelma H T; Mushahwar, Vivian K

    2014-08-01

    Spinal cord injuries (SCI) can disrupt communications between the brain and the body, resulting in loss of control over otherwise intact neuromuscular systems. Functional electrical stimulation (FES) of the central and peripheral nervous system can use these intact neuromuscular systems to provide therapeutic exercise options to allow functional restoration and to manage medical complications following SCI. The use of FES for the restoration of muscular and organ functions may significantly decrease the morbidity and mortality following SCI. Many FES devices are commercially available and should be considered as part of the lifelong rehabilitation care plan for all eligible persons with SCI. PMID:25064792

  8. Effects of Brain-Computer Interface-controlled Functional Electrical Stimulation Training on Shoulder Subluxation for Patients with Stroke: A Randomized Controlled Trial.

    PubMed

    Jang, Yun Young; Kim, Tae Hoon; Lee, Byoung Hee

    2016-06-01

    The purpose of this study was to investigate the effects of brain-computer interface (BCI)-controlled functional electrical stimulation (FES) training on shoulder subluxation of patients with stroke. Twenty subjects were randomly divided into two groups: the BCI-FES group (n = 10) and the FES group (n = 10). Patients in the BCI-FES group were administered conventional therapy with the BCI-FES on the shoulder subluxation area of the paretic upper extremity, five times per week during 6 weeks, while the FES group received conventional therapy with FES only. All patients were assessed for shoulder subluxation (vertical distance, VD; horizontal distance, HD), pain (visual analogue scale, VAS) and the Manual Function Test (MFT) at the time of recruitment to the study and after 6 weeks of the intervention. The BCI-FES group demonstrated significant improvements in VD, HD, VAS and MFT after the intervention period, while the FES group demonstrated significant improvements in HD, VAS and MFT. There were also significant differences in the VD and two items (shoulder flexion and abduction) of the MFT between the two groups. The results of this study suggest that BCI-FES training may be effective in improving shoulder subluxation of patients with stroke by facilitating motor recovery. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26876690

  9. Effects of brain-computer interface-based functional electrical stimulation on balance and gait function in patients with stroke: preliminary results

    PubMed Central

    Chung, EunJung; Park, Sang-In; Jang, Yun-Yung; Lee, Byoung-Hee

    2015-01-01

    [Purpose] The purpose of this study was to determine the effects of brain-computer interface (BCI)-based functional electrical stimulation (FES) on balance and gait function in patients with stroke. [Subjects] Subjects were randomly allocated to a BCI-FES group (n=5) and a FES group (n=5). [Methods] The BCI-FES group received ankle dorsiflexion training with FES according to a BCI-based program for 30 minutes per day for 5 days. The FES group received ankle dorsiflexion training with FES for the same duration. [Results] Following the intervention, the BCI-FES group showed significant differences in Timed Up and Go test value, cadence, and step length on the affected side. The FES group showed no significant differences after the intervention. However, there were no significant differences between the 2 groups after the intervention. [Conclusion] The results of this study suggest that BCI-based FES training is a more effective exercise for balance and gait function than FES training alone in patients with stroke. PMID:25729205

  10. Effect of Laryngopharyngeal Neuromuscular Electrical Stimulation on Dysphonia Accompanied by Dysphagia in Post-stroke and Traumatic Brain Injury Patients: A Pilot Study

    PubMed Central

    2016-01-01

    Objective To investigate the effect of laryngopharyngeal neuromuscular electrical stimulation (NMES) on dysphonia in patients with dysphagia caused by stroke or traumatic brain injury (TBI). Methods Eighteen patients participated in this study. The subjects were divided into NMES (n=12) and conventional swallowing training only (CST, n=6) groups. The NMES group received NMES combined with CST for 2 weeks, followed by CST without NMES for the next 2 weeks. The CST group received only CST for 4 weeks. All of the patients were evaluated before and at 2 and 4 weeks into the study. The outcome measurements included perceptual, acoustic and aerodynamic analyses. The correlation between dysphonia and swallowing function was also investigated. Results There were significant differences in the GRBAS (grade, roughness, breathiness, asthenia and strain scale) total score and sound pressure level (SPL) between the two groups over time. The NMES relative to the CST group showed significant improvements in total GRBAS score and SPL at 2 weeks, though no inter-group differences were evident at 4 weeks. The improvement of the total GRBAS scores at 2 weeks was positively correlated with the improved pharyngeal phase scores on the functional dysphagia scale at 2 weeks. Conclusion The results demonstrate that laryngopharyngeal NMES in post-stroke or TBI patients with dysphonia can have promising effects on phonation. Therefore, laryngopharyngeal NMES may be considered as an additional treatment option for dysphonia accompanied by dysphagia after stroke or TBI. PMID:27606266

  11. Noninvasive transcranial brain stimulation and pain.

    PubMed

    Rosen, Allyson C; Ramkumar, Mukund; Nguyen, Tam; Hoeft, Fumiko

    2009-02-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are two noninvasive brain stimulation techniques that can modulate activity in specific regions of the cortex. At this point, their use in brain stimulation is primarily investigational; however, there is clear evidence that these tools can reduce pain and modify neurophysiologic correlates of the pain experience. TMS has also been used to predict response to surgically implanted stimulation for the treatment of chronic pain. Furthermore, TMS and tDCS can be applied with other techniques, such as event-related potentials and pharmacologic manipulation, to illuminate the underlying physiologic mechanisms of normal and pathological pain. This review presents a description and overview of the uses of two major brain stimulation techniques and a listing of useful references for further study. PMID:19126365

  12. External trial deep brain stimulation device for the application of desynchronizing stimulation techniques

    NASA Astrophysics Data System (ADS)

    Hauptmann, C.; Roulet, J.-C.; Niederhauser, J. J.; Döll, W.; Kirlangic, M. E.; Lysyansky, B.; Krachkovskyi, V.; Bhatti, M. A.; Barnikol, U. B.; Sasse, L.; Bührle, C. P.; Speckmann, E.-J.; Götz, M.; Sturm, V.; Freund, H.-J.; Schnell, U.; Tass, P. A.

    2009-12-01

    In the past decade deep brain stimulation (DBS)—the application of electrical stimulation to specific target structures via implanted depth electrodes—has become the standard treatment for medically refractory Parkinson's disease and essential tremor. These diseases are characterized by pathological synchronized neuronal activity in particular brain areas. We present an external trial DBS device capable of administering effectively desynchronizing stimulation techniques developed with methods from nonlinear dynamics and statistical physics according to a model-based approach. These techniques exploit either stochastic phase resetting principles or complex delayed-feedback mechanisms. We explain how these methods are implemented into a safe and user-friendly device.

  13. Developments in deep brain stimulation using time dependent magnetic fields

    SciTech Connect

    Crowther, L.J.; Nlebedim, I.C.; Jiles, D.C.

    2012-03-07

    The effect of head model complexity upon the strength of field in different brain regions for transcranial magnetic stimulation (TMS) has been investigated. Experimental measurements were used to verify the validity of magnetic field calculations and induced electric field calculations for three 3D human head models of varying complexity. Results show the inability for simplified head models to accurately determine the site of high fields that lead to neuronal stimulation and highlight the necessity for realistic head modeling for TMS applications.

  14. Deep brain stimulation, ethics, and society.

    PubMed

    Bell, Emily; Racine, Eric

    2010-01-01

    Discussion surrounding ethical and social issues in deep brain stimulation (DBS) has increased. This article introduces a special section on the ethics of DBS in The Journal of Clinical Ethics. PMID:20866015

  15. Brain Stimulation May Help People with Anorexia

    MedlinePlus

    ... html Brain Stimulation May Help People With Anorexia Depression treatment cut urge to restrict food, study says To ... after they underwent repetitive transcranial stimulation (rTMS), a treatment approved for depression. "With rTMS we targeted ... an area of the ...

  16. A linearized current stimulator for deep brain stimulation.

    PubMed

    Shen, Ding-Lan; Chu, Yu-Jung

    2010-01-01

    This paper develops the front end of the stimulator which is applied in the implantable deep brain stimulation (DBS) for the therapy of Parkinson's disease. This stimulator adopts the low power switched-capacitor DAC accompanying with voltage-to-current transconductance amplifiers to obtain the adjustable output currents. The proposed distortion cancellation technique improves the linearity of the current stimulator. Multiple transconductance amplifiers sharing a single DAC save the circuit area. The biphasic stimulation waveform is generated from the bridge switching technique and the programmable pulse. This stimulation circuit provides the 0 approximately 165 microA current for a typical loading of 10 kΩ, 8 approximately 120 micros pulse width, and 126 approximately 244 Hz frequencies with a 0.35 microm CMOS technology at 3.3 V supply voltage. PMID:21096724

  17. Effects of Action Observational Training Plus Brain-Computer Interface-Based Functional Electrical Stimulation on Paretic Arm Motor Recovery in Patient with Stroke: A Randomized Controlled Trial.

    PubMed

    Kim, TaeHoon; Kim, SeongSik; Lee, ByoungHee

    2016-03-01

    The purpose of this study was to investigate whether action observational training (AOT) plus brain-computer interface-based functional electrical stimulation (BCI-FES) has a positive influence on motor recovery of paretic upper extremity in patients with stroke. This was a hospital-based, randomized controlled trial with a blinded assessor. Thirty patients with a first-time stroke were randomly allocated to one of two groups: the BCI-FES group (n = 15) and the control group (n = 15). The BCI-FES group administered to AOT plus BCI-FES on the paretic upper extremity five times per week during 4 weeks while both groups received conventional therapy. The primary outcomes were the Fugl-Meyer Assessment of the Upper Extremity, Motor Activity Log (MAL), Modified Barthel Index and range of motion of paretic arm. A blinded assessor evaluated the outcomes at baseline and 4 weeks. All baseline outcomes did not differ significantly between the two groups. After 4 weeks, the Fugl-Meyer Assessment of the Upper Extremity sub-items (total, shoulder and wrist), MAL (MAL-Activity of Use and Quality of Movement), Modified Barthel Index and wrist flexion range of motion were significantly higher in the BCI-FES group (p < 0.05). AOT plus BCI-based FES is effective in paretic arm rehabilitation by improving the upper extremity performance. The motor improvements suggest that AOT plus BCI-based FES can be used as a therapeutic tool for stroke rehabilitation. The limitations of the study are that subjects had a certain limited level of upper arm function, and the sample size was comparatively small; hence, it is recommended that future large-scale trials should consider stratified and lager populations according to upper arm function. PMID:26301519

  18. Penfield’s Prediction: A Mechanism for Deep Brain Stimulation

    PubMed Central

    Murrow, Richard W.

    2014-01-01

    Context: Despite its widespread use, the precise mechanism of action of Deep Brain Stimulation (DBS) therapy remains unknown. The modern urgency to publish more and new data can obscure previously learned lessons by the giants who have preceded us and whose shoulders we now stand upon. Wilder Penfield extensively studied the effects of artificial electrical brain stimulation and his comments on the subject are still very relevant today. In particular, he noted two very different (and seemingly opposite) effects of stimulation within the human brain. In some structures, artificial electrical stimulation has an effect, which mimics ablation, while, in other structures, it produces a stimulatory effect on that tissue. Hypothesis: The hypothesis of this paper is fourfold. First, it proposes that some neural circuits are widely synchronized with other neural circuits, while some neural circuits are unsynchronized and operate independently. Second, it proposes that artificial high-frequency electrical stimulation of a synchronized neural circuit results in an ablative effect, but artificial high-frequency electrical stimulation of an unsynchronized neural circuit results in a stimulatory effect. Third, it suggests a part of the mechanism by which large-scale physiologic synchronization of widely distributed independently processed information streams may occur. This may be the neural mechanism underlying Penfield’s “centrencephalic system,” which he emphasized so many years ago. Fourth, it outlines the specific anatomic distribution of this physiologic synchronization, which Penfield has already clearly delineated as the distribution of his centrencephalic system. Evidence: This paper draws on a brief overview of previous theory regarding the mechanism of action of DBS and on historical, as well as widely known modern clinical data regarding the observed effects of stimulation delivered to various targets within the brain. Basic science investigations, which

  19. Braille line using electrical stimulation

    NASA Astrophysics Data System (ADS)

    Puertas, A.; Purés, P.; Echenique, A. M.; Ensinck, J. P. Graffigna y. G.

    2007-11-01

    Conceived within the field of Rehabilitation Technologies for visually impaired persons, the present work aims at enabling the blind user to read written material by means of a tactile display. Once he is familiarized to operate this system, the user will be able to achieve greater performance in study, academic and job activities, thus achieving a rapid and easier social inclusion. The devise accepts any kind of text that is computer-loadable (documents, books, Internet information, and the like) which, through digital means, can be read as Braille text on the pad. This tactile display is composed of an electrodes platform that simulate, through stimulation the writing/reading Braille characters. In order to perceive said characters in similar way to the tactile feeling from paper material, the skin receptor of fingers are stimulated electrically so as to simulate the same pressure and depressions as those of the paper-based counterpart information. Once designed and developed, the display was tested with blind subjects, with relatively satisfactory results. As a continuing project, this prototype is currently being improved as regards.

  20. It takes two: noninvasive brain stimulation combined with neurorehabilitation.

    PubMed

    Page, Stephen J; Cunningham, David A; Plow, Ela; Blazak, Brittani

    2015-04-01

    The goal of postacute neurorehabilitation is to maximize patient function, ideally by using surviving brain and central nervous system tissue when possible. However, the structures incorporated into neurorehabilitative approaches often differ from this target, which may explain why the efficacy of conventional clinical treatments targeting neurologic impairment varies widely. Noninvasive brain stimulation (eg, transcranial magnetic stimulation [TMS], transcranial direct current stimulation [tDCS]) offers the possibility of directly targeting brain structures to facilitate or inhibit their activity to steer neural plasticity in recovery and measure neuronal output and interactions for evaluating progress. The latest advances as stereotactic navigation and electric field modeling are enabling more precise targeting of patient's residual structures in diagnosis and therapy. Given its promise, this supplement illustrates the wide-ranging significance of TMS and tDCS in neurorehabilitation, including in stroke, pediatrics, traumatic brain injury, focal hand dystonia, neuropathic pain, and spinal cord injury. TMS and tDCS are still not widely used and remain poorly understood in neurorehabilitation. Therefore, the present supplement includes articles that highlight ready clinical application of these technologies, including their comparative diagnostic capabilities relative to neuroimaging, their therapeutic benefit, their optimal delivery, the stratification of likely responders, and the variable benefits associated with their clinical use because of interactions between pathophysiology and the innate reorganization of the patient's brain. Overall, the supplement concludes that whether provided in isolation or in combination, noninvasive brain stimulation and neurorehabilitation are synergistic in the potential to transform clinical practice. PMID:25813373

  1. Functional Electrical Stimulation and Spinal Cord Injury

    PubMed Central

    Ho, Chester H.; Triolo, Ronald J.; Elias, Anastasia L.; Kilgore, Kevin L.; DiMarco, Anthony F.; Bogie, Kath; Vette, Albert H.; Audu, Musa; Kobetic, Rudi; Chang, Sarah R.; Chan, K. Ming; Dukelow, Sean; Bourbeau, Dennis J.; Brose, Steven W.; Gustafson, Kenneth J.; Kiss, Zelma; Mushahwar, Vivian K.

    2015-01-01

    Synopsis Spinal cord injuries (SCI) can disrupt communications between the brain and the body, leading to a loss of control over otherwise intact neuromuscular systems. The use of electrical stimulation (ES) of the central and peripheral nervous system can take advantage of these intact neuromuscular systems to provide therapeutic exercise options, to allow functional restoration, and even to manage or prevent many medical complications following SCI. The use of ES for the restoration of upper extremity, lower extremity and truncal functions can make many activities of daily living a potential reality for individuals with SCI. Restoring bladder and respiratory functions and preventing pressure ulcers may significantly decrease the morbidity and mortality following SCI. Many of the ES devices are already commercially available and should be considered by all SCI clinicians routinely as part of the lifelong rehabilitation care plan for all eligible individuals with SCI. PMID:25064792

  2. Modulating Hippocampal Plasticity with In Vivo Brain Stimulation

    PubMed Central

    Carhuatanta, Kim A.; McInturf, Shawn M.; Miklasevich, Molly K.; Jankord, Ryan

    2015-01-01

    Investigations into the use of transcranial direct current stimulation (tDCS) in relieving symptoms of neurological disorders and enhancing cognitive or motor performance have exhibited promising results. However, the mechanisms by which tDCS effects brain function remain under scrutiny. We have demonstrated that in vivo tDCS in rats produced a lasting effect on hippocampal synaptic plasticity, as measured using extracellular recordings. Ex vivo preparations of hippocampal slices from rats that have been subjected to tDCS of 0.10 or 0.25 mA for 30 min followed by 30 min of recovery time displayed a robust twofold enhancement in long-term potentiation (LTP) induction accompanied by a 30% increase in paired-pulse facilitation (PPF). The magnitude of the LTP effect was greater with 0.25 mA compared with 0.10 mA stimulations, suggesting a dose-dependent relationship between tDCS intensity and its effect on synaptic plasticity. To test the persistence of these observed effects, animals were stimulated in vivo for 30 min at 0.25 mA and then allowed to return to their home cage for 24 h. Observation of the enhanced LTP induction, but not the enhanced PPF, continued 24 h after completion of 0.25 mA of tDCS. Addition of the NMDA blocker AP-5 abolished LTP in both control and stimulated rats but maintained the PPF enhancement in stimulated rats. The observation of enhanced LTP and PPF after tDCS demonstrates that non-invasive electrical stimulation is capable of modifying synaptic plasticity. SIGNIFICANCE STATEMENT Researchers have used brain stimulation such as transcranial direct current stimulation on human subjects to alleviate symptoms of neurological disorders and enhance their performance. Here, using rats, we have investigated the potential mechanisms of how in vivo brain stimulation can produce such effect. We recorded directly on viable brain slices from rats after brain stimulation to detect lasting changes in pattern of neuronal activity. Our results showed that

  3. Vomiting Center reanalyzed: An electrical stimulation study

    NASA Technical Reports Server (NTRS)

    Miller, A. D.; Wilson, V. J.

    1982-01-01

    Electrical stimulation of the brainstem of 15 decerebrate cats produced stimulus-bound vomiting in only 4 animals. Vomiting was reproducible in only one cat. Effective stimulating sites were located in the solitary tract and reticular formation. Restricted localization of a vomiting center, stimulation of which evoked readily reproducible results, could not be obtained.

  4. Matching geometry and stimulation parameters of electrodes for deep brain stimulation experiments--numerical considerations.

    PubMed

    Gimsa, Ulrike; Schreiber, Ute; Habel, Beate; Flehr, Jürgen; van Rienen, Ursula; Gimsa, Jan

    2006-01-30

    Deep brain stimulation, the electric stimulation of basal ganglia nuclei, is a treatment for movement disorders such as Parkinson's disease. The underlying mechanisms are studied in animals, e.g. rodents. Designs and materials of commercially available microelectrodes, as well as experimentally applied driving signals vary tremendously. We used finite integration modeling to compare the electric field and current density distributions induced by various electrodes. Current density or field strength "hot spots", which are located particularly at sites of high curvature and material interfaces coincided with corrosion and erosion at poles and insulation, respectively, as shown by scanning electron microscopy of stainless steel electrodes. Cell constants, i.e. geometry factors relating the electrode impedance to the specific medium conductivity, were calculated to determine the electrode voltage for a given stimulation current. Nevertheless, for electrodes of the same cell constant but of different geometry, current and field distributions may be very dissimilar. We found geometry-dependent limiting values of the stimulation current, above which electric tissue damage may occur. These values limit the reach of the stimulation signal for a given electrode geometry. Also, electrode geometries determine the shape of the stimulated tissue volume. This study provides tools for choosing the most appropriate geometry for targeting different-sized brain areas. PMID:16095718

  5. Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain

    NASA Astrophysics Data System (ADS)

    Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

    1998-12-01

    Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

  6. Adaptive deep brain stimulation in Parkinson's disease.

    PubMed

    Beudel, M; Brown, P

    2016-01-01

    Although Deep Brain Stimulation (DBS) is an established treatment for Parkinson's disease (PD), there are still limitations in terms of effectivity, side-effects and battery consumption. One of the reasons for this may be that not only pathological but also physiological neural activity can be suppressed whilst stimulating. For this reason, adaptive DBS (aDBS), where stimulation is applied according to the level of pathological activity, might be advantageous. Initial studies of aDBS demonstrate effectiveness in PD, but there are still many questions to be answered before aDBS can be applied clinically. Here we discuss the feedback signals and stimulation algorithms involved in adaptive stimulation in PD and sketch a potential road-map towards clinical application. PMID:26411502

  7. Optimal Geometry and Stimulating Mechanism of Deep-brain Electrode—Role of Electrode Contact Geometry

    NASA Astrophysics Data System (ADS)

    Lian, Qin; Wang, Jue; Liu, Hongzhong; Li, DiChen

    2008-09-01

    Deep brain stimulation has been demonstrated as an effective treatment for various locomotion disorders; however, the stimulating mechanism by which these high frequency electrical pulses intertwined with the geometry of electrode act on neuronal activity is unclear. Finite element analytic model of electrode in deep brain stimulation was established in this paper to investigate the impact of changes of electrode contact geometry on the cerebral electric field. The computational calculation showed that electrode contact configuration not only determined the stimulation position of electrode in the deep brain, but also played an important role on stimulated tissue area and stimulated field strength, which can provide more practical design rule for the electrode in deep brain stimulation.

  8. Mimicking muscle activity with electrical stimulation

    NASA Astrophysics Data System (ADS)

    Johnson, Lise A.; Fuglevand, Andrew J.

    2011-02-01

    Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.

  9. Advances in functional electrical stimulation (FES).

    PubMed

    Popović, Dejan B

    2014-12-01

    This review discusses the advancements that are needed to enhance the effects of electrical stimulation for restoring or assisting movement in humans with an injury/disease of the central nervous system. A complex model of the effects of electrical stimulation of peripheral systems is presented. The model indicates that both the motor and sensory systems are activated by electrical stimulation. We propose that a hierarchical hybrid controller may be suitable for functional electrical stimulation (FES) because this type of controller acts as a structural mimetic of its biological counterpart. Specific attention is given to the neural systems at the periphery with respect to the required electrodes and stimulators. Furthermore, we note that FES with surface electrodes is preferred for the therapy, although there is a definite advantage associated with implantable technology for life-long use. The last section of the review discusses the potential need to combine FES and robotic systems to provide assistance in some cases. PMID:25287528

  10. Mechanism of Deep Brain Stimulation: Inhibition, Excitation, or Disruption?

    PubMed

    Chiken, Satomi; Nambu, Atsushi

    2016-06-01

    Deep brain stimulation (DBS), applying high-frequency electrical stimulation to deep brain structures, has now provided an effective therapeutic option for treatment of various neurological and psychiatric disorders. DBS targeting the internal segment of the globus pallidus, subthalamic nucleus, and thalamus is used to treat symptoms of movement disorders, such as Parkinson's disease, dystonia, and tremor. However, the mechanism underlying the beneficial effects of DBS remains poorly understood and is still under debate: Does DBS inhibit or excite local neuronal elements? In this short review, we would like to introduce our recent work on the physiological mechanism of DBS and propose an alternative explanation: DBS dissociates input and output signals, resulting in the disruption of abnormal information flow through the stimulation site. PMID:25888630

  11. Electrical stimulation to accelerate wound healing

    PubMed Central

    Thakral, Gaurav; LaFontaine, Javier; Najafi, Bijan; Talal, Talal K.; Kim, Paul; Lavery, Lawrence A.

    2013-01-01

    Background There are several applications of electrical stimulation described in medical literature to accelerate wound healing and improve cutaneous perfusion. This is a simple technique that could be incorporated as an adjunctive therapy in plastic surgery. The objective of this review was to evaluate the results of randomized clinical trials that use electrical stimulation for wound healing. Method We identified 21 randomized clinical trials that used electrical stimulation for wound healing. We did not include five studies with treatment groups with less than eight subjects. Results Electrical stimulation was associated with faster wound area reduction or a higher proportion of wounds that healed in 14 out of 16 wound randomized clinical trials. The type of electrical stimulation, waveform, and duration of therapy vary in the literature. Conclusion Electrical stimulation has been shown to accelerate wound healing and increase cutaneous perfusion in human studies. Electrical stimulation is an adjunctive therapy that is underutilized in plastic surgery and could improve flap and graft survival, accelerate postoperative recovery, and decrease necrosis following foot reconstruction. PMID:24049559

  12. Electrical stimulation mapping of nouns and verbs in Broca's area.

    PubMed

    Havas, Viktória; Gabarrós, Andreu; Juncadella, Montserrat; Rifa-Ros, Xavi; Plans, Gerard; Acebes, Juan José; de Diego Balaguer, Ruth; Rodríguez-Fornells, Antoni

    2015-01-01

    Electric stimulation mapping (ESM) is frequently used during brain surgery to localise higher cognitive functions to avoid post-chirurgical disabilities. Experiments with brain imaging techniques and neuropsychological studies showed differences in the cortical representation and processing of nouns and verbs. The goal of the present study was to investigate whether electric stimulation in specific sites in the frontal cortex disrupted noun and verb production selectively. We found that most of the stimulated areas showed disruption of both verbs and nouns at the inferior frontal gyrus. However, when selective effects were obtained, verbs were more prone to disruption than nouns with important individual differences. The overall results indicate that selective impairments can be observed at inferior and middle frontal regions and the action naming task seems to be more suitable to avoid post-chirurgical language disabilities, as it shows a greater sensitivity to disruption with ESM than the classical object naming task. PMID:25957505

  13. Dynamics of Parkinsonian tremor during deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Titcombe, Michèle S.; Glass, Leon; Guehl, Dominique; Beuter, Anne

    2001-12-01

    The mechanism by which chronic, high frequency, electrical deep brain stimulation (HF-DBS) suppresses tremor in Parkinson's disease is unknown. Rest tremor in subjects with Parkinson's disease receiving HF-DBS was recorded continuously throughout switching the deep brain stimulator on (at an effective frequency) and off. These data suggest that the stimulation induces a qualitative change in the dynamics, called a Hopf bifurcation, so that the stable oscillations are destabilized. We hypothesize that the periodic stimulation modifies a parameter affecting the oscillation in a time dependent way and thereby induces a Hopf bifurcation. We explore this hypothesis using a schematic network model of an oscillator interacting with periodic stimulation. The mechanism of time-dependent change of a control parameter in the model captures two aspects of the dynamics observed in the data: (1) a gradual increase in tremor amplitude when the stimulation is switched off and a gradual decrease in tremor amplitude when the stimulation is switched on and (2) a time delay in the onset and offset of the oscillations. This mechanism is consistent with these rest tremor transition data and with the idea that HF-DBS acts via the gradual change of a network property.

  14. Focusing and targeting of magnetic brain stimulation using multiple coils.

    PubMed

    Ruohonen, J; Ilmoniemi, R J

    1998-05-01

    Neurones can be excited by an externally applied time-varying electromagnetic field. Focused magnetic brain stimulation is attained using multiple small coils instead of one large coil, the resultant induced electric field being a superposition of the fields from each coil. In multichannel magnetic brain stimulation, partial cancellation of fields from individual coils provides a significant improvement in the focusing of the stimulating field, and independent coil channels allow targeting of the stimuli on a given spot without moving the coils. The problem of shaping the stimulating field in multichannel stimulation is analysed, and a method is derived that yields the driving currents required to induce a field with a user-defined shape. The formulation makes use of lead fields and minimum-norm estimation from magneto-encephalography. Using these methods, some properties of multichannel coil arrays are examined. Computer-assisted multichannel stimulation of the cortex will enable several new studies, including quick determination of the cortical regions, the stimulation of which disrupts cortical processing required by a task. PMID:9747568

  15. Electrical Cerebral Stimulation Modifies Inhibitory Systems

    NASA Astrophysics Data System (ADS)

    Cuéllar-Herrera, M.; Rocha, L.

    2003-09-01

    Electrical stimulation of the nervous tissue has been proposed as a method to treat some neurological disorders, such as epilepsy. Epileptic seizures result from excessive, synchronous, abnormal firing patterns of neurons that are located predominantly in the cerebral cortex. Many people with epilepsy continue presenting seizures even though they are under regimens of antiepileptic medications. An alternative therapy for treatment resistant epilepsy is cerebral electrical stimulation. The present study is focused to review the effects of different types of electrical stimulation and specifically changes in amino acids.

  16. Deep brain transcranial magnetic stimulation using variable "Halo coil" system

    NASA Astrophysics Data System (ADS)

    Meng, Y.; Hadimani, R. L.; Crowther, L. J.; Xu, Z.; Qu, J.; Jiles, D. C.

    2015-05-01

    Transcranial Magnetic Stimulation has the potential to treat various neurological disorders non-invasively and safely. The "Halo coil" configuration can stimulate deeper regions of the brain with lower surface to deep-brain field ratio compared to other coil configurations. The existing "Halo coil" configuration is fixed and is limited in varying the site of stimulation in the brain. We have developed a new system based on the current "Halo coil" design along with a graphical user interface system that enables the larger coil to rotate along the transverse plane. The new system can also enable vertical movement of larger coil. Thus, this adjustable "Halo coil" configuration can stimulate different regions of the brain by adjusting the position and orientation of the larger coil on the head. We have calculated magnetic and electric fields inside a MRI-derived heterogeneous head model for various positions and orientations of the coil. We have also investigated the mechanical and thermal stability of the adjustable "Halo coil" configuration for various positions and orientations of the coil to ensure safe operation of the system.

  17. Closing the loop of deep brain stimulation.

    PubMed

    Carron, Romain; Chaillet, Antoine; Filipchuk, Anton; Pasillas-Lépine, William; Hammond, Constance

    2013-01-01

    High-frequency deep brain stimulation is used to treat a wide range of brain disorders, like Parkinson's disease. The stimulated networks usually share common electrophysiological signatures, including hyperactivity and/or dysrhythmia. From a clinical perspective, HFS is expected to alleviate clinical signs without generating adverse effects. Here, we consider whether the classical open-loop HFS fulfills these criteria and outline current experimental or theoretical research on the different types of closed-loop DBS that could provide better clinical outcomes. In the first part of the review, the two routes followed by HFS-evoked axonal spikes are explored. In one direction, orthodromic spikes functionally de-afferent the stimulated nucleus from its downstream target networks. In the opposite direction, antidromic spikes prevent this nucleus from being influenced by its afferent networks. As a result, the pathological synchronized activity no longer propagates from the cortical networks to the stimulated nucleus. The overall result can be described as a reversible functional de-afferentation of the stimulated nucleus from its upstream and downstream nuclei. In the second part of the review, the latest advances in closed-loop DBS are considered. Some of the proposed approaches are based on mathematical models, which emphasize different aspects of the parkinsonian basal ganglia: excessive synchronization, abnormal firing-rate rhythms, and a deficient thalamo-cortical relay. The stimulation strategies are classified depending on the control-theory techniques on which they are based: adaptive and on-demand stimulation schemes, delayed and multi-site approaches, stimulations based on proportional and/or derivative control actions, optimal control strategies. Some of these strategies have been validated experimentally, but there is still a large reservoir of theoretical work that may point to ways of improving practical treatment. PMID:24391555

  18. Brain networks modulated by subthalamic nucleus deep brain stimulation.

    PubMed

    Accolla, Ettore A; Herrojo Ruiz, Maria; Horn, Andreas; Schneider, Gerd-Helge; Schmitz-Hübsch, Tanja; Draganski, Bogdan; Kühn, Andrea A

    2016-09-01

    Deep brain stimulation of the subthalamic nucleus is an established treatment for the motor symptoms of Parkinson's disease. Given the frequent occurrence of stimulation-induced affective and cognitive adverse effects, a better understanding about the role of the subthalamic nucleus in non-motor functions is needed. The main goal of this study is to characterize anatomical circuits modulated by subthalamic deep brain stimulation, and infer about the inner organization of the nucleus in terms of motor and non-motor areas. Given its small size and anatomical intersubject variability, functional organization of the subthalamic nucleus is difficult to investigate in vivo with current methods. Here, we used local field potential recordings obtained from 10 patients with Parkinson's disease to identify a subthalamic area with an analogous electrophysiological signature, namely a predominant beta oscillatory activity. The spatial accuracy was improved by identifying a single contact per macroelectrode for its vicinity to the electrophysiological source of the beta oscillation. We then conducted whole brain probabilistic tractography seeding from the previously identified contacts, and further described connectivity modifications along the macroelectrode's main axis. The designated subthalamic 'beta' area projected predominantly to motor and premotor cortical regions additional to connections to limbic and associative areas. More ventral subthalamic areas showed predominant connectivity to medial temporal regions including amygdala and hippocampus. We interpret our findings as evidence for the convergence of different functional circuits within subthalamic nucleus' portions deemed to be appropriate as deep brain stimulation target to treat motor symptoms in Parkinson's disease. Potential clinical implications of our study are illustrated by an index case where deep brain stimulation of estimated predominant non-motor subthalamic nucleus induced hypomanic behaviour. PMID

  19. Neuroethics of deep brain stimulation for mental disorders: brain stimulation reward in humans.

    PubMed

    Oshima, Hideki; Katayama, Yoichi

    2010-01-01

    The theoretical basis of some deep brain stimulation (DBS) trials undertaken in the early years was the phenomenon of "brain stimulation reward (BSR)," which was first identified in rats. The animals appeared to be rewarded by pleasure caused by the stimulation of certain brain regions (reward system), such as the septal area. "Self-stimulation" experiments, in which rats were allowed to stimulate their own brain by pressing a freely accessible lever, they quickly learned lever pressing and sometimes continued to stimulate until they exhausted themselves. BSR was also observed with DBS of the septal area in humans. DBS trials in later years were undertaken on other theoretical bases, but unexpected BSR was sometimes induced by stimulation of some areas, such as the locus coeruleus complex. When BSR was induced, the subjects experienced feelings that were described as "cheerful," "alert," "good," "well-being," "comfort," "relaxation," "joy," or "satisfaction." Since the DBS procedure is equivalent to a "self-stimulation" experiment, they could become "addicted to the stimulation itself" or "compulsive about the stimulation," and stimulate themselves "for the entire day," "at maximum amplitude" and, in some instances, "into convulsions." DBS of the reward system has recently been applied to alleviate anhedonia in patients with refractory major depression. Although this approach appears promising, there remains a difficult problem: who can adjust their feelings and reward-oriented behavior within the normal range? With a self-stimulation procedure, the BSR may become uncontrollable. To develop DBS to the level of a standard therapy for mental disorders, we need to discuss "Who has the right to control the mental condition?" and "Who makes decisions" on "How much control is appropriate?" in daily life. PMID:20885119

  20. Network effects of deep brain stimulation.

    PubMed

    Alhourani, Ahmad; McDowell, Michael M; Randazzo, Michael J; Wozny, Thomas A; Kondylis, Efstathios D; Lipski, Witold J; Beck, Sarah; Karp, Jordan F; Ghuman, Avniel S; Richardson, R Mark

    2015-10-01

    The ability to differentially alter specific brain functions via deep brain stimulation (DBS) represents a monumental advance in clinical neuroscience, as well as within medicine as a whole. Despite the efficacy of DBS in the treatment of movement disorders, for which it is often the gold-standard therapy when medical management becomes inadequate, the mechanisms through which DBS in various brain targets produces therapeutic effects is still not well understood. This limited knowledge is a barrier to improving efficacy and reducing side effects in clinical brain stimulation. A field of study related to assessing the network effects of DBS is gradually emerging that promises to reveal aspects of the underlying pathophysiology of various brain disorders and their response to DBS that will be critical to advancing the field. This review summarizes the nascent literature related to network effects of DBS measured by cerebral blood flow and metabolic imaging, functional imaging, and electrophysiology (scalp and intracranial electroencephalography and magnetoencephalography) in order to establish a framework for future studies. PMID:26269552

  1. In vivo impedance spectroscopy of deep brain stimulation electrodes

    NASA Astrophysics Data System (ADS)

    Lempka, Scott F.; Miocinovic, Svjetlana; Johnson, Matthew D.; Vitek, Jerrold L.; McIntyre, Cameron C.

    2009-08-01

    Deep brain stimulation (DBS) represents a powerful clinical technology, but a systematic characterization of the electrical interactions between the electrode and the brain is lacking. The goal of this study was to examine the in vivo changes in the DBS electrode impedance that occur after implantation and during clinically relevant stimulation. Clinical DBS devices typically apply high-frequency voltage-controlled stimulation, and as a result, the injected current is directly regulated by the impedance of the electrode-tissue interface. We monitored the impedance of scaled-down clinical DBS electrodes implanted in the thalamus and subthalamic nucleus of a rhesus macaque using electrode impedance spectroscopy (EIS) measurements ranging from 0.5 Hz to 10 kHz. To further characterize our measurements, equivalent circuit models of the electrode-tissue interface were used to quantify the role of various interface components in producing the observed electrode impedance. Following implantation, the DBS electrode impedance increased and a semicircular arc was observed in the high-frequency range of the EIS measurements, commonly referred to as the tissue component of the impedance. Clinically relevant stimulation produced a rapid decrease in electrode impedance with extensive changes in the tissue component. These post-operative and stimulation-induced changes in impedance could play an important role in the observed functional effects of voltage-controlled DBS and should be considered during clinical stimulation parameter selection and chronic animal research studies.

  2. A new brain stimulation method: Noninvasive transcranial magneto–acoustical stimulation

    NASA Astrophysics Data System (ADS)

    Yuan, Yi; Chen, Yu-Dong; Li, Xiao-Li

    2016-08-01

    We investigate transcranial magneto–acoustical stimulation (TMAS) for noninvasive brain neuromodulation in vivo. TMAS as a novel technique uses an ultrasound wave to induce an electric current in the brain tissue in the static magnetic field. It has the advantage of high spatial resolution and penetration depth. The mechanism of TMAS onto a neuron is analyzed by combining the TMAS principle and Hodgkin–Huxley neuron model. The anesthetized rats are stimulated by TMAS, resulting in the local field potentials which are recorded and analyzed. The simulation results show that TMAS can induce neuronal action potential. The experimental results indicate that TMAS can not only increase the amplitude of local field potentials but also enhance the effect of focused ultrasound stimulation on the neuromodulation. In summary, TMAS can accomplish brain neuromodulation, suggesting a potentially powerful noninvasive stimulation method to interfere with brain rhythms for diagnostic and therapeutic purposes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503321 and 61273063) and the Natural Science Foundation of Hebei Province, China (Grant No. F2014203161).

  3. Deep Brain Stimulation for Parkinson Disease

    PubMed Central

    Bronstein, Jeff M.; Tagliati, Michele; Alterman, Ron L.; Lozano, Andres M.; Volkmann, Jens; Stefani, Alessandro; Horak, Fay B.; Okun, Michael S.; Foote, Kelly D.; Krack, Paul; Pahwa, Rajesh; Henderson, Jaimie M.; Hariz, Marwan I.; Bakay, Roy A.; Rezai, Ali; Marks, William J.; Moro, Elena; Vitek, Jerrold L.; Weaver, Frances M.; Gross, Robert E.; DeLong, Mahlon R.

    2015-01-01

    Objective To provide recommendations to patients, physicians, and other health care providers on several issues involving deep brain stimulation (DBS) for Parkinson disease (PD). Data Sources and Study Selection An international consortium of experts organized, reviewed the literature, and attended the workshop. Topics were introduced at the workshop, followed by group discussion. Data Extraction and Synthesis A draft of a consensus statement was presented and further edited after plenary debate. The final statements were agreed on by all members. Conclusions (1) Patients with PD without significant active cognitive or psychiatric problems who have medically intractable motor fluctuations, intractable tremor, or intolerance of medication adverse effects are good candidates for DBS. (2) Deep brain stimulation surgery is best performed by an experienced neurosurgeon with expertise in stereotactic neurosurgery who is working as part of a interprofessional team. (3) Surgical complication rates are extremely variable, with infection being the most commonly reported complication of DBS. (4) Deep brain stimulation programming is best accomplished by a highly trained clinician and can take 3 to 6 months to obtain optimal results. (5) Deep brain stimulation improves levodopa-responsive symptoms, dyskinesia, and tremor; benefits seem to be long-lasting in many motor domains. (6) Subthalamic nuclei DBS may be complicated by increased depression, apathy, impulsivity, worsened verbal fluency, and executive dysfunction in a subset of patients. (7) Both globus pallidus pars interna and subthalamic nuclei DBS have been shown to be effective in addressing the motor symptoms of PD. (8) Ablative therapy is still an effective alternative and should be considered in a select group of appropriate patients. PMID:20937936

  4. A programmable high-voltage compliance neural stimulator for deep brain stimulation in vivo.

    PubMed

    Gong, Cihun-Siyong Alex; Lai, Hsin-Yi; Huang, Sy-Han; Lo, Yu-Chun; Lee, Nicole; Chen, Pin-Yuan; Tu, Po-Hsun; Yang, Chia-Yen; Lin, James Chang-Chieh; Chen, You-Yin

    2015-01-01

    Deep brain stimulation (DBS) is one of the most effective therapies for movement and other disorders. The DBS neurosurgical procedure involves the implantation of a DBS device and a battery-operated neurotransmitter, which delivers electrical impulses to treatment targets through implanted electrodes. The DBS modulates the neuronal activities in the brain nucleus for improving physiological responses as long as an electric discharge above the stimulation threshold can be achieved. In an effort to improve the performance of an implanted DBS device, the device size, implementation cost, and power efficiency are among the most important DBS device design aspects. This study aims to present preliminary research results of an efficient stimulator, with emphasis on conversion efficiency. The prototype stimulator features high-voltage compliance, implemented with only a standard semiconductor process, without the use of extra masks in the foundry through our proposed circuit structure. The results of animal experiments, including evaluation of evoked responses induced by thalamic electrical stimuli with our fabricated chip, were shown to demonstrate the proof of concept of our design. PMID:26029954

  5. A Programmable High-Voltage Compliance Neural Stimulator for Deep Brain Stimulation in Vivo

    PubMed Central

    Gong, Cihun-Siyong Alex; Lai, Hsin-Yi; Huang, Sy-Han; Lo, Yu-Chun; Lee, Nicole; Chen, Pin-Yuan; Tu, Po-Hsun; Yang, Chia-Yen; Lin, James Chang-Chieh; Chen, You-Yin

    2015-01-01

    Deep brain stimulation (DBS) is one of the most effective therapies for movement and other disorders. The DBS neurosurgical procedure involves the implantation of a DBS device and a battery-operated neurotransmitter, which delivers electrical impulses to treatment targets through implanted electrodes. The DBS modulates the neuronal activities in the brain nucleus for improving physiological responses as long as an electric discharge above the stimulation threshold can be achieved. In an effort to improve the performance of an implanted DBS device, the device size, implementation cost, and power efficiency are among the most important DBS device design aspects. This study aims to present preliminary research results of an efficient stimulator, with emphasis on conversion efficiency. The prototype stimulator features high-voltage compliance, implemented with only a standard semiconductor process, without the use of extra masks in the foundry through our proposed circuit structure. The results of animal experiments, including evaluation of evoked responses induced by thalamic electrical stimuli with our fabricated chip, were shown to demonstrate the proof of concept of our design. PMID:26029954

  6. It Takes Two: Non Invasive Brain Stimulation Combined with Neurorehabilitation

    PubMed Central

    Page, Stephen J.; Cunningham, David A; Plow, Ela; Blazak, Brittani

    2015-01-01

    The goal of post-acute neurorehabilitation is to maximize patients' function, ideally by using surviving brain and central nervous system tissue when possible. Yet the structures incorporated into neurorehabilitative approaches often differ from this target, which may explain why efficacy of conventional clinical treatments targeting neurological impairments varies widely. Non-invasive brain stimulation such as with Transcranial Magnetic Stimulation (TMS) and transcranial direct current stimulation (tDCS) offers the possibility of directly targeting brain structures to facilitate or inhibit their activity so as to steer neural plasticity in recovery, and measure neuronal output and interactions for evaluating progress. Latest advances as stereotactic navigation and electric field modeling are enabling more precise targeting of patient's residual structures in diagnosis and therapy. Given its promise, this supplement illustrates the wide-ranging significance of TMS and tDCS in neurorehabilitation, including in stroke, pediatrics, traumatic brain injury, focal hand dystonia, neuropathic pain and spinal cord injury. TMS and tDCS are still not widely used and remain poorly understood in neurorehabilitation. Thus, the present supplement includes articles that highlight ready clinical application of these technologies, including their comparative diagnostic capabilities relative to neuroimaging, their therapeutic benefit, their optimal delivery, the stratification of likely responders, and the variable benefits associated with their clinical use due to interactions between pathophysiology and the innate reorganization of the patient's brain. Overall, the supplement concludes that whether provided in isolation or in combination, non-invasive brain stimulation with neuro-rehabilitation are synergistic in the potential to transform clinical practice. PMID:25813373

  7. [Transcranial and invasive brain stimulation for depression].

    PubMed

    Plewnia, C; Padberg, F

    2012-08-01

    Considering the substantial proportion of depressed patients which does not sufficiently benefit from antidepressant pharmacotherapy or psychotherapy, there is increasing interest in non-pharmacological antidepressant strategies. Thus, a whole array of stimulation approaches has been developed as potential new antidepressant interventions. These methods include transcranial convulsive and non-convulsive approaches, e.g. electroconvulsive therapy (ECT), magnetic seizure therapy (MST), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) as well as invasive techniques, e.g. deep brain stimulation (DBS), vagus nerve stimulation (VNS) and epidural cortical stimulation (ECS). Each method represents a specific therapeutic approach with distinct targets within neural networks involved in the pathophysiology of depression. The ECT procedure is an established treatment with the highest efficacy of all antidepressant interventions and TMS reaches the highest level of evidence among the novel neurostimulation approaches and may be clinically used. However, the field yields a promising rapid development which may substantially enrich the armamentarium of antidepressant interventions in the near future. PMID:22843027

  8. Modeling the current distribution across the depth electrode-brain interface in deep brain stimulation.

    PubMed

    Yousif, Nada; Liu, Xuguang

    2007-09-01

    The mismatch between the extensive clinical use of deep brain stimulation (DBS), which is being used to treat an increasing number of neurological disorders, and the lack of understanding of the underlying mechanisms is confounded by the difficulty of measuring the spread of electric current in the brain in vivo. In this article we present a brief review of the recent computational models that simulate the electric current and field distribution in 3D space and, consequently, make estimations of the brain volume being modulated by therapeutic DBS. Such structural modeling work can be categorized into three main approaches: target-specific modeling, models of instrumentation and modeling the electrode-brain interface. Comments are made for each of these approaches with emphasis on our electrode-brain interface modeling, since the stimulating current must travel across the electrode-brain interface in order to reach the surrounding brain tissue and modulate the pathological neural activity. For future modeling work, a combined approach needs to be taken to reveal the underlying mechanisms, and both structural and dynamic models need to be clinically validated to make reliable predictions about the therapeutic effect of DBS in order to assist clinical practice. PMID:17850197

  9. 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. PMID:23787954

  10. Enhancing duration processing with parietal brain stimulation.

    PubMed

    Dormal, Valérie; Javadi, Amir-Homayoun; Pesenti, Mauro; Walsh, Vincent; Cappelletti, Marinella

    2016-05-01

    Numerosity and duration are thought to share common magnitude-based mechanisms in brain regions including the right parietal and frontal cortices like the supplementary motor area, SMA. Numerosity and duration are, however, also different in several intrinsic features. For instance, in a quantification context, numerosity is known for being more automatically accessed than temporal events, and durations are by definition sequential whereas numerosity can be both sequential and simultaneous. Moreover, numerosity and duration processing diverge in terms of their neuronal correlates. Whether these observed neuronal specificities can be accounted for by differences in automaticity or presentation-mode is however not clear. To address this issue, we used brain stimulation (transcranial random noise stimulation, tRNS) to the right parietal cortex or the SMA combined with experimental stimuli differing in their level of automaticity (numerosity and duration) and presentation mode (sequential or simultaneous). Compared to a no stimulation group, performance changed in duration but not in numerosity categorisation following right parietal but not SMA stimulation. These results indicate that the right parietal cortex is critical for duration processing, and suggest that tRNS has a stronger effect on less automatic processes such as duration. PMID:27037043

  11. Transcutaneous functional electrical stimulator "Compex Motion".

    PubMed

    Keller, Thierry; Popovic, Milos R; Pappas, Ion P I; Müller, Pierre-Yves

    2002-03-01

    Research groups in the field of functional electrical stimulation (FES) are often confronted with the fact that existing and commercially available FES stimulators do not provide sufficient flexibility and cannot be used to perform different FES tasks. The lack of flexibility of the commercial systems until now forced various FES research teams to develop their own stimulators. This paper presents a newly developed firmware and graphical programming software for the commercial Compex 2 stimulator which enhances the versatility and capabilities of the stimulator from a medical and therapeutic device to a neuroprosthesis and research tool. The new stimulator, called Compex Motion, can now be used to develop various custom-made neuroprostheses, neurological assessment devices, muscle exercise systems, and experimental setups for physiological studies. It can be programmed to generate any arbitrary stimulation sequence that can be controlled or regulated by various external sensors, sensory systems, or laboratory equipment. By interconnecting two or more Compex Motion stimulators, the number of stimulation channels can be increased to multiples of four channels, 8, 12, 16, 20, and so forth. The stimulation sequences and the control strategies are programmed and stored on exchangeable credit card-sized memory chip cards. The stimulator has four biphasic current-regulated stimulation channels and two general purpose analog input channels that can be configured to measure the output voltage of a variety of sensors such as goniometers, inclinometers, gyroscopes, or electromyographic (EMG) sensors. For real-time EMG control of the stimulation patterns, an EMG processing algorithm with software stimulation artifact blanking was implemented. The Compex Motion stimulator is manufactured by the Swiss company Compex SA and is currently undergoing clinical trials. PMID:11940017

  12. Technological Advances in Deep Brain Stimulation.

    PubMed

    Ughratdar, Ismail; Samuel, Michael; Ashkan, Keyoumars

    2015-01-01

    Functional and stereotactic neurosurgery has always been regarded as a subspecialty based on and driven by technological advances. However until recently, the fundamentals of deep brain stimulation (DBS) hardware and software design had largely remained stagnant since its inception almost three decades ago. Recent improved understanding of disease processes in movement disorders as well clinician and patient demands has resulted in new avenues of development for DBS technology. This review describes new advances both related to hardware and software for neuromodulation. New electrode designs with segmented contacts now enable sophisticated shaping and sculpting of the field of stimulation, potentially allowing multi-target stimulation and avoidance of side effects. To avoid lengthy programming sessions utilising multiple lead contacts, new user-friendly software allows for computational modelling and individualised directed programming. Therapy delivery is being improved with the next generation of smaller profile, longer-lasting, re-chargeable implantable pulse generators (IPGs). These include IPGs capable of delivering constant current stimulation or personalised closed-loop adaptive stimulation. Post-implantation Magnetic Resonance Imaging (MRI) has long been an issue which has been partially overcome with 'MRI conditional devices' and has enabled verification of DBS lead location. Surgical technique is considering a shift from frame-based to frameless stereotaxy or greater role for robot assisted implantation. The challenge for these contemporary techniques however, will be in demonstrating equivalent safety and accuracy to conventional methods. We also discuss potential future direction utilising wireless technology allowing for miniaturisation of hardware. PMID:26406128

  13. The rationale for deep brain stimulation in Alzheimer's disease.

    PubMed

    Mirzadeh, Zaman; Bari, Ausaf; Lozano, Andres M

    2016-07-01

    Alzheimer's disease is a major worldwide health problem with no effective therapy. Deep brain stimulation (DBS) has emerged as a useful therapy for certain movement disorders and is increasingly being investigated for treatment of other neural circuit disorders. Here we review the rationale for investigating DBS as a therapy for Alzheimer's disease. Phase I clinical trials of DBS targeting memory circuits in Alzheimer's disease patients have shown promising results in clinical assessments of cognitive function, neurophysiological tests of cortical glucose metabolism, and neuroanatomical volumetric measurements showing reduced rates of atrophy. These findings have been supported by animal studies, where electrical stimulation of multiple nodes within the memory circuit have shown neuroplasticity through stimulation-enhanced hippocampal neurogenesis and improved performance in memory tasks. The precise mechanisms by which DBS may enhance memory and cognitive functions in Alzheimer's disease patients and the degree of its clinical efficacy continue to be examined in ongoing clinical trials. PMID:26443701

  14. Prediction and control of neural responses to pulsatile electrical stimulation

    NASA Astrophysics Data System (ADS)

    Campbell, Luke J.; Sly, David James; O'Leary, Stephen John

    2012-04-01

    This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

  15. Functional MRI during Hippocampal Deep Brain Stimulation in the Healthy Rat Brain

    PubMed Central

    Van Den Berge, Nathalie; Vanhove, Christian; Descamps, Benedicte; Dauwe, Ine; van Mierlo, Pieter; Vonck, Kristl; Keereman, Vincent; Raedt, Robrecht; Boon, Paul; Van Holen, Roel

    2015-01-01

    Deep Brain Stimulation (DBS) is a promising treatment for neurological and psychiatric disorders. The mechanism of action and the effects of electrical fields administered to the brain by means of an electrode remain to be elucidated. The effects of DBS have been investigated primarily by electrophysiological and neurochemical studies, which lack the ability to investigate DBS-related responses on a whole-brain scale. Visualization of whole-brain effects of DBS requires functional imaging techniques such as functional Magnetic Resonance Imaging (fMRI), which reflects changes in blood oxygen level dependent (BOLD) responses throughout the entire brain volume. In order to visualize BOLD responses induced by DBS, we have developed an MRI-compatible electrode and an acquisition protocol to perform DBS during BOLD fMRI. In this study, we investigate whether DBS during fMRI is valuable to study local and whole-brain effects of hippocampal DBS and to investigate the changes induced by different stimulation intensities. Seven rats were stereotactically implanted with a custom-made MRI-compatible DBS-electrode in the right hippocampus. High frequency Poisson distributed stimulation was applied using a block-design paradigm. Data were processed by means of Independent Component Analysis. Clusters were considered significant when p-values were <0.05 after correction for multiple comparisons. Our data indicate that real-time hippocampal DBS evokes a bilateral BOLD response in hippocampal and other mesolimbic structures, depending on the applied stimulation intensity. We conclude that simultaneous DBS and fMRI can be used to detect local and whole-brain responses to circuit activation with different stimulation intensities, making this technique potentially powerful for exploration of cerebral changes in response to DBS for both preclinical and clinical DBS. PMID:26193653

  16. The ethics of deep brain stimulation (DBS).

    PubMed

    Unterrainer, Marcus; Oduncu, Fuat S

    2015-11-01

    Deep brain stimulation (DBS) is an invasive technique designed to stimulate certain deep brain regions for therapeutic purposes and is currently used mainly in patients with neurodegenerative disorders, such as Parkinson's disease. However, DBS is also used increasingly for other experimental applications, such as the treatment of psychiatric disorders (e.g. severe depression), weight reduction. Apart from its therapeutic potential, DBS can cause severe adverse effects, some that might also have a significant impact on the patient's personality and autonomy by the external stimulation of DBS which effects lie beyond the individual's control and free will. The article's purpose is to outline the procedures of DBS currently used in therapeutic and experimental applications and to discuss the ethical concerns regarding this procedure. It will address the clinical benefit-risk-ratio, the particular ethics of research in this field, and the ethical issues raised by affecting a patient's or an individual's personality and autonomous behaviour. Moreover, a potential ethical guideline, the Ulysses contract is discussed for the field of clinical application as well as the question of responsibility. PMID:25597042

  17. Adaptive Inverse optimal neuromuscular electrical stimulation.

    PubMed

    Wang, Qiang; Sharma, Nitin; Johnson, Marcus; Gregory, Chris M; Dixon, Warren E

    2013-12-01

    Neuromuscular electrical stimulation (NMES) is a prescribed treatment for various neuromuscular disorders, where an electrical stimulus is provided to elicit a muscle contraction. Barriers to the development of NMES controllers exist because the muscle response to an electrical stimulation is nonlinear and the muscle model is uncertain. Efforts in this paper focus on the development of an adaptive inverse optimal NMES controller. The controller yields desired limb trajectory tracking while simultaneously minimizing a cost functional that is positive in the error states and stimulation input. The development of this framework allows tradeoffs to be made between tracking performance and control effort by putting different penalties on error states and control input, depending on the clinical goal or functional task. The controller is examined through a Lyapunov-based analysis. Experiments on able-bodied individuals are provided to demonstrate the performance of the developed controller. PMID:23757569

  18. Novel applications of deep brain stimulation

    PubMed Central

    Sankar, Tejas; Tierney, Travis S.; Hamani, Clement

    2012-01-01

    The success of deep brain stimulation (DBS) surgery in treating medically refractory symptoms of some movement disorders has inspired further investigation into a wide variety of other treatment-resistant conditions. These range from disorders of gait, mood, and memory to problems as diverse as obesity, consciousness, and addiction. We review the emerging indications, rationale, and outcomes for some of the most promising new applications of DBS in the treatment of postural instability associated with Parkinson's disease, depression, obsessive–compulsive disorder, obesity, substance abuse, epilepsy, Alzheimer′s-type dementia, and traumatic brain injury. These studies reveal some of the excitement in a field at the edge of a rapidly expanding frontier. Much work still remains to be done on basic mechanism of DBS, optimal target and patient selection, and long-term durability of this technology in treating new indications. PMID:22826807

  19. Paradoxical augmented relapse in alcohol-dependent rats during deep-brain stimulation in the nucleus accumbens

    PubMed Central

    Hadar, R; Vengeliene, V; Barroeta Hlusicke, E; Canals, S; Noori, H R; Wieske, F; Rummel, J; Harnack, D; Heinz, A; Spanagel, R; Winter, C

    2016-01-01

    Case reports indicate that deep-brain stimulation in the nucleus accumbens may be beneficial to alcohol-dependent patients. The lack of clinical trials and our limited knowledge of deep-brain stimulation call for translational experiments to validate these reports. To mimic the human situation, we used a chronic-continuous brain-stimulation paradigm targeting the nucleus accumbens and other brain sites in alcohol-dependent rats. To determine the network effects of deep-brain stimulation in alcohol-dependent rats, we combined electrical stimulation of the nucleus accumbens with functional magnetic resonance imaging (fMRI), and studied neurotransmitter levels in nucleus accumbens-stimulated versus sham-stimulated rats. Surprisingly, we report here that electrical stimulation of the nucleus accumbens led to augmented relapse behavior in alcohol-dependent rats. Our associated fMRI data revealed some activated areas, including the medial prefrontal cortex and caudate putamen. However, when we applied stimulation to these areas, relapse behavior was not affected, confirming that the nucleus accumbens is critical for generating this paradoxical effect. Neurochemical analysis of the major activated brain sites of the network revealed that the effect of stimulation may depend on accumbal dopamine levels. This was supported by the finding that brain-stimulation-treated rats exhibited augmented alcohol-induced dopamine release compared with sham-stimulated animals. Our data suggest that deep-brain stimulation in the nucleus accumbens enhances alcohol-liking probably via augmented dopamine release and can thereby promote relapse. PMID:27327255

  20. Paradoxical augmented relapse in alcohol-dependent rats during deep-brain stimulation in the nucleus accumbens.

    PubMed

    Hadar, R; Vengeliene, V; Barroeta Hlusicke, E; Canals, S; Noori, H R; Wieske, F; Rummel, J; Harnack, D; Heinz, A; Spanagel, R; Winter, C

    2016-01-01

    Case reports indicate that deep-brain stimulation in the nucleus accumbens may be beneficial to alcohol-dependent patients. The lack of clinical trials and our limited knowledge of deep-brain stimulation call for translational experiments to validate these reports. To mimic the human situation, we used a chronic-continuous brain-stimulation paradigm targeting the nucleus accumbens and other brain sites in alcohol-dependent rats. To determine the network effects of deep-brain stimulation in alcohol-dependent rats, we combined electrical stimulation of the nucleus accumbens with functional magnetic resonance imaging (fMRI), and studied neurotransmitter levels in nucleus accumbens-stimulated versus sham-stimulated rats. Surprisingly, we report here that electrical stimulation of the nucleus accumbens led to augmented relapse behavior in alcohol-dependent rats. Our associated fMRI data revealed some activated areas, including the medial prefrontal cortex and caudate putamen. However, when we applied stimulation to these areas, relapse behavior was not affected, confirming that the nucleus accumbens is critical for generating this paradoxical effect. Neurochemical analysis of the major activated brain sites of the network revealed that the effect of stimulation may depend on accumbal dopamine levels. This was supported by the finding that brain-stimulation-treated rats exhibited augmented alcohol-induced dopamine release compared with sham-stimulated animals. Our data suggest that deep-brain stimulation in the nucleus accumbens enhances alcohol-liking probably via augmented dopamine release and can thereby promote relapse. PMID:27327255

  1. Deep brain stimulation for major depression.

    PubMed

    Schlaepfer, T E; Bewernick, B H

    2013-01-01

    A third of patients suffering from major depression cannot be helped by conventional treatment methods. These patients face reduced quality of life, high risk of suicide, and little hope of recovery. Deep brain stimulation (DBS) is under scientific evaluation as a new treatment option for these treatment-resistant patients. First clinical studies with small samples have been stimulated at the subgenual cingulate gyrus (Cg25/24), the anterior limb of the capsula interna (ALIC), and the nucleus accumbens (NAcc). Long-term antidepressant effects, augmentation of social functioning, and normalization of brain metabolism have been shown in about 50% of patients. Cognitive safety regarding attention, learning, and memory has been reported. Adverse events were wound infection, suicide, and hypomania, amongst others. Larger studies are under way to confirm these preliminary encouraging results. New hypothesis-guided targets (e.g., medial forebrain bundle, habenula) are about to be assessed in clinical trials. The application of DBS for other psychiatric diseases (e.g., bipolar disorder, alcohol dependency, opioid addiction, schizophrenia) is debated and single case studies are under way. Standards are needed for study registration, target selection, patient inclusion and monitoring, and publication of results to guarantee safety for the patients and scientific exchange. PMID:24112897

  2. Deep brain stimulation for chronic pain.

    PubMed

    Boccard, Sandra G J; Pereira, Erlick A C; Aziz, Tipu Z

    2015-10-01

    Deep brain stimulation (DBS) is a neurosurgical intervention popularised in movement disorders such as Parkinson's disease, and also reported to improve symptoms of epilepsy, Tourette's syndrome, obsessive compulsive disorders and cluster headache. Since the 1950s, DBS has been used as a treatment to relieve intractable pain of several aetiologies including post stroke pain, phantom limb pain, facial pain and brachial plexus avulsion. Several patient series have shown benefits in stimulating various brain areas, including the sensory thalamus (ventral posterior lateral and medial), the periaqueductal and periventricular grey, or, more recently, the anterior cingulate cortex. However, this technique remains "off label" in the USA as it does not have Federal Drug Administration approval. Consequently, only a small number of surgeons report DBS for pain using current technology and techniques and few regions approve it. Randomised, blinded and controlled clinical trials that may use novel trial methodologies are desirable to evaluate the efficacy of DBS in patients who are refractory to other therapies. New imaging techniques, including tractography, may help optimise electrode placement and clinical outcome. PMID:26122383

  3. 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…

  4. Modeling direct activation of corticospinal axons using transcranial electrical stimulation.

    PubMed

    Suihko, V

    1998-06-01

    Corticospinal axons can be directly activated using anodal transcranial electrical stimulation. The purpose of this work was to find the location of the direct activation. The response to stimulation was modeled with a spherical head model and an active model of a corticospinal nerve. The nerve model had a deep bend at a location corresponding to a corticospinal fiber entering the midbrain. The threshold activation initiated close to brain surface; the exact location depended on whether the cell body located in the surface layers of the brain or in the bank of the central sulcus. The stimulation time constant was 44 micros. When the stimulus amplitude was increased, the site of activation shifted gradually to deeper level, until the activation initiated directly at the bend causing a half millisecond latency jump at spinal level. These results support the theory that the corticospinal axons can be directly activated at deep locations using anodal transcranial electrical stimulation. However, the high amplitude needed for the direct activation suggests that not only the bends on the fibers, but also the shape of surrounding volume conductor (intracranial cavity) favor activation at this location. PMID:9741790

  5. Impairment of aversive memory reconsolidation by localized intracranial electrical stimulation.

    PubMed

    Stehberg, Jimmy; Levy, Dino; Zangen, Abraham

    2009-03-01

    Reconsolidation of long-term memory is blocked in animal models by macromolecular synthesis inhibitors, resulting in item-specific post-retrieval amnesia. The induction of such amnesia could ameliorate traumatic memories and phobias. However, this pharmacological approach is of limited value in humans because of toxicity. Here we report that reconsolidation of conditioned taste aversion in the rat is impaired by localized intracranial electrical stimulation. Lasting impairment was obtained only when stimulation was applied during memory reactivation and only to the dysgranular insular cortex bilaterally, which subserves the memory, but not to adjacent brain sites. The ability to learn a new association was not affected. The same method blocked new memory consolidation, but produced anterograde amnesia, reminiscent of the known effect of non-localized electroconvulsive therapy. Our results suggest that localized electrical microstimulation, such as produced by deep-brain stimulation or deep transcranial magnetic stimulation, could be used to impair long-term memory if applied during memory reactivation, and could lead to the development of a novel treatment for intractable post-traumatic stress disorder. PMID:19200060

  6. Determinants of the electric field during transcranial direct current stimulation.

    PubMed

    Opitz, Alexander; Paulus, Walter; Will, Susanne; Antunes, Andre; Thielscher, Axel

    2015-04-01

    Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field distribution in the brain during tDCS. We constructed anatomically realistic finite element (FEM) models of two individual heads including conductivity anisotropy and different skull layers. We simulated a widely employed electrode montage to induce motor cortex plasticity and moved the stimulating electrode over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant to electrode positioning. Our results give valuable novel insights in the biophysical foundation of tDCS and highlight the importance to account for individual anatomical factors when choosing an electrode montage. PMID:25613437

  7. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates.

    PubMed

    Opitz, Alexander; Falchier, Arnaud; Yan, Chao-Gan; Yeagle, Erin M; Linn, Gary S; Megevand, Pierre; Thielscher, Axel; Deborah A, Ross; Milham, Michael P; Mehta, Ashesh D; Schroeder, Charles E

    2016-01-01

    Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 mV/mm. Our results provide crucial information of the underlying biophysics in TES applications in humans and the optimization and design of TES stimulation protocols. In addition, our findings have broad implications concerning electric field propagation in non-invasive recording techniques such as EEG/MEG. PMID:27535462

  8. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates

    PubMed Central

    Opitz, Alexander; Falchier, Arnaud; Yan, Chao-Gan; Yeagle, Erin M.; Linn, Gary S.; Megevand, Pierre; Thielscher, Axel; Deborah A., Ross; Milham, Michael P.; Mehta, Ashesh D.; Schroeder, Charles E.

    2016-01-01

    Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 mV/mm. Our results provide crucial information of the underlying biophysics in TES applications in humans and the optimization and design of TES stimulation protocols. In addition, our findings have broad implications concerning electric field propagation in non-invasive recording techniques such as EEG/MEG. PMID:27535462

  9. Brain stimulation in rats exposed to hyperbaric environments.

    PubMed

    Ackerman, M J; Spencer, J W

    1976-12-01

    Six rats were trained to make an operant response to receive brief trains of electrical current to the lateral hypothalamus (self-stimulation). All animals were then randomly exposed to pressures of 4.03, 5.51, 7.06, or 10.1 ATA breathing either compressed air or N2-O2 and 13.1 ATA (N2-O2 only). When the subjects breathed air at pressures of 7.06 and 10.1 ATA, rate of self-stimulation decreased by 32 and 43%, respectively. No differences were observed in rate of response at any pressure when the animals breathed N2-O2 with the partial pressure of oxygen maintained at 0.2 ATA. When an oxygen-nitrogen mixture was breathed at 3 ATA in which the PO2 was similar to compressed air at 10.1 ATA, self-stimulation rate was decreased by 40%; this suggests that PO2 is a critical variable influencing behavior mediated by brain stimulation. Results are discussed in terms of the use of self-stimulation as one tool for better understanding the neuronal mechanisms of behavior as they relate to breathing-gas mixtures at increased pressures. PMID:10897863

  10. Electrical stimulation of the dorsolateral prefrontal cortex improves memory monitoring.

    PubMed

    Chua, Elizabeth F; Ahmed, Rifat

    2016-05-01

    The ability to accurately monitor one's own memory is an important feature of normal memory function. Converging evidence from neuroimaging and lesion studies have implicated the dorsolateral prefrontal cortex (DLPFC) in memory monitoring. Here we used high definition transcranial direct stimulation (HD-tDCS), a non-invasive form of brain stimulation, to test whether the DLPFC has a causal role in memory monitoring, and the nature of that role. We used a metamemory monitoring task, in which participants first attempted to recall the answer to a general knowledge question, then gave a feeling-of-knowing (FOK) judgment, followed by a forced choice recognition task. When participants received DLPFC stimulation, their feeling-of-knowing judgments were better predictors of memory performance, i.e., they had better memory monitoring accuracy, compared to stimulation of a control site, the anterior temporal lobe (ATL). Effects of DLPFC stimulation were specific to monitoring accuracy, as there was no significant increase in memory performance, and if anything, there was poorer memory performance with DLPFC stimulation. Thus we have demonstrated a causal role for the DLPFC in memory monitoring, and showed that electrically stimulating the left DLPFC led people to more accurately monitor and judge their own memory. PMID:26970142

  11. Optogenetic versus Electrical Stimulation of Human Cardiomyocytes: Modeling Insights

    PubMed Central

    Williams, John C.; Entcheva, Emilia

    2015-01-01

    Optogenetics provides an alternative to electrical stimulation to manipulate membrane voltage, and trigger or modify action potentials (APs) in excitable cells. We compare biophysically and energetically the cellular responses to direct electrical current injection versus optical stimulation mediated by genetically expressed light-sensitive ion channels, e.g., Channelrhodopsin-2 (ChR2). Using a computational model of ChR2(H134R mutant), we show that both stimulation modalities produce similar-in-morphology APs in human cardiomyocytes, and that electrical and optical excitability vary with cell type in a similar fashion. However, whereas the strength-duration curves for electrical excitation in ventricular and atrial cardiomyocytes closely follow the theoretical exponential relationship for an equivalent RC circuit, the respective optical strength-duration curves significantly deviate, exhibiting higher nonlinearity. We trace the origin of this deviation to the waveform of the excitatory current—a nonrectangular self-terminating inward current produced in optical stimulation due to ChR2 kinetics and voltage-dependent rectification. Using a unifying charge measure to compare energy needed for electrical and optical stimulation, we reveal that direct electrical current injection (rectangular pulse) is more efficient at short pulses, whereas voltage-mediated negative feedback leads to self-termination of ChR2 current and renders optical stimulation more efficient for long low-intensity pulses. This applies to cardiomyocytes but not to neuronal cells (with much shorter APs). Furthermore, we demonstrate the cell-specific use of ChR2 current as a unique modulator of intrinsic activity, allowing for optical control of AP duration in atrial and, to a lesser degree, in ventricular myocytes. For self-oscillatory cells, such as Purkinje, constant light at extremely low irradiance can be used for fine control of oscillatory frequency, whereas constant electrical stimulation

  12. Optogenetic versus Electrical Stimulation of Human Cardiomyocytes: Modeling Insights.

    PubMed

    Williams, John C; Entcheva, Emilia

    2015-04-21

    Optogenetics provides an alternative to electrical stimulation to manipulate membrane voltage, and trigger or modify action potentials (APs) in excitable cells. We compare biophysically and energetically the cellular responses to direct electrical current injection versus optical stimulation mediated by genetically expressed light-sensitive ion channels, e.g., Channelrhodopsin-2 (ChR2). Using a computational model of ChR2(H134R mutant), we show that both stimulation modalities produce similar-in-morphology APs in human cardiomyocytes, and that electrical and optical excitability vary with cell type in a similar fashion. However, whereas the strength-duration curves for electrical excitation in ventricular and atrial cardiomyocytes closely follow the theoretical exponential relationship for an equivalent RC circuit, the respective optical strength-duration curves significantly deviate, exhibiting higher nonlinearity. We trace the origin of this deviation to the waveform of the excitatory current-a nonrectangular self-terminating inward current produced in optical stimulation due to ChR2 kinetics and voltage-dependent rectification. Using a unifying charge measure to compare energy needed for electrical and optical stimulation, we reveal that direct electrical current injection (rectangular pulse) is more efficient at short pulses, whereas voltage-mediated negative feedback leads to self-termination of ChR2 current and renders optical stimulation more efficient for long low-intensity pulses. This applies to cardiomyocytes but not to neuronal cells (with much shorter APs). Furthermore, we demonstrate the cell-specific use of ChR2 current as a unique modulator of intrinsic activity, allowing for optical control of AP duration in atrial and, to a lesser degree, in ventricular myocytes. For self-oscillatory cells, such as Purkinje, constant light at extremely low irradiance can be used for fine control of oscillatory frequency, whereas constant electrical stimulation is

  13. Neuropsychiatric deep brain stimulation for translational neuroimaging.

    PubMed

    Höflich, Anna; Savli, Markus; Comasco, Erika; Moser, Ulrike; Novak, Klaus; Kasper, Siegfried; Lanzenberger, Rupert

    2013-10-01

    From a neuroimaging point of view, deep brain stimulation (DBS) in psychiatric disorders represents a unique source of information to probe results gained in functional, structural and molecular neuroimaging studies in vivo. However, the implementation has, up to now, been restricted by the heterogeneity of the data reported in DBS studies. The aim of the present study was therefore to provide a comprehensive and standardized database of currently used DBS targets in selected psychiatric disorders (obsessive-compulsive disorder (OCD), treatment-resistant depression (TRD), Gilles de la Tourette syndrome (GTS)) to enable topological comparisons between neuroimaging results and stimulation areas. A systematic literature research was performed and all peer-reviewed publications until the year 2012 were included. Literature research yielded a total of 84 peer-reviewed studies including about 296 psychiatric patients. The individual stimulation data of 37 of these studies meeting the inclusion criteria which included a total of 202 patients (63 OCD, 89 TRD, 50 GTS) was translated into MNI stereotactic space with respect to AC origin in order to identify key targets. The created database can be used to compare DBS target areas in MNI stereotactic coordinates with: 1) activation patterns in functional brain imaging (fMRI, phfMRI, PET, MET, EEG); 2) brain connectivity data (e.g., MR-based DTI/tractography, functional and effective connectivity); 3) quantitative molecular distribution data (e.g., neuroreceptor PET, post-mortem neuroreceptor mapping); 4) structural data (e.g., VBM for neuroplastic changes). Vice versa, the structural, functional and molecular data may provide a rationale to define new DBS targets and adjust/fine-tune currently used targets in DBS based on this overview in stereotactic coordinates. Furthermore, the availability of DBS data in stereotactic space may facilitate the investigation and interpretation of treatment effects and side effect of DBS by

  14. Metallic taste from electrical and chemical stimulation.

    PubMed

    Lawless, Harry T; Stevens, David A; Chapman, Kathryn W; Kurtz, Anne

    2005-03-01

    A series of three experiments investigated the nature of metallic taste reports after stimulation with solutions of metal salts and after stimulation with metals and electric currents. To stimulate with electricity, a device was fabricated consisting of a small battery affixed to a plastic handle with the anode side exposed for placement on the tongue or oral tissues. Intensity of taste from metals and batteries was dependent upon the voltage and was more robust in areas dense in fungiform papillae. Metallic taste was reported from stimulation with ferrous sulfate solutions, from metals and from electric stimuli. However, reports of metallic taste were more frequent when the word 'metallic' was presented embedded in a list of choices, as opposed to simple free-choice labeling. Intensity decreased for ferrous sulfate when the nose was occluded, consistent with a decrease in retronasal smell, as previously reported. Intensity of taste evoked by copper metal, bimetallic stimuli (zinc/copper) or small batteries (1.5-3 V) was not affected by nasal occlusion. This difference suggests two distinct mechanisms for evocation of metallic taste reports, one dependent upon retronasal smell and a second mediated by oral chemoreceptors. PMID:15741603

  15. Cognitive enhancement with central thalamic electrical stimulation

    PubMed Central

    Shirvalkar, Prasad; Seth, Malika; Schiff, Nicholas D.; Herrera, Daniel G.

    2006-01-01

    Central thalamic electrical stimulation has been proposed as a method for remediation of acquired cognitive disability. Long-standing experimental and clinical observations indicate a key role for neurons within the central thalamus in maintaining the alert waking state and facilitating attended behaviors. Here, we show that continuous high frequency (100 Hz) electrical stimulation of the central thalamus generates widespread cortical activation of c-fos across all cortical layers and a selective pattern of regulation of zif268 within the supragranular, granular, and infragranular cortical laminae. Significant elevation of both immediate early genes also is seen in the dentate gyrus of the hippocampus. Use of the same stimulation parameters is shown to facilitate untrained goal-directed seeking behavior and object recognition memory in rodents. An overall increase of exploratory motor behaviors and grooming activity also is observed, consistent with a global increase in arousal. Taken together, these studies indicate that electrical stimulation of the central thalamus may enhance cognitive performance through neocortical and hippocampal neuronal activation and specific regulation of gene expression. PMID:17065322

  16. Deep brain stimulation for obesity: past, present, and future targets.

    PubMed

    Dupré, Derrick A; Tomycz, Nestor; Oh, Michael Y; Whiting, Donald

    2015-06-01

    The authors review the history of deep brain stimulation (DBS) in patients for treating obesity, describe current DBS targets in the brain, and discuss potential DBS targets and nontraditional stimulation parameters that may improve the effectiveness of DBS for ameliorating obesity. Deep brain stimulation for treating obesity has been performed both in animals and in humans with intriguing preliminary results. The brain is an attractive target for addressing obesity because modulating brain activity may permit influencing both sides of the energy equation--caloric intake and energy expenditure. PMID:26030707

  17. 21 CFR 882.1870 - Evoked response electrical stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring...

  18. 21 CFR 882.1870 - Evoked response electrical stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring...

  19. 21 CFR 882.1870 - Evoked response electrical stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring...

  20. 21 CFR 882.1870 - Evoked response electrical stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Evoked response electrical stimulator. 882.1870... electrical stimulator. (a) Identification. An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring...

  1. Closed-loop cortical neuromodulation in Parkinson's disease: An alternative to deep brain stimulation?

    PubMed

    Beuter, Anne; Lefaucheur, Jean-Pascal; Modolo, Julien

    2014-05-01

    Deep brain stimulation (DBS) is usually performed to treat advanced Parkinson's disease (PD) patients with electrodes permanently implanted in basal ganglia while the stimulator delivers electrical impulses continuously and independently of any feedback (open-loop stimulation). Conversely, in closed-loop stimulation, electrical stimulation is delivered as a function of neuronal activities recorded and analyzed online. There is an emerging development of closed-loop DBS in the treatment of PD and a growing discussion about proposing cortical stimulation rather than DBS for this purpose. Why does it make sense to "close the loop" to treat parkinsonian symptoms? Could closed-loop stimulation applied to the cortex become a valuable therapeutic strategy for PD? Can mathematical modeling contribute to the development of this technique? We review the various evidences in favor of the use of closed-loop cortical stimulation for the treatment of advanced PD, as an emerging technique which might offer substantial clinical benefits for PD patients. PMID:24555921

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

    PubMed

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

    2015-01-01

    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. PMID:26436986

  3. Deep brain stimulation to reduce sexual drive

    PubMed Central

    Fuss, Johannes; Auer, Matthias K.; Biedermann, Sarah V.; Briken, Peer; Hacke, Werner

    2015-01-01

    To date there are few treatment options to reduce high sexual drive or sexual urges in paraphilic patients with a risk for sexual offending. Pharmacological therapy aims to reduce sexual drive by lowering testosterone at the cost of severe side effects. We hypothesize that high sexual drive could also be reduced with deep brain stimulation (DBS) of circuits that generate sexual drive. This approach would help to avoid systemic side effects of antiandrogenic drug therapies. So far the best investigated target to reduce sexual drive is the ventromedial hypothalamus, which was lesioned unilaterally and bilaterally by stereotaxic interventions in paraphilic patients in the 1970s. Here, we discuss DBS as a treatment strategy in patients with severe paraphilic disorders with a serious risk of sexual offending. There are profound ethical and practical issues associated with DBS treatment of paraphilic patients that must be solved before considering such a treatment approach. PMID:26057198

  4. Tractography patterns of subthalamic nucleus deep brain stimulation.

    PubMed

    Vanegas-Arroyave, Nora; Lauro, Peter M; Huang, Ling; Hallett, Mark; Horovitz, Silvina G; Zaghloul, Kareem A; Lungu, Codrin

    2016-04-01

    Deep brain stimulation therapy is an effective symptomatic treatment for Parkinson's disease, yet the precise mechanisms responsible for its therapeutic effects remain unclear. Although the targets of deep brain stimulation are grey matter structures, axonal modulation is known to play an important role in deep brain stimulation's therapeutic mechanism. Several white matter structures in proximity to the subthalamic nucleus have been implicated in the clinical benefits of deep brain stimulation for Parkinson's disease. We assessed the connectivity patterns that characterize clinically beneficial electrodes in Parkinson's disease patients, after deep brain stimulation of the subthalamic nucleus. We evaluated 22 patients with Parkinson's disease (11 females, age 57 ± 9.1 years, disease duration 13.3 ± 6.3 years) who received bilateral deep brain stimulation of the subthalamic nucleus at the National Institutes of Health. During an initial electrode screening session, one month after deep brain stimulation implantation, the clinical benefits of each contact were determined. The electrode was localized by coregistering preoperative magnetic resonance imaging and postoperative computer tomography images and the volume of tissue activated was estimated from stimulation voltage and impedance. Brain connectivity for the volume of tissue activated of deep brain stimulation contacts was assessed using probabilistic tractography with diffusion-tensor data. Areas most frequently connected to clinically effective contacts included the thalamus, substantia nigra, brainstem and superior frontal gyrus. A series of discriminant analyses demonstrated that the strength of connectivity to the superior frontal gyrus and the thalamus were positively associated with clinical effectiveness. The connectivity patterns observed in our study suggest that the modulation of white matter tracts directed to the superior frontal gyrus and the thalamus is associated with favourable clinical

  5. The adaptive deep brain stimulation challenge.

    PubMed

    Arlotti, Mattia; Rosa, Manuela; Marceglia, Sara; Barbieri, Sergio; Priori, Alberto

    2016-07-01

    Sub-optimal clinical outcomes of conventional deep brain stimulation (cDBS) in treating Parkinson's Disease (PD) have boosted the development of new solutions to improve DBS therapy. Adaptive DBS (aDBS), consisting of closed-loop, real-time changing of stimulation parameters according to the patient's clinical state, promises to achieve this goal and is attracting increasing interest in overcoming all of the challenges posed by its development and adoption. In the design, implementation, and application of aDBS, the choice of the control variable and of the control algorithm represents the core challenge. The proposed approaches, in fact, differ in the choice of the control variable and control policy, in the system design and its technological limits, in the patient's target symptom, and in the surgical procedure needed. Here, we review the current proposals for aDBS systems, focusing on the choice of the control variable and its advantages and drawbacks, thus providing a general overview of the possible pathways for the clinical translation of aDBS with its benefits, limitations and unsolved issues. PMID:27079257

  6. Emerging applications of deep brain stimulation.

    PubMed

    Sharma, Mayur; Naik, Vikas; Deogaonkar, Milind

    2016-06-01

    Deep brain stimulation (DBS) implantation surgery is an established treatment modality for a variety of medical refractory movement disorders such as Parkinson's disease, essential tremors and dystonia. Following the success of DBS in these movement disorders with a high rate of safety and efficacy, there is a resurgence of interest in the utility of this modality in other medical refractory disorders. Consequently, neuromodulation has been explored for a variety of refractory conditions such as neuropsychiatric disorders (major depressive disorders, obsessive-compulsive disorders, addictions), eating disorders including obesity, traumatic brain injury, post-traumatic stress disorders (PTSD), dementias and chronic pain. This review provides an overview of the emerging applications of DBS in these disorders, including summary of the published literature. We have highlighted the pathophysiology and likely aberrant neural circuits involved in these refractory disorders. Current and possible surgical targets for neurosurgical intervention related to these disorders have also been discussed. Furthermore, recent advances such as closed loop systems; responsive neurostimulation systems and optogenetics techniques have been addressed. PMID:26788743

  7. "Asleep" deep brain stimulation for essential tremor.

    PubMed

    Chen, Tsinsue; Mirzadeh, Zaman; Chapple, Kristina; Lambert, Margaret; Dhall, Rohit; Ponce, Francisco A

    2016-06-01

    OBJECT Deep brain stimulation (DBS) performed under general anesthesia ("asleep" DBS) has not been previously reported for essential tremor. This is in part due to the inability to visualize the target (the ventral intermediate nucleus [VIM]) on MRI. The authors evaluate the efficacy of this asleep technique in treating essential tremor by indirect VIM targeting. METHODS The authors retrospectively reviewed consecutive cases of initial DBS for essential tremor performed by a single surgeon. DBS was performed with patients awake (n = 40, intraoperative test stimulation without microelectrode recording) or asleep (n = 17, under general anesthesia). Targeting proceeded with standardized anatomical coordinates on preoperative MRI. Intraoperative CT was used for stereotactic registration and lead position confirmation. Functional outcomes were evaluated with pre- and postoperative Bain and Findley Tremor Activities of Daily Living scores. RESULTS A total of 29 leads were placed in asleep patients, and 60 were placed in awake patients. Bain and Findley Tremor Activities of Daily Living Questionnaire scores were not significantly different preoperatively for awake versus asleep cohorts (p = 0.2). The percentage of postoperative improvement was not significantly different between asleep (48.6%) and awake (45.5%) cohorts (p = 0.35). Euclidean error (mm) was higher for awake versus asleep patients (1.7 ± 0.8 vs 1.2 ± 0.4, p = 0.01), and radial error (mm) trended higherfor awake versus asleep patients (1.3 ± 0.8 vs 0.9 ± 0.5, p = 0.06). There were no perioperative complications. CONCLUSIONS In the authors' initial experience, asleep VIM DBS for essential tremor without intraoperative test stimulation can be performed safely and effectively. PMID:26613177

  8. Tissue damage thresholds during therapeutic electrical stimulation

    NASA Astrophysics Data System (ADS)

    Cogan, Stuart F.; Ludwig, Kip A.; Welle, Cristin G.; Takmakov, Pavel

    2016-04-01

    Objective. Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue damage. Approach. In this review, we explore what is known and unknown in published literature regarding tissue damage from electrical stimulation. Main results. For macroelectrodes, the potential for tissue damage is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a damage threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue damage, the analysis is limited by the experimental parameters of the original studies. Tissue damage is influenced by factors not explicitly incorporated into the Shannon equation, including pulse frequency, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue damage is framed in the context of available reports from modeling and in vivo studies. Significance. It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional damage thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue damage, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device

  9. Charge-balanced biphasic electrical stimulation inhibits neurite extension of spiral ganglion neurons.

    PubMed

    Shen, Na; Liang, Qiong; Liu, Yuehong; Lai, Bin; Li, Wen; Wang, Zhengmin; Li, Shufeng

    2016-06-15

    Intracochlear application of exogenous or transgenic neurotrophins, such as neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF), could promote the resprouting of spiral ganglion neuron (SGN) neurites in deafened animals. These resprouting neurites might reduce the gap between cochlear implant electrodes and their targeting SGNs, allowing for an improvement of spatial resolution of electrical stimulation. This study is to investigate the impact of electrical stimulation employed in CI on the extension of resprouting SGN neurites. We established an in vitro model including the devices delivering charge-balanced biphasic electrical stimulation, and spiral ganglion (SG) dissociated culture treated with BDNF and NT-3. After electrical stimulation with varying durations and intensities, we quantified neurite lengths and Schwann cell densities in SG cultures. Stimulations that were greater than 50μA or longer than 8h significantly decreased SG neurite length. Schwann cell density under 100μA electrical stimulation for 48h was significantly lower compared to that in non-stimulated group. These electrical stimulation-induced decreases of neurite extension and Schwann cell density were attenuated by various types of voltage-dependent calcium channel (VDCC) blockers, or completely prevented by their combination, cadmium or calcium-free medium. Our study suggested that charge-balanced biphasic electrical stimulation inhibited the extension of resprouting SGN neurites and decreased Schwann cell density in vitro. Calcium influx through multiple types of VDCCs was involved in the electrical stimulation-induced inhibition. PMID:27163199

  10. Stochastic Phase Resetting: a Theory for Deep Brain Stimulation

    NASA Astrophysics Data System (ADS)

    Tass, Peter A.

    2000-03-01

    A stochastic approach to phase resetting in clusters of interacting oscillators is presented. This theory explains how a stimulus, especially a single pulse, induces synchronization and desynchronization processes. The theory is used to design a new technique for deep brain stimulation in patients suffering from Parkinson's disease or essential tremor that do no longer respond to drug therapy. This stimulation mode is a feedback controlled single pulse stimulation. The feedback signal is registered with the deep brain electrode, and the desynchronizing pulses are administered via the same electrode. The stochastic phase resetting theory is used as a starting point of a model based design of intelligent and gentle deep brain stimulation techniques.

  11. Stimulation-Based Control of Dynamic Brain Networks.

    PubMed

    Muldoon, Sarah Feldt; Pasqualetti, Fabio; Gu, Shi; Cieslak, Matthew; Grafton, Scott T; Vettel, Jean M; Bassett, Danielle S

    2016-09-01

    The ability to modulate brain states using targeted stimulation is increasingly being employed to treat neurological disorders and to enhance human performance. Despite the growing interest in brain stimulation as a form of neuromodulation, much remains unknown about the network-level impact of these focal perturbations. To study the system wide impact of regional stimulation, we employ a data-driven computational model of nonlinear brain dynamics to systematically explore the effects of targeted stimulation. Validating predictions from network control theory, we uncover the relationship between regional controllability and the focal versus global impact of stimulation, and we relate these findings to differences in the underlying network architecture. Finally, by mapping brain regions to cognitive systems, we observe that the default mode system imparts large global change despite being highly constrained by structural connectivity. This work forms an important step towards the development of personalized stimulation protocols for medical treatment or performance enhancement. PMID:27611328

  12. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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 nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator (neuromuscular blockade monitor)...

  13. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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 nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator (neuromuscular blockade monitor)...

  14. Functional Electrical Stimulation in Children and Adolescents with Cerebral Palsy

    ERIC Educational Resources Information Center

    van der Linden, Marietta

    2012-01-01

    In this article, the author talks about functional electrical stimulation in children and adolescents with cerebral palsy. Functional electrical stimulation (FES) is defined as the electrical stimulation of muscles that have impaired motor control, in order to produce a contraction to obtain functionally useful movement. It was first proposed in…

  15. Electrical stimulation systems for cardiac tissue engineering

    PubMed Central

    Tandon, Nina; Cannizzaro, Christopher; Chao, Pen-Hsiu Grace; Maidhof, Robert; Marsano, Anna; Au, Hoi Ting Heidi; Radisic, Milica; Vunjak-Novakovic, Gordana

    2009-01-01

    We describe a protocol for tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cells with the application of pulsatile electrical fields designed to mimic those present in the native heart. Tissue culture is conducted in a customized chamber built to allow for cultivation of (i) engineered three-dimensional (3D) cardiac tissue constructs, (ii) cell monolayers on flat substrates or (iii) cells on patterned substrates. This also allows for analysis of the individual and interactive effects of pulsatile electrical field stimulation and substrate topography on cell differentiation and assembly. The protocol is designed to allow for delivery of predictable electrical field stimuli to cells, monitoring environmental parameters, and assessment of cell and tissue responses. The duration of the protocol is 5 d for two-dimensional cultures and 10 d for 3D cultures. PMID:19180087

  16. Deep Brain Stimulation for the Treatment of Severe, Medically Refractory Obsessive-Compulsive Disorder

    PubMed Central

    Sedrak, Mark; Wong, William; Wilson, Paul; Bruce, Diana; Bernstein, Ivan; Khandhar, Suketu; Pappas, Conrad; Heit, Gary; Sabelman, Eric

    2013-01-01

    Deep brain stimulation is a rapidly expanding therapy initially designed for the treatment of movement disorders and pain syndromes. The therapy includes implantation of electrodes in specific targets of the brain, delivering programmable small and safe electric impulses, like a pacemaker, that modulates both local and broad neurologic networks. The effects are thought to primarily involve a focus in the brain, probably inhibitory, which then restores a network of neural circuitry. Psychiatric diseases can be refractory and severe, leading to high medical costs, significant morbidity, and even death. Whereas surgery for psychiatric disease used to include destructive procedures, deep brain stimulation allows safe, reversible, and adjustable treatment that can be tailored for each patient. Deep brain stimulation offers new hope for these unfortunate patients, and the preliminary results are promising. PMID:24361021

  17. Memory enhancement induced by hypothalamic/fornix deep brain stimulation.

    PubMed

    Hamani, Clement; McAndrews, Mary Pat; Cohn, Melanie; Oh, Michael; Zumsteg, Dominik; Shapiro, Colin M; Wennberg, Richard A; Lozano, Andres M

    2008-01-01

    Bilateral hypothalamic deep brain stimulation was performed to treat a patient with morbid obesity. We observed, quite unexpectedly, that stimulation evoked detailed autobiographical memories. Associative memory tasks conducted in a double-blinded "on" versus "off" manner demonstrated that stimulation increased recollection but not familiarity-based recognition, indicating a functional engagement of the hippocampus. Electroencephalographic source localization showed that hypothalamic deep brain stimulation drove activity in mesial temporal lobe structures. This shows that hypothalamic stimulation in this patient modulates limbic activity and improves certain memory functions. PMID:18232017

  18. Non-invasive electrical stimulation of the brain (ESB) modifies the resting-state network connectivity of the primary motor cortex: a proof of concept fMRI study.

    PubMed

    Alon, G; Roys, S R; Gullapalli, R P; Greenspan, J D

    2011-07-27

    An innovative method to obtain fMRI resting-state network maps during non-invasive electrical stimulation of the brain (ESB) was developed and tested. Five healthy volunteers participated in 2 fMRI sessions. In session one, a transcranial direct current stimulator (tDCS) was applied placing the positive electrode (31.5 cm(2)) over the right M1 of the cortex and the negative electrode (31.5 cm(2)) over the left supra-orbital area of the head. In session two, a monophasic pulsed current stimulator (tPCS) was applied using the identical electrode placement. Imaging was performed on a Siemens 3T Tim Trio scanner with a 12-channel head coil. At each session, five consecutive functional scans were obtained: 1) resting-state without stimulation (Rest-1), 2) a motor scan consisting of self-paced, bilateral finger-thumb opposition task, 3) resting-state with ESB (Stim-1), 4) resting-state without stimulation (Rest-2), and 5) resting-state with ESB, replicating Stim-1 (Stim-2). Data were analyzed using AFNI and MATLAB. For motor task fMRI analysis, a general linear model (GLM) determined the voxels in the right and left M1 that were significantly correlated with the motor task paradigm. The resting-state time series from the voxels in the R-M1 were averaged and the resulting time series used as a regressor in a GLM analysis to identify M1 connectivity maps. Connectivity maps were quantified as R(2) values, and then combined to give overlap maps for each of the experimental conditions. Fourier analysis determined the energy in the normalized signal average time courses extracted from L-M1 and R-M1 for each of the resting-state scans. Both tDCS and tPCS lowered the R(2) values and energy of the averaged time course in the right and left M1 ROI. The effect of the tPCS appeared more pronounced and less variable among subjects. Applying non-invasive ESB during fMRI scanning may down regulate the motor cortex's resting-state network connectivity. PMID:21696709

  19. A Review on Brain Stimulation Using Low Intensity Focused Ultrasound

    PubMed Central

    Rezayat, Ehsan; Toostani, Iman Ghodrati

    2016-01-01

    Brain stimulation techniques are important in both basic and clinical studies. Majority of well-known brain stimulating techniques have low spatial resolution or entail invasive processes. Low intensity focused ultrasound (LIFU) seems to be a proper candidate for dealing with such deficiencies. This review recapitulates studies which explored the effects of LIFU on brain structures and its function, in both research and clinical areas. Although the mechanism of LIFU action is still unclear, its different effects from molecular level up to behavioral level can be explored in animal and human brain. It can also be coupled with brain imaging assessments in future research. PMID:27563411

  20. Auricular electrical stimulation and dental pain threshold.

    PubMed Central

    Simmons, M. S.; Oleson, T. D.

    1993-01-01

    A modified double-blind evaluation of naloxone reversibility of dental analgesia produced by auricular electrical stimulation (AES) was examined in 40 subjects assigned randomly to one of four groups: AES followed by saline (AS), AES followed by naloxone (AN), placebo AES followed by saline (PS), and placebo AES followed by naloxone (PN). Dental pain threshold was tested using a hand-held dental pulp tester. A second investigator administered the true or placebo AES using an electrical stimulator. A third investigator injected intravenously saline or naloxone. The subjects and investigators 1 and 3 were blind to all treatment conditions. A repeated measures analysis of variance revealed a significant difference among the four groups. The AES groups exhibited a statistically significant 18% elevation of pain threshold, whereas the two placebo stimulation groups (PS and PN) remained essentially unchanged. The mean pain threshold increased to more than 23% for group AS, but fell to less than 12% for the subjects in group AN, who were given naloxone. These findings indicate a small but significant elevation of pain threshold by AES, an effect partially blocked by naloxone, suggesting an endogenous opioid system as one mechanism for AES analgesia. Images Figure 1 Figure 2 PMID:8185085

  1. Ethical Issues in Deep Brain Stimulation

    PubMed Central

    Schermer, Maartje

    2011-01-01

    Deep brain stimulation (DBS) is currently used to treat neurological disorders like Parkinson's disease, essential tremor, and dystonia, and is explored as an experimental treatment for psychiatric disorders like major depression and obsessive compulsive disorder. This mini review discusses ethical issues in DBS treatment and research, as they have been discussed in the medical and ethical literature. With regard to DBS treatment, the most important issues are balancing risks and benefits and ensuring respect for the autonomous wish of the patient. This implies special attention to patient selection, psycho-social impact of treatment, effects on personal identity, and treatment of children. Moreover, it implies a careful informed consent process in which unrealistic expectations of patients and their families are addressed and in which special attention is given to competence. In the context of research, the fundamental ethical challenge is to promote high-quality scientific research in the interest of future patients, while at the same time safeguarding the rights and interests of vulnerable research subjects. Several guidelines have been proposed to ensure this. One of the preconditions to further development of responsible and transparent research practices is the establishment of a comprehensive registry. PMID:21625629

  2. Deep Brain Stimulation for Chronic Pain.

    PubMed

    Falowski, Steven M

    2015-07-01

    Deep brain stimulation (DBS) is a commonly performed procedure and has been used for the treatment of chronic pain since the early 1970s. A review of the literature was performed utilizing the PubMed database evaluating the use of DBS in the treatment of various pain syndromes. Literature over the last 30 years was included with a focus on those articles in the last 10 years dealing with pain conditions with the highest success as well as the targets utilized for treatment. DBS carries favorable results for the treatment of chronic pain, especially when other methods have not been successful such as medications, conservative measures, and extracranial procedures. Various chronic pain conditions reported in the literature respond to DBS including failed back surgery syndrome (FBSS), phantom limb pain, and peripheral neuropathic pain with a higher response rate for those with nociceptive pain compared to neuropathic pain. Cephaligias have promising results, with cluster headaches carrying the best success rates. DBS plays a role in the treatment of chronic pain conditions. Although considered investigational in the USA, it carries promising success rates in a recalcitrant patient population. PMID:26049773

  3. An investigation into the induced electric fields from transcranial magnetic stimulation

    NASA Astrophysics Data System (ADS)

    Hadimani, Ravi; Lee, Erik; Duffy, Walter; Waris, Mohammed; Siddiqui, Waquar; Islam, Faisal; Rajamani, Mahesh; Nathan, Ryan; Jiles, David; David C Jiles Team; Walter Duffy Collaboration

    Transcranial magnetic stimulation (TMS) is a promising tool for noninvasive brain stimulation that has been approved by the FDA for the treatment of major depressive disorder. To stimulate the brain, TMS uses large, transient pulses of magnetic field to induce an electric field in the head. This transient magnetic field is large enough to cause the depolarization of cortical neurons and initiate a synaptic signal transmission. For this study, 50 unique head models were created from MRI images. Previous simulation studies have primarily used a single head model, and thus give a limited image of the induced electric field from TMS. This study uses finite element analysis simulations on 50 unique, heterogeneous head models to better investigate the relationship between TMS and the electric field induced in brain tissues. Results showed a significant variation in the strength of the induced electric field in the brain, which can be reasonably predicted by the distance from the TMS coil to the stimulated brain. Further, it was seen that some models had high electric field intensities in over five times as much brain volume as other models.

  4. Suppression and facilitation of auditory neurons through coordinated acoustic and midbrain stimulation: investigating a deep brain stimulator for tinnitus

    NASA Astrophysics Data System (ADS)

    Offutt, Sarah J.; Ryan, Kellie J.; Konop, Alexander E.; Lim, Hubert H.

    2014-12-01

    Objective. The inferior colliculus (IC) is the primary processing center of auditory information in the midbrain and is one site of tinnitus-related activity. One potential option for suppressing the tinnitus percept is through deep brain stimulation via the auditory midbrain implant (AMI), which is designed for hearing restoration and is already being implanted in deaf patients who also have tinnitus. However, to assess the feasibility of AMI stimulation for tinnitus treatment we first need to characterize the functional connectivity within the IC. Previous studies have suggested modulatory projections from the dorsal cortex of the IC (ICD) to the central nucleus of the IC (ICC), though the functional properties of these projections need to be determined. Approach. In this study, we investigated the effects of electrical stimulation of the ICD on acoustic-driven activity within the ICC in ketamine-anesthetized guinea pigs. Main Results. We observed ICD stimulation induces both suppressive and facilitatory changes across ICC that can occur immediately during stimulation and remain after stimulation. Additionally, ICD stimulation paired with broadband noise stimulation at a specific delay can induce greater suppressive than facilitatory effects, especially when stimulating in more rostral and medial ICD locations. Significance. These findings demonstrate that ICD stimulation can induce specific types of plastic changes in ICC activity, which may be relevant for treating tinnitus. By using the AMI with electrode sites positioned with the ICD and the ICC, the modulatory effects of ICD stimulation can be tested directly in tinnitus patients.

  5. Optogenetic versus electrical stimulation of dopamine terminals in the nucleus accumbens reveals local modulation of presynaptic release

    PubMed Central

    Melchior, James R.; Ferris, Mark J.; Stuber, Garret D.; Riddle, David R.; Jones, Sara R.

    2015-01-01

    The nucleus accumbens is highly heterogeneous, integrating regionally distinct afferent projections and accumbal interneurons, resulting in diverse local microenvironments. Dopamine (DA) neuron terminals similarly express a heterogeneous collection of terminal receptors that modulate DA signaling. Cyclic voltammetry is often used to probe DA terminal dynamics in brain slice preparations; however, this method traditionally requires electrical stimulation to induce DA release. Electrical stimulation excites all of the neuronal processes in the stimulation field, potentially introducing simultaneous, multi-synaptic modulation of DA terminal release. We used optogenetics to selectively stimulate DA terminals and used voltammetry to compare DA responses from electrical and optical stimulation of the same area of tissue around a recording electrode. We found that with multiple pulse stimulation trains, optically stimulated DA release increasingly exceeded that of electrical stimulation. Furthermore, electrical stimulation produced inhibition of DA release across longer duration stimulations. The GABAB antagonist, CGP 55845, increased electrically stimulated DA release significantly more than light stimulated release. The nicotinic acetylcholine receptor antagonist, dihydro-β-erythroidine hydrobromide, inhibited single pulse electrically stimulated DA release while having no effect on optically stimulated DA release. Our results demonstrate that electrical stimulation introduces local multi-synaptic modulation of DA release that is absent with optogenetically targeted stimulation. PMID:26011081

  6. Tinnitus: Is there a place for brain stimulation?

    PubMed Central

    van Zwieten, Gusta; Smit, Jasper V.; Jahanshahi, Ali; Temel, Yasin; Stokroos, Robert J.

    2016-01-01

    Tinnitus is the perception of a “phantom sound” and has a high prevalence. Although many therapies have been investigated within the last decades, there is still no effective standard therapy. Animal studies and human functional imaging studies revealed that tinnitus perception is associated with many complex changes in multiple brain structures. There is growing evidence that brain stimulation might be able to interrupt the local altered neuronal activity and hereby inhibit tinnitus perception. In this editorial review, an update is given on the most promising targets for brain stimulation. Promising structures for stimulation are the dorsal cochlear nucleus, the inferior colliculus and the medial geniculate body of the thalamus. For cortical stimulation, the auditory cortex is considered as a target. Nevertheless, the field is waiting for evidence from well-designed clinical trials, based on supporting evidence from experimental/mechanistic research, to support or discourage the application of brain stimulation in tinnitus. PMID:26958429

  7. Changes in brain gray matter due to repetitive painful stimulation.

    PubMed

    Teutsch, S; Herken, W; Bingel, U; Schoell, E; May, A

    2008-08-15

    Using functional imaging, we recently investigated how repeated painful stimulation over several days is processed, perceived and modulated in the healthy human brain. Considering that activation-dependent brain plasticity in humans on a structural level has already been demonstrated in adults, we were interested in whether repeated painful stimulation may lead to structural changes of the brain. 14 healthy subjects were stimulated daily with a 20 min pain paradigm for 8 consecutive days, using structural MRI performed on days 1, 8, 22 and again after 1 year. Using voxel based morphometry, we are able to show that repeated painful stimulation resulted in a substantial increase of gray matter in pain transmitting areas, including mid-cingulate and somatosensory cortex. These changes are stimulation dependent, i.e. they recede after the regular nociceptive input is stopped. This data raises some interesting questions regarding structural plasticity of the brain concerning the experience of both acute and chronic pain. PMID:18582579

  8. A computational model for bipolar deep brain stimulation of the subthalamic nucleus.

    PubMed

    Iacono, Maria I; Neufeld, Esra; Bonmassar, Giorgio; Akinnagbe, Esther; Jakab, Andras; Cohen, Ethan; Kuster, Niels; Kainz, Wolfgang; Angelone, Leonardo M

    2014-01-01

    Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been shown to reduce some of the symptoms of advanced, levodopa-responsive Parkinson's disease that are not adequately controlled with medication. However, the precise mechanism of the therapeutic action of DBS is still unclear. Stimulation-induced side effects are not uncommon and require electrical "dose" adjustments. Quantitative methods are needed to fully characterize the electric field in the deep brain region that surrounds the electrodes in order to help with adjustments and maximize the efficacy of the device. Herein we report a magnetic resonance imaging (MRI)-based head model proposed for analysis of fields generated by deep brain stimulation (DBS). The model was derived from multimodal image data at 0.5mm isotropic spatial resolution and distinguishes 142 anatomical structures, including the basal ganglia and 38 nuclei of the thalamus. Six bipolar electrode configurations (1-2, 1-3, 1-4, 2-3, 2-4, 3-4) were modeled in order to assess the effects of the inter-electrode distance of the electric field. Increasing the distance between the electrodes results in an attenuated stimulation, with up to 25% reduction in electric field amplitude delivered (2-3 vs. 1-4). The map of the deep brain structures provided a highly precise anatomical detail which is useful for the quantitative assessment of current spread around the electrode and a better evaluation of the stimulation setting for the treatment optimization. PMID:25571427

  9. A Novel Brain Stimulation Technology Provides Compatibility with MRI

    PubMed Central

    Serano, Peter; Angelone, Leonardo M.; Katnani, Husam; Eskandar, Emad; Bonmassar, Giorgio

    2015-01-01

    Clinical electrical stimulation systems — such as pacemakers and deep brain stimulators (DBS) — are an increasingly common therapeutic option to treat a large range of medical conditions. Despite their remarkable success, one of the significant limitations of these medical devices is the limited compatibility with magnetic resonance imaging (MRI), a standard diagnostic tool in medicine. During an MRI exam, the leads used with these devices, implanted in the body of the patient, act as an electric antenna potentially causing a large amount of energy to be absorbed in the tissue, which can lead to serious heat-related injury. This study presents a novel lead design that reduces the antenna effect and allows for decreased tissue heating during MRI. The optimal parameters of the wire design were determined by a combination of computational modeling and experimental measurements. The results of these simulations were used to build a prototype, which was tested in a gel phantom during an MRI scan. Measurement results showed a three-fold decrease in heating when compared to a commercially available DBS lead. Accordingly, the proposed design may allow a significantly increased number of patients with medical implants to have safe access to the diagnostic benefits of MRI. PMID:25924189

  10. Individual differences in transcranial electrical stimulation current density

    PubMed Central

    Russell, Michael J; Goodman, Theodore; Pierson, Ronald; Shepherd, Shane; Wang, Qiang; Groshong, Bennett; Wiley, David F

    2013-01-01

    Transcranial electrical stimulation (TCES) is effective in treating many conditions, but it has not been possible to accurately forecast current density within the complex anatomy of a given subject's head. We sought to predict and verify TCES current densities and determine the variability of these current distributions in patient-specific models based on magnetic resonance imaging (MRI) data. Two experiments were performed. The first experiment estimated conductivity from MRIs and compared the current density results against actual measurements from the scalp surface of 3 subjects. In the second experiment, virtual electrodes were placed on the scalps of 18 subjects to model simulated current densities with 2 mA of virtually applied stimulation. This procedure was repeated for 4 electrode locations. Current densities were then calculated for 75 brain regions. Comparison of modeled and measured external current in experiment 1 yielded a correlation of r = .93. In experiment 2, modeled individual differences were greatest near the electrodes (ten-fold differences were common), but simulated current was found in all regions of the brain. Sites that were distant from the electrodes (e.g. hypothalamus) typically showed two-fold individual differences. MRI-based modeling can effectively predict current densities in individual brains. Significant variation occurs between subjects with the same applied electrode configuration. Individualized MRI-based modeling should be considered in place of the 10-20 system when accurate TCES is needed. PMID:24285948

  11. Non-invasive brain stimulation in early rehabilitation after stroke.

    PubMed

    Blesneag, A V; Popa, L; Stan, A D

    2015-01-01

    The new tendency in rehabilitation involves non-invasive tools that, if applied early after stroke, promote neurorecovery. Repetitive transcranial magnetic stimulation and transcranial direct current stimulation may correct the disruption of cortical excitability and effectively contribute to the restoration of movement and speech. The present paper analyses the results of non-invasive brain stimulation (NIBS) trials, highlighting different aspects related to the repetitive transcranial magnetic stimulation frequency, transcranial direct current stimulation polarity, the period and stimulation places in acute and subacute ischemic strokes. The risk of adverse events, the association with motor or language recovery specific training, and the cumulative positive effect evaluation are also discussed. PMID:26361512

  12. A technical guide to tDCS, and related non-invasive brain stimulation tools.

    PubMed

    Woods, A J; Antal, A; Bikson, M; Boggio, P S; Brunoni, A R; Celnik, P; Cohen, L G; Fregni, F; Herrmann, C S; Kappenman, E S; Knotkova, H; Liebetanz, D; Miniussi, C; Miranda, P C; Paulus, W; Priori, A; Reato, D; Stagg, C; Wenderoth, N; Nitsche, M A

    2016-02-01

    Transcranial electrical stimulation (tES), including transcranial direct and alternating current stimulation (tDCS, tACS) are non-invasive brain stimulation techniques increasingly used for modulation of central nervous system excitability in humans. Here we address methodological issues required for tES application. This review covers technical aspects of tES, as well as applications like exploration of brain physiology, modelling approaches, tES in cognitive neurosciences, and interventional approaches. It aims to help the reader to appropriately design and conduct studies involving these brain stimulation techniques, understand limitations and avoid shortcomings, which might hamper the scientific rigor and potential applications in the clinical domain. PMID:26652115

  13. Neuromechanism study of insect-machine interface: flight control by neural electrical stimulation.

    PubMed

    Zhao, Huixia; Zheng, Nenggan; Ribi, Willi A; Zheng, Huoqing; Xue, Lei; Gong, Fan; Zheng, Xiaoxiang; Hu, Fuliang

    2014-01-01

    The insect-machine interface (IMI) is a novel approach developed for man-made air vehicles, which directly controls insect flight by either neuromuscular or neural stimulation. In our previous study of IMI, we induced flight initiation and cessation reproducibly in restrained honeybees (Apis mellifera L.) via electrical stimulation of the bilateral optic lobes. To explore the neuromechanism underlying IMI, we applied electrical stimulation to seven subregions of the honeybee brain with the aid of a new method for localizing brain regions. Results showed that the success rate for initiating honeybee flight decreased in the order: α-lobe (or β-lobe), ellipsoid body, lobula, medulla and antennal lobe. Based on a comparison with other neurobiological studies in honeybees, we propose that there is a cluster of descending neurons in the honeybee brain that transmits neural excitation from stimulated brain areas to the thoracic ganglia, leading to flight behavior. This neural circuit may involve the higher-order integration center, the primary visual processing center and the suboesophageal ganglion, which is also associated with a possible learning and memory pathway. By pharmacologically manipulating the electrically stimulated honeybee brain, we have shown that octopamine, rather than dopamine, serotonin and acetylcholine, plays a part in the circuit underlying electrically elicited honeybee flight. Our study presents a new brain stimulation protocol for the honeybee-machine interface and has solved one of the questions with regard to understanding which functional divisions of the insect brain participate in flight control. It will support further studies to uncover the involved neurons inside specific brain areas and to test the hypothesized involvement of a visual learning and memory pathway in IMI flight control. PMID:25409523

  14. Neuromechanism Study of Insect–Machine Interface: Flight Control by Neural Electrical Stimulation

    PubMed Central

    Zhao, Huixia; Zheng, Nenggan; Ribi, Willi A.; Zheng, Huoqing; Xue, Lei; Gong, Fan; Zheng, Xiaoxiang; Hu, Fuliang

    2014-01-01

    The insect–machine interface (IMI) is a novel approach developed for man-made air vehicles, which directly controls insect flight by either neuromuscular or neural stimulation. In our previous study of IMI, we induced flight initiation and cessation reproducibly in restrained honeybees (Apis mellifera L.) via electrical stimulation of the bilateral optic lobes. To explore the neuromechanism underlying IMI, we applied electrical stimulation to seven subregions of the honeybee brain with the aid of a new method for localizing brain regions. Results showed that the success rate for initiating honeybee flight decreased in the order: α-lobe (or β-lobe), ellipsoid body, lobula, medulla and antennal lobe. Based on a comparison with other neurobiological studies in honeybees, we propose that there is a cluster of descending neurons in the honeybee brain that transmits neural excitation from stimulated brain areas to the thoracic ganglia, leading to flight behavior. This neural circuit may involve the higher-order integration center, the primary visual processing center and the suboesophageal ganglion, which is also associated with a possible learning and memory pathway. By pharmacologically manipulating the electrically stimulated honeybee brain, we have shown that octopamine, rather than dopamine, serotonin and acetylcholine, plays a part in the circuit underlying electrically elicited honeybee flight. Our study presents a new brain stimulation protocol for the honeybee–machine interface and has solved one of the questions with regard to understanding which functional divisions of the insect brain participate in flight control. It will support further studies to uncover the involved neurons inside specific brain areas and to test the hypothesized involvement of a visual learning and memory pathway in IMI flight control. PMID:25409523

  15. Technical aspects of neurostimulation: Focus on equipment, electric field modeling, and stimulation protocols.

    PubMed

    Klooster, D C W; de Louw, A J A; Aldenkamp, A P; Besseling, R M H; Mestrom, R M C; Carrette, S; Zinger, S; Bergmans, J W M; Mess, W H; Vonck, K; Carrette, E; Breuer, L E M; Bernas, A; Tijhuis, A G; Boon, P

    2016-06-01

    Neuromodulation is a field of science, medicine, and bioengineering that encompasses implantable and non-implantable technologies for the purpose of improving quality of life and functioning of humans. Brain neuromodulation involves different neurostimulation techniques: transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), which are being used both to study their effects on cognitive brain functions and to treat neuropsychiatric disorders. The mechanisms of action of neurostimulation remain incompletely understood. Insight into the technical basis of neurostimulation might be a first step towards a more profound understanding of these mechanisms, which might lead to improved clinical outcome and therapeutic potential. This review provides an overview of the technical basis of neurostimulation focusing on the equipment, the present understanding of induced electric fields, and the stimulation protocols. The review is written from a technical perspective aimed at supporting the use of neurostimulation in clinical practice. PMID:27021215

  16. Injectable microstimulator for functional electrical stimulation.

    PubMed

    Loeb, G E; Zamin, C J; Schulman, J H; Troyk, P R

    1991-11-01

    A family of digitally controlled devices is constructed for functional electrical stimulation in which each module is an hermetically sealed glass capsule that is small enough to be injected through the lumen of a hypodermic needle. The overall design and component characteristics of microstimulators that receive power and command signals by inductive coupling from a single, externally worn coil are described. Each device stores power between stimulus pulses by charging an electrolytic capacitor formed by its two electrodes, made of sintered, anodised tantalum and electrochemically activated iridium, respectively. Externally, a highly efficient class E amplifier provides power and digitally encoded command signals to control the amplitude, duration and timing of pulses from up to 256 such microstimulators. PMID:1813741

  17. Changes of somatomotor and parietal regions produced by different amounts of electrical stimulation.

    PubMed

    Bittencourt, Juliana; Velasques, Bruna; Machado, Sergio; Cunha, Marlo; Budde, Henning; Basile, Luis F; Cagy, Mauricio; Piedade, Roberto; Ribeiro, Pedro

    2010-01-18

    Our study aims to investigate changes in electrocortical activity by observing the variations in absolute theta power in the primary somatomotor and parietal regions of the brain under three different electrical stimulation conditions: control group (without stimulation), group 24 (24 trials of stimulation) and group 36 (36 trials of stimulation). Thus, our hypothesis is that the application of different patterns of electrical stimulation will promote different states of habituation in these regions. The sample was composed of 24 healthy (absence of mental and physical impairments) students (14 male and 10 female), with ages varying from 25 to 40 years old (32.5+/-7.5), who are right-handed (Edinburgh Inventory). The subjects were randomly distributed into three groups: control (n=8), G24 (n=8) and G36 (n=8). We use the Functional electrical stimulation (FES) equipment (NeuroCompact-2462) to stimulate the right index finger extensor muscle, while the electroencephalographic signal was simultaneously recorded. We found an interaction between condition and block factors for the C3 and P3 electrode, a condition and block main effects for the C4 electrode, and a condition main effect for the P4 electrode. Our results support the hypothesis that electrical stimulation promotes neurophysiological changes. It appears that stimulus adaptation (accommodation) of specific circuits can strengthen the brain's ability to distinguish between and respond to such stimuli over time. PMID:19945508

  18. Surface electrical stimulation to evoke referred sensation.

    PubMed

    Forst, Johanna C; Blok, Derek C; Slopsema, Julia P; Boss, John M; Heyboer, Lane A; Tobias, Carson M; Polasek, Katharine H

    2015-01-01

    Surface electrical stimulation (SES) is being investigated as a noninvasive method to evoke natural sensations distal to electrode location. This may improve treatment for phantom limb pain as well as provide an alternative method to deliver sensory feedback. The median and/or ulnar nerves of 35 subjects were stimulated at the elbow using surface electrodes. Strength-duration curves of hand sensation were found for each subject. All subjects experienced sensation in their hand, which was mostly described as a paresthesia-like sensation. The rheobase and chronaxie values were found to be lower for the median nerve than the ulnar nerve, with no significant difference between sexes. Repeated sessions with the same subject resulted in sufficient variability to suggest that recalculating the strength-duration curve for each electrode placement is necessary. Most of the recruitment curves in this study were generated with 28 to 36 data points. To quickly reproduce these curves with limited increase in error, we recommend 10 data points. Future studies will focus on obtaining different sensations using SES with the strength-duration curve defining the threshold of the effective parameter space. PMID:26348194

  19. Brain responses to acupuncture stimulation in the prosthetic hand of an amputee patient.

    PubMed

    Lee, In-Seon; Jung, Won-Mo; Lee, Ye-Seul; Wallraven, Christian; Chae, Younbyoung

    2015-10-01

    This report describes the brain responses to acupuncture in an upper limb amputee patient. A 62-year-old male had previously undergone a lower left arm amputation following an electrical accident. Using functional MRI, we investigated brain responses to acupuncture stimulation in the aforementioned amputee under three conditions: (a) intact hand, (b) prosthetic hand (used by the patient), and (c) fake fabric hand. The patient described greater de qi sensation when he received acupuncture stimulation in his prosthetic hand compared to a fake hand, with both stimulations performed in a similar manner. We found enhanced brain activation in the insula and sensorimotor cortex in response to acupuncture stimulation in the amputee's prosthetic hand, while there was only minimal activation in the visual cortex in response to acupuncture stimulation in a fake hand. The enhanced brain responses to acupuncture stimulation of the patient's prosthetic hand might be derived from cortical reorganisation, as he has been using his prosthetic hand for over 40 years. Our findings suggest the possible use of acupuncture stimulation in a prosthetic hand as an enhanced sensory feedback mechanism, which may represent a new treatment approach for phantom limb pain. PMID:26033865

  20. Intrusive Thoughts Elicited by Direct Electrical Stimulation during Stereo-Electroencephalography.

    PubMed

    Popa, Irina; Donos, Cristian; Barborica, Andrei; Opris, Ioan; Mălîia, Mihai Dragoş; Ene, Mirela; Ciurea, Jean; Mîndruţă, Ioana

    2016-01-01

    Cortical direct electrical stimulation (DES) is a method of brain mapping used during invasive presurgical evaluation of patients with intractable epilepsy. Intellectual auras like intrusive thoughts, also known as forced thinking (FT), have been reported during frontal seizures. However, there are few reports on FT obtained during DES in frontal cortex. We report three cases in which we obtained intrusive thoughts while stimulating the dorsolateral prefrontal cortex and the white matter in the prefrontal region. In order to highlight the effective connectivity that might explain this clinical response, we have analyzed cortico-cortical potentials evoked by single pulse electrical stimulation. PMID:27486431

  1. Intrusive Thoughts Elicited by Direct Electrical Stimulation during Stereo-Electroencephalography

    PubMed Central

    Popa, Irina; Donos, Cristian; Barborica, Andrei; Opris, Ioan; Mălîia, Mihai Dragoş; Ene, Mirela; Ciurea, Jean; Mîndruţă, Ioana

    2016-01-01

    Cortical direct electrical stimulation (DES) is a method of brain mapping used during invasive presurgical evaluation of patients with intractable epilepsy. Intellectual auras like intrusive thoughts, also known as forced thinking (FT), have been reported during frontal seizures. However, there are few reports on FT obtained during DES in frontal cortex. We report three cases in which we obtained intrusive thoughts while stimulating the dorsolateral prefrontal cortex and the white matter in the prefrontal region. In order to highlight the effective connectivity that might explain this clinical response, we have analyzed cortico-cortical potentials evoked by single pulse electrical stimulation. PMID:27486431

  2. The present indication and future of deep brain stimulation.

    PubMed

    Sugiyama, Kenji; Nozaki, Takao; Asakawa, Tetsuya; Koizumi, Shinichiro; Saitoh, Osamu; Namba, Hiroki

    2015-01-01

    The use of electrical stimulation to treat pain in human disease dates back to ancient Rome or Greece. Modern deep brain stimulation (DBS) was initially applied for pain treatment in the 1960s, and was later used to treat movement disorders in the 1990s. After recognition of DBS as a therapy for central nervous system (CNS) circuit disorders, DBS use showed drastic increase in terms of adaptability to disease and the patient's population. More than 100,000 patients have received DBS therapy worldwide. The established indications for DBS are Parkinson's disease, tremor, and dystonia, whereas global indications of DBS expanded to other neuronal diseases or disorders such as neuropathic pain, epilepsy, and tinnitus. DBS is also experimentally used to manage cognitive disorders and psychiatric diseases such as major depression, obsessive-compulsive disorder (OCD), Tourette's syndrome, and eating disorders. The importance of ethics and conflicts surrounding the regulation and freedom of choice associated with the application of DBS therapy for new diseases or disorders is increasing. These debates are centered on the use of DBS to treat new diseases and disorders as well as its potential to enhance ability in normal healthy individuals. Here we present three issues that need to be addressed in the future: (1) elucidation of the mechanisms of DBS, (2) development of new DBS methods, and (3) miniaturization of the DBS system. With the use of DBS, functional neurosurgery entered into the new era that man can manage and control the brain circuit to treat intractable neuronal diseases and disorders. PMID:25925757

  3. The Present Indication and Future of Deep Brain Stimulation

    PubMed Central

    SUGIYAMA, Kenji; NOZAKI, Takao; ASAKAWA, Tetsuya; KOIZUMI, Shinichiro; SAITOH, Osamu; NAMBA, Hiroki

    2015-01-01

    The use of electrical stimulation to treat pain in human disease dates back to ancient Rome or Greece. Modern deep brain stimulation (DBS) was initially applied for pain treatment in the 1960s, and was later used to treat movement disorders in the 1990s. After recognition of DBS as a therapy for central nervous system (CNS) circuit disorders, DBS use showed drastic increase in terms of adaptability to disease and the patient’s population. More than 100,000 patients have received DBS therapy worldwide. The established indications for DBS are Parkinson’s disease, tremor, and dystonia, whereas global indications of DBS expanded to other neuronal diseases or disorders such as neuropathic pain, epilepsy, and tinnitus. DBS is also experimentally used to manage cognitive disorders and psychiatric diseases such as major depression, obsessive-compulsive disorder (OCD), Tourette’s syndrome, and eating disorders. The importance of ethics and conflicts surrounding the regulation and freedom of choice associated with the application of DBS therapy for new diseases or disorders is increasing. These debates are centered on the use of DBS to treat new diseases and disorders as well as its potential to enhance ability in normal healthy individuals. Here we present three issues that need to be addressed in the future: (1) elucidation of the mechanisms of DBS, (2) development of new DBS methods, and (3) miniaturization of the DBS system. With the use of DBS, functional neurosurgery entered into the new era that man can manage and control the brain circuit to treat intractable neuronal diseases and disorders. PMID:25925757

  4. Noninvasive brain stimulation: from physiology to network dynamics and back

    PubMed Central

    Dayan, Eran; Censor, Nitzan; Buch, Ethan R; Sandrini, Marco; Cohen, Leonardo G

    2016-01-01

    Noninvasive brain stimulation techniques have been widely used for studying the physiology of the CNS, identifying the functional role of specific brain structures and, more recently, exploring large-scale network dynamics. Here we review key findings that contribute to our understanding of the mechanisms underlying the physiological and behavioral effects of these techniques. We highlight recent innovations using noninvasive stimulation to investigate global brain network dynamics and organization. New combinations of these techniques, in conjunction with neuroimaging, will further advance the utility of their application. PMID:23799477

  5. Electrical stimulation in the bed nucleus of the stria terminalis alleviates severe obsessive-compulsive disorder.

    PubMed

    Luyten, L; Hendrickx, S; Raymaekers, S; Gabriëls, L; Nuttin, B

    2016-09-01

    In 1998, we proposed deep brain stimulation as a last-resort treatment option for patients suffering from severe, treatment-resistant obsessive-compulsive disorder (OCD). Here, 24 OCD patients were included in a long-term follow-up study to evaluate the effects of electrical stimulation in the anterior limbs of the internal capsule (ALIC) and bed nucleus of the stria terminalis (BST). We find that electrical stimulation in the ALIC/BST area is safe and significantly decreases obsessions, compulsions, and associated anxiety and depressive symptoms, and improves global functioning in a blinded crossover trial (n=17), after 4 years (n=18), and at last follow-up (up to 171 months, n=24). Moreover, our data indicate that BST may be a better stimulation target compared with ALIC to alleviate OCD symptoms. We conclude that electrical stimulation in BST is a promising therapeutic option for otherwise treatment-resistant OCD patients. PMID:26303665

  6. 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. PMID:25664378

  7. New controller for functional electrical stimulation systems.

    PubMed

    Fisekovic, N; Popovic, D B

    2001-07-01

    A novel, self-contained controller for functional electrical stimulation systems has been designed. The development was motivated by the need to have a general purpose, easy to use controller capable of stimulating many muscle groups, thus restoring complex motor functions (e.g. standing, walking, reaching, and grasping). The designed controller can regulate the frequency, pulse duration, and charge balance on up to 16 channels, and execute pre-programmed and sensory-driven control operations. The controller supports up to eight analog and six digital sensors, and comprises a memory block for including history of the sensory data (time series). Five independent timers provide the basis for the multi-modal and multi-level control of movement. The PC compatible interface is realised via an IR serial communication channel. The PC based software is user friendly and fully menu driven. This paper also presents a case study where the controller was implemented to restore walking in a paraplegic subject. The assistive system comprised the novel controller, the power and output stages of an eight-channel FES system (IEEE Trans Rehabil Eng, TRE-2 (1994) 234), ankle-foot orthoses, and a rolling walker. Stimulation was applied with surface electrodes positioned over the motoneurons that innervate muscles responsible for the hip and knee flexion and extension. The sensory system included goniometers at knee and hip joints, force-sensing resistors built in the shoe insoles, and digital accelerometers at the hips. A rule-based control algorithm was generated following a two-step procedure: (1) simulation and (2) machine learning as described in earlier studies (IEEE Trans Rehab Eng, TRE-7 (1999) 69). The paraplegic subject walked faster, and with less physiological effort, when automatic control was applied as compared to hand-control. This case study, as well as a previous one for assisting grasping (The design and testing of a new programmable electronic stimulator. N

  8. Bioreactor for modulation of cardiac microtissue phenotype by combined static stretch and electrical stimulation

    PubMed Central

    Miklas, Jason W; Nunes, Sara S; Sofla, Aarash; Reis, Lewis A; Pahnke, Aric; Xiao, Yun; Laschinger, Carol; Radisic, Milica

    2014-01-01

    We describe here a bioreactor capable of simultaneously applying mechanical and electrical field stimulation in conjunction with static strain and on-line force of contraction measurements. It consisted of a polydimethylsiloxane (PDMS) tissue chamber and a pneumatically driven stretch platform. The chamber contained eight tissue microwells (8.05 mm in length and 2.5 mm in width) with a pair of posts (2.78 mm in height and 0.8 mm in diameter) in each well to serve as fixation points and for measurements of contraction force. Carbon rods, stimulating electrodes, were placed into the PDMS chamber such that one pair stimulated four microwells. For feasibility studies, neonatal rat cardiomyocytes were seeded in collagen gels into the microwells. Following three days of gel compaction, electrical field stimulation at 3–4 V/cm and 1Hz, mechanical stimulation of 5% static strain or electromechanical stimulation (field stimulation at 3–4 V/cm, 1Hz and 5% static strain) were applied for 3 days. Cardiac microtissues subjected to electromechanical stimulation exhibited elevated amplitude of contraction and improved sarcomere structure as evidenced by sarcomeric α-actinin, actin and troponin T staining compared to microtissues subjected to electrical or mechanical stimulation alone or non-stimulated controls. The expression of atrial natriuretic factor and brain natriuretic peptide was also elevated in the electromechanically stimulated group. PMID:24876342

  9. External globus pallidus stimulation modulates brain connectivity in Huntington's disease.

    PubMed

    Ligot, Noémie; Krystkowiak, Pierre; Simonin, Clémence; Goldman, Serge; Peigneux, Philippe; Van Naemen, John; Monclus, Michel; Lacroix, Simon Frédéric; Devos, David; Dujardin, Kathy; Delmaire, Christine; Bardinet, Eric; Delval, Arnaud; Delliaux, Marie; Defebvre, Luc; Yelnik, Jerome; Blond, Serge; Destée, Alain; De Tiège, Xavier

    2011-01-01

    Positron emission tomography with O-15-labeled water was used to study at rest the neurophysiological effects of bilateral external globus pallidus (GPe) deep brain stimulation in patients with Huntington's disease (HD). Five patients were compared with a control group in the on and off states of the stimulator. External globus pallidus stimulation decreased neuronal activity and modulated cerebral connectivity within the basal ganglia-thalamocortical circuitry, the sensorimotor, and the default-mode networks. These data indicate that GPe stimulation modulates functional integration in HD patients in accordance with the basal ganglia-thalamocortical circuit model. PMID:20959850

  10. External globus pallidus stimulation modulates brain connectivity in Huntington's disease

    PubMed Central

    Ligot, Noémie; Krystkowiak, Pierre; Simonin, Clémence; Goldman, Serge; Peigneux, Philippe; Van Naemen, John; Monclus, Michel; Lacroix, Simon Frédéric; Devos, David; Dujardin, Kathy; Delmaire, Christine; Bardinet, Eric; Delval, Arnaud; Delliaux, Marie; Defebvre, Luc; Yelnik, Jerome; Blond, Serge; Destée, Alain; De Tiège, Xavier

    2011-01-01

    Positron emission tomography with O-15-labeled water was used to study at rest the neurophysiological effects of bilateral external globus pallidus (GPe) deep brain stimulation in patients with Huntington's disease (HD). Five patients were compared with a control group in the on and off states of the stimulator. External globus pallidus stimulation decreased neuronal activity and modulated cerebral connectivity within the basal ganglia-thalamocortical circuitry, the sensorimotor, and the default-mode networks. These data indicate that GPe stimulation modulates functional integration in HD patients in accordance with the basal ganglia-thalamocortical circuit model. PMID:20959850

  11. Non-invasive brain stimulation of the aging brain: State of the art and future perspectives.

    PubMed

    Tatti, Elisa; Rossi, Simone; Innocenti, Iglis; Rossi, Alessandro; Santarnecchi, Emiliano

    2016-08-01

    Favored by increased life expectancy and reduced birth rate, worldwide demography is rapidly shifting to older ages. The golden age of aging is not only an achievement but also a big challenge because of the load of the elderly on social and medical health care systems. Moreover, the impact of age-related decline of attention, memory, reasoning and executive functions on self-sufficiency emphasizes the need of interventions to maintain cognitive abilities at a useful degree in old age. Recently, neuroscientific research explored the chance to apply Non-Invasive Brain Stimulation (NiBS) techniques (as transcranial electrical and magnetic stimulation) to healthy aging population to preserve or enhance physiologically-declining cognitive functions. The present review will update and address the current state of the art on NiBS in healthy aging. Feasibility of NiBS techniques will be discussed in light of recent neuroimaging (either structural or functional) and neurophysiological models proposed to explain neural substrates of the physiologically aging brain. Further, the chance to design multidisciplinary interventions to maximize the efficacy of NiBS techniques will be introduced as a necessary future direction. PMID:27221544

  12. A tripolar current-steering stimulator ASIC for field shaping in deep brain stimulation.

    PubMed

    Valente, Virgilio; Demosthenous, Andreas; Bayford, Richard

    2012-06-01

    A significant problem with clinical deep brain stimulation (DBS) is the high variability of its efficacy and the frequency of side effects, related to the spreading of current beyond the anatomical target area. This is the result of the lack of control that current DBS systems offer on the shaping of the electric potential distribution around the electrode. This paper presents a stimulator ASIC with a tripolar current-steering output stage, aiming at achieving more selectivity and field shaping than current DBS systems. The ASIC was fabricated in a 0.35-μ m CMOS technology occupying a core area of 0.71 mm(2). It consists of three current sourcing/sinking channels. It is capable of generating square and exponential-decay biphasic current pulses with five different time constants up to 28 ms and delivering up to 1.85 mA of cathodic current, in steps of 4 μA, from a 12 V power supply. Field shaping was validated by mapping the potential distribution when injecting current pulses through a multicontact DBS electrode in saline. PMID:23853142

  13. A history of deep brain stimulation: Technological innovation and the role of clinical assessment tools

    PubMed Central

    2013-01-01

    Deep brain stimulation involves using a pacemaker-like device to deliver constant electrical stimulation to problematic areas within the brain. It has been used to treat over 40,000 people with Parkinson’s disease and essential tremor worldwide and is currently undergoing clinical trials as a treatment for depression and obsessive–compulsive disorder. This article will provide an historical account of deep brain stimulation in order to illustrate the plurality of interests involved in the development and stabilization of deep brain stimulation technology. Using Latour’s notion of immutable mobiles, this article will illustrate the importance of clinical assessment tools in shaping technological development in the era of medical device regulation. Given that such tools can serve commercial and professional interests, this article suggests that it is necessary to scrutinise their application in research contexts to ensure that they capture clinical changes that are meaningful for patients and their families. This is particularly important in relation to potentially ethically problematic therapies such as deep brain stimulation for psychiatric disorders.

  14. Uncovering the mechanism(s) of deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Gang, Li; Chao, Yu; Ling, Lin; C-Y Lu, Stephen

    2005-01-01

    Deep brain stimulators, often called `pacemakers for the brain', are implantable devices which continuously deliver impulse stimulation to specific targeted nuclei of deep brain structure, namely deep brain stimulation (DBS). To date, deep brain stimulation (DBS) is the most effective clinical technique for the treatment of several medically refractory movement disorders (e.g., Parkinson's disease, essential tremor, and dystonia). In addition, new clinical applications of DBS for other neurologic and psychiatric disorders (e.g., epilepsy and obsessive-compulsive disorder) have been put forward. Although DBS has been effective in the treatment of movement disorders and is rapidly being explored for the treatment of other neurologic disorders, the scientific understanding of its mechanisms of action remains unclear and continues to be debated in the scientific community. Optimization of DBS technology for present and future therapeutic applications will depend on identification of the therapeutic mechanism(s) of action. The goal of this review is to address our present knowledge of the effects of high-frequency stimulation within the central nervous system and comment on the functional implications of this knowledge for uncovering the mechanism(s) of DBS.

  15. Friends, not foes: Magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation

    PubMed Central

    Neuling, Toralf; Ruhnau, Philipp; Fuscà, Marco; Demarchi, Gianpaolo; Herrmann, Christoph S.; Weisz, Nathan

    2015-01-01

    Brain oscillations are supposedly crucial for normal cognitive functioning and alterations are associated with cognitive dysfunctions. To demonstrate their causal role on behavior, entrainment approaches in particular aim at driving endogenous oscillations via rhythmic stimulation. Within this context, transcranial electrical stimulation, especially transcranial alternating current stimulation (tACS), has received renewed attention. This is likely due to the possibility of defining oscillatory stimulation properties precisely. Also, measurements comparing pre-tACS with post-tACS electroencephalography (EEG) have shown impressive modulations. However, the period during tACS has remained a blackbox until now, due to the enormous stimulation artifact. By means of application of beamforming to magnetoencephalography (MEG) data, we successfully recovered modulations of the amplitude of brain oscillations during weak and strong tACS. Additionally, we demonstrate that also evoked responses to visual and auditory stimuli can be recovered during tACS. The main contribution of the present study is to provide critical evidence that during ongoing tACS, subtle modulations of oscillatory brain activity can be reconstructed even at the stimulation frequency. Future tACS experiments will be able to deliver direct physiological insights in order to further the understanding of the contribution of brain oscillations to cognition and behavior. PMID:26080310

  16. The Ferrier Lecture 2004 What can transcranial magnetic stimulation tell us about how the brain works?

    PubMed Central

    Cowey, Alan

    2005-01-01

    Transcranial magnetic stimulation (TMS) is a technique whereby parts of the cerebral cortex and underlying white matter can be excited by a brief electrical current induced by a similarly brief, rapidly fluctuating magnetic field which is itself produced by rapidly discharging a current through an insulated coil held against the scalp. When combined with magnetic resonance structural and functional images of the subject's brain, the stimulation can be directed at specific cortical areas. Over a period of only 15 years, TMS has revealed hitherto unsuspected aspects of brain function, such as the role of distant parts of the brain in recovery from stroke, and has helped to resolve several previously intractable disputes, such as the neuronal basis of conscious awareness. This article describes and discusses the origins and nature of TMS, its applications and limitations, and its especial usefulness in conjunction with other techniques of evaluating or imaging brain activity. PMID:16147516

  17. New perspectives on using brain imaging to study CNS stimulants.

    PubMed

    Lukas, Scott E

    2014-12-01

    While the recent application of brain imaging to study CNS stimulants has offered new insights into the fundamental factors that contribute to their use and abuse, many gaps remain. Brain circuits that mediate pleasure, dependence, craving and relapse are anatomically, neurophysiologically and neurochemically distinct from one another, which has guided the search for correlates of stimulant-seeking and taking behavior. However, unlike other drugs of abuse, metrics for tolerance and physical dependence on stimulants are not obvious. The dopamine theory of stimulant abuse does not sufficiently explain this disorder as serotonergic, GABAergic and glutamagergic circuits are clearly involved in stimulant pharmacology and so tracking the source of the "addictive" processes must adopt a more multimodal, multidisciplinary approach. To this end, both anatomical and functional magnetic resonance imaging (MRI), MR spectroscopy (MRS) and positron emission tomography (PET) are complementary and have equally contributed to our understanding of how stimulants affect the brain and behavior. New vistas in this area include nanotechnology approaches to deliver small molecules to receptors and use MRI to resolve receptor dynamics. Anatomical and blood flow imaging has yielded data showing that cognitive enhancers might be useful adjuncts in treating CNS stimulant dependence, while MRS has opened opportunities to examine the brain's readiness to accept treatment as GABA tone normalizes after detoxification. A desired outcome of the above approaches is being able to offer evidence-based rationales for treatment approaches that can be implemented in a more broad geographic area, where access to brain imaging facilities may be limited. This article is part of the Special Issue entitled 'CNS Stimulants'. PMID:25080072

  18. Imaging human brain networks to improve the clinical efficacy of non-invasive brain stimulation.

    PubMed

    Sale, Martin V; Mattingley, Jason B; Zalesky, Andrew; Cocchi, Luca

    2015-10-01

    The flexible integration of segregated neural processes is essential to healthy brain function. Advances in neuroimaging techniques have revealed that psychiatric and neurological disorders are characterized by anomalies in the dynamic integration of widespread neural populations. Re-establishing optimal neural activity is an important component of the treatment of such disorders. Non-invasive brain stimulation is emerging as a viable tool to selectively restore both local and widespread neural activity in patients affected by psychiatric and neurological disorders. Importantly, the different forms of non-invasive brain stimulation affect neural activity in distinct ways, which has important ramifications for their clinical efficacy. In this review, we discuss how non-invasive brain stimulation techniques influence widespread neural integration across brain regions. We suggest that the efficacy of such techniques in the treatment of psychiatric and neurological conditions is contingent on applying the appropriate stimulation paradigm to restore specific aspects of altered neural integration. PMID:26409343

  19. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrical peripheral nerve stimulator. 868.2775 Section 868.2775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification....

  20. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrical peripheral nerve stimulator. 868.2775 Section 868.2775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification....

  1. Gender Differences in Current Received during Transcranial Electrical Stimulation

    PubMed Central

    Russell, Michael; Goodman, Theodore; Wang, Qiang; Groshong, Bennett; Lyeth, Bruce G.

    2014-01-01

    Low current transcranial electrical stimulation (tCS) is an effective but somewhat inconsistent tool for augmenting neuromodulation. In this study, we used 3D MRI guided electrical transcranial stimulation modeling to estimate the range of current intensities received at cortical brain tissues. Combined T1, T2, and proton density MRIs from 24 adult subjects (12 male and 12 female) were modeled with virtual electrodes placed at F3, F4, C3, and C4. Two sizes of electrodes 20 mm round and 50 mm × 45 mm were examined at 0.5, 1, and 2 mA input currents. The intensity of current received was sampled in a 1-cm sphere placed at the cortex directly under each scalp electrode. There was a 10-fold difference in the amount of current received by individuals. A large gender difference was observed with female subjects receiving significantly less current at targeted parietal cortex than male subjects when stimulated at identical current levels (P < 0.05). Larger electrodes delivered somewhat larger amounts of current than the smaller ones (P < 0.01). Electrodes in the frontal regions delivered less current than those in the parietal region (P < 0.05). There were large individual differences in current levels that the subjects received. Analysis of the cranial bone showed that the gender difference and the frontal parietal differences are due to differences in cranial bone. Males have more cancelous parietal bone and females more dense parietal bone (P < 0.01). These differences should be considered when planning tCS studies and call into question earlier reports of gender differences due to hormonal influences. PMID:25177301

  2. Electrical Stimulation Counteracts Muscle Decline in Seniors

    PubMed Central

    Kern, Helmut; Barberi, Laura; Löfler, Stefan; Sbardella, Simona; Burggraf, Samantha; Fruhmann, Hannah; Carraro, Ugo; Mosole, Simone; Sarabon, Nejc; Vogelauer, Michael; Mayr, Winfried; Krenn, Matthias; Cvecka, Jan; Romanello, Vanina; Pietrangelo, Laura; Protasi, Feliciano; Sandri, Marco; Zampieri, Sandra; Musaro, Antonio

    2014-01-01

    The loss in muscle mass coupled with a decrease in specific force and shift in fiber composition are hallmarks of aging. Training and regular exercise attenuate the signs of sarcopenia. However, pathologic conditions limit the ability to perform physical exercise. We addressed whether electrical stimulation (ES) is an alternative intervention to improve muscle recovery and defined the molecular mechanism associated with improvement in muscle structure and function. We analyzed, at functional, structural, and molecular level, the effects of ES training on healthy seniors with normal life style, without routine sport activity. ES was able to improve muscle torque and functional performances of seniors and increased the size of fast muscle fibers. At molecular level, ES induced up-regulation of IGF-1 and modulation of MuRF-1, a muscle-specific atrophy-related gene. ES also induced up-regulation of relevant markers of differentiating satellite cells and of extracellular matrix remodeling, which might guarantee shape and mechanical forces of trained skeletal muscle as well as maintenance of satellite cell function, reducing fibrosis. Our data provide evidence that ES is a safe method to counteract muscle decline associated with aging. PMID:25104935

  3. Best of both worlds: promise of combining brain stimulation and brain connectome.

    PubMed

    Luft, Caroline Di Bernardi; Pereda, Ernesto; Banissy, Michael J; Bhattacharya, Joydeep

    2014-01-01

    Transcranial current brain stimulation (tCS) is becoming increasingly popular as a non-pharmacological non-invasive neuromodulatory method that alters cortical excitability by applying weak electrical currents to the scalp via a pair of electrodes. Most applications of this technique have focused on enhancing motor and learning skills, as well as a therapeutic agent in neurological and psychiatric disorders. In these applications, similarly to lesion studies, tCS was used to provide a causal link between a function or behavior and a specific brain region (e.g., primary motor cortex). Nonetheless, complex cognitive functions are known to rely on functionally connected multitude of brain regions with dynamically changing patterns of information flow rather than on isolated areas, which are most commonly targeted in typical tCS experiments. In this review article, we argue in favor of combining tCS method with other neuroimaging techniques (e.g., fMRI, EEG) and by employing state-of-the-art connectivity data analysis techniques (e.g., graph theory) to obtain a deeper understanding of the underlying spatiotemporal dynamics of functional connectivity patterns and cognitive performance. Finally, we discuss the possibilities of using these combined techniques to investigate the neural correlates of human creativity and to enhance creativity. PMID:25126060

  4. Best of both worlds: promise of combining brain stimulation and brain connectome

    PubMed Central

    Luft, Caroline Di Bernardi; Pereda, Ernesto; Banissy, Michael J.; Bhattacharya, Joydeep

    2014-01-01

    Transcranial current brain stimulation (tCS) is becoming increasingly popular as a non-pharmacological non-invasive neuromodulatory method that alters cortical excitability by applying weak electrical currents to the scalp via a pair of electrodes. Most applications of this technique have focused on enhancing motor and learning skills, as well as a therapeutic agent in neurological and psychiatric disorders. In these applications, similarly to lesion studies, tCS was used to provide a causal link between a function or behavior and a specific brain region (e.g., primary motor cortex). Nonetheless, complex cognitive functions are known to rely on functionally connected multitude of brain regions with dynamically changing patterns of information flow rather than on isolated areas, which are most commonly targeted in typical tCS experiments. In this review article, we argue in favor of combining tCS method with other neuroimaging techniques (e.g., fMRI, EEG) and by employing state-of-the-art connectivity data analysis techniques (e.g., graph theory) to obtain a deeper understanding of the underlying spatiotemporal dynamics of functional connectivity patterns and cognitive performance. Finally, we discuss the possibilities of using these combined techniques to investigate the neural correlates of human creativity and to enhance creativity. PMID:25126060

  5. Deep brain stimulation affects conditioned and unconditioned anxiety in different brain areas.

    PubMed

    van Dijk, A; Klanker, M; van Oorschot, N; Post, R; Hamelink, R; Feenstra, M G P; Denys, D

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) has proven to be an effective treatment for therapy refractory obsessive-compulsive disorder. Clinical observations show that anxiety symptoms decrease rapidly following DBS. As in clinical studies different regions are targeted, it is of principal interest to understand which brain area is responsible for the anxiolytic effect and whether high-frequency stimulation of different areas differentially affect unconditioned (innate) and conditioned (learned) anxiety. In this study, we examined the effect of stimulation in five brain areas in rats (NAc core and shell, bed nucleus of the stria terminalis (BNST), internal capsule (IC) and the ventral medial caudate nucleus (CAU)). The elevated plus maze was used to test the effect of stimulation on unconditioned anxiety, the Vogel conflict test for conditioned anxiety, and an activity test for general locomotor behaviour. We found different anxiolytic effects of stimulation in the five target areas. Stimulation of the CAU decreased both conditioned and unconditioned anxiety, while stimulation of the IC uniquely reduced conditioned anxiety. Remarkably, neither the accumbens nor the BNST stimulation affected conditioned or unconditioned anxiety. Locomotor activity increased with NAc core stimulation but decreased with the BNST. These findings suggest that (1) DBS may have a differential effect on unconditioned and conditioned anxiety depending on the stimulation area, and that (2) stimulation of the IC exclusively reduces conditioned anxiety. This suggests that the anxiolytic effects of DBS seen in OCD patients may not be induced by stimulation of the NAc, but rather by the IC. PMID:23900312

  6. Conditioning of brain stimulation-induced presleep behavior.

    PubMed

    Wyrwicka, W; Chase, M H

    1994-11-01

    Experiments were conducted on three chronic unanesthetized, undrugged cats. Electrical stimulation of the basal forebrain area (BFA) resulted in presleep behavior (i.e., the cats would sit or lie down, and EEG spindles would arise). After several sessions (conducted twice a week), two of these cats began to exhibit presleep behavior almost immediately after entering the experimental compartment, even before the application of BFA stimulation. The third cat often ate some food (which was always present in the compartment) before showing presleep behavior. When stimulation was withheld during an extinction procedure, the cats still exhibited presleep behavior in the absence of stimulation during several sessions. We conclude that repeated BFA stimulation led to conditioning of the stimulation effects, that is, the presleep behavior that was evoked by the environmental situation alone, without BFA stimulation or any other intermittent stimulus. PMID:7824587

  7. Frequency dependence of behavioral modulation by hippocampal electrical stimulation

    PubMed Central

    La Corte, Giorgio; Wei, Yina; Chernyy, Nick; Gluckman, Bruce J.

    2013-01-01

    Electrical stimulation offers the potential to develop novel strategies for the treatment of refractory medial temporal lobe epilepsy. In particular, direct electrical stimulation of the hippocampus presents the opportunity to modulate pathological dynamics at the ictal focus, although the neuroanatomical substrate of this region renders it susceptible to altering cognition and affective processing as a side effect. We investigated the effects of three electrical stimulation paradigms on separate groups of freely moving rats (sham, 8-Hz and 40-Hz sine-wave stimulation of the ventral/intermediate hippocampus, where 8- and 40-Hz stimulation were chosen to mimic naturally occurring hippocampal oscillations). Animals exhibited attenuated locomotor and exploratory activity upon stimulation at 40 Hz, but not at sham or 8-Hz stimulation. Such behavioral modifications were characterized by a significant reduction in rearing frequency, together with increased freezing behavior. Logistic regression analysis linked the observed changes in animal locomotion to 40-Hz electrical stimulation independently of time-related variables occurring during testing. Spectral analysis, conducted to monitor the electrophysiological profile in the CA1 area of the dorsal hippocampus, showed a significant reduction in peak theta frequency, together with reduced theta power in the 40-Hz vs. the sham stimulation animal group, independent of locomotion speed (theta range: 4–12 Hz). These findings contribute to the development of novel and safe medical protocols by indicating a strategy to constrain or optimize parameters in direct hippocampal electrical stimulation. PMID:24198322

  8. CAN NONINVASIVE BRAIN STIMULATION ENHANCE COGNITION IN NEUROPSYCHIATRIC DISORDERS?

    PubMed Central

    Demirtas-Tatlidede, Asli; Vahabzadeh-Hagh, Andrew M.; Pascual-Leone, Alvaro

    2013-01-01

    Cognitive impairment is a core symptom of many neuropsychiatric diseases and a key contributor to the patient’s quality of life. However, an effective therapeutic strategy has yet to be developed. Noninvasive brain stimulation techniques, namely transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), are promising techniques that are under investigation for a variety of otherwise treatment-resistant neuropsychiatric diseases. Notably, these tools can induce alterations in neural networks subserving cognitive operations and thus may provide a means for cognitive restoration. The purpose of this article is to review the available evidence concerning cognitive enhancing properties of noninvasive brain stimulation in neuropsychiatry. We specifically focus on major depression, Alzheimer’s disease, schizophrenia, autism and attention deficit hyperactivity disorder (ADHD), where cognitive dysfunction is a major symptom and some studies have been completed with promising results. We provide a critical assessment of the available research and suggestions to guide future efforts. PMID:22749945

  9. Stochastic Phase Resetting: A Theory for Deep Brain Stimulation

    NASA Astrophysics Data System (ADS)

    Tass, P. A.

    The basic principles of a stochastic approach to phase resetting in populations of interacting phase oscillators are presented in this article. This theory explains how synchronization and desynchronization processes are caused by a pulsatile stimulus. It is a central goal of this approach to establish a theoretical basis for the design of efficient and intelligent new deep brain stimulation techniques. Accordingly, the theory is used to design a new deep brain stimulation technique with feedback control in patients suffering from Parkinson's disease or essential tremor.

  10. Pedunculopontine arousal system physiology – Deep brain stimulation (DBS)

    PubMed Central

    Garcia-Rill, Edgar; Luster, Brennon; D’Onofrio, Stasia; Mahaffey, Susan; Bisagno, Veronica; Urbano, Francisco J.

    2015-01-01

    This review describes the wake/sleep symptoms present in Parkinson׳s disease, and the role of the pedunculopontine nucleus in these symptoms. The physiology of PPN cells is important not only because it is a major element of the reticular activating system, but also because it is a novel target for deep brain stimulation in the treatment of gait and postural deficits in Parkinson׳s disease. A greater understanding of the physiology of the target nuclei within the brainstem and basal ganglia, amassed over the past decades, has enabled increasingly better patient outcomes from deep brain stimulation for movement disorders. PMID:26779322

  11. Deep Brain Stimulation for Essential Vocal Tremor: A Technical Report.

    PubMed

    Ho, Allen L; Choudhri, Omar; Sung, C Kwang; DiRenzo, Elizabeth E; Halpern, Casey H

    2015-03-01

    Essential vocal tremor (EVT) is the presence of a tremulous voice that is commonly associated with essential tremor. Patients with EVT often report a necessary increase in vocal effort that significantly worsens with stress and anxiety and can significantly impact quality of life despite optimal medical and behavioral treatment options. Deep brain stimulation (DBS) has been proposed as an effective therapy for vocal tremor, but very few studies exist in the literature that comprehensively evaluate the efficacy of DBS for specifically addressing EVT. We present a technical report on our multidisciplinary, comprehensive operative methodology for treatment of EVT with frameless, awake deep brain stimulation (DBS). PMID:26180680

  12. Clinical utility of brain stimulation modalities following traumatic brain injury: current evidence

    PubMed Central

    Li, Shasha; Zaninotto, Ana Luiza; Neville, Iuri Santana; Paiva, Wellingson Silva; Nunn, Danuza; Fregni, Felipe

    2015-01-01

    Traumatic brain injury (TBI) remains the main cause of disability and a major public health problem worldwide. This review focuses on the neurophysiology of TBI, and the rationale and current state of evidence of clinical application of brain stimulation to promote TBI recovery, particularly on consciousness, cognitive function, motor impairments, and psychiatric conditions. We discuss the mechanisms of different brain stimulation techniques including major noninvasive and invasive stimulations. Thus far, most noninvasive brain stimulation interventions have been nontargeted and focused on the chronic phase of recovery after TBI. In the acute stages, there is limited available evidence of the efficacy and safety of brain stimulation to improve functional outcomes. Comparing the studies across different techniques, transcranial direct current stimulation is the intervention that currently has the higher number of properly designed clinical trials, though total number is still small. We recognize the need for larger studies with target neuroplasticity modulation to fully explore the benefits of brain stimulation to effect TBI recovery during different stages of recovery. PMID:26170670

  13. Experimental and theoretical characterization of the voltage distribution generated by deep brain stimulation

    PubMed Central

    Miocinovic, Svjetlana; Lempka, Scott F.; Russo, Gary S.; Maks, Christopher B.; Butson, Christopher R.; Sakaie, Ken E.; Vitek, Jerrold L.; McIntyre, Cameron C.

    2008-01-01

    Deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson’s disease and shows great promise for numerous other disorders. While the fundamental purpose of DBS is to modulate neural activity with electric fields, little is known about the actual voltage distribution generated in the brain by DBS electrodes and as a result it is difficult to accurately predict which brain areas are directly affected by the stimulation. The goal of this study was to characterize the spatial and temporal characteristics of the voltage distribution generated by DBS electrodes. We experimentally recorded voltages around active DBS electrodes in either a saline bath or implanted in the brain of a non-human primate. Recordings were made during voltage-controlled and current-controlled stimulation. The experimental findings were compared to volume conductor electric field models of DBS parameterized to match the different experiments. Three factors directly affected the experimental and theoretical voltage measurements: 1) DBS electrode impedance, primarily dictated by a voltage drop at the electrode-electrolyte interface and the conductivity of the tissue medium, 2) capacitive modulation of the stimulus waveform, and 3) inhomogeneity and anisotropy of the tissue medium. While the voltage distribution does not directly predict the neural response to DBS, the results of this study do provide foundational building blocks for understanding the electrical parameters of DBS and characterizing its effects on the nervous system. PMID:19118551

  14. Fabrication and initial testing of the μDBS: a novel Deep Brain Stimulation electrode with thousands of individually controllable contacts.

    PubMed

    Willsie, Andrew; Dorval, Alan

    2015-01-01

    High frequency electrical stimulation of deep brain structures such as the subthalamic nucleus in Parkinson's disease or thalamus for essential tremor is used clinically to reduce symptom severity. Deep brain stimulation activates neurons in specific brain structures and connection pathways, overriding aberrant neural activity associated with symptoms. While optimal deep brain stimulation might activate a particular neural structure precisely, existing deep brain stimulation can only generate roughly-spherical regions of activation that do not overlap with any target anatomy. Additionally, side effects linked to stimulation may be the result of limited control over placement of stimulation and its subsequent spread out of optimal target boundaries. We propose a novel lead with thousands of individually controllable contacts capable of asymmetric stimulation profiles. Here we outline the design motivation, manufacturing process, and initial testing of this new electrode design, placing it on track for further directional stimulation studies. PMID:25981752

  15. A novel numerical meshless approach for electric potential estimation in transcranial stimulation

    NASA Astrophysics Data System (ADS)

    Ala, Guido; Fasshauer, Gregory E.; Francomano, Elisa; Ganci, Salvatore; McCourt, Michael J.; Vitabile, Salvatore

    2015-12-01

    In this paper, a first application of the method of fundamental solutions in estimating the electric potential and the spatial current density distribution in the brain due to transcranial stimulation, is presented. The coupled boundary value p roblems for the electric potential are solved in a meshless way, so avoiding the use of grid based numerical methods. A multi-spherical geometry is considered and numerical results are discussed.

  16. Electrical Stimulation to Enhance Spinal Fusion: A Systematic Review

    PubMed Central

    Park, Paul; Lau, Darryl; Brodt, Erika D.; Dettori, Joseph R.

    2014-01-01

    Study Design Systematic review. Clinical Questions Compared with no stimulation, does electrical stimulation promote bone fusion after lumbar spinal fusion procedures? Does the effect differ based on the type of electrical stimulation used? Methods Electronic databases and reference lists of key articles were searched up to October 15, 2013, to identify randomized controlled trials (RCTs) comparing the effect of electrical stimulation to no electrical stimulation on fusion rates after lumbar spinal fusion for the treatment of degenerative disease. Two independent reviewers assessed the strength of evidence using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) criteria. Results Six RCTs met the inclusion criteria. The following types of electrical stimulation were investigated: direct current (three studies), pulsed electromagnetic field (three studies), and capacitive coupling (one study). The control groups consisted of no stimulation (two studies) or placebo (four studies). Marked heterogeneity in study populations, characteristics, and design prevented a meta-analysis. Regardless of the type of electrical stimulation used, cumulative incidences of fusion varied widely across the RCTs, ranging from 35.4 to 90.6% in the intervention groups and from 33.3 to 81.9% in the control groups across 9 to 24 months of follow-up. Similarly, when stratified by the type of electrical stimulation used, fusion outcomes from individual studies varied, leading to inconsistent and conflicting results. Conclusion Given the inconsistency in study results, possibly due to heterogeneity in study populations/characteristics and quality, we are unable to conclude that electrical stimulation results in better fusion outcomes compared with no stimulation. The overall strength of evidence for the conclusions is low. PMID:25278882

  17. The effects of subthalamic deep brain stimulation on metaphor comprehension and language abilities in Parkinson's disease.

    PubMed

    Tremblay, Christina; Macoir, Joël; Langlois, Mélanie; Cantin, Léo; Prud'homme, Michel; Monetta, Laura

    2015-02-01

    The effects of subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) on different language abilities are still controversial and its impact on high-level language abilities such as metaphor comprehension has been overlooked. The aim of this study was to determine the effects of STN electrical stimulation on metaphor comprehension and language abilities such as lexical and semantic capacities. Eight PD individuals with bilateral STN-DBS were first evaluated OFF-DBS and, at least seven weeks later, ON-DBS. Performance on metaphor comprehension, lexical decision, word association and verbal fluency tasks were compared ON and OFF-DBS in addition to motor symptoms evaluation. STN stimulation had a significant beneficial effect on motor symptoms in PD. However, this stimulation did not have any effect on metaphor comprehension or any other cognitive ability evaluated in this study. These outcomes suggest that STN stimulation may have dissociable effects on motor and language functions. PMID:25577507

  18. Electrical stimulation of the insular region attenuates nicotine-taking and nicotine-seeking behaviors.

    PubMed

    Pushparaj, Abhiram; Hamani, Clement; Yu, Wilson; Shin, Damian S; Kang, Bin; Nobrega, José N; Le Foll, Bernard

    2013-03-01

    Pharmacological inactivation of the granular insular cortex is able to block nicotine-taking and -seeking behaviors in rats. In this study, we explored the potential of modulating activity in the insular region using electrical stimulation. Animals were trained to self-administer nicotine (0.03 mg/kg per infusion) under a fixed ratio-5 (FR-5) schedule of reinforcement followed by a progressive ratio (PR) schedule. Evaluation of the effect of stimulation in the insular region was performed on nicotine self-administration under FR-5 and PR schedules, as well on reinstatement of nicotine-seeking behavior induced by nicotine-associated cues or nicotine-priming injections. The effect of stimulation was also examined in brain slices containing insular neurons. Stimulation significantly attenuated nicotine-taking, under both schedules of reinforcement, as well as nicotine-seeking behavior induced by cues and priming. These effects appear to be specific to nicotine-associated behaviors, as stimulation did not have any effect on food-taking behavior. They appear to be anatomically specific, as stimulation surrounding the insular region had no effect on behavior. Stimulation of brain slices containing the insular region was found to inactivate insular neurons. Our results suggest that deep brain stimulation to modulate insular activity should be further explored. PMID:23249816

  19. Revealing humans' sensorimotor functions with electrical cortical stimulation.

    PubMed

    Desmurget, Michel; Sirigu, Angela

    2015-09-19

    Direct electrical stimulation (DES) of the human brain has been used by neurosurgeons for almost a century. Although this procedure serves only clinical purposes, it generates data that have a great scientific interest. Had DES not been employed, our comprehension of the organization of the sensorimotor systems involved in movement execution, language production, the emergence of action intentionality or the subjective feeling of movement awareness would have been greatly undermined. This does not mean, of course, that DES is a gold standard devoid of limitations and that other approaches are not of primary importance, including electrophysiology, modelling, neuroimaging or psychophysics in patients and healthy subjects. Rather, this indicates that the contribution of DES cannot be restricted, in humans, to the ubiquitous concepts of homunculus and somatotopy. DES is a fundamental tool in our attempt to understand the human brain because it represents a unique method for mapping sensorimotor pathways and interfering with the functioning of localized neural populations during the performance of well-defined behavioural tasks. PMID:26240422

  20. Toward rational design of electrical stimulation strategies for epilepsy control.

    PubMed

    Sunderam, Sridhar; Gluckman, Bruce; Reato, Davide; Bikson, Marom

    2010-01-01

    Electrical stimulation is emerging as a viable alternative for patients with epilepsy whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical tuning of parameters and protocols. We highlight concurrent treatment goals with potentially conflicting design constraints that must be resolved when formulating rational strategies for epilepsy electrotherapy, namely, seizure reduction versus cognitive impairment, stimulation efficacy versus tissue safety, and mechanistic insight versus clinical pragmatism. First, treatment markers, objectives, and metrics relevant to electrical stimulation for epilepsy are discussed from a clinical perspective. Then the experimental perspective is presented, with the biophysical mechanisms and modalities of open-loop electrical stimulation, and the potential benefits of closed-loop control for epilepsy. PMID:19926525

  1. Toward rational design of electrical stimulation strategies for epilepsy control

    PubMed Central

    Sunderam, Sridhar; Gluckman, Bruce; Reato, Davide; Bikson, Marom

    2009-01-01

    Electrical stimulation is emerging as a viable alternative for epilepsy patients whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical tuning of parameters and protocols. We highlight concurrent treatment goals with potentially conflicting design constraints that must be resolved when formulating rational strategies for epilepsy electrotherapy: namely seizure reduction versus cognitive impairment, stimulation efficacy versus tissue safety, and mechanistic insight versus clinical pragmatism. First, treatment markers, objectives, and metrics relevant to electrical stimulation for epilepsy are discussed from a clinical perspective. Then the experimental perspective is presented, with the biophysical mechanisms and modalities of open-loop electrical stimulation, and the potential benefits of closed-loop control for epilepsy. PMID:19926525

  2. Noninvasive brain stimulation in Huntington's disease.

    PubMed

    Berardelli, Alfredo; Suppa, Antonio

    2013-01-01

    Several important advances in the pathophysiology of Huntington's disease (HD) have been achieved by means of neurophysiological techniques designed to investigate the excitability and plasticity of brainstem and cortical circuits in patients with the condition. Studies designed to investigate brainstem reflexes, with paired-pulse and repetitive stimulation of the supraorbital nerve (blink reflex), have demonstrated abnormal excitability and plasticity of brainstem interneurons. In addition, several authors have tested the excitability of the primary motor cortex (M1) with the transcranial magnetic stimulation (TMS) technique and reported abnormal excitability of inhibitory intracortical circuits (cortical silent period, short afferent inhibition). Studies investigating plasticity processes by means of repetitive TMS (rTMS) protocols have demonstrated altered short-term as well as long-term M1 plasticity. Abnormal cortical excitability and plasticity can be present in the early phase of HD and in asymptomatic HD carriers. Evidence from a single study of small cohorts of patients with HD supports the therapeutic application of rTMS for symptomatic improvement of chorea in HD. PMID:24112923

  3. Probabilistic analysis of activation volumes generated during deep brain stimulation.

    PubMed

    Butson, Christopher R; Cooper, Scott E; Henderson, Jaimie M; Wolgamuth, Barbara; McIntyre, Cameron C

    2011-02-01

    Deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson's disease (PD) and shows great promise for the treatment of several other disorders. However, while the clinical analysis of DBS has received great attention, a relative paucity of quantitative techniques exists to define the optimal surgical target and most effective stimulation protocol for a given disorder. In this study we describe a methodology that represents an evolutionary addition to the concept of a probabilistic brain atlas, which we call a probabilistic stimulation atlas (PSA). We outline steps to combine quantitative clinical outcome measures with advanced computational models of DBS to identify regions where stimulation-induced activation could provide the best therapeutic improvement on a per-symptom basis. While this methodology is relevant to any form of DBS, we present example results from subthalamic nucleus (STN) DBS for PD. We constructed patient-specific computer models of the volume of tissue activated (VTA) for 163 different stimulation parameter settings which were tested in six patients. We then assigned clinical outcome scores to each VTA and compiled all of the VTAs into a PSA to identify stimulation-induced activation targets that maximized therapeutic response with minimal side effects. The results suggest that selection of both electrode placement and clinical stimulation parameter settings could be tailored to the patient's primary symptoms using patient-specific models and PSAs. PMID:20974269

  4. Bilateral adaptive deep brain stimulation is effective in Parkinson's disease

    PubMed Central

    Little, Simon; Beudel, Martijn; Zrinzo, Ludvic; Foltynie, Thomas; Limousin, Patricia; Hariz, Marwan; Neal, Spencer; Cheeran, Binith; Cagnan, Hayriye; Gratwicke, James; Aziz, Tipu Z; Pogosyan, Alex; Brown, Peter

    2016-01-01

    Introduction & objectives Adaptive deep brain stimulation (aDBS) uses feedback from brain signals to guide stimulation. A recent acute trial of unilateral aDBS showed that aDBS can lead to substantial improvements in contralateral hemibody Unified Parkinson’s Disease Rating Scale (UPDRS) motor scores and may be superior to conventional continuous DBS in Parkinson’s disease (PD). We test whether potential benefits are retained with bilateral aDBS and in the face of concurrent medication. Methods We applied bilateral aDBS in 4 patients with PD undergoing DBS of the subthalamic nucleus. aDBS was delivered bilaterally with independent triggering of stimulation according to the amplitude of β activity at the corresponding electrode. Mean stimulation voltage was 3.0±0.1 volts. Motor assessments consisted of double-blinded video-taped motor UPDRS scores that included both limb and axial features. Results UPDRS scores were 43% (p=0.04; Cohen’s d=1.62) better with aDBS than without stimulation. Motor improvement with aDBS occurred despite an average time on stimulation (ToS) of only 45%. Levodopa was well tolerated during aDBS and led to further reductions in ToS. Conclusion Bilateral aDBS can improve both axial and limb symptoms and can track the need for stimulation across drug states. PMID:26424898

  5. Repeated BOLD-fMRI imaging of deep brain stimulation responses in rats.

    PubMed

    Chao, Tzu-Hao Harry; Chen, Jyh-Horng; Yen, Chen-Tung

    2014-01-01

    Functional magnetic resonance imaging (fMRI) provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol) with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP) thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1). The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91), and location (overlap ratio from 0.61 to 0.67). The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI. PMID:24825464

  6. Repeated BOLD-fMRI Imaging of Deep Brain Stimulation Responses in Rats

    PubMed Central

    Chao, Tzu-Hao Harry; Chen, Jyh-Horng; Yen, Chen-Tung

    2014-01-01

    Functional magnetic resonance imaging (fMRI) provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol) with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP) thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1). The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91), and location (overlap ratio from 0.61 to 0.67). The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI. PMID:24825464

  7. Using brain stimulation to disentangle neural correlates of conscious vision

    PubMed Central

    de Graaf, Tom A.; Sack, Alexander T.

    2014-01-01

    Research into the neural correlates of consciousness (NCCs) has blossomed, due to the advent of new and increasingly sophisticated brain research tools. Neuroimaging has uncovered a variety of brain processes that relate to conscious perception, obtained in a range of experimental paradigms. But methods such as functional magnetic resonance imaging or electroencephalography do not always afford inference on the functional role these brain processes play in conscious vision. Such empirical NCCs could reflect neural prerequisites, neural consequences, or neural substrates of a conscious experience. Here, we take a closer look at the use of non-invasive brain stimulation (NIBS) techniques in this context. We discuss and review how NIBS methodology can enlighten our understanding of brain mechanisms underlying conscious vision by disentangling the empirical NCCs. PMID:25295015

  8. Complications of deep brain stimulation surgery.

    PubMed

    Beric, A; Kelly, P J; Rezai, A; Sterio, D; Mogilner, A; Zonenshayn, M; Kopell, B

    2001-01-01

    Although technological advances have reduced device-related complications, DBS surgery still carries a significant risk of transient and permanent complications. We report our experience in 86 patients and 149 DBS implants. Patients with Parkinson's disease, essential tremor and dystonia were treated. There were 8 perioperative, 8 postoperative, 9 hardware-related complications and 4 stimulation-induced side effects. Only 5 patients (6%) sustained some persistent neurological sequelae, however, 26 of the 86 patients undergoing 149 DBS implants in this series experienced some untoward event with the procedure. Although there were no fatalities or permanent severe disabilities encountered, it is important to extend the informed consent to include all potential complications. PMID:12378060

  9. Models to Tailor Brain Stimulation Therapies in Stroke

    PubMed Central

    Plow, E. B.; Sankarasubramanian, V.; Cunningham, D. A.; Potter-Baker, K.; Varnerin, N.; Cohen, L. G.; Sterr, A.; Conforto, A. B.; Machado, A. G.

    2016-01-01

    A great challenge facing stroke rehabilitation is the lack of information on how to derive targeted therapies. As such, techniques once considered promising, such as brain stimulation, have demonstrated mixed efficacy across heterogeneous samples in clinical studies. Here, we explain reasons, citing its one-type-suits-all approach as the primary cause of variable efficacy. We present evidence supporting the role of alternate substrates, which can be targeted instead in patients with greater damage and deficit. Building on this groundwork, this review will also discuss different frameworks on how to tailor brain stimulation therapies. To the best of our knowledge, our report is the first instance that enumerates and compares across theoretical models from upper limb recovery and conditions like aphasia and depression. Here, we explain how different models capture heterogeneity across patients and how they can be used to predict which patients would best respond to what treatments to develop targeted, individualized brain stimulation therapies. Our intent is to weigh pros and cons of testing each type of model so brain stimulation is successfully tailored to maximize upper limb recovery in stroke. PMID:27006833

  10. Vascular effects of free radicals generated by electrical stimulation

    SciTech Connect

    Lamb, F.S.; Webb, R.C.

    1984-11-01

    Electrical field stimulation (9 V, 1.0 ms, 4 Hz) of isolated segments of rat tail arteries and dog coronary arteries inhibits contractile response to exogenous norephinephrine and elevated potassium concentration. This inhibitory effect of electrical stimulation is blocked by various agents that alter oxygen metabolism: superoxide dismutase, catalase, glutathione, ascorbate, and dimethyl sulfoxide. The observations suggest that the inhibitory effect is due to an action of oxygen free radical metabolites that are generated by the electrical stimulation of the oxygen-rich buffer. These free radical metabolites have two actions: 1) they oxidize drugs in the experimental system, and 2) they exert a direct inhbitory action on vascular smooth muscle.

  11. Affective Brain-Computer Interfaces As Enabling Technology for Responsive Psychiatric Stimulation

    PubMed Central

    Widge, Alik S.; Dougherty, Darin D.; Moritz, Chet T.

    2014-01-01

    There is a pressing clinical need for responsive neurostimulators, which sense a patient’s brain activity and deliver targeted electrical stimulation to suppress unwanted symptoms. This is particularly true in psychiatric illness, where symptoms can fluctuate throughout the day. Affective BCIs, which decode emotional experience from neural activity, are a candidate control signal for responsive stimulators targeting the limbic circuit. Present affective decoders, however, cannot yet distinguish pathologic from healthy emotional extremes. Indiscriminate stimulus delivery would reduce quality of life and may be actively harmful. We argue that the key to overcoming this limitation is to specifically decode volition, in particular the patient’s intention to experience emotional regulation. Those emotion-regulation signals already exist in prefrontal cortex (PFC), and could be extracted with relatively simple BCI algorithms. We describe preliminary data from an animal model of PFC-controlled limbic brain stimulation and discuss next steps for pre-clinical testing and possible translation. PMID:25580443

  12. [Non-invasive brain stimulation for Parkinson's disease].

    PubMed

    Gajo, Gianandrea; Pollak, Pierre; Lüscher, Christian; Benninger, David

    2015-04-29

    Parkinson's disease (PD) is a major socio-economic burden increasing with the aging population. In advanced PD, the emergence of symptoms refractory to conventional therapy poses a therapeutic challenge. The success of deep brain stimulation (DBS) and advances in the understanding of the pathophysiology of PD have raised interest in non-invasive brain stimulation (NIBS) as an alternative therapeutic tool. NIBS could offer an alternative approach for patients at risk who are excluded from surgery and/or to treat refractory symptoms. The treatment of the freezing of gait, a major cause of disability and falls in PD patients, could be enhanced by transcranial direct current stimulation (tDCS). A therapeutic study is currently performed at the Department of Neurology at the CHUV. PMID:26062225

  13. Task-dependent changes in the size of response to magnetic brain stimulation in human first dorsal interosseous muscle.

    PubMed Central

    Datta, A K; Harrison, L M; Stephens, J A

    1989-01-01

    1. Electromyographic responses have been recorded from human first dorsal interosseous muscle (FDI) in response to magnetic and transcutaneous electrical stimulation of the brain. 2. Following magnetic but not electrical stimulation of the brain, the recorded EMG response was larger when FDI was active during voluntary isometric index finger abduction than during a power grip. 3. In the same experiment, cutaneous reflex responses have been recorded from FDI following electrical stimulation of the digital nerves. The long-latency excitatory component at about 60 ms (E2) was larger when recorded during voluntary finger abduction than during a power grip. This difference in size of E2 with task bore no simple relationship to the difference in size with task of the motor response to magnetic brain stimulation. 4. The results are discussed in relation to the presumed site of action of magnetic and electrical brain stimulation. It is concluded that the results may best be interpreted by assuming a higher level of cortical activity during a voluntary index finger abduction than during a grip and that this could in part explain the task-dependent changes in the long-latency response to cutaneous stimulation. PMID:2621614

  14. Abnormal hemodynamic response to forepaw stimulation in rat brain after cocaine injection

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Park, Kicheon; Choi, Jeonghun; Pan, Yingtian; Du, Congwu

    2015-03-01

    Simultaneous measurement of hemodynamics is of great importance to evaluate the brain functional changes induced by brain diseases such as drug addiction. Previously, we developed a multimodal-imaging platform (OFI) which combined laser speckle contrast imaging with multi-wavelength imaging to simultaneously characterize the changes in cerebral blood flow (CBF), oxygenated- and deoxygenated- hemoglobin (HbO and HbR) from animal brain. Recently, we upgraded our OFI system that enables detection of hemodynamic changes in response to forepaw electrical stimulation to study potential brain activity changes elicited by cocaine. The improvement includes 1) high sensitivity to detect the cortical response to single forepaw electrical stimulation; 2) high temporal resolution (i.e., 16Hz/channel) to resolve dynamic variations in drug-delivery study; 3) high spatial resolution to separate the stimulation-evoked hemodynamic changes in vascular compartments from those in tissue. The system was validated by imaging the hemodynamic responses to the forepaw-stimulations in the somatosensory cortex of cocaine-treated rats. The stimulations and acquisitions were conducted every 2min over 40min, i.e., from 10min before (baseline) to 30min after cocaine challenge. Our results show that the HbO response decreased first (at ~4min) followed by the decrease of HbR response (at ~6min) after cocaine, and both did not fully recovered for over 30min. Interestingly, while CBF decreased at 4min, it partially recovered at 18min after cocaine administration. The results indicate the heterogeneity of cocaine's effects on vasculature and tissue metabolism, demonstrating the unique capability of optical imaging for brain functional studies.

  15. Towards a Switched-Capacitor based Stimulator for efficient deep-brain stimulation.

    PubMed

    Vidal, Jose; Ghovanloo, Maysam

    2010-01-01

    We have developed a novel 4-channel prototype stimulation circuit for implantable neurological stimulators (INS). This Switched-Capacitor based Stimulator (SCS) aims to utilize charge storage and charge injection techniques to take advantage of both the efficiency of conventional voltage-controlled stimulators (VCS) and the safety and controllability of current-controlled stimulators (CCS). The discrete SCS prototype offers fine control over stimulation parameters such as voltage, current, pulse width, frequency, and active electrode channel via a LabVIEW graphical user interface (GUI) when connected to a PC through USB. Furthermore, the prototype utilizes a floating current sensor to provide charge-balanced biphasic stimulation and ensure safety. The stimulator was analyzed using an electrode-electrolyte interface (EEI) model as well as with a pair of pacing electrodes in saline. The primary motivation of this research is to test the feasibility and functionality of a safe, effective, and power-efficient switched-capacitor based stimulator for use in Deep Brain Stimulation. PMID:21095987

  16. Brain State-Dependent Closed-Loop Modulation of Paired Associative Stimulation Controlled by Sensorimotor Desynchronization

    PubMed Central

    Royter, Vladislav; Gharabaghi, Alireza

    2016-01-01

    Background: Pairing peripheral electrical stimulation (ES) and transcranial magnetic stimulation (TMS) increases corticospinal excitability when applied with a specific temporal pattern. When the two stimulation techniques are applied separately, motor imagery (MI)-related oscillatory modulation amplifies both ES-related cortical effects—sensorimotor event-related desynchronization (ERD), and TMS-induced peripheral responses—motor-evoked potentials (MEP). However, the influence of brain self-regulation on the associative pairing of these stimulation techniques is still unclear. Objective: The aim of this pilot study was to investigate the effects of MI-related ERD during associative ES and TMS on subsequent corticospinal excitability. Method: The paired application of functional electrical stimulation (FES) of the extensor digitorum communis (EDC) muscle and subsequent single-pulse TMS (110% resting motor threshold (RMT)) of the contralateral primary motor cortex (M1) was controlled by beta-band (16–22 Hz) ERD during MI of finger extension and applied within a brain-machine interface environment in six healthy subjects. Neural correlates were probed by acquiring the stimulus-response curve (SRC) of both MEP peak-to-peak amplitude and area under the curve (AUC) before and after the intervention. Result: The application of approximately 150 pairs of associative FES and TMS resulted in a significant increase of MEP amplitudes and AUC, indicating that the induced increase of corticospinal excitability was mediated by the recruitment of additional neuronal pools. MEP increases were brain state-dependent and correlated with beta-band ERD, but not with the background EDC muscle activity; this finding was independent of the FES intensity applied. Conclusion: These results could be relevant for developing closed-loop therapeutic approaches such as the application of brain state-dependent, paired associative stimulation (PAS) in the context of neurorehabilitation. PMID

  17. Selective Activation of Neuronal Targets With Sinusoidal Electric Stimulation

    PubMed Central

    Freeman, Daniel K.; Eddington, Donald K.; Rizzo, Joseph F.

    2010-01-01

    Electric stimulation of the CNS is being evaluated as a treatment modality for a variety of neurological, psychiatric, and sensory disorders. Despite considerable success in some applications, existing stimulation techniques offer little control over which cell types or neuronal substructures are activated by stimulation. The ability to more precisely control neuronal activation would likely improve the clinical outcomes associated with these applications. Here, we show that specific frequencies of sinusoidal stimulation can be used to preferentially activate certain retinal cell types: photoreceptors are activated at 5 Hz, bipolar cells at 25 Hz, and ganglion cells at 100 Hz. In addition, low-frequency stimulation (≤25 Hz) did not activate passing axons but still elicited robust synaptically mediated responses in ganglion cells; therefore, elicited neural activity is confined to within a focal region around the stimulating electrode. Our results suggest that sinusoidal stimulation provides significantly improved control over elicited neural activity relative to conventional pulsatile stimulation. PMID:20810683

  18. Facilitate Insight by Non-Invasive Brain Stimulation

    PubMed Central

    Chi, Richard P.; Snyder, Allan W.

    2011-01-01

    Our experiences can blind us. Once we have learned to solve problems by one method, we often have difficulties in generating solutions involving a different kind of insight. Yet there is evidence that people with brain lesions are sometimes more resistant to this so-called mental set effect. This inspired us to investigate whether the mental set effect can be reduced by non-invasive brain stimulation. 60 healthy right-handed participants were asked to take an insight problem solving task while receiving transcranial direct current stimulation (tDCS) to the anterior temporal lobes (ATL). Only 20% of participants solved an insight problem with sham stimulation (control), whereas 3 times as many participants did so (p = 0.011) with cathodal stimulation (decreased excitability) of the left ATL together with anodal stimulation (increased excitability) of the right ATL. We found hemispheric differences in that a stimulation montage involving the opposite polarities did not facilitate performance. Our findings are consistent with the theory that inhibition to the left ATL can lead to a cognitive style that is less influenced by mental templates and that the right ATL may be associated with insight or novel meaning. Further studies including neurophysiological imaging are needed to elucidate the specific mechanisms leading to the enhancement. PMID:21311746

  19. Pallidal deep brain stimulation relieves camptocormia in primary dystonia.

    PubMed

    Hagenacker, Tim; Gerwig, Marcus; Gasser, Thomas; Miller, Dorothea; Kastrup, Oliver; Jokisch, Daniel; Sure, Ulrich; Frings, Markus

    2013-07-01

    Camptocormia, characterised by a forward flexion of the thoracolumbar spine may occur in various movement disorders, mainly in Parkinson's disease or in primary dystonia. In severe cases, patients with camptocormia are unable to walk. While treatment options are limited, deep brain stimulation (DBS) with bilateral stimulation of the subthalamic nucleus or globus pallidus internus (GPi) has been proposed as a therapeutic option in refractory cases of Parkinson's disease. Here we present two patients with severe camptocormia as an isolated form of dystonia and as part of generalised dystonia, respectively, which were both treated with bilateral stimulation of the GPi. Symptoms of dystonia were assessed using the Burke-Fahn-Marsden dystonia rating scale (BFM) before and during deep brain stimulation. In both patients there was a significant functional improvement following long-term bilateral GPi stimulation and both patients gained ability to walk. In the first patient with an isolated dystonic camptocormia the BFM motor subscore for the truncal flexion improved by 75 %. The total BFM motor score in the second patient with a camptocormia in generalised dystonia improved by 45 %, while the BFM score for truncal flexion improved by 87 %. In both patients the effect of the bilateral GPi stimulation on camptocormia was substantial, independent of generalisation of dystonia. Therefore, GPi DBS is a possible treatment option for this rare disease. PMID:23483215

  20. Study of Driving Fatigue Alleviation by Transcutaneous Acupoints Electrical Stimulations

    PubMed Central

    Wang, Fuwang; Wang, Hong

    2014-01-01

    Driving fatigue is more likely to bring serious safety trouble to traffic. Therefore, accurately and rapidly detecting driving fatigue state and alleviating fatigue are particularly important. In the present work, the electrical stimulation method stimulating the Láogóng point (劳宫PC8) of human body is proposed, which is used to alleviate the mental fatigue of drivers. The wavelet packet decomposition (WPD) is used to extract θ, α, and β subbands of drivers' electroencephalogram (EEG) signals. Performances of the two algorithms (θ + α)/(α + β) and θ/β are also assessed as possible indicators for fatigue detection. Finally, the differences between the drivers with electrical stimulation and normal driving are discussed. It is shown that stimulating the Láogóng point (劳宫PC8) using electrical stimulation method can alleviate driver fatigue effectively during longtime driving. PMID:25254242

  1. Electrical stimulation therapies for spinal fusions: current concepts

    PubMed Central

    Glazer, Paul A.

    2006-01-01

    Electrical stimulation therapies have been used for more than 30 years to enhance spinal fusions. Although their positive effects on spinal fusions have been widely reported, the mechanisms of action of the technologies were only recently identified. Three types of technologies are available clinically: direct current, capacitive coupling, and inductive coupling. The latter is the basis of pulsed electromagnetic fields and combined magnetic fields. This review summarizes the current concepts on the mechanisms of action, animal and clinical studies, and cost justification for the use of electrical stimulation for spinal fusions. Scientific studies support the validity of electrical stimulation treatments. The mechanisms of action of each of the three electrical stimulation therapies are different. New data demonstrates that the upregulation of several growth factors may be responsible for the clinical success seen with the use of such technologies. PMID:16604354

  2. A CONTINUED INVESTIGATION OF ELECTRICALLY STIMULATED FABRIC FILTRATION

    EPA Science Inventory

    The report summarizes three experiments performed by Southern Research Institute under a cooperative agreement with EPA. First was a demonstration of electrostatically stimulated fabric filtration (ESFF) used to collect particulate matter (PM) from fossil fuel electrical power pl...

  3. Do electrically stimulated sensory inputs and movements lead to long-term plasticity and rehabilitation gains?

    PubMed

    Dobkin, Bruce H

    2003-12-01

    Peripheral and cortical magnetic and electrical stimulation may find a therapeutic niche as augmentative rehabilitation interventions for lessening impairments and disabilities after brain and spinal cord injury. The momentum for these approaches arose from recent physiological studies that examined the effects of paradigms of stimulation on synaptic and biological adaptations within the cortex and lumbar cord. A case report about improvements made by Christopher Reeve is driving requests by patients with profound spinal cord injury for interventions that include resistance pedaling facilitated by electrical neuromuscular stimulation. Although the evidence for this particular approach is less than convincing, reorganization-inducing cortical and peripheral afferent stimulation protocols offer insights into the steps needed for scientific designs of these potential rehabilitation interventions. PMID:14624077

  4. 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.

  5. 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

  6. [Deep brain stimulation for movement disorders: indications, results and complications].

    PubMed

    Fleury, Vanessa; Vingerhoets, François; Horvath, Judit; Pollak, Pierre; Burkhard, Pierre

    2015-04-29

    Movement disorders such as Parkinson's disease (PD), essential tremor (ET) and dystonia can benefit from deep brain stimulation (DBS). DBS is considered when symptoms are disabling despite optimal medical therapy. Contraindications include dementia, uncontrolled psychiatric disease and/or comorbid conditions with potential for evolution. Targets are the subthalamic nucleus for PD, the ventral intermediate nucleus for ET and the globus pallidus internus for dystonia. The beneficial effet of DBS has been well documented for symptom control. Optimal target localization of the electrodes reduces the occurrence of side-effects. Stimulation-induced adverse effects can usually be abolished by turning the stimulation off, changing the active contact or other stimulation parameters. PMID:26062221

  7. Transcranial magnetic stimulation of mouse brain using high-resolution anatomical models

    NASA Astrophysics Data System (ADS)

    Crowther, L. J.; Hadimani, R. L.; Kanthasamy, A. G.; Jiles, D. C.

    2014-05-01

    Transcranial magnetic stimulation (TMS) offers the possibility of non-invasive treatment of brain disorders in humans. Studies on animals can allow rapid progress of the research including exploring a variety of different treatment conditions. Numerical calculations using animal models are needed to help design suitable TMS coils for use in animal experiments, in particular, to estimate the electric field induced in animal brains. In this paper, we have implemented a high-resolution anatomical MRI-derived mouse model consisting of 50 tissue types to accurately calculate induced electric field in the mouse brain. Magnetic field measurements have been performed on the surface of the coil and compared with the calculations in order to validate the calculated magnetic and induced electric fields in the brain. Results show how the induced electric field is distributed in a mouse brain and allow investigation of how this could be improved for TMS studies using mice. The findings have important implications in further preclinical development of TMS for treatment of human diseases.

  8. Primary auditory cortical responses to electrical stimulation of the thalamus.

    PubMed

    Atencio, Craig A; Shih, Jonathan Y; Schreiner, Christoph E; Cheung, Steven W

    2014-03-01

    Cochlear implant electrical stimulation of the auditory system to rehabilitate deafness has been remarkably successful. Its deployment requires both an intact auditory nerve and a suitably patent cochlear lumen. When disease renders prerequisite conditions impassable, such as in neurofibromatosis type II and cochlear obliterans, alternative treatment targets are considered. Electrical stimulation of the cochlear nucleus and midbrain in humans has delivered encouraging clinical outcomes, buttressing the promise of central auditory prostheses to mitigate deafness in those who are not candidates for cochlear implantation. In this study we explored another possible implant target: the auditory thalamus. In anesthetized cats, we first presented pure tones to determine frequency preferences of thalamic and cortical sites. We then electrically stimulated tonotopically organized thalamic sites while recording from primary auditory cortical sites using a multichannel recording probe. Cathode-leading biphasic thalamic stimulation thresholds that evoked cortical responses were much lower than published accounts of cochlear and midbrain stimulation. Cortical activation dynamic ranges were similar to those reported for cochlear stimulation, but they were narrower than those found through midbrain stimulation. Our results imply that thalamic stimulation can activate auditory cortex at low electrical current levels and suggest an auditory thalamic implant may be a viable central auditory prosthesis. PMID:24335216

  9. Deep brain stimulation for the treatment of uncommon tremor syndromes

    PubMed Central

    Ramirez-Zamora, Adolfo; Okun, Michael S.

    2016-01-01

    ABSTRACT Introduction: Deep brain stimulation (DBS) has become a standard therapy for the treatment of select cases of medication refractory essential tremor and Parkinson’s disease however the effectiveness and long-term outcomes of DBS in other uncommon and complex tremor syndromes has not been well established. Traditionally, the ventralis intermedius nucleus (VIM) of the thalamus has been considered the main target for medically intractable tremors; however alternative brain regions and improvements in stereotactic techniques and hardware may soon change the horizon for treatment of complex tremors. Areas covered: In this article, we conducted a PubMed search using different combinations between the terms ‘Uncommon tremors’, ‘Dystonic tremor’, ‘Holmes tremor’ ‘Midbrain tremor’, ‘Rubral tremor’, ‘Cerebellar tremor’, ‘outflow tremor’, ‘Multiple Sclerosis tremor’, ‘Post-traumatic tremor’, ‘Neuropathic tremor’, and ‘Deep Brain Stimulation/DBS’. Additionally, we examined and summarized the current state of evolving interventions for treatment of complex tremor syndromes. Expert c ommentary: Recently reported interventions for rare tremors include stimulation of the posterior subthalamic area, globus pallidus internus, ventralis oralis anterior/posterior thalamic subnuclei, and the use of dual lead stimulation in one or more of these targets. Treatment should be individualized and dictated by tremor phenomenology and associated clinical features. PMID:27228280

  10. Reducing proactive aggression through non-invasive brain stimulation.

    PubMed

    Dambacher, Franziska; Schuhmann, Teresa; Lobbestael, Jill; Arntz, Arnoud; Brugman, Suzanne; Sack, Alexander T

    2015-10-01

    Aggressive behavior poses a threat to human collaboration and social safety. It is of utmost importance to identify the functional mechanisms underlying aggression and to develop potential interventions capable of reducing dysfunctional aggressive behavior already at a brain level. We here experimentally shifted fronto-cortical asymmetry to manipulate the underlying motivational emotional states in both male and female participants while assessing the behavioral effects on proactive and reactive aggression. Thirty-two healthy volunteers received either anodal transcranial direct current stimulation to increase neural activity within right dorsolateral prefrontal cortex, or sham stimulation. Aggressive behavior was measured with the Taylor Aggression Paradigm. We revealed a general gender effect, showing that men displayed more behavioral aggression than women. After the induction of right fronto-hemispheric dominance, proactive aggression was reduced in men. This study demonstrates that non-invasive brain stimulation can reduce aggression in men. This is a relevant and promising step to better understand how cortical brain states connect to impulsive actions and to examine the causal role of the prefrontal cortex in aggression. Ultimately, such findings could help to examine whether the brain can be a direct target for potential supportive interventions in clinical settings dealing with overly aggressive patients and/or violent offenders. PMID:25680991

  11. Complex networks in brain electrical activity

    NASA Astrophysics Data System (ADS)

    Ray, C.; Ruffini, G.; Marco-Pallarés, J.; Fuentemilla, L.; Grau, C.

    2007-08-01

    This letter reports a method to extract a functional network of the human brain from electroencephalogram measurements. A network analysis was performed on the resultant network and the statistics of the cluster coefficient, node degree, path length, and physical distance of the links, were studied. Even given the low electrode count of the experimental data the method was able to extract networks with network parameters that clearly depend on the type of stimulus presented to the subject. This type of analysis opens a door to studying the cerebral networks underlying brain electrical activity, and links the fields of complex networks and cognitive neuroscience.

  12. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation.

    PubMed

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-01-01

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes. PMID:26193273

  13. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    PubMed Central

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-01-01

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes. PMID:26193273

  14. The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke

    PubMed Central

    Gandolla, Marta; Ward, Nick S.; Molteni, Franco; Guanziroli, Eleonora; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    Neurorehabilitation effective delivery for stroke is likely to be improved by establishing a mechanistic understanding of how to enhance adaptive plasticity. Functional electrical stimulation is effective at reducing poststroke foot drop; in some patients, the effect persists after therapy has finished with an unknown mechanism. We used fMRI to examine neural correlates of functional electrical stimulation key elements, volitional intent to move and concurrent stimulation, in a group of chronic stroke patients receiving functional electrical stimulation for foot-drop correction. Patients exhibited task-related activation in a complex network, sharing bilateral sensorimotor and supplementary motor activation with age-matched controls. We observed consistent separation of patients with and without carryover effect on the basis of brain responses. Patients who experienced the carryover effect had responses in supplementary motor area that correspond to healthy controls; the interaction between experimental factors in contralateral angular gyrus was seen only in those without carryover. We suggest that the functional electrical stimulation carryover mechanism of action is based on movement prediction and sense of agency/body ownership—the ability of a patient to plan the movement and to perceive the stimulation as a part of his/her own control loop is important for carryover effect to take place. PMID:27073701

  15. The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke.

    PubMed

    Gandolla, Marta; Ward, Nick S; Molteni, Franco; Guanziroli, Eleonora; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    Neurorehabilitation effective delivery for stroke is likely to be improved by establishing a mechanistic understanding of how to enhance adaptive plasticity. Functional electrical stimulation is effective at reducing poststroke foot drop; in some patients, the effect persists after therapy has finished with an unknown mechanism. We used fMRI to examine neural correlates of functional electrical stimulation key elements, volitional intent to move and concurrent stimulation, in a group of chronic stroke patients receiving functional electrical stimulation for foot-drop correction. Patients exhibited task-related activation in a complex network, sharing bilateral sensorimotor and supplementary motor activation with age-matched controls. We observed consistent separation of patients with and without carryover effect on the basis of brain responses. Patients who experienced the carryover effect had responses in supplementary motor area that correspond to healthy controls; the interaction between experimental factors in contralateral angular gyrus was seen only in those without carryover. We suggest that the functional electrical stimulation carryover mechanism of action is based on movement prediction and sense of agency/body ownership-the ability of a patient to plan the movement and to perceive the stimulation as a part of his/her own control loop is important for carryover effect to take place. PMID:27073701

  16. [Shining light on translational research in deep brain stimulation].

    PubMed

    Lüscher, Christian; Davoine, Elise; Bellone, Carmilla

    2015-04-29

    For the last decade, optogenetics has revolutionised the neurosciences by enabling an unprecedented characterisation of the circuits involved in brain diseases, in particular addiction, depression, and obsessive compulsive disorders (OCD) and other anxiety disorders. Recently, the technique has also been used to propose blueprints for novel treatments of these diseases. For many reasons, optogenetics cannot be applied to humans applications anytime soon; we therefore argue that an intermediate step would be novel deep brain stimulation (DBS) protocols that emulate successful optogenetic "treatments" in animal models. Here we provide a roadmap of a translational path to rational, optogenetically inspired DBS protocols to refine existing approaches and expand it to novel indications. PMID:26062226

  17. Transcranial electrical stimulator producing high amplitude pulses and pulse trains.

    PubMed

    Suihko, V; Eskola, H

    1998-01-01

    Transcranial electrical stimulation can be used for clinical investigations of the central nervous system and for monitoring of motor nerve tracts during surgical operations. We wished to reduce the pain involved with the transcranial electrical stimulation and to improve the usefulness of the method for monitoring during surgical operations. A dedicated transcranial electrical stimulator was designed having special features to reduce the pain sensation and the nerve blocking effect of anaesthetics. It provides constant current and constant voltage stimulation pulses with very short duration and high amplitude. The pulse length is adjustable in the range of 15 to 125 microseconds, while the maximum amplitude is 100 V and 1 A for voltage and current stimulation modes, respectively. Special features included high-repetition-rate pulse trains (50-2000 pulses s-1) and a three-electrode stimulation configuration. We suggest that the electrical transcranial stimulation has the potential to be a relatively painless method for routine clinical investigations and a reliable method for monitoring during surgery. PMID:9807743

  18. Combined optical and electrical stimulation of neural tissue in vivo

    NASA Astrophysics Data System (ADS)

    Duke, Austin R.; Cayce, Jonathan M.; Malphrus, Jonathan D.; Konrad, Peter; Mahadevan-Jansen, Anita; Jansen, E. Duco

    2009-11-01

    Low-intensity, pulsed infrared light provides a novel nerve stimulation modality that avoids the limitations of traditional electrical methods such as necessity of contact, presence of a stimulation artifact, and relatively poor spatial precision. Infrared neural stimulation (INS) is, however, limited by a 2:1 ratio of threshold radiant exposures for damage to that for stimulation. We have shown that this ratio is increased to nearly 6:1 by combining the infrared pulse with a subthreshold electrical stimulus. Our results indicate a nonlinear relationship between the subthreshold depolarizing electrical stimulus and additional optical energy required to reach stimulation threshold. The change in optical threshold decreases linearly as the delay between the electrical and optical pulses is increased. We have shown that the high spatial precision of INS is maintained for this combined stimulation modality. Results of this study will facilitate the development of applications for infrared neural stimulation, as well as target the efforts to uncover the mechanism by which infrared light activates neural tissue.

  19. A novel lead design enables selective deep brain stimulation of neural populations in the subthalamic region

    NASA Astrophysics Data System (ADS)

    van Dijk, Kees J.; Verhagen, Rens; Chaturvedi, Ashutosh; McIntyre, Cameron C.; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2015-08-01

    Objective. The clinical effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) as a treatment for Parkinson’s disease are sensitive to the location of the DBS lead within the STN. New high density (HD) lead designs have been created which are hypothesized to provide additional degrees of freedom in shaping the stimulating electric field. The objective of this study is to compare the performances of a new HD lead with a conventional cylindrical contact (CC) lead. Approach. A computational model, consisting of a finite element electric field model combined with multi-compartment neuron and axon models representing different neural populations in the subthalamic region, was used to evaluate the two leads. We compared ring-mode and steering-mode stimulation with the HD lead to single contact stimulation with the CC lead. These stimulation modes were tested for the lead: (1) positioned in the centroid of the STN, (2) shifted 1 mm towards the internal capsule (IC), and (3) shifted 2 mm towards the IC. Under these conditions, we quantified the number of STN neurons that were activated without activating IC fibers, which are known to cause side-effects. Main results. The modeling results show that the HD lead is able to mimic the stimulation effect of the CC lead. Additionally, in steering-mode stimulation there was a significant increase of activated STN neurons compared to the CC mode. Significance. From the model simulations we conclude that the HD lead in steering-mode with optimized stimulation parameter selection can stimulate more STN cells. Next, the clinical impact of the increased number of activated STN cells should be tested and balanced across the increased complexity of identifying the optimized stimulation parameter settings for the HD lead.

  20. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrical peripheral nerve stimulator. 868.2775 Section 868.2775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2775 Electrical peripheral...

  1. Effects of Deep Brain Stimulation on Autonomic Function.

    PubMed

    Basiago, Adam; Binder, Devin K

    2016-01-01

    Over the course of the development of deep brain stimulation (DBS) into a well-established therapy for Parkinson's disease, essential tremor, and dystonia, its utility as a potential treatment for autonomic dysfunction has emerged. Dysfunction of autonomic processes is common in neurological diseases. Depending on the specific target in the brain, DBS has been shown to raise or lower blood pressure, normalize the baroreflex, to alter the caliber of bronchioles, and eliminate hyperhidrosis, all through modulation of the sympathetic nervous system. It has also been shown to improve cortical control of the bladder, directly induce or inhibit the micturition reflex, and to improve deglutition and gastric emptying. In this review, we will attempt to summarize the relevant available studies describing these effects of DBS on autonomic function, which vary greatly in character and magnitude with respect to stimulation target. PMID:27537920

  2. Future of brain stimulation: new targets, new indications, new technology.

    PubMed

    Hariz, Marwan; Blomstedt, Patric; Zrinzo, Ludvic

    2013-11-01

    In the last quarter of a century, DBS has become an established neurosurgical treatment for Parkinson's disease (PD), dystonia, and tremors. Improved understanding of brain circuitries and their involvement in various neurological and psychiatric illnesses, coupled with the safety of DBS and its exquisite role as a tool for ethical study of the human brain, have unlocked new opportunities for this technology, both for future therapies and in research. Serendipitous discoveries and advances in structural and functional imaging are providing abundant "new" brain targets for an ever-increasing number of pathologies, leading to investigations of DBS in diverse neurological, psychiatric, behavioral, and cognitive conditions. Trials and "proof of concept" studies of DBS are underway in pain, epilepsy, tinnitus, OCD, depression, and Gilles de la Tourette syndrome, as well as in eating disorders, addiction, cognitive decline, consciousness, and autonomic states. In parallel, ongoing technological development will provide pulse generators with longer battery longevity, segmental electrode designs allowing a current steering, and the possibility to deliver "on-demand" stimulation based on closed-loop concepts. The future of brain stimulation is certainly promising, especially for movement disorders-that will remain the main indication for DBS for the foreseeable future-and probably for some psychiatric disorders. However, brain stimulation as a technique may be at risk of gliding down a slippery slope: Some reports indicate a disturbing trend with suggestions that future DBS may be proposed for enhancement of memory in healthy people, or as a tool for "treatment" of "antisocial behavior" and for improving "morality." PMID:24123327

  3. Network Perspectives on the Mechanisms of Deep Brain Stimulation

    PubMed Central

    McIntyre, Cameron C.; Hahn, Philip J.

    2009-01-01

    Deep brain stimulation (DBS) is an established medical therapy for the treatment of movement disorders and shows great promise for several other neurological disorders. However, after decades of clinical utility the underlying therapeutic mechanisms remain undefined. Early attempts to explain the mechanisms of DBS focused on hypotheses that mimicked an ablative lesion to the stimulated brain region. More recent scientific efforts have explored the wide-spread changes in neural activity generated throughout the stimulated brain network. In turn, new theories on the mechanisms of DBS have taken a systems-level approach to begin to decipher the network activity. This review provides an introduction to some of the network based theories on the function and pathophysiology of the cortico-basal-ganglia-thalamo-cortical loops commonly targeted by DBS. We then analyze some recent results on the effects of DBS on these networks, with a focus on subthalamic DBS for the treatment of Parkinson's disease. Finally we attempt to summarize how DBS could be achieving its therapeutic effects by overriding pathological network activity. PMID:19804831

  4. Electrical stimulation and tinnitus: neuroplasticity, neuromodulation, neuroprotection.

    PubMed

    Abraham, Shulman; Barbara, Goldstein; Arnold, Strashun

    2013-01-01

    Neuroplasticity (NPL), neuromodulation (NM), and neuroprotection (NPT) are ongoing biophysiological processes that are linked together in sensory systems, the goal being the maintenance of a homeostasis of normal sensory function in the central nervous system. It is hypothesized that when the balance between excitatory - inhibitory action is broken in sensory systems, predominantly due to neuromodulatory activity with reduced induced inhibition and excitation predominates, sensory circuits become plastic with adaptation at synaptic levels to environmental inputs(1). Tinnitus an aberrant auditory sensation, for all clinical types, is clinically considered to reflect a failure of NPL, NM, and NPT to maintain normal auditory function at synaptic levels in sensory cortex and projected to downstream levels in the central auditory system in brain and sensorineural elements in ear. Clinically, the tinnitus sensation becomes behaviorally manifest with varying degrees of annoyance, reflecting a principle of sensory physiology that each sensation has components, i.e. sensory, affect/behavior, psychomotor and memory. Modalities of tinnitus therapies, eg instrumentation, pharmacology, surgery, target a particular component of tinnitus, with resultant activation of neuromodulators at multiple neuromodulatory centers in brain and ear. Effective neuromodulation at sensory neuronal synaptic levels results in NPL in sensory cortex, NPT and tinnitus relief. Functional brain imaging, metabolic (PET brain) and electrophysiology quantitative electroencephalography (QEEG) data in a cochlear implant soft failure patient demonstrates what is clinically considered to reflect NPL, NM, NPT. The reader is provided with a rationale for tinnitus diagnosis and treatment, with a focus on ES, reflecting the biology underlying NPL, NM, NPT. PMID:24995902

  5. Brain sites mediating corticosteroid feedback inhibition of stimulated ACTH secretion

    SciTech Connect

    Jacobson, L.

    1989-01-01

    There is substantial evidence that the brain mediates stress-induced and circadian increases in ACTH secretion and that corticosteroid concentrations which normalize basal plasma ACTH are insufficient to normalize ACTH responses to circadian or stressful stimuli in adrenalectomized rats. To identify brain sites mediating corticosteroid inhibition of stimulated ACTH secretion, two approaches were used. The first compared brain ({sup 14}C)-2-deoxyglucose uptake in rats with differential ACTH responses to stress. Relative to sham-adrenalectomized (SHAM) rats, adrenalectomized rats replaced with low, constant corticosterone levels via a subcutaneous corticosterone pellet (B-PELLET) exhibited elevated and prolonged ACTH responses to a variety of stimuli. Adrenalectomized rate given a circadian corticosterone rhythm via corticosterone in their drinking water exhibited elevated ACTH levels immediately after stress, but unlike B-PELLET rats, terminated stress induced ACTH secretion normally relative to SHAMS. Therefore, the abnormal ACTH responses to stress in B-PELLET rats were due to the lack of both circadian variations and stress-induced increases in corticosterone. Hypoxia was selected as a standardized stimulus for correlating brain ({sup 14}C)-2-deoxyglucose uptake with ACTH secretion. In intact rats, increases in plasma ACTH and decreases in arterial PO{sub 2} correlated with the severity of hypoxia at arterial PCO{sub 2} below 60 mm Hg. Hypoxia PELLET vs. SHAM rats. However, in preliminary experiments, although hypoxia increased brain 2-deoxyglucose uptake in most brain regions, plasma ACTH correlated poorly with 2-deoxyglucose uptake at 12% and 10% O{sub 2}.

  6. Deep brain stimulation for psychiatric disorders: where we are now.

    PubMed

    Cleary, Daniel R; Ozpinar, Alp; Raslan, Ahmed M; Ko, Andrew L

    2015-06-01

    Fossil records showing trephination in the Stone Age provide evidence that humans have sought to influence the mind through physical means since before the historical record. Attempts to treat psychiatric disease via neurosurgical means in the 20th century provided some intriguing initial results. However, the indiscriminate application of these treatments, lack of rigorous evaluation of the results, and the side effects of ablative, irreversible procedures resulted in a backlash against brain surgery for psychiatric disorders that continues to this day. With the advent of psychotropic medications, interest in invasive procedures for organic brain disease waned. Diagnosis and classification of psychiatric diseases has improved, due to a better understanding of psychiatric patho-physiology and the development of disease and treatment biomarkers. Meanwhile, a significant percentage of patients remain refractory to multiple modes of treatment, and psychiatric disease remains the number one cause of disability in the world. These data, along with the safe and efficacious application of deep brain stimulation (DBS) for movement disorders, in principle a reversible process, is rekindling interest in the surgical treatment of psychiatric disorders with stimulation of deep brain sites involved in emotional and behavioral circuitry. This review presents a brief history of psychosurgery and summarizes the development of DBS for psychiatric disease, reviewing the available evidence for the current application of DBS for disorders of the mind. PMID:26030702

  7. Non-invasive brain stimulation (NIBS) and motor recovery after stroke.

    PubMed

    Simonetta-Moreau, M

    2014-11-01

    Recovery of motor function after stroke occurs largely on the basis of a sustained capacity of the adult brain for plastic changes. This brain plasticity has been validated by functional imaging and electrophysiological studies. Various concepts of how to enhance beneficial plasticity and in turn improve functional recovery are emerging based on the concept of functional interhemispheric balance between the two motor cortices. Besides conventional rehabilitation interventions and the most recent neuropharmacological approaches, non-invasive brain stimulation (NIBS) has recently been proposed as an add-on method to promote motor function recovery after stroke. Several methods can be used based either on transcranial magnetic stimulation (repetitive mode: rTMS, TBS) via a coil, or small electric current via larges electrodes placed on the scalp, (transcranial direct current stimulation tDCS). Depending on the different electrophysiological parameters of stimulation used, NIBS can induce a transient modulation of the excitability of the stimulated motor cortex (facilitation or inhibition) via a probable LTP-LTD-like mechanism. Several small studies have shown feasible and positive treatment effects for most of these strategies and their potential clinical relevance to help restoring the disruption of interhemispheric imbalance after stroke. Results of these studies are encouraging but many questions remain unsolved: what are the optimal stimulation parameters? What is the best NIBS intervention? Which cortex, injured or intact, should be stimulated? What is the best window of intervention? Is there a special subgroup of stroke patients who could strongly benefit from these interventions? Finally is it possible to boost NIBS treatment effect by motor training of the paretic hand or by additional neuropharmacological interventions? There is clearly a need for large-scale, controlled, multicenter trials to answer these questions before proposing their routine use in the

  8. Ethical considerations in deep brain stimulation for psychiatric illness.

    PubMed

    Grant, Ryan A; Halpern, Casey H; Baltuch, Gordon H; O'Reardon, John P; Caplan, Arthur

    2014-01-01

    Deep brain stimulation (DBS) is an efficacious surgical treatment for many conditions, including obsessive-compulsive disorder and treatment-resistant depression. DBS provides a unique opportunity to not only ameliorate disease but also to study mood, cognition, and behavioral effects in the brain. However, there are many ethical questions that must be fully addressed in designing clinical research trials. It is crucial to maintain sound ethical boundaries in this new era so as to permit the proper testing of the potential therapeutic role DBS may play in ameliorating these devastating and frequently treatment-refractory psychiatric disorders. In this review, we focus on the selection of patients for study, informed consent, clinical trial design, DBS in the pediatric population, concerns about intentionally or inadvertently altering an individual's personal identity, potential use of DBS for brain enhancement, direct modification of behavior through neuromodulation, and resource allocation. PMID:24055023

  9. Chronic deep brain stimulation in mesial temporal lobe epilepsy.

    PubMed

    Boëx, Colette; Seeck, Margitta; Vulliémoz, Serge; Rossetti, Andrea O; Staedler, Claudio; Spinelli, Laurent; Pegna, Alan J; Pralong, Etienne; Villemure, Jean-Guy; Foletti, Giovanni; Pollo, Claudio

    2011-07-01

    The objective of this study was to evaluate the efficiency and the effects of changes in parameters of chronic amygdala-hippocampal deep brain stimulation (AH-DBS) in mesial temporal lobe epilepsy (TLE). Eight pharmacoresistant patients, not candidates for ablative surgery, received chronic AH-DBS (130 Hz, follow-up 12-24 months): two patients with hippocampal sclerosis (HS) and six patients with non-lesional mesial TLE (NLES). The effects of stepwise increases in intensity (0-Off to 2 V) and stimulation configuration (quadripolar and bipolar), on seizure frequency and neuropsychological performance were studied. The two HS patients obtained a significant decrease (65-75%) in seizure frequency with high voltage bipolar DBS (≥1 V) or with quadripolar stimulation. Two out of six NLES patients became seizure-free, one of them without stimulation, suggesting a microlesional effect. Two NLES patients experienced reductions of seizure frequency (65-70%), whereas the remaining two showed no significant seizure reduction. Neuropsychological evaluations showed reversible memory impairments in two patients under strong stimulation only. AH-DBS showed long-term efficiency in most of the TLE patients. It is a valuable treatment option for patients who suffer from drug resistant epilepsy and who are not candidates for resective surgery. The effects of changes in the stimulation parameters suggest that a large zone of stimulation would be required in HS patients, while a limited zone of stimulation or even a microlesional effect could be sufficient in NLES patients, for whom the importance of the proximity of the electrode to the epileptogenic zone remains to be studied. Further studies are required to ascertain these latter observations. PMID:21489828

  10. Conceptualization and validation of an open-source closed-loop deep brain stimulation system in rat

    PubMed Central

    Wu, Hemmings; Ghekiere, Hartwin; Beeckmans, Dorien; Tambuyzer, Tim; van Kuyck, Kris; Aerts, Jean-Marie; Nuttin, Bart

    2015-01-01

    Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input, and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation, and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability, and affordability. Our open-source closed-loop DBS system is effective, and warrants further research using open-source hardware for closed-loop neuromodulation. PMID:25897892

  11. Conceptualization and validation of an open-source closed-loop deep brain stimulation system in rat.

    PubMed

    Wu, Hemmings; Ghekiere, Hartwin; Beeckmans, Dorien; Tambuyzer, Tim; van Kuyck, Kris; Aerts, Jean-Marie; Nuttin, Bart

    2015-01-01

    Conventional deep brain stimulation (DBS) applies constant electrical stimulation to specific brain regions to treat neurological disorders. Closed-loop DBS with real-time feedback is gaining attention in recent years, after proved more effective than conventional DBS in terms of pathological symptom control clinically. Here we demonstrate the conceptualization and validation of a closed-loop DBS system using open-source hardware. We used hippocampal theta oscillations as system input, and electrical stimulation in the mesencephalic reticular formation (mRt) as controller output. It is well documented that hippocampal theta oscillations are highly related to locomotion, while electrical stimulation in the mRt induces freezing. We used an Arduino open-source microcontroller between input and output sources. This allowed us to use hippocampal local field potentials (LFPs) to steer electrical stimulation in the mRt. Our results showed that closed-loop DBS significantly suppressed locomotion compared to no stimulation, and required on average only 56% of the stimulation used in open-loop DBS to reach similar effects. The main advantages of open-source hardware include wide selection and availability, high customizability, and affordability. Our open-source closed-loop DBS system is effective, and warrants further research using open-source hardware for closed-loop neuromodulation. PMID:25897892

  12. Electric field stimulated growth of Zn whiskers

    NASA Astrophysics Data System (ADS)

    Niraula, D.; McCulloch, J.; Warrell, G. R.; Irving, R.; Karpov, V. G.; Shvydka, Diana

    2016-07-01

    We have investigated the impact of strong (˜104 V/cm) electric fields on the development of Zn whiskers. The original samples, with considerable whisker infestation were cut from Zn-coated steel floors and then exposed to electric fields stresses for 10-20 hours at room temperature. We used various electric field sources, from charges accumulated in samples irradiated by: (1) the electron beam of a scanning electron microscope (SEM), (2) the electron beam of a medical linear accelerator, and (3) the ion beam of a linear accelerator; we also used (4) the electric field produced by a Van der Graaf generator. In all cases, the exposed samples exhibited a considerable (tens of percent) increase in whiskers concentration compared to the control sample. The acceleration factor defined as the ratio of the measured whisker growth rate over that in zero field, was estimated to approach several hundred. The statistics of lengths of e-beam induced whiskers was found to follow the log-normal distribution known previously for metal whiskers. The observed accelerated whisker growth is attributed to electrostatic effects. These results offer promise for establishing whisker-related accelerated life testing protocols.

  13. A General Method for Evaluating Deep Brain Stimulation Effects on Intravenous Methamphetamine Self-Administration

    PubMed Central

    Batra, Vinita; Guerin, Glenn F.; Goeders, Nicholas E.; Wilden, Jessica A.

    2016-01-01

    Substance use disorders, particularly to methamphetamine, are devastating, relapsing diseases that disproportionally affect young people. There is a need for novel, effective and practical treatment strategies that are validated in animal models. Neuromodulation, including deep brain stimulation (DBS) therapy, refers to the use of electricity to influence pathological neuronal activity and has shown promise for psychiatric disorders, including drug dependence. DBS in clinical practice involves the continuous delivery of stimulation into brain structures using an implantable pacemaker-like system that is programmed externally by a physician to alleviate symptoms. This treatment will be limited in methamphetamine users due to challenging psychosocial situations. Electrical treatments that can be delivered intermittently, non-invasively and remotely from the drug-use setting will be more realistic. This article describes the delivery of intracranial electrical stimulation that is temporally and spatially separate from the drug-use environment for the treatment of IV methamphetamine dependence. Methamphetamine dependence is rapidly developed in rodents using an operant paradigm of intravenous (IV) self-administration that incorporates a period of extended access to drug and demonstrates both escalation of use and high motivation to obtain drug. PMID:26863392

  14. Why intra-epidermal electrical stimulation achieves stimulation of small fibres selectively: a simulation study

    NASA Astrophysics Data System (ADS)

    Motogi, Jun; Sugiyama, Yukiya; Laakso, Ilkka; Hirata, Akimasa; Inui, Koji; Tamura, Manabu; Muragaki, Yoshihiro

    2016-06-01

    The in situ electric field in the peripheral nerve of the skin is investigated to discuss the selective stimulation of nerve fibres. Coaxial planar electrodes with and without intra-epidermal needle tip were considered as electrodes of a stimulator. From electromagnetic analysis, the tip depth of the intra-epidermal electrode should be larger than the thickness of the stratum corneum, the electrical conductivity of which is much lower than the remaining tissue. The effect of different radii of the outer ring electrode on the in situ electric field is marginal. The minimum threshold in situ electric field (rheobase) for free nerve endings is estimated to be 6.3 kV m‑1. The possible volume for electrostimulation, which can be obtained from the in situ electric field distribution, becomes deeper and narrower with increasing needle depth, suggesting that possible stimulation sites may be controlled by changing the needle depth. The injection current amplitude should be adjusted when changing the needle depth because the peak field strength also changes. This study shows that intra-epidermal electrical stimulation can achieve stimulation of small fibres selectively, because Aβ-, Aδ-, and C-fibre terminals are located at different depths in the skin.

  15. Why intra-epidermal electrical stimulation achieves stimulation of small fibres selectively: a simulation study.

    PubMed

    Motogi, Jun; Sugiyama, Yukiya; Laakso, Ilkka; Hirata, Akimasa; Inui, Koji; Tamura, Manabu; Muragaki, Yoshihiro

    2016-06-21

    The in situ electric field in the peripheral nerve of the skin is investigated to discuss the selective stimulation of nerve fibres. Coaxial planar electrodes with and without intra-epidermal needle tip were considered as electrodes of a stimulator. From electromagnetic analysis, the tip depth of the intra-epidermal electrode should be larger than the thickness of the stratum corneum, the electrical conductivity of which is much lower than the remaining tissue. The effect of different radii of the outer ring electrode on the in situ electric field is marginal. The minimum threshold in situ electric field (rheobase) for free nerve endings is estimated to be 6.3 kV m(-1). The possible volume for electrostimulation, which can be obtained from the in situ electric field distribution, becomes deeper and narrower with increasing needle depth, suggesting that possible stimulation sites may be controlled by changing the needle depth. The injection current amplitude should be adjusted when changing the needle depth because the peak field strength also changes. This study shows that intra-epidermal electrical stimulation can achieve stimulation of small fibres selectively, because Aβ-, Aδ-, and C-fibre terminals are located at different depths in the skin. PMID:27223492

  16. Gastric Electrical Stimulation with the Enterra System: A Systematic Review

    PubMed Central

    Lal, Nikhil; Livemore, Sam; Dunne, Declan; Khan, Iftikhar

    2015-01-01

    Background. Gastric electrical stimulation (GES) is a surgically implanted treatment option for refractory gastroparesis. Aim. To systematically appraise the current evidence for the use of gastric electrical stimulation and suggest a method of standardisation of assessment and follow-up in these patients. Methods. A systematic review of PubMed, Web of Science, DISCOVER, and Cochrane Library was conducted using the keywords including gastric electrical stimulation, gastroparesis, nausea, and vomiting and neuromodulation, stomach, central nervous system, gastric pacing, electrical stimulation, and gastrointestinal. Results. 1139 potentially relevant articles were identified, of which 21 met the inclusion criteria and were included. The quality of studies was variable. There was a variation in outcome measures and follow-up methodology. Included studies suggested significant reductions in symptom severity reporting over the study period, but improvements in gastric emptying time were variable and rarely correlated with symptom improvement. Conclusion. The evidence in support of gastric electrical stimulation is limited and heterogeneous in quality. While current evidence has shown a degree of efficacy in these patients, high-quality, large clinical trials are needed to establish the efficacy of this therapy and to identify the patients for whom this therapy is inappropriate. A consensus view on essential preoperative assessment and postoperative measurement is needed. PMID:26246804

  17. Safe neuromuscular electrical stimulator designed for the elderly.

    PubMed

    Krenn, Matthias; Haller, Michael; Bijak, Manfred; Unger, Ewald; Hofer, Christian; Kern, Helmut; Mayr, Winfried

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials. PMID:21401669

  18. 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.

  19. Spatiotemporal visualization of deep brain stimulation-induced effects in the subthalamic nucleus.

    PubMed

    Yousif, Nada; Borisyuk, Roman; Pavese, Nicola; Nandi, Dipankar; Bain, Peter

    2012-07-01

    Deep brain stimulation (DBS) is a successful surgical therapy used to treat the disabling symptoms of movement disorders such as Parkinson's disease. It involves the chronic stimulation of disorder-specific nuclei. However, the mechanisms that lead to clinical improvements remain unclear. Consequently, this slows the optimization of present-day DBS therapy and hinders its future development and application. We used a computational model to calculate the distribution of electric potential induced by DBS and study the effect of stimulation on the spiking activity of a subthalamic nucleus (STN) projection neuron. We previously showed that such a model can reveal detailed spatial effects of stimulation in the vicinity of the electrode. However, this multi-compartmental STN neuron model can fire in either a burst or tonic mode and, in this study, we hypothesized that the firing mode of the cell will have a major impact on the DBS-induced effects. Our simulations showed that the bursting model exhibits behaviour observed in studies of high-frequency stimulation of STN neurons, such as the presence of a silent period at stimulation offset and frequency-dependent stimulation effects. We validated the model by simulating the clinical parameter settings used for a Parkinsonian patient and showed, in a patient-specific anatomical model, that the region of affected tissue is consistent with clinical observations of the optimal DBS site. Our results demonstrated a method of quantitatively assessing neuronal changes induced by DBS, to maximize therapeutic benefit and minimize unwanted side effects. PMID:22805069

  20. Evaluation of high-perimeter electrode designs for deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Howell, Bryan; Grill, Warren M.

    2014-08-01

    Objective. Deep brain stimulation (DBS) is an effective treatment for movement disorders and a promising therapy for treating epilepsy and psychiatric disorders. Despite its clinical success, complications including infections and mis-programing following surgical replacement of the battery-powered implantable pulse generator adversely impact the safety profile of this therapy. We sought to decrease power consumption and extend battery life by modifying the electrode geometry to increase stimulation efficiency. The specific goal of this study was to determine whether electrode contact perimeter or area had a greater effect on increasing stimulation efficiency. Approach. Finite-element method (FEM) models of eight prototype electrode designs were used to calculate the electrode access resistance, and the FEM models were coupled with cable models of passing axons to quantify stimulation efficiency. We also measured in vitro the electrical properties of the prototype electrode designs and measured in vivo the stimulation efficiency following acute implantation in anesthetized cats. Main results. Area had a greater effect than perimeter on altering the electrode access resistance; electrode (access or dynamic) resistance alone did not predict stimulation efficiency because efficiency was dependent on the shape of the potential distribution in the tissue; and, quantitative assessment of stimulation efficiency required consideration of the effects of the electrode-tissue interface impedance. Significance. These results advance understanding of the features of electrode geometry that are important for designing the next generation of efficient DBS electrodes.

  1. Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.

    PubMed

    Sperdin, Holger F; Spierer, Lucas; Becker, Robert; Michel, Christoph M; Landis, Theodor

    2015-04-01

    Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. PMID:25487054

  2. In Vivo Mapping of Cortical Columnar Networks in the Monkey with Focal Electrical and Optical Stimulation

    PubMed Central

    Roe, Anna Wang; Chernov, Mykyta M.; Friedman, Robert M.; Chen, Gang

    2015-01-01

    There are currently largescale efforts to understand the brain as a connection machine. However, there has been little emphasis on understanding connection patterns between functionally specific cortical columns. Here, we review development and application of focal electrical and optical stimulation methods combined with optical imaging and fMRI mapping in the non-human primate. These new approaches, when applied systematically on a large scale, will elucidate functionally specific intra-areal and inter-areal network connection patterns. Such functionally specific network data can provide accurate views of brain network topology. PMID:26635539

  3. Evaluation of novel stimulus waveforms for deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Foutz, Thomas J.; McIntyre, Cameron C.

    2010-12-01

    Deep brain stimulation (DBS) is an established therapy for the treatment of a wide range of neurological disorders. Historically, DBS and other neurostimulation technologies have relied on rectangular stimulation waveforms to impose their effects on the nervous system. Recent work has suggested that non-rectangular waveforms may have advantages over the traditional rectangular pulse. Therefore, we used detailed computer models to compare a range of charge-balanced biphasic waveforms with rectangular, exponential, triangular, Gaussian and sinusoidal stimulus pulse shapes. We explored the neural activation energy of these waveforms for both intracellular and extracellular current-controlled stimulation conditions. In the context of extracellular stimulation, we compared their effects on both axonal fibers of passage and projection neurons. Finally, we evaluated the impact of delivering the waveforms through a clinical DBS electrode, as opposed to a theoretical point source. Our results suggest that DBS with a 1 ms centered-triangular pulse can decrease energy consumption by 64% when compared with the standard 100 µs rectangular pulse (energy cost of 48 and 133 nJ, respectively, to stimulate 50% of a distributed population of axons) and can decrease energy consumption by 10% when compared with the most energy efficient rectangular pulse (1.25 ms duration). In turn, there may be measureable energy savings when using appropriately designed non-rectangular pulses in clinical DBS applications, thereby warranting further experimental investigation.

  4. Chronic electrical stimulation homeostatically decreases spontaneous activity, but paradoxically increases evoked network activity

    PubMed Central

    Goel, Anubhuti

    2013-01-01

    Neural dynamics generated within cortical networks play a fundamental role in brain function. However, the learning rules that allow recurrent networks to generate functional dynamic regimes, and the degree to which these regimes are themselves plastic, are not known. In this study we examined plasticity of network dynamics in cortical organotypic slices in response to chronic changes in activity. Studies have typically manipulated network activity pharmacologically; we used chronic electrical stimulation to increase activity in in vitro cortical circuits in a more physiological manner. Slices were stimulated with “implanted” electrodes for 4 days. Chronic electrical stimulation or treatment with bicuculline decreased spontaneous activity as predicted by homeostatic learning rules. Paradoxically, however, whereas bicuculline decreased evoked network activity, chronic stimulation actually increased the likelihood that evoked stimulation elicited polysynaptic activity, despite a decrease in evoked monosynaptic strength. Furthermore, there was an inverse correlation between spontaneous and evoked activity, suggesting a homeostatic tradeoff between spontaneous and evoked activity. Within-slice experiments revealed that cells close to the stimulated electrode exhibited more evoked polysynaptic activity and less spontaneous activity than cells close to a control electrode. Collectively, our results establish that chronic stimulation changes the dynamic regimes of networks. In vitro studies of homeostatic plasticity typically lack any external input, and thus neurons must rely on “spontaneous” activity to reach homeostatic “set points.” However, in the presence of external input we propose that homeostatic learning rules seem to shift networks from spontaneous to evoked regimes. PMID:23324317

  5. Non-invasive neuromuscular electrical stimulation in patients with central nervous system lesions: an educational review.

    PubMed

    Schuhfried, Othmar; Crevenna, Richard; Fialka-Moser, Veronika; Paternostro-Sluga, Tatjana

    2012-02-01

    The aim of this educational review is to provide an overview of the clinical application of transcutaneous electrical stimulation of the extremities in patients with upper motor neurone lesions. In general two methods of electrical stimulation can be distinguished: (i) therapeutic electrical stimulation, and (ii) functional electrical stimulation. Therapeutic electrical stimulation improves neuromuscular functional condition by strengthening muscles, increasing motor control, reducing spasticity, decreasing pain and increasing range of motion. Transcutaneous electrical stimulation may be used for neuromuscular electrical stimulation inducing repetitive muscle contraction, electromyography-triggered neuromuscular electrical stimulation, position-triggered electrical stimulation and subsensory or sensory transcutaneous electric stimulation. Functional electrical stimulation provokes muscle contraction and thereby produces a functionally useful movement during stimulation. In patients with spinal cord injuries or stroke, electrical upper limb neuroprostheses are applied to enhance upper limb and hand function, and electrical lower limb neuroprostheses are applied for restoration of standing and walking. For example, a dropped foot stimulator is used to trigger ankle dorsiflexion to restore gait function. A review of the literature and clinical experience of the use of therapeutic electrical stimulation as well as of functional electrical stimulation in combination with botulinum toxin, exercise therapy and/or splinting are presented. Although the evidence is limited we conclude that neuromuscular electrical stimulation in patients with central nervous system lesions can be an effective modality to improve function, and that combination with other treatments has an additive therapeutic effect. PMID:22334346

  6. Mapping of electrical muscle stimulation using MRI

    NASA Technical Reports Server (NTRS)

    Adams, Gregory R.; Harris, Robert T.; Woodard, Daniel; Dudley, Gary A.

    1993-01-01

    The pattern of muscle contractile activity elicited by electromyostimulation (EMS) was mapped and compared to the contractile-activity pattern produced by voluntary effort. This was done by examining the patterns and the extent of contrast shift, as indicated by T2 values, im magnetic resonance (MR) images after isometric activity of the left m. quadriceps of human subjects was elicited by EMS (1-sec train of 500-microsec sine wave pulses at 50 Hz) or voluntary effort. The results suggest that, whereas EMS stimulates the same fibers repeatedly, thereby increasing the metabolic demand and T2 values, the voluntary efforts are performed by more diffuse asynchronous activation of skeletal muscle even at forces up to 75 percent of maximal to maintain performance.

  7. Electrical stimulation of the globus pallidus preceding stereotactic posteroventral pallidotomy.

    PubMed

    Berić, A; Sterio, D; Dogali, M; Alterman, R; Kelly, P

    1996-01-01

    Physiological methods such as microelectrode recording of neuronal activity and electrical stimulation of target structures can improve the safety and efficacy of certain stereotactic surgeries. The globus pallidus (GP) was electrically stimulated in 136 patients with Parkinson's disease prior to unilateral posteroventral pallidotomy to identify functional areas and prevent deficits. We found that electrical stimulation of the GP elicited two principal responses: contractions of the contralateral hand and flashing lights. The mean voltage that evoked motor responses was 4.3 V (range 1.7-9.0 V), while higher intensity was necessary to elicit visual responses (mean 6.8 V; range 3.5-9.9 V). Contralateral tremor, speech impairment, paresthesias, and warm sensations were also elicited. PMID:9144871

  8. Electrical Stimulation of Schwann Cells Promotes Sustained Increases in Neurite Outgrowth

    PubMed Central

    Koppes, Abigail N.; Nordberg, Andrea L.; Paolillo, Gina M.; Goodsell, Nicole M.; Darwish, Haley A.; Zhang, Linxia

    2014-01-01

    Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite outgrowth and a more pronounced effect was observed if both peripheral glia (Schwann cells) and neurons were co-stimulated. If electrical stimulation is delivered to an injury site, both the neurons and all resident non-neuronal cells [e.g., Schwann cells, endothelial cells, fibroblasts] will be treated and this biophysical stimuli can influence axonal growth directly or indirectly via changes to the resident, non-neuronal cells. In this work, non-neuronal cells were electrically stimulated, and changes in morphology and neuro-supportive cells were evaluated. Schwann cell response (morphology and orientation) was examined after an 8 h stimulation over a range of DC fields (0–200 mV/mm, DC 1 mA), and changes in orientation were observed. Electrically prestimulating Schwann cells (50 mV/mm) promoted 30% more neurite outgrowth relative to co-stimulating both Schwann cells with neurons, suggesting that electrical stimulation modifies Schwann cell phenotype. Conditioned medium from the electrically prestimulated Schwann cells promoted a 20% increase in total neurite outgrowth and was sustained for 72 h poststimulation. An 11-fold increase in nerve growth factor but not brain-derived neurotrophic factor or glial-derived growth factor was found in the electrically prestimulated Schwann cell-conditioned medium. No significant changes in fibroblast or endothelial morphology and neuro-supportive behavior were observed poststimulation. Electrical stimulation is widely used in

  9. Glia: A Neglected Player in Non-invasive Direct Current Brain Stimulation.

    PubMed

    Gellner, Anne-Kathrin; Reis, Janine; Fritsch, Brita

    2016-01-01

    Non-invasive electrical brain stimulation by application of direct current (DCS) promotes plasticity in neuronal networks in vitro and in in vivo. This effect has been mainly attributed to the direct modulation of neurons. Glia represents approximately 50% of cells in the brain. Glial cells are electrically active and participate in synaptic plasticity. Despite of that, effects of DCS on glial structures and on interaction with neurons are only sparsely investigated. In this perspectives article we review the current literature, present own dose response data and provide a framework for future research from two points of view: first, the direct effects of DCS on glia and second, the contribution of glia to DCS related neuronal plasticity. PMID:27551261

  10. Glia: A Neglected Player in Non-invasive Direct Current Brain Stimulation

    PubMed Central

    Gellner, Anne-Kathrin; Reis, Janine; Fritsch, Brita

    2016-01-01

    Non-invasive electrical brain stimulation by application of direct current (DCS) promotes plasticity in neuronal networks in vitro and in in vivo. This effect has been mainly attributed to the direct modulation of neurons. Glia represents approximately 50% of cells in the brain. Glial cells are electrically active and participate in synaptic plasticity. Despite of that, effects of DCS on glial structures and on interaction with neurons are only sparsely investigated. In this perspectives article we review the current literature, present own dose response data and provide a framework for future research from two points of view: first, the direct effects of DCS on glia and second, the contribution of glia to DCS related neuronal plasticity. PMID:27551261

  11. Numerical characterization of intraoperative and chronic electrodes in deep brain stimulation

    PubMed Central

    Paffi, Alessandra; Camera, Francesca; Apollonio, Francesca; d’Inzeo, Guglielmo; Liberti, Micaela

    2015-01-01

    An intraoperative electrode (microelectrode) is used in the deep brain stimulation (DBS) technique to pinpoint the brain target and to choose the best parameters for the electrical stimulus. However, when the intraoperative electrode is replaced with the chronic one (macroelectrode), the observed effects do not always coincide with predictions. To investigate the causes of such discrepancies, a 3D model of the basal ganglia has been considered and realistic models of both intraoperative and chronic electrodes have been developed and numerically solved. Results of simulations of the electric potential (V) and the activating function (AF) along neuronal fibers show that the different geometries and sizes of the two electrodes do not change the distributions and polarities of these functions, but rather the amplitudes. This effect is similar to the one produced by the presence of different tissue layers (edema or glial tissue) in the peri-electrode space. Conversely, an inaccurate positioning of the chronic electrode with respect to the intraoperative one (electric centers not coincident) may induce a completely different electric stimulation in some groups of fibers. PMID:25745397

  12. Using Brain Electrical Activity Mapping to Diagnose Learning Disabilities.

    ERIC Educational Resources Information Center

    Torello, Michael, W.; Duffy, Frank H.

    1985-01-01

    Cognitive neuroscience assumes that measurement of brain electrical activity should relate to cognition. Brain Electrical Activity Mapping (BEAM), a non-invasive technique, is used to record changes in activity from one brain area to another and is 80 to 90 percent successful in classifying subjects as dyslexic or normal. (MT)

  13. Modulation of Untruthful Responses with Non-Invasive Brain Stimulation

    PubMed Central

    Fecteau, Shirley; Boggio, Paulo; Fregni, Felipe; Pascual-Leone, Alvaro

    2013-01-01

    Deceptive abilities have long been studied in relation to personality traits. More recently, studies explored the neural substrates associated with deceptive skills suggesting a critical role of the prefrontal cortex. Here we investigated whether non-invasive brain stimulation over the dorsolateral prefrontal cortex (DLPFC) could modulate generation of untruthful responses about subject’s personal life across contexts (i.e., deceiving on guilt-free questions on daily activities; generating previously memorized lies about past experience; and producing spontaneous lies about past experience), as well as across modality responses (verbal and motor responses). Results reveal that real, but not sham, transcranial direct current stimulation (tDCS) over the DLPFC can reduce response latency for untruthful over truthful answers across contexts and modality responses. Also, contexts of lies seem to incur a different hemispheric laterality. These findings add up to previous studies demonstrating that it is possible to modulate some processes involved in generation of untruthful answers by applying non-invasive brain stimulation over the DLPFC and extend these findings by showing a differential hemispheric contribution of DLPFCs according to contexts. PMID:23550273

  14. Exploring Selective Neural Electrical Stimulation for Upper Limb Function Restoration

    PubMed Central

    Tigra, Wafa; Guiraud, David; Andreu, David; Coulet, Bertrand; Gelis, Anthony; Fattal, Charles; Maciejasz, Pawel; Picq, Chloé; Rossel, Olivier; Teissier, Jacques; Coste, Christine Azevedo

    2016-01-01

    This article introduces a new approach of selective neural electrical stimulation of the upper limb nerves. Median and radial nerves of individuals with tetraplegia are stimulated via a multipolar cuff electrode to elicit movements of wrist and hand in acute conditions during a surgical intervention. Various configurations corresponding to various combinations of a 12-poles cuff electrode contacts are tested. Video recording and electromyographic (EMG) signals recorded via sterile surface electrodes are used to evaluate the selectivity of each stimulation configuration in terms of activated muscles. In this abstract we introduce the protocol and preliminary results will be presented during the conference. PMID:27478571

  15. Deep brain stimulation in tinnitus: current and future perspectives.

    PubMed

    Smit, J V; Janssen, M L F; Schulze, H; Jahanshahi, A; Van Overbeeke, J J; Temel, Y; Stokroos, R J

    2015-05-22

    Chronic tinnitus, also known as ringing in the ears, affects up to 15% of the adults and causes a serious socio-economic burden. At present, there is no treatment available which substantially reduces the perception of this phantom sound. In the past few years, preclinical and clinical studies have unraveled central mechanisms involved in the pathophysiology of tinnitus, replacing the classical periphery-based hypothesis. In subcortical auditory and non-auditory regions, increased spontaneous activity, neuronal bursting and synchrony were found. When reaching the auditory cortex, these neuronal alterations become perceptually relevant and consequently are perceived as phantom sound. A therapy with a potential to counteract deeply located pathological activity is deep brain stimulation, which has already been demonstrated to be effective in neurological diseases such as Parkinson's disease. In this review, several brain targets are discussed as possible targets for deep brain stimulation in tinnitus. The potential applicability of this treatment in tinnitus is discussed with examples from the preclinical field and clinical case studies. PMID:25758066

  16. A connectomics approach combining structural and effective connectivity assessed by intracranial electrical stimulation.

    PubMed

    Donos, Cristian; Mălîia, Mihai Dragoş; Mîndruţă, Ioana; Popa, Irina; Ene, Mirela; Bălănescu, Bogdan; Ciurea, Ana; Barborica, Andrei

    2016-05-15

    In the context of the human brain, the term "connectivity" can refer to structural, functional or effective connectivity. Intracranial electrical stimulation is perhaps the most direct way of investigating the effective connectivity. We propose a method of mapping the effective connectivity, revealed by the electrical stimulation of brain structures, over the structural connectome (SC), obtained through diffusion spectrum imaging (DSI), to form a structural-effective connectome (SEC). A number of 24 patients with refractory epilepsy were implanted with depth electrodes for pre-surgical evaluation. Effective connectivity was assessed by analyzing the responses to single pulse electrical stimulation (SPES). Stimulation pulses having variable amplitude were applied to each pair of adjacent contacts and responses evoked by stimulation were recorded from other contacts located in other brain areas. Early responses (10-110 ms) on the stimulation-activated contacts located outside the epileptogenic zone were averaged for each patient, resulting in a patient-level physiological effective connectome (EC). The population level EC is computed by averaging the connections of the individual ECs, on a structure by structure basis. A fiber activation factor is used to weight the number of fibers connecting a pair of structures in the SC by its corresponding normalized EC value. The resulting number of effectively activated fibers describes the directional connection strength between two structures in the SEC. A physiological SEC comprising directional connections between 70 segmented brain areas in both hemispheres, was obtained by inclusion of structures outside the epileptogenic zone only. Over the entire structure set, the Spearman's correlation coefficient ρ between the number of fibers extracted from the DSI Atlas and the normalized RMS responses to SPES was ρ=0.21 (p<0.001), while Kendall's tau coefficients ranged -0.52-0.44 (p<0.05). The physiological structural

  17. Magnetoelectric ‘spin’ on stimulating the brain

    PubMed Central

    Guduru, Rakesh; Liang, Ping; Hong, J; Rodzinski, Alexandra; Hadjikhani, Ali; Horstmyer, Jeffrey; Levister, Ernest; Khizroev, Sakhrat

    2015-01-01

    Aim: The in vivo study on imprinting control region mice aims to show that magnetoelectric nanoparticles may directly couple the intrinsic neural activity-induced electric fields with external magnetic fields. Methods: Approximately 10 µg of CoFe2O4–BaTiO3 30-nm nanoparticles have been intravenously administrated through a tail vein and forced to cross the blood–brain barrier via a d.c. field gradient of 3000 Oe/cm. A surgically attached two-channel electroencephalography headmount has directly measured the modulation of intrinsic electric waveforms by an external a.c. 100-Oe magnetic field in a frequency range of 0–20 Hz. Results: The modulated signal has reached the strength comparable to that due the regular neural activity. Conclusion: The study opens a pathway to use multifunctional nanoparticles to control intrinsic fields deep in the brain. PMID:25953069

  18. Using Saccadometry with Deep Brain Stimulation to Study Normal and Pathological Brain Function.

    PubMed

    Antoniades, Chrystalina A; FitzGerald, James J

    2016-01-01

    The oculomotor system involves a large number of brain areas including parts of the basal ganglia, and various neurodegenerative diseases including Parkinson's and Huntington's can disrupt it. People with Parkinson's disease, for example, tend to have increased saccadic latencies. Consequently, the quantitative measurement of saccadic eye movements has received considerable attention as a potential biomarker for neurodegenerative conditions. A lot more can be learned about the brain in both health and disease by observing what happens to eye movements when the function of specific brain areas is perturbed. Deep brain stimulation is a surgical intervention used for the management of a range of neurological conditions including Parkinson's disease, in which stimulating electrodes are placed in specific brain areas including several sites in the basal ganglia. Eye movement measurements can then be made with the stimulator systems both off and on and the results compared. With suitable experimental design, this approach can be used to study the pathophysiology of the disease being treated, the mechanism by which DBS exerts it beneficial effects, and even aspects of normal neurophysiology. PMID:27501123

  19. Treatment of Wilson's disease motor complications with deep brain stimulation.

    PubMed

    Hedera, Peter

    2014-05-01

    A considerable proportion of patients with Wilson's disease (WD) experience neurologic symptoms that are functionally disabling. The most common neurologic problems in advanced WD include dystonia and tremor. Medically refractory idiopathic dystonia and essential tremor (ET) have been successfully treated with deep brain stimulation (DBS), functional surgical therapy targeting the globus pallidus pars interna (GPi), or the ventral intermediate (Vim) thalamic nucleus. Even though the pathophysiology of tremor is different in WD and ET, available experience supports DBS targeting the Vim for WD patients. Dystonia associated with WD is classified as secondary dystonia and GPi stimulation has yielded mixed results in these patients. The presence of structural changes in the basal ganglia may limit the therapeutic success of DBS for WD dystonia compared with idiopathic dystonia. In spite of these limitations, DBS in WD may be an effective approach to treat medically refractory residual neurologic symptoms in carefully selected patients. PMID:24547944

  20. Drowning hazard with deep brain stimulation: case report.

    PubMed

    Bangash, Omar K; Thorburn, Megan; Garcia-Vega, Jimena; Walters, Susan; Stell, Rick; Starkstein, Sergio E; Lind, Christopher R P

    2016-05-01

    The caudal zona incerta target within the posterior subthalamic area is an investigational site for deep brain stimulation (DBS) in Parkinson disease (PD) and tremor. The authors report on a patient with tremor-predominant PD who, despite excellent tremor control and an otherwise normal neurological examination, exhibited profound difficulty swimming during stimulation. Over the last 20 years, anecdotal reports have been received of 3 other patients with PD who underwent thalamic or pallidal lesioning or DBS surgery performed at the authors' center and subsequently drowned. It may be that DBS puts patients at risk for drowning by specifically impairing their ability to swim. Until this finding can be further examined in larger cohorts, patients should be warned to swim under close supervision soon after DBS surgery. PMID:26566200

  1. Differential effects of deep brain stimulation on verbal fluency.

    PubMed

    Ehlen, Felicitas; Schoenecker, Thomas; Kühn, Andrea A; Klostermann, Fabian

    2014-07-01

    We aimed at gaining insights into principles of subcortical lexical processing. Therefore, effects of deep brain stimulation (DBS) in different target structures on verbal fluency (VF) were tested. VF was assessed with active vs. inactivated DBS in 13 and 14 patients with DBS in the vicinity of the thalamic ventral intermediate nucleus (VIM) and, respectively, of the subthalamic nucleus (STN). Results were correlated to electrode localizations in postoperative MRI, and compared to those of 12 age-matched healthy controls. Patients' VF performance was generally below normal. However, while activation of DBS in the vicinity of VIM provoked marked VF decline, it induced subtle phonemic VF enhancement in the vicinity of STN. The effects correlated with electrode localizations in left hemispheric stimulation sites. The results show distinct dependencies of VF on DBS in the vicinity of VIM vs. STN. Particular risks for deterioration occur in patients with relatively ventromedial thalamic electrodes. PMID:24815947

  2. Deep-Brain Stimulation for Basal Ganglia Disorders

    PubMed Central

    Wichmann, Thomas; DeLong, Mahlon R.

    2011-01-01

    The realization that medications used to treat movement disorders and psychiatric conditions of basal ganglia origin have significant shortcomings, as well as advances in the understanding of the functional organization of the brain, has led to a renaissance in functional neurosurgery, and particularly the use of deep brain stimulation (DBS). Movement disorders are now routinely being treated with DBS of ‘motor’ portions of the basal ganglia output nuclei, specifically the subthalamic nucleus and the internal pallidal segment. These procedures are highly effective and generally safe. Use of DBS is also being explored in the treatment of neuropsychiatric disorders, with targeting of the ‘limbic’ basal ganglia-thalamocortical circuitry. The results of these procedures are also encouraging, but many unanswered questions remain in this emerging field. This review summarizes the scientific rationale and practical aspects of using DBS for neurologic and neuropsychiatric disorders. PMID:21804953

  3. The Use of Deep Brain Stimulation in Tourette Syndrome.

    PubMed

    Akbarian-Tefaghi, Ladan; Zrinzo, Ludvic; Foltynie, Thomas

    2016-01-01

    Tourette syndrome (TS) is a childhood neurobehavioural disorder, characterised by the presence of motor and vocal tics, typically starting in childhood but persisting in around 20% of patients into adulthood. In those patients who do not respond to pharmacological or behavioural therapy, deep brain stimulation (DBS) may be a suitable option for potential symptom improvement. This manuscript attempts to summarise the outcomes of DBS at different targets, explore the possible mechanisms of action of DBS in TS, as well as the potential of adaptive DBS. There will also be a focus on the future challenges faced in designing optimized trials. PMID:27548235

  4. Time and Frequency-Dependent Modulation of Local Field Potential Synchronization by Deep Brain Stimulation

    PubMed Central

    McCracken, Clinton B.; Kiss, Zelma H. T.

    2014-01-01

    High-frequency electrical stimulation of specific brain structures, known as deep brain stimulation (DBS), is an effective treatment for movement disorders, but mechanisms of action remain unclear. We examined the time-dependent effects of DBS applied to the entopeduncular nucleus (EP), the rat homolog of the internal globus pallidus, a target used for treatment of both dystonia and Parkinson’s disease (PD). We performed simultaneous multi-site local field potential (LFP) recordings in urethane-anesthetized rats to assess the effects of high-frequency (HF, 130 Hz; clinically effective), low-frequency (LF, 15 Hz; ineffective) and sham DBS delivered to EP. LFP activity was recorded from dorsal striatum (STR), ventroanterior thalamus (VA), primary motor cortex (M1), and the stimulation site in EP. Spontaneous and acute stimulation-induced LFP oscillation power and functional connectivity were assessed at baseline, and after 30, 60, and 90 minutes of stimulation. HF EP DBS produced widespread alterations in spontaneous and stimulus-induced LFP oscillations, with some effects similar across regions and others occurring in a region- and frequency band-specific manner. Many of these changes evolved over time. HF EP DBS produced an initial transient reduction in power in the low beta band in M1 and STR; however, phase synchronization between these regions in the low beta band was markedly suppressed at all time points. DBS also enhanced low gamma synchronization throughout the circuit. With sustained stimulation, there were significant reductions in low beta synchronization between M1-VA and STR-VA, and increases in power within regions in the faster frequency bands. HF DBS also suppressed the ability of acute EP stimulation to induce beta oscillations in all regions along the circuit. This dynamic pattern of synchronizing and desynchronizing effects of EP DBS suggests a complex modulation of activity along cortico-BG-thalamic circuits underlying the therapeutic effects

  5. Recording of the Neural Activity Induced by the Electrical Subthalamic Stimulation Using Ca2+ Imaging

    NASA Astrophysics Data System (ADS)

    Tamura, Atsushi; Yagi, Tetsuya; Osanai, Makoto

    The basal ganglia (BG) have important roles in some kind of motor control and learning. Parkinson's disease is one of the motor impairment disease. Recently, to recover a motor severity in patients of Parkinsonism, the stimulus electrode is implanted to the subthalamic nucleus, which is a part of the basal ganglia, and the deep brain stimulation (DBS) is often conducted. However, the effects of the DBS on the subthalamic neurons have not been elucidated. Thus, to analyze the effects of the electrical stimulation on the subthalamic neurons, we conducted the calcium imaging at the mouse subthalamic nucleus. When the single stimulus was applied to the subthalamic nucleus, the intracellular calcium ([Ca2+]i) transients were observed. In the case of application of the single electrical stimulation, the [Ca2+]i arose near the stimulus position. When 100 Hz 10-100 times tetanic stimulations were applied, the responded area and the amplitudes of [Ca2+]i transients were increased. The [Ca2+]i transients were disappeared almost completely on the action potential blockade, but blockade of the excitatory and the inhibitory synaptic transmission had little effects on the responded area and the amplitudes of the [Ca2+]i transients. These results suggested that the electrical stimulation to the subthalamic neurons led to activate the subthalamic neurons directly but not via synaptic transmissions. Thus, DBS may change the activity of the subthalamic neurons, hence, may alter the input-output relationship of the subthalamic neurons

  6. Spatially Patterned Electrical Stimulation to Enhance Resolution of Retinal Prostheses

    PubMed Central

    Hottowy, Paweł; Mathieson, Keith; Gunning, Deborah E.; Dąbrowski, Władysław; Litke, Alan M.; Chichilnisky, E. J.

    2014-01-01

    Retinal prostheses electrically stimulate neurons to produce artificial vision in people blinded by photoreceptor degenerative diseases. The limited spatial resolution of current devices results in indiscriminate stimulation of interleaved cells of different types, precluding veridical reproduction of natural activity patterns in the retinal output. Here we investigate the use of spatial patterns of current injection to increase the spatial resolution of stimulation, using high-density multielectrode recording and stimulation of identified ganglion cells in isolated macaque retina. As previously shown, current passed through a single electrode typically induced a single retinal ganglion cell spike with submillisecond timing precision. Current passed simultaneously through pairs of neighboring electrodes modified the probability of activation relative to injection through a single electrode. This modification could be accurately summarized by a piecewise linear model of current summation, consistent with a simple biophysical model based on multiple sites of activation. The generalizability of the piecewise linear model was tested by using the measured responses to stimulation with two electrodes to predict responses to stimulation with three electrodes. Finally, the model provided an accurate prediction of which among a set of spatial stimulation patterns maximized selective activation of a cell while minimizing activation of a neighboring cell. The results demonstrate that tailored multielectrode stimulation patterns based on a piecewise linear model may be useful in increasing the spatial resolution of retinal prostheses. PMID:24695706

  7. Diffusion Tractography in Deep Brain Stimulation Surgery: A Review

    PubMed Central

    Calabrese, Evan

    2016-01-01

    Deep brain stimulation (DBS) is believed to exert its therapeutic effects through modulation of brain circuitry, yet conventional preoperative planning does not allow direct targeting or visualization of white matter pathways. Diffusion MRI tractography (DT) is virtually the only non-invasive method of visualizing structural connectivity in the brain, leading many to suggest its use to guide DBS targeting. DT-guided DBS not only has the potential to allow direct white matter targeting for established applications [e.g., Parkinson’s disease (PD), essential tremor (ET), dystonia], but may also aid in the discovery of new therapeutic targets for a variety of other neurologic and psychiatric diseases. Despite these exciting opportunities, DT lacks standardization and rigorous anatomic validation, raising significant concern for the use of such data in stereotactic brain surgery. This review covers the technical details, proposed methods, and initial clinical data for the use of DT in DBS surgery. Rather than focusing on specific disease applications, this review focuses on methods that can be applied to virtually any DBS target. PMID:27199677

  8. Computational modeling of an endovascular approach to deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Teplitzky, Benjamin A.; Connolly, Allison T.; Bajwa, Jawad A.; Johnson, Matthew D.

    2014-04-01

    Objective. Deep brain stimulation (DBS) therapy currently relies on a transcranial neurosurgical technique to implant one or more electrode leads into the brain parenchyma. In this study, we used computational modeling to investigate the feasibility of using an endovascular approach to target DBS therapy. Approach. Image-based anatomical reconstructions of the human brain and vasculature were used to identify 17 established and hypothesized anatomical targets of DBS, of which five were found adjacent to a vein or artery with intraluminal diameter ≥1 mm. Two of these targets, the fornix and subgenual cingulate white matter (SgCwm) tracts, were further investigated using a computational modeling framework that combined segmented volumes of the vascularized brain, finite element models of the tissue voltage during DBS, and multi-compartment axon models to predict the direct electrophysiological effects of endovascular DBS. Main results. The models showed that: (1) a ring-electrode conforming to the vessel wall was more efficient at neural activation than a guidewire design, (2) increasing the length of a ring-electrode had minimal effect on neural activation thresholds, (3) large variability in neural activation occurred with suboptimal placement of a ring-electrode along the targeted vessel, and (4) activation thresholds for the fornix and SgCwm tracts were comparable for endovascular and stereotactic DBS, though endovascular DBS was able to produce significantly larger contralateral activation for a unilateral implantation. Significance. Together, these results suggest that endovascular DBS can serve as a complementary approach to stereotactic DBS in select cases.

  9. Restoration of grasp following paralysis through brain-controlled stimulation of muscles.

    PubMed

    Ethier, C; Oby, E R; Bauman, M J; Miller, L E

    2012-05-17

    Patients with spinal cord injury lack the connections between brain and spinal cord circuits that are essential for voluntary movement. Clinical systems that achieve muscle contraction through functional electrical stimulation (FES) have proven to be effective in allowing patients with tetraplegia to regain control of hand movements and to achieve a greater measure of independence in daily activities. In existing clinical systems, the patient uses residual proximal limb movements to trigger pre-programmed stimulation that causes the paralysed muscles to contract, allowing use of one or two basic grasps. Instead, we have developed an FES system in primates that is controlled by recordings made from microelectrodes permanently implanted in the brain. We simulated some of the effects of the paralysis caused by C5 or C6 spinal cord injury by injecting rhesus monkeys with a local anaesthetic to block the median and ulnar nerves at the elbow. Then, using recordings from approximately 100 neurons in the motor cortex, we predicted the intended activity of several of the paralysed muscles, and used these predictions to control the intensity of stimulation of the same muscles. This process essentially bypassed the spinal cord, restoring to the monkeys voluntary control of their paralysed muscles. This achievement is a major advance towards similar restoration of hand function in human patients through brain-controlled FES. We anticipate that in human patients, this neuroprosthesis would allow much more flexible and dexterous use of the hand than is possible with existing FES systems. PMID:22522928

  10. Restoration of grasp following paralysis through brain-controlled stimulation of muscles

    PubMed Central

    Ethier, C.; Oby, E.R.; Bauman, M.J.; Miller, L.E.

    2012-01-01

    Patients with spinal cord injury lack the connections between brain and spinal cord circuits essential for voluntary movement. Clinical systems that achieve muscle contraction through functional electrical stimulation (FES) have proven to be effective in allowing patients with tetraplegia to regain control of hand movement and to achieve a greater measure of independence in activities of daily living 1,2. In typical systems, the patient uses residual proximal limb movements to trigger pre-programmed stimulation that causes the paralyzed muscles to contract, allowing use of one or two basic grasps. Instead, we have developed, in primates, an FES system that is controlled by recordings made from microelectrodes permanently implanted in the brain. We simulated some of the effects of the paralysis caused by C5-C6 spinal cord injury 3 by injecting a local anesthetic to block the median and ulnar nerves at the elbow. Then, using recordings from approximately 100 neurons in the motor cortex, we predicted the intended activity of several of the paralyzed muscles, and used these predictions to control the intensity of stimulation of the same muscles. This process essentially bypassed the spinal cord, restoring to the monkeys voluntary control of their paralyzed muscles. This achievement represents a major advance toward similar restoration of hand function in human patients through brain-controlled FES. We anticipate that in human patients, this neuroprosthesis would allow much more flexible and dexterous use of the hand than is possible with existing FES systems. PMID:22522928

  11. Carbon Nanofiber Nanoelectrodes for Neural Stimulation and Chemical Detection: The Era of Smart Deep Brain Stimulation

    NASA Technical Reports Server (NTRS)

    Koehne, Jessica E.

    2016-01-01

    A sensor platform based on vertically aligned carbon nanofibers (CNFs) has been developed. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report two studies using vertically aligned CNF nanoelectrodes for biomedical applications. CNF arrays are investigated as neural stimulation and neurotransmitter recording electrodes for application in deep brain stimulation (DBS). Polypyrrole coated CNF nanoelectrodes have shown great promise as stimulating electrodes due to their large surface area, low impedance, biocompatibility and capacity for highly localized stimulation. CNFs embedded in SiO2 have been used as sensing electrodes for neurotransmitter detection. Our approach combines a multiplexed CNF electrode chip, developed at NASA Ames Research Center, with the Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) system, developed at the Mayo Clinic. Preliminary results indicate that the CNF nanoelectrode arrays are easily integrated with WINCS for neurotransmitter detection in a multiplexed array format. In the future, combining CNF based stimulating and recording electrodes with WINCS may lay the foundation for an implantable "smart" therapeutic system that utilizes neurochemical feedback control while likely resulting in increased DBS application in various neuropsychiatric disorders. In total, our goal is to take advantage of the nanostructure of CNF arrays for biosensing studies requiring ultrahigh sensitivity, high-degree of miniaturization, and selective biofunctionalization.

  12. Electrical stimulation characteristics of denervated orbicularis oculi muscle.

    PubMed

    Zhang, Yi; Li, Keyong; Jin, Cheng; Wang, Yiting; Geng, Liang; Sun, Yajing; Tian, Hongchang

    2015-08-01

    This research is to study the electrical stimulation characteristics of orbicularis oculi muscle and the characteristics of the mechanical contraction. We observed the stimulus current diffusion regularity and its relationship with mechanical contraction in the orbicularis oculi muscle using an electrode gathering line. Under different stimulus intensities of 2 or 4 mA, the closer the recording electrodes were to the stimulating electrode, the larger was the amplitude. When the recording electrode and stimulating electrode distance increased, the amplitude declined linearly with decreasing function. In addition, current conduction across the muscle fiber was studied. Under different stimulus intensities of 2 or 4 mA, it was found that the closer the recording electrodes were to the stimulating electrode, the larger was the amplitude. When the recording electrode and stimulating electrode distance increased, the amplitude declined linearly with decreasing function. The transverse current reached a maximum 4 mA range, and increasing the current intensity did not increase the propagation range. Under different stimulation intensities, the larger the stimulus intensity, the greater is the potential change and the faster is the attenuation. Longitudinal current, even in the range of 6 mm, can still record electrical activity. While a transverse current diffuser has a maximum range of 4 mm, increasing the current intensity does not increase the propagation range. PMID:25724806

  13. DEVELOPMENT OF ADVANCED ESFF (ELECTRICAL STIMULATION OF FABRIC FILTRATION) TECHNOLOGY

    EPA Science Inventory

    The report summarizes work on electrical stimulation of fabric filtration (ESFF) with the major objectives of defining the role of some primary variables and understanding the mechanisms of electrostatic enhancement. It was concluded that the magnitude of particle charge has a st...

  14. Neuromuscular Electrical Stimulation for Motor Restoration in Hemiplegia.

    PubMed

    Knutson, Jayme S; Fu, Michael J; Sheffler, Lynne R; Chae, John

    2015-11-01

    This article reviews the most common therapeutic and neuroprosthetic applications of neuromuscular electrical stimulation (NMES) for upper and lower extremity stroke rehabilitation. Fundamental NMES principles and purposes in stroke rehabilitation are explained. NMES modalities used for upper and lower limb rehabilitation are described, and efficacy studies are summarized. The evidence for peripheral and central mechanisms of action is also summarized. PMID:26522909

  15. Computational Modeling and Neuroimaging Techniques for Targeting during Deep Brain Stimulation

    PubMed Central

    Sweet, Jennifer A.; Pace, Jonathan; Girgis, Fady; Miller, Jonathan P.

    2016-01-01

    Accurate surgical localization of the varied targets for deep brain stimulation (DBS) is a process undergoing constant evolution, with increasingly sophisticated techniques to allow for highly precise targeting. However, despite the fastidious placement of electrodes into specific structures within the brain, there is increasing evidence to suggest that the clinical effects of DBS are likely due to the activation of widespread neuronal networks directly and indirectly influenced by the stimulation of a given target. Selective activation of these complex and inter-connected pathways may further improve the outcomes of currently treated diseases by targeting specific fiber tracts responsible for a particular symptom in a patient-specific manner. Moreover, the delivery of such focused stimulation may aid in the discovery of new targets for electrical stimulation to treat additional neurological, psychiatric, and even cognitive disorders. As such, advancements in surgical targeting, computational modeling, engineering designs, and neuroimaging techniques play a critical role in this process. This article reviews the progress of these applications, discussing the importance of target localization for DBS, and the role of computational modeling and novel neuroimaging in improving our understanding of the pathophysiology of diseases, and thus paving the way for improved selective target localization using DBS. PMID:27445709

  16. Treatment of neurological and psychiatric disorders with deep brain stimulation; raising hopes and future challenges.

    PubMed

    Sharifi, Mohammad Sharif

    2013-01-01

    The technology of Neural Stimulation in recent years has become the focus of the research and treatment, although it has been around for many years. The potential use of stimulating the brain and nerves ranges from the spinal cord stimulation to the implantations of cochlear and bionic eyes with a large discrepancy between the clinical readiness for these various uses. Electrical high-frequency Deep Brain Stimulation (DBS) was developed as an alternative option to treat a few neurological disorders. However, with advancing in surgical procedures, technologies and safeties, the applications of DBS are expanding not only for therapeutic purposes but also for research. Although the exact mechanisms of action/s are not fully understood, the outcome of the ongoing research and clinical trials are promising. DBS has been used to treat the essential tremor since 1997, Parkinson's disease (PD) since 2002 and dystonia since 2003. It has also been used to treat various disorders, including major depression. The therapeutic effect of DBS in PD is well established but for other diseases such as epilepsy the outcomes are unclear and ambiguous. This article is a succinct review of the literature, focusing on PD, epilepsy and Obsessive Compulsive Disorder (OCD). PMID:25337356

  17. Numerical analysis and design of single-source multicoil TMS for deep and focused brain stimulation.

    PubMed

    Gomez, Luis; Cajko, Frantishek; Hernandez-Garcia, Luis; Grbic, Anthony; Michielssen, Eric

    2013-10-01

    Transcranial magnetic stimulation (TMS) is a tool for noninvasive stimulation of neuronal tissue used for research in cognitive neuroscience and to treat neurological disorders. Many TMS applications call for large electric fields to be sharply focused on regions that often lie deep inside the brain. Unfortunately, the fields generated by present-day TMS coils diffuse and decay rapidly as they penetrate into the head. As a result, they tend to stimulate relatively large regions of tissue near the brain surface. Earlier studies suggested that a focused TMS excitation can be attained using multiple nonuniformly fed coils in a multichannel array. We propose a systematic, genetic algorithm-based technique for synthesizing multichannel arrays that minimize the volume of the excited region required to achieve a prescribed penetration depth and maintain realistic values for the input driving currents. Because multichannel arrays are costly to build, we also propose a method to convert the multichannel arrays into single-channel ones while minimally materially deteriorating performance. Numerical results show that the new multi- and single-channel arrays stimulate tissue 2.4 cm into the head while exciting 3.0 and 2.6 times less volume than conventional Figure-8 coils, respectively. PMID:23708768

  18. Stimulation mapping of white matter tracts to study brain functional connectivity.

    PubMed

    Duffau, Hugues

    2015-05-01

    Despite advances in the new science of connectomics, which aims to comprehensively map neural connections at both structural and functional levels, techniques to directly study the function of white matter tracts in vivo in humans have proved elusive. Direct electrical stimulation (DES) mapping of the subcortical fibres offers a unique opportunity to investigate the functional connectivity of the brain. This original method permits real-time anatomo-functional correlations, especially with regard to neural pathways, in awake patients undergoing brain surgery. In this article, the goal is to review new insights, gained from axonal DES, into the functional connectivity underlying the sensorimotor, visuospatial, language and sociocognitive systems. Interactions between these neural networks and multimodal systems, such as working memory, attention, executive functions and consciousness, can also be investigated by axonal stimulation. In this networking model of conation and cognition, brain processing is not conceived as the sum of several subfunctions, but results from the integration and potentiation of parallel-though partially overlapping-subnetworks. This hodotopical account, supported by axonal DES, improves our understanding of neuroplasticity and its limitations. The clinical implications of this paradigmatic shift from localizationism to hodotopy, in the context of brain surgery, neurology, neurorehabilitation and psychiatry, are discussed. PMID:25848923

  19. Measurement of evoked potentials during thalamic deep brain stimulation

    PubMed Central

    Kent, Alexander R.; Swan, Brandon D.; Brocker, David T.; Turner, Dennis A.; Gross, Robert E.; Grill, Warren M.

    2014-01-01

    Background Deep brain stimulation (DBS) treats the symptoms of several movement disorders, but optimal selection of stimulation parameters remains a challenge. The evoked compound action potential (ECAP) reflects synchronized neural activation near the DBS lead, and may be useful for feedback control and automatic adjustment of stimulation parameters in closed-loop DBS systems. Objectives Determine the feasibility of recording ECAPs in the clinical setting, understand the neural origin of the ECAP and sources of any stimulus artifact, and correlate ECAP characteristics with motor symptoms. Methods The ECAP and tremor response were measured simultaneously during intraoperative studies of thalamic DBS, conducted in patients who were either undergoing surgery for initial lead implantation or replacement of their internal pulse generator. Results There was large subject-to-subject variation in stimulus artifact amplitude, which model-based analysis suggested may have been caused by glial encapsulation of the lead, resulting in imbalances in the tissue impedance between the contacts. ECAP recordings obtained from both acute and chronically implanted electrodes revealed that specific phase characteristics of the signal varied systematically with stimulation parameters. Further, a trend was observed in some patients between the energy of the initial negative and positive ECAP phases, as well as secondary phases, and changes in tremor from baseline. A computational model of thalamic DBS indicated that direct cerebellothalamic fiber activation dominated the clinically measured ECAP, suggesting that excitation of these fibers is critical in DBS therapy. Conclusions This work demonstrated that ECAPs can be recorded in the clinical setting and may provide a surrogate feedback control signal for automatic adjustment of stimulation parameters to reduce tremor amplitude. PMID:25457213

  20. Orosensory self-stimulation by sucrose involves brain dopaminergic mechanisms.

    PubMed

    Schneider, L H

    1989-01-01

    The most convincing body of evidence supporting a role for brain dopaminergic mechanisms in sweet taste reward has been obtained using the sham-feeding rat. In rats prepared with a chronic gastric fistula and tested with the cannula open, intake is a direct function of the palatability of the solution offered as well as of the state of food deprivation. Because essentially none of the ingested fluid passes on to the intestine, negative postingestive feedback is eliminated. Thus, the relative orosensory/hedonic potency of the food determines and sustains the rate of sham intake; long periods of food deprivation are not required. In this way, the sham feeding of sweet solutions may be considered a form of oral self-stimulation behavior and afford a preparation through which the neurochemical and neuranatomical substrates of sweet taste reward may be identified. The results obtained in the series of experiments summarized in this paper clearly indicate that central D-1 and D-2 receptor mechanisms are critical for the orosensory self-stimulation by sucrose in the rat. In conclusion, I suggest that such investigations of the roles of brain dopaminergic mechanisms in the sucrose sham-feeding rat preparation may further our understanding of normal and aberrant attractions to sweet fluids in humans (see Cabanac, Drewnowski, and Halmi, this volume), as an innate, positive affective response of human neonates to sucrose and the sustained positive hedonic ratings for glucose when tasted but not when consumed have demonstrated. PMID:2699194

  1. Weight Gain following Pallidal Deep Brain Stimulation: A PET Study.

    PubMed

    Sauleau, Paul; Drapier, Sophie; Duprez, Joan; Houvenaghel, Jean-François; Dondaine, Thibaut; Haegelen, Claire; Drapier, Dominique; Jannin, Pierre; Robert, Gabriel; Le Jeune, Florence; Vérin, Marc

    2016-01-01

    The mechanisms behind weight gain following deep brain stimulation (DBS) surgery seem to be multifactorial and suspected depending on the target, either the subthalamic nucleus (STN) or the globus pallidus internus (GPi). Decreased energy expenditure following motor improvement and behavioral and/or metabolic changes are possible explanations. Focusing on GPi target, our objective was to analyze correlations between changes in brain metabolism (measured with PET) and weight gain following GPi-DBS in patients with Parkinson's disease (PD). Body mass index was calculated and brain activity prospectively measured using 2-deoxy-2[18F]fluoro-D-glucose PET four months before and four months after the start of GPi-DBS in 19 PD patients. Dopaminergic medication was included in the analysis to control for its possible influence on brain metabolism. Body mass index increased significantly by 0.66 ± 1.3 kg/m2 (p = 0.040). There were correlations between weight gain and changes in brain metabolism in premotor areas, including the left and right superior gyri (Brodmann area, BA 6), left superior gyrus (BA 8), the dorsolateral prefrontal cortex (right middle gyrus, BAs 9 and 46), and the left and right somatosensory association cortices (BA 7). However, we found no correlation between weight gain and metabolic changes in limbic and associative areas. Additionally, there was a trend toward a correlation between reduced dyskinesia and weight gain (r = 0.428, p = 0.067). These findings suggest that, unlike STN-DBS, motor improvement is the major contributing factor for weight gain following GPi-DBS PD, confirming the motor selectivity of this target. PMID:27070317

  2. Weight Gain following Pallidal Deep Brain Stimulation: A PET Study

    PubMed Central

    Sauleau, Paul; Drapier, Sophie; Duprez, Joan; Houvenaghel, Jean-François; Dondaine, Thibaut; Haegelen, Claire; Drapier, Dominique; Jannin, Pierre; Robert, Gabriel; Le Jeune, Florence; Vérin, Marc

    2016-01-01

    The mechanisms behind weight gain following deep brain stimulation (DBS) surgery seem to be multifactorial and suspected depending on the target, either the subthalamic nucleus (STN) or the globus pallidus internus (GPi). Decreased energy expenditure following motor improvement and behavioral and/or metabolic changes are possible explanations. Focusing on GPi target, our objective was to analyze correlations between changes in brain metabolism (measured with PET) and weight gain following GPi-DBS in patients with Parkinson’s disease (PD). Body mass index was calculated and brain activity prospectively measured using 2-deoxy-2[18F]fluoro-D-glucose PET four months before and four months after the start of GPi-DBS in 19 PD patients. Dopaminergic medication was included in the analysis to control for its possible influence on brain metabolism. Body mass index increased significantly by 0.66 ± 1.3 kg/m2 (p = 0.040). There were correlations between weight gain and changes in brain metabolism in premotor areas, including the left and right superior gyri (Brodmann area, BA 6), left superior gyrus (BA 8), the dorsolateral prefrontal cortex (right middle gyrus, BAs 9 and 46), and the left and right somatosensory association cortices (BA 7). However, we found no correlation between weight gain and metabolic changes in limbic and associative areas. Additionally, there was a trend toward a correlation between reduced dyskinesia and weight gain (r = 0.428, p = 0.067). These findings suggest that, unlike STN-DBS, motor improvement is the major contributing factor for weight gain following GPi-DBS PD, confirming the motor selectivity of this target. PMID:27070317

  3. Volume conductor model of transcutaneous electrical stimulation with kilohertz signals

    NASA Astrophysics Data System (ADS)

    Medina, Leonel E.; Grill, Warren M.

    2014-12-01

    Objective. Incorporating high-frequency components in transcutaneous electrical stimulation (TES) waveforms may make it possible to stimulate deeper nerve fibers since the impedance of tissue declines with increasing frequency. However, the mechanisms of high-frequency TES remain largely unexplored. We investigated the properties of TES with frequencies beyond those typically used in neural stimulation. Approach. We implemented a multilayer volume conductor model including dispersion and capacitive effects, coupled to a cable model of a nerve fiber. We simulated voltage- and current-controlled transcutaneous stimulation, and quantified the effects of frequency on the distribution of potentials and fiber excitation. We also quantified the effects of a novel transdermal amplitude modulated signal (TAMS) consisting of a non-zero offset sinusoidal carrier modulated by a square-pulse train. Main results. The model revealed that high-frequency signals generated larger potentials at depth than did low frequencies, but this did not translate into lower stimulation thresholds. Both TAMS and conventional rectangular pulses activated more superficial fibers in addition to the deeper, target fibers, and at no frequency did we observe an inversion of the strength-distance relationship. Current regulated stimulation was more strongly influenced by fiber depth, whereas voltage regulated stimulation was more strongly influenced by skin thickness. Finally, our model reproduced the threshold-frequency relationship of experimentally measured motor thresholds. Significance. The model may be used for prediction of motor thresholds in TES, and contributes to the understanding of high-frequency TES.

  4. Electrical Stimulation of Coleopteran Muscle for Initiating Flight.

    PubMed

    Choo, Hao Yu; Li, Yao; Cao, Feng; Sato, Hirotaka

    2016-01-01

    Some researchers have long been interested in reconstructing natural insects into steerable robots or vehicles. However, until recently, these so-called cyborg insects, biobots, or living machines existed only in science fiction. Owing to recent advances in nano/micro manufacturing, data processing, and anatomical and physiological biology, we can now stimulate living insects to induce user-desired motor actions and behaviors. To improve the practicality and applicability of airborne cyborg insects, a reliable and controllable flight initiation protocol is required. This study demonstrates an electrical stimulation protocol that initiates flight in a beetle (Mecynorrhina torquata, Coleoptera). A reliable stimulation protocol was determined by analyzing a pair of dorsal longitudinal muscles (DLMs), flight muscles that oscillate the wings. DLM stimulation has achieved with a high success rate (> 90%), rapid response time (< 1.0 s), and small variation (< 0.33 s; indicating little habituation). Notably, the stimulation of DLMs caused no crucial damage to the free flight ability. In contrast, stimulation of optic lobes, which was earlier demonstrated as a successful flight initiation protocol, destabilized the beetle in flight. Thus, DLM stimulation is a promising secure protocol for inducing flight in cyborg insects or biobots. PMID:27050093

  5. Electrical Stimulation of Coleopteran Muscle for Initiating Flight

    PubMed Central

    Choo, Hao Yu; Li, Yao; Cao, Feng; Sato, Hirotaka

    2016-01-01

    Some researchers have long been interested in reconstructing natural insects into steerable robots or vehicles. However, until recently, these so-called cyborg insects, biobots, or living machines existed only in science fiction. Owing to recent advances in nano/micro manufacturing, data processing, and anatomical and physiological biology, we can now stimulate living insects to induce user-desired motor actions and behaviors. To improve the practicality and applicability of airborne cyborg insects, a reliable and controllable flight initiation protocol is required. This study demonstrates an electrical stimulation protocol that initiates flight in a beetle (Mecynorrhina torquata, Coleoptera). A reliable stimulation protocol was determined by analyzing a pair of dorsal longitudinal muscles (DLMs), flight muscles that oscillate the wings. DLM stimulation has achieved with a high success rate (> 90%), rapid response time (< 1.0 s), and small variation (< 0.33 s; indicating little habituation). Notably, the stimulation of DLMs caused no crucial damage to the free flight ability. In contrast, stimulation of optic lobes, which was earlier demonstrated as a successful flight initiation protocol, destabilized the beetle in flight. Thus, DLM stimulation is a promising secure protocol for inducing flight in cyborg insects or biobots. PMID:27050093

  6. Classification of methods in transcranial electrical stimulation (tES) and evolving strategy from historical approaches to contemporary innovations.

    PubMed

    Guleyupoglu, Berkan; Schestatsky, Pedro; Edwards, Dylan; Fregni, Felipe; Bikson, Marom

    2013-10-15

    Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES. PMID:23954780

  7. Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

    PubMed Central

    Guleyupoglu, Berkan; Schestatsky, Pedro; Edwards, Dylan; Fregni, Felipe; Bikson, Marom

    2013-01-01

    Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of trans-cranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES. PMID:23954780

  8. Deep brain stimulation abolishes slowing of reactions to unlikely stimuli.

    PubMed

    Antoniades, Chrystalina A; Bogacz, Rafal; Kennard, Christopher; FitzGerald, James J; Aziz, Tipu; Green, Alexander L

    2014-08-13

    The cortico-basal-ganglia circuit plays a critical role in decision making on the basis of probabilistic information. Computational models have suggested how this circuit could compute the probabilities of actions being appropriate according to Bayes' theorem. These models predict that the subthalamic nucleus (STN) provides feedback that normalizes the neural representation of probabilities, such that if the probability of one action increases, the probabilities of all other available actions decrease. Here we report the results of an experiment testing a prediction of this theory that disrupting information processing in the STN with deep brain stimulation should abolish the normalization of the neural representation of probabilities. In our experiment, we asked patients with Parkinson's disease to saccade to a target that could appear in one of two locations, and the probability of the target appearing in each location was periodically changed. When the stimulator was switched off, the target probability affected the reaction times (RT) of patients in a similar way to healthy participants. Specifically, the RTs were shorter for more probable targets and, importantly, they were longer for the unlikely targets. When the stimulator was switched on, the patients were still faster for more probable targets, but critically they did not increase RTs as the target was becoming less likely. This pattern of results is consistent with the prediction of the model that the patients on DBS no longer normalized their neural representation of prior probabilities. We discuss alternative explanations for the data in the context of other published results. PMID:25122887

  9. The stimulated social brain: effects of transcranial direct current stimulation on social cognition.

    PubMed

    Sellaro, Roberta; Nitsche, Michael A; Colzato, Lorenza S

    2016-04-01

    Transcranial direct current stimulation (tDCS) is an increasingly popular noninvasive neuromodulatory tool in the fields of cognitive and clinical neuroscience and psychiatry. It is an inexpensive, painless, and safe brain-stimulation technique that has proven to be effective in modulating cognitive and sensory-perceptual functioning in healthy individuals and clinical populations. Importantly, recent findings have shown that tDCS may also be an effective and promising tool for probing the neural mechanisms of social cognition. In this review, we present the state-of-the-art of the field of tDCS research in social cognition. By doing so, we aim to gather knowledge of the potential of tDCS to modulate social functioning and social decision making in healthy humans, and to inspire future research investigations. PMID:27206250

  10. Comparing neural response to painful electrical stimulation with functional MRI at 3 and 7 T.

    PubMed

    Hahn, Andreas; Kranz, Georg S; Seidel, Eva-Maria; Sladky, Ronald; Kraus, Christoph; Küblböck, Martin; Pfabigan, Daniela M; Hummer, Allan; Grahl, Arvina; Ganger, Sebastian; Windischberger, Christian; Lamm, Claus; Lanzenberger, Rupert

    2013-11-15

    Progressing from 3T to 7 T functional MRI enables marked improvements of human brain imaging in vivo. Although direct comparisons demonstrated advantages concerning blood oxygen level dependent (BOLD) signal response and spatial specificity, these mostly focused on single brain regions with rather simple tasks. Considering that physiological noise also increases with higher field strength, it is not entirely clear whether the advantages of 7T translate equally to the entire brain during tasks which elicit more complex neuronal processing. Therefore, we investigated the difference between 3T and 7 T in response to transcutaneous electrical painful and non-painful stimulation in 22 healthy subjects. For painful stimuli vs. baseline, stronger activations were observed at 7 T in several brain regions including the insula and supplementary motor area, but not the secondary somatosensory cortex (p<0.05 FWE-corrected). Contrasting painful vs. non-painful stimulation limited the differences between the field strengths to the periaqueductal gray (PAG, p<0.001 uncorrected) due to a similar signal increase at 7 T for both the target and specific control condition in most brain regions. This regional specificity obtained for the PAG at higher field strengths was confirmed by an additional spatial normalization strategy optimized for the brainstem. Here, robust BOLD responses were obtained in the dorsal PAG at 7 T (p<0.05 FWE-corrected), whereas at 3T activation was completely missing for the contrast against non-painful stimuli. To summarize, our findings support previously reported benefits obtained at ultra-high field strengths also for complex activation patterns elicited by painful electrical stimulation. However, this advantage depends on the region and even more on the contrast of interest. The greatest gain at 7 T was observed within the small brainstem region of the PAG, where the increased field strength offered marked improvement for the localization of activation

  11. Fast multigrid-based computation of the induced electric field for transcranial magnetic stimulation.

    PubMed

    Laakso, Ilkka; Hirata, Akimasa

    2012-12-01

    In transcranial magnetic stimulation (TMS), the distribution of the induced electric field, and the affected brain areas, depends on the position of the stimulation coil and the individual geometry of the head and brain. The distribution of the induced electric field in realistic anatomies can be modelled using computational methods. However, existing computational methods for accurately determining the induced electric field in realistic anatomical models have suffered from long computation times, typically in the range of tens of minutes or longer. This paper presents a matrix-free implementation of the finite-element method with a geometric multigrid method that can potentially reduce the computation time to several seconds or less even when using an ordinary computer. The performance of the method is studied by computing the induced electric field in two anatomically realistic models. An idealized two-loop coil is used as the stimulating coil. Multiple computational grid resolutions ranging from 2 to 0.25 mm are used. The results show that, for macroscopic modelling of the electric field in an anatomically realistic model, computational grid resolutions of 1 mm or 2 mm appear to provide good numerical accuracy compared to higher resolutions. The multigrid iteration typically converges in less than ten iterations independent of the grid resolution. Even without parallelization, each iteration takes about 1.0 s or 0.1 s for the 1 and 2 mm resolutions, respectively. This suggests that calculating the electric field with sufficient accuracy in real time is feasible. PMID:23128377

  12. Direct-current electrical stimulation of tendon healing in vitro

    SciTech Connect

    Nessler, J.P.; Mass, D.P.

    1987-04-01

    The intrinsic capacity of tendons to heal in response to injury has recently been demonstrated by many investigators. Electrical stimulation is often assumed to augment regeneration of various tissues. Using newly developed methods of whole-tendon culture, the authors examined the effect of direct-current electricity on healing in vitro. Deep flexor tendons of rabbits were excised, transected, repaired, and grown in an acellular culture medium for seven, 14, 21, or 42 days. Tendons through which a continuous 7-microAmp current was passed at the repair site were compared with nonstimulated controls. The incorporation of (/sup 14/C)proline and its conversion to (/sup 14/C)hydroxyproline was measured at seven days. The mean (/sup 14/C)proline and (/sup 14/C)hydroxyproline activities were 91% and 255% greater, respectively, in the stimulated group. The activity was also higher in the stimulated group, by 42 days. Histologic sections showed that intrinsic tenoblastic repair may be enhanced with electrical stimulation in vitro.

  13. Remote electrical stimulation by means of implanted rectifiers.

    PubMed

    Ivorra, Antoni

    2011-01-01

    Miniaturization of active implantable medical devices is currently compromised by the available means for electrically powering them. Most common energy supply techniques for implants--batteries and inductive couplers--comprise bulky parts which, in most cases, are significantly larger than the circuitry they feed. Here, for overcoming such miniaturization bottleneck in the case of implants for electrical stimulation, it is proposed to make those implants act as rectifiers of high frequency bursts supplied by remote electrodes. In this way, low frequency currents will be generated locally around the implant and these low frequency currents will perform stimulation of excitable tissues whereas the high frequency currents will cause only innocuous heating. The present study numerically demonstrates that low frequency currents capable of stimulation can be produced by a miniature device behaving as a diode when high frequency currents, neither capable of thermal damage nor of stimulation, flow through the tissue where the device is implanted. Moreover, experimental evidence is provided by an in vivo proof of concept model consisting of an anesthetized earthworm in which a commercial diode was implanted. With currently available microelectronic techniques, very thin stimulation capsules (diameter <500 µm) deliverable by injection are easily conceivable. PMID:21850274

  14. Toward an implantable functional electrical stimulation device to correct strabismus

    PubMed Central

    Velez, Federico G.; Isobe, Jun; Zealear, David; Judy, Jack W.; Edgerton, V. Reggie; Patnode, Stephanie; Lee, Hyowon; Hahn, Brian T.

    2010-01-01

    PURPOSE To investigate the feasibility of electrically stimulating the lateral rectus muscle to recover its physiologic abduction ability in cases of complete sixth cranial (abducens) nerve palsy. METHODS In the feline lateral rectus muscle model, the effects of a charge-balanced, biphasic, current-controlled stimulus on the movement of the eye were investigated while stimulation frequency, amplitude, and pulse duration was varied. Eye deflection was measured with a force transducer. Denervated conditions were simulated by injection of botulinum toxin A. RESULTS Three chemically denervated and 4 control lateral rectus muscles were analyzed. In control lateral rectus muscles, the minimum fusion frequency was approximately 170 Hz, and the maximum evoked abduction was 27°. The minimum fusion frequency was unchanged after 4 weeks of chemical denervation. Stimulation of chemically denervated lateral rectus muscle resulted in 17° of abduction. For both innervated and chemically denervated lateral rectus muscle, frequencies greater than 175 Hz yielded very little increase in abduction. Modulating amplitude produced noticeable movement throughout the tested range (0.2 to 9 mA). CONCLUSIONS Results from the feline lateral rectus muscle showed that electrical stimulation is a feasible approach to evoke a contraction from a denervated lateral rectus muscle. The degree of denervation of the feline lateral rectus muscle was indeterminate. Varying the stimulation amplitude allowed greater eye movement. It is very likely that both frequency and amplitude must be modulated for finer control of static eye position. PMID:19375369

  15. Remote Electrical Stimulation by Means of Implanted Rectifiers

    PubMed Central

    Ivorra, Antoni

    2011-01-01

    Miniaturization of active implantable medical devices is currently compromised by the available means for electrically powering them. Most common energy supply techniques for implants – batteries and inductive couplers – comprise bulky parts which, in most cases, are significantly larger than the circuitry they feed. Here, for overcoming such miniaturization bottleneck in the case of implants for electrical stimulation, it is proposed to make those implants act as rectifiers of high frequency bursts supplied by remote electrodes. In this way, low frequency currents will be generated locally around the implant and these low frequency currents will perform stimulation of excitable tissues whereas the high frequency currents will cause only innocuous heating. The present study numerically demonstrates that low frequency currents capable of stimulation can be produced by a miniature device behaving as a diode when high frequency currents, neither capable of thermal damage nor of stimulation, flow through the tissue where the device is implanted. Moreover, experimental evidence is provided by an in vivo proof of concept model consisting of an anesthetized earthworm in which a commercial diode was implanted. With currently available microelectronic techniques, very thin stimulation capsules (diameter <500 µm) deliverable by injection are easily conceivable. PMID:21850274

  16. Electrical Stimulation Elicits Neural Stem Cells Activation: New Perspectives in CNS Repair

    PubMed Central

    Huang, Yanhua; Li, YeE; Chen, Jian; Zhou, Hongxing; Tan, Sheng

    2015-01-01

    Researchers are enthusiastically concerned about neural stem cell (NSC) therapy in a wide array of diseases, including stroke, neurodegenerative disease, spinal cord injury, and depression. Although enormous evidences have demonstrated that neurobehavioral improvement may benefit from NSC-supporting regeneration in animal models, approaches to endogenous and transplanted NSCs are blocked by hurdles of migration, proliferation, maturation, and integration of NSCs. Electrical stimulation (ES) may be a selective non-drug approach for mobilizing NSCs in the central nervous system. This technique is suitable for clinical application, because it is well established and its potential complications are manageable. Here, we provide a comprehensive review of the emerging positive role of different electrical cues in regulating NSC biology in vitro and in vivo, as well as biomaterial-based and chemical stimulation of NSCs. In the future, ES combined with stem cell therapy or other cues probably becomes an approach for promoting brain repair. PMID:26539102

  17. Electrical stimulation of primary neonatal rat ventricular cardiomyocytes using pacemakers.

    PubMed

    Martherus, Ruben S R M; Zeijlemaker, Volkert A; Ayoubi, Torik A Y

    2010-01-01

    The study of gene regulation in cardiac myocytes requires a reliable in vitro model. However, monolayer cultures used for this purpose are typically not exposed to electrical stimulation, though this has been shown to strongly affect cardiomyocyte gene expression. Based on pacemakers for clinical use, we developed an easy-to-use portable system that allows the user to perform electro-stimulation of cardiomyocyte cultures in standard tissue incubators without the need for bulky equipment. In addition, we present a refined protocol for culturing high-purity cardiomyocyte cultures with excellent contractile properties for a wide variety of applications. PMID:20078430

  18. Computational modeling of pedunculopontine nucleus deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Zitella, Laura M.; Mohsenian, Kevin; Pahwa, Mrinal; Gloeckner, Cory; Johnson, Matthew D.

    2013-08-01

    Objective. Deep brain stimulation (DBS) near the pedunculopontine nucleus (PPN) has been posited to improve medication-intractable gait and balance problems in patients with Parkinson's disease. However, clinical studies evaluating this DBS target have not demonstrated consistent therapeutic effects, with several studies reporting the emergence of paresthesia and oculomotor side effects. The spatial and pathway-specific extent to which brainstem regions are modulated during PPN-DBS is not well understood. Approach. Here, we describe two computational models that estimate the direct effects of DBS in the PPN region for human and translational non-human primate (NHP) studies. The three-dimensional models were constructed from segmented histological images from each species, multi-compartment neuron models and inhomogeneous finite element models of the voltage distribution in the brainstem during DBS. Main Results. The computational models predicted that: (1) the majority of PPN neurons are activated with -3 V monopolar cathodic stimulation; (2) surgical targeting errors of as little as 1 mm in both species decrement activation selectivity; (3) specifically, monopolar stimulation in caudal, medial, or anterior PPN activates a significant proportion of the superior cerebellar peduncle (up to 60% in the human model and 90% in the NHP model at -3 V) (4) monopolar stimulation in rostral, lateral or anterior PPN activates a large percentage of medial lemniscus fibers (up to 33% in the human model and 40% in the NHP model at -3 V) and (5) the current clinical cylindrical electrode design is suboptimal for isolating the modulatory effects to PPN neurons. Significance. We show that a DBS lead design with radially-segmented electrodes may yield improved functional outcome for PPN-DBS.

  19. Modulation of Human Time Processing by Subthalamic Deep Brain Stimulation

    PubMed Central

    Timmermann, Lars; Reck, Christiane; Maarouf, Mohammad; Jörgens, Silke; Ploner, Markus; Südmeyer, Martin; Groiss, Stefan Jun; Sturm, Volker; Niedeggen, Michael; Schnitzler, Alfons

    2011-01-01

    Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsońs disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≥130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≥130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds. PMID:21931767

  20. Neurodoping: brain stimulation as a performance-enhancing measure.

    PubMed

    Davis, Nick J

    2013-08-01

    Doping may be defined, broadly, as the use of unauthorised means to increase performance in sport. Doping is most commonly associated with the use of drugs. In this paper, I discuss the use of emerging techniques for the modulation of brain activity in healthy people using electric or magnetic fields, and suggest how they might be used to enhance physical and mental performance in sports. I will suggest that neurodoping may have different uses in different sports, and I argue that each sport must determine whether neurodoping should be considered as cheating, or should be considered a legitimate aid to training or performance. PMID:23504390

  1. Electrical stimulation of the parabrachial nucleus induces reanimation from isoflurane general anesthesia.

    PubMed

    Muindi, Fanuel; Kenny, Jonathan D; Taylor, Norman E; Solt, Ken; Wilson, Matthew A; Brown, Emery N; Van Dort, Christa J

    2016-06-01

    Clinically, emergence from general anesthesia is viewed as a passive process where anesthetics are discontinued at the end of surgery and anesthesiologists wait for the drugs to wear off. The mechanisms involved in emergence are not well understood and there are currently no drugs that can actively reverse the state of general anesthesia. An emerging hypothesis states that brain regions that control arousal become active during emergence and are a key part of the return to wakefulness. In this study, we tested the hypothesis that electrical activation of the glutamatergic parabrachial nucleus (PBN) in the brainstem is sufficient to induce reanimation (active emergence) during continuous isoflurane general anesthesia. Using c-Fos immunohistochemistry as a marker of neural activity, we first show a selective increase in active neurons in the PBN during passive emergence from isoflurane anesthesia. We then electrically stimulated the PBN to assess whether it is sufficient to induce reanimation from isoflurane general anesthesia. Stimulation induced behavioral arousal and restoration of the righting reflex during continuous isoflurane general anesthesia. In contrast, stimulation of the nearby central inferior colliculus (CIC) did not restore the righting reflex. Spectral analysis of the electroencephalogram (EEG) revealed that stimulation produced a significant decrease in EEG delta power during PBN stimulation. The results are consistent with the hypothesis that the PBN provides critical arousal input during emergence from isoflurane anesthesia. PMID:26971629

  2. Deep brain stimulation (DBS) at the interface of neurology and psychiatry

    PubMed Central

    Williams, Nolan R.; Okun, Michael S.

    2013-01-01

    Deep brain stimulation (DBS) is an emerging interventional therapy for well-screened patients with specific treatment-resistant neuropsychiatric diseases. Some neuropsychiatric conditions, such as Parkinson disease, have available and reasonable guideline and efficacy data, while other conditions, such as major depressive disorder and Tourette syndrome, have more limited, but promising results. This review summarizes both the efficacy and the neuroanatomical targets for DBS in four common neuropsychiatric conditions: Parkinson disease, Tourette syndrome, major depressive disorder, and obsessive-compulsive disorder. Based on emerging new research, we summarize novel approaches to optimization of stimulation for each neuropsychiatric disease and we review the potential positive and negative effects that may be observed following DBS. Finally, we summarize the likely future innovations in the field of electrical neural-network modulation. PMID:24177464

  3. MRI-Related Heating near Deep Brain Stimulation Electrodes: More Data Are Needed

    PubMed Central

    Gupte, Akshay A.; Shrivastava, Devashish; Spaniol, Maggie A.; Abosch, Aviva

    2011-01-01

    Magnetic resonance imaging (MRI) of patients with implanted deep brain stimulation (DBS) devices poses a challenge for healthcare providers. As a consequence of safety concerns about magnetic field interactions with the device, induced electrical currents and thermal damage due to radiofrequency heating, a number of stringent guidelines have been proposed by the device manufacturer. Very few detailed investigations of these safety issues have been published to date, and the stringent manufacturer guidelines have gone unchallenged, leading some hospitals and imaging centers around the world to ban or restrict the use of MRI in DBS patients. The purpose of this review is to stimulate research towards defining appropriate guidelines for the use of MRI in patients with DBS. Additionally, this review is intended to help healthcare providers and researchers make sound clinical judgments about the use of MRI in the setting of implanted DBS devices. PMID:21494064

  4. Electrical Stimulation of Visual Cortex Can Immediately Improve Spatial Vision.

    PubMed

    Reinhart, Robert M G; Xiao, Wenxi; McClenahan, Laura J; Woodman, Geoffrey F

    2016-07-25

    We can improve human vision by correcting the optics of our lenses [1-3]. However, after the eye transduces the light, visual cortex has its own limitations that are challenging to correct [4]. Overcoming these limitations has typically involved innovative training regimes that improve vision across many days [5, 6]. In the present study, we wanted to determine whether it is possible to immediately improve the precision of spatial vision with noninvasive direct-current stimulation. Previous work suggested that visual processing could be modulated with such stimulation [7-9]. However, the short duration and variability of such effects made it seem unlikely that spatial vision could be improved for more than several minutes [7, 10]. Here we show that visual acuity in the parafoveal belt can be immediately improved by delivering noninvasive direct current to visual cortex. Twenty minutes of anodal stimulation improved subjects' vernier acuity by approximately 15% and increased the amplitude of the earliest visually evoked potentials in lockstep with the behavioral effects. When we reversed the orientation of the electric field, we impaired resolution and reduced the amplitude of visually evoked potentials. Next, we found that anodal stimulation improved acuity enough to be measurable with the relatively coarse Snellen test and that subjects with the poorest acuity benefited the most from stimulation. Finally, we found that stimulation-induced acuity improvements were accompanied by changes in contrast sensitivity at high spatial frequencies. PMID:27374337

  5. Electrical stimulation for pressure sore prevention and wound healing.

    PubMed

    Bogie, K M; Reger, S I; Levine, S P; Sahgal, V

    2000-01-01

    This paper reviews applications of therapeutic electrical stimulation (ES) specific to wound healing and pressure sore prevention. The application of ES for wound healing has been found to increase the rate of healing by more than 50%. Furthermore, the total number of wounds healed is also increased. However, optimal delivery techniques for ES therapy have not been established to date. A study of stimulation current effects on wound healing in a pig model has shown that direct current (DC) stimulation is most effective in wound area reduction and alternating current (AC) stimulation for wound volume reduction at current densities of 127 microA/cm2 and 1,125 microA/cm2, respectively. Preliminary studies have been carried out at two research centers to assess the role of ES in pressure sore prevention. Surface stimulation studies have shown that ES can produce positive short-term changes in tissue health variables such as regional blood flow and pressure distribution. The use of an implanted stimulation system consisting of intramuscular electrodes with percutaneous leads has been found to produce additional long-term changes. Specifically, gluteal muscle thickness increased by 50% with regular long-term ES application concurrent with a 20% decrease in regional interface pressures and increased tissue oxygen levels. These findings indicate that an implantable ES system may have great potential for pressure sore prevention, particularly for individuals who lack sensation or who are physically unable to perform regular independent pressure relief. PMID:11067577

  6. Transcranial magnetic stimulation and brain atrophy: a computer-based human brain model study

    PubMed Central

    Eden, Uri; Fregni, Felipe; Valero-Cabre, Antoni; Ramos-Estebanez, Ciro; Pronio-Stelluto, Valerie; Grodzinsky, Alan; Zahn, Markus; Pascual-Leone, Alvaro

    2012-01-01

    This paper is aimed at exploring the effect of cortical brain atrophy on the currents induced by transcranial magnetic stimulation (TMS). We compared the currents induced by various TMS conditions on several different MRI derived finite element head models of brain atrophy, incorporating both decreasing cortical volume and widened sulci. The current densities induced in the cortex were dependent upon the degree and type of cortical atrophy and were altered in magnitude, location, and orientation when compared to healthy head models. Predictive models of the degree of current density attenuation as a function of the scalp-to-cortex distance were analyzed, concluding that those which ignore the electromagnetic field–tissue interactions lead to inaccurate conclusions. Ultimately, the precise site and population of neural elements stimulated by TMS in an atrophic brain cannot be predicted based on healthy head models which ignore the effects of the altered cortex on the stimulating currents. Clinical applications of TMS should be carefully considered in light of these findings. PMID:18193208

  7. Neuromuscular Electrical Stimulation for Mobility Support of Elderly

    PubMed Central

    2015-01-01

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within “MOBIL” we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in “compliance data storage” as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  8. Neuromuscular Electrical Stimulation for Mobility Support of Elderly.

    PubMed

    Mayr, Winfried

    2015-08-24

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in "compliance data storage" as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  9. Understanding the biophysical effects of transcranial magnetic stimulation on brain tissue: the bridge between brain stimulation and cognition.

    PubMed

    Neggers, Sebastiaan F W; Petrov, Petar I; Mandija, Stefano; Sommer, Iris E C; van den Berg, Nico A T

    2015-01-01

    Transcranial magnetic stimulation (TMS) is rapidly being adopted in neuroscience, medicine, psychology, and biology, for basic research purposes, diagnosis, and therapy. However, a coherent picture of how TMS affects neuronal processing, and especially how this in turn influences behavior, is still largely unavailable despite several studies that investigated aspects of the underlying neurophysiological effects of TMS. Perhaps as a result from this "black box approach," TMS studies show a large interindividual variability in applied paradigms and TMS treatment outcome can be quite variable, hampering its general efficacy and introduction into the clinic. A better insight into the biophysical, neuronal, and cognitive mechanisms underlying TMS is crucial in order to apply it effectively in the clinic and to increase our understanding of brain-behavior relationship. Therefore, computational and experimental efforts have been started recently to understand and control the effect TMS has on neuronal functioning. Especially, how the brain shapes magnetic fields induced by a TMS coil, how currents are generated locally in the cortical surface, and how they interact with complex functional neuronal circuits within and between brain areas are crucial to understand the observed behavioral changes and potential therapeutic effects resulting from TMS. Here, we review the current knowledge about the biophysical underpinnings of single-pulse TMS and argue how to move forward to fully understand and exploit the powerful technique that TMS can be. PMID:26541383

  10. Psychophysics of electrical stimulation of striate cortex in macaques.

    PubMed

    Bartlett, John R; DeYoe, Edgar A; Doty, Robert W; Lee, Barry B; Lewine, Jeffrey D; Negrão, Nubio; Overman, William H

    2005-11-01

    Macaques indicated their detection of onset or alteration of 0.2-ms pulses applied in various configurations through electrodes implanted in striate cortex. When microelectrodes were introduced and left in place, the threshold for detection of 100-Hz pulses nearly doubled within 24 h. However, for chronically implanted platinum-alloy macroelectrodes detection thresholds usually remained stable for many months, independently of location within striate cortex or its immediately subjacent white matter. Thresholds were unaffected by the visual conditions, such as light versus darkness, or movement of the eyes; but in one animal blind after acute glaucoma thresholds for loci in striate cortex were permanently decreased by about 50%. Learning to respond to electrical stimulation of the optic tract produced no tendency to respond to such stimulation of striate cortex. Onset of stimulation at a given locus could be detected even in the face of continuous supraliminal stimulation at four surrounding loci on a 3-mm radius. The surround stimulation did alter the threshold of the central locus, but such stimuli could not summate if they were subliminal by some 10%. Cessation of stimulation that had been continuing for 1 min to 1 h could be detected if it were being applied at a level 20-75% above that needed for detection of stimulus onset. Continuous stimulation had a pronounced "priming" effect, in that modulation of frequency or intensity of such stimulation by as little as 5% could be detected (e.g., 20 microA in a background of 500 microA, or <2-ms interpulse interval with pulses at 50 Hz). Using pulses inserted in various phase relations to ongoing pulses at 2-5 Hz, it could be determined that stimulus pulses were surrounded by a strong facilitatory period for about 30 ms, which was then replaced by refractoriness. Given the congruence of macaque and human visual anatomy and psychophysics, these results further encourage efforts to develop a cortical prosthesis for the

  11. Investigation into Deep Brain Stimulation Lead Designs: A Patient-Specific Simulation Study.

    PubMed

    Alonso, Fabiola; Latorre, Malcolm A; Göransson, Nathanael; Zsigmond, Peter; Wårdell, Karin

    2016-01-01

    New deep brain stimulation (DBS) electrode designs offer operation in voltage and current mode and capability to steer the electric field (EF). The aim of the study was to compare the EF distributions of four DBS leads at equivalent amplitudes (3 V and 3.4 mA). Finite element method (FEM) simulations (n = 38) around cylindrical contacts (leads 3389, 6148) or equivalent contact configurations (leads 6180, SureStim1) were performed using homogeneous and patient-specific (heterogeneous) brain tissue models. Steering effects of 6180 and SureStim1 were compared with symmetric stimulation fields. To make relative comparisons between simulations, an EF isolevel of 0.2 V/mm was chosen based on neuron model simulations (n = 832) applied before EF visualization and comparisons. The simulations show that the EF distribution is largely influenced by the heterogeneity of the tissue, and the operating mode. Equivalent contact configurations result in similar EF distributions. In steering configurations, larger EF volumes were achieved in current mode using equivalent amplitudes. The methodology was demonstrated in a patient-specific simulation around the zona incerta and a "virtual" ventral intermediate nucleus target. In conclusion, lead design differences are enhanced when using patient-specific tissue models and current stimulation mode. PMID:27618109

  12. Clinical application of neuromuscular electrical stimulation induced cardiovascular exercise.

    PubMed

    Caulfield, Brian; Crowe, Louis; Coughlan, Garrett; Minogue, Conor

    2011-01-01

    We need to find novel ways of increasing exercise participation, particularly in those populations who find it difficult to participate in voluntary exercise. In recent years researchers have started to investigate the potential for using electrical stimulation to artificially stimulate a pattern of muscle activity that would induce a physiological response consistent with cardiovascular exercise. Work to date has indicated that this is best achieved by using a stimulation protocol that results in rapid rhythmical isometric contractions of the large leg muscle groups at sub tetanic frequencies. Studies completed by our group indicate that this technique can serve as a viable alternative to voluntary cardiovascular exercise. Apart from being able to induce a cardiovascular exercise effect in patient populations (e.g. heart failure, COPD, spinal cord injury, obesity), this approach may also have value in promotion of exercise activity in a microgravity environment. PMID:22255036

  13. A programmable system of functional electrical stimulation (FES).

    PubMed

    Velloso, J B; Souza, M N

    2007-01-01

    The development of a novel system intended to perform functional electrical stimulation (FES) is presented. A virtual instrument developed in Labview communicates with a PC through USB and controls the hardware compound of analog and digital circuits. The block diagram of the hardware and the main characteristics of the virtual instrument are presented, as well the results of the electrical safety tests and the errors associated to the programmed and real values of the amplitude, pulse width and frequency of the output current. The results point the equipment can be used in the therapy of paraplegic patients maintaining safety limits reported in the literature. PMID:18002435

  14. Clinical applications of electrical stimulation after spinal cord injury.

    PubMed

    Creasey, Graham H; Ho, Chester H; Triolo, Ronald J; Gater, David R; DiMarco, Anthony F; Bogie, Kath M; Keith, Michael W

    2004-01-01

    During the last one-half century, electrical stimulation has become clinically significant for improving health and restoring useful function after spinal cord injury. Short-term stimulation can be provided by electrodes on the skin or percutaneous fine wires, but implanted systems are preferable for long-term use. Electrical stimulation of intact lower motor neurons can exercise paralyzed muscles and reverse wasting; improve strength, endurance, and cardiovascular fitness; and may reduce the progression of osteoporosis. Other potential therapeutic uses being investigated include reduction of spasticity, prevention of deep vein thrombosis, and improvement of tissue health. Pacing of intact phrenic nerves in high tetraplegia can produce effective respiration without mechanical ventilation, allowing improved speech, increased mobility, and increased sense of well-being. Improvement of cough has also been demonstrated. Stimulation of intact sacral nerves can produce effective micturition and reduce urinary tract infection; it can also improve bowel function and erection. It is usually combined with posterior sacral rhizotomy to improve continence and bladder capacity, and the combination has been shown to reduce costs of care. Electroejaculation can now produce semen in most men with spinal cord injury. Significant achievements have also been made in restoring limb function. Useful hand grasp can be provided in C5 and C6 tetraplegia, reducing dependence on adapted equipment and assistants. Standing, assistance with transfers, and walking for short distances can be provided to selected persons with paraplegia, improving their access to objects, places, and opportunities that are inaccessible from a wheelchair. This review summarizes the current state of therapeutic and neuroprosthetic applications of electrical stimulation after spinal cord injury and identifies some future directions of research and clinical and commercial development. PMID:15484667

  15. Deep brain stimulation for Parkinson's disease using frameless technology.

    PubMed

    Cheng, Chun-Yuan; Hsing, Ming-Tai; Chen, Yung-Hsiang; Wu, Sey-Lin; Sy, Hiu Ngar; Chen, Chien-Min; Yang, Yu-Jen; Lee, Meng-Chih

    2014-06-01

    Historically deep brain stimulation (DBS) for Parkinson's disease (PD) has been performed by frame-based stereotaxy. However, recently the option of frameless stereotaxy has become available. This avoids the potential discomfort the patient may experience because of the frame fixed to the head. This study compared clinical outcomes of DBS performed using frame-based and frameless procedures for PD patients. Twelve patients underwent DBS operations; from these patients, six underwent frame-based and six underwent frameless DBS operations, and assessed 6 months later. Operation time, subthalamic electrode contact length, microelectrode recording (MER) tracts, and unified PD rating scale scores were evaluated and the scores were compared. This small study found no differences between frameless or frame based DBS, and concludes that framless system maybe an acceptable alternative. PMID:24138684

  16. Clustered Desynchronization from High-Frequency Deep Brain Stimulation

    PubMed Central

    Wilson, Dan; Moehlis, Jeff

    2015-01-01

    While high-frequency deep brain stimulation is a well established treatment for Parkinson’s disease, its underlying mechanisms remain elusive. Here, we show that two competing hypotheses, desynchronization and entrainment in a population of model neurons, may not be mutually exclusive. We find that in a noisy group of phase oscillators, high frequency perturbations can separate the population into multiple clusters, each with a nearly identical proportion of the overall population. This phenomenon can be understood by studying maps of the underlying deterministic system and is guaranteed to be observed for small noise strengths. When we apply this framework to populations of Type I and Type II neurons, we observe clustered desynchronization at many pulsing frequencies. PMID:26713619

  17. Anesthetic Challenges for Deep Brain Stimulation: A Systematic Approach

    PubMed Central

    Chakrabarti, Rajkalyan; Ghazanwy, Mahmood; Tewari, Anurag

    2014-01-01

    Ablative intracranial surgery for Parkinson's disease has advanced to embedding electrodes into precise areas of the basal ganglia. Electrode implantation surgery, referred to as deep brain stimulation (DBS), is preferred in view of its reversibility, adjustability, and capability to be safely performed bilaterally. DBS is been increasingly used for other movement disorders, intractable tremors epilepsy, and sometimes chronic pain. Anesthesiologists need to amalgamate the knowledge of neuroanatomical structures and surgical techniques involved in placement of microelectrodes in defined cerebral target areas. Perioperative verbal communication with the patient during the procedure is quintessential and may attenuate the need for pharmacological agents. This review will endeavor to assimilate the present knowledge regarding the patient selection, available/practiced anesthesia regimens, and perioperative complications after our thorough search for literature published between 1991 and 2013. PMID:25210668

  18. Dystonia and the Role of Deep Brain Stimulation

    PubMed Central

    Ellis, Thomas L.

    2011-01-01

    Dystonia is a painful, disabling disease whose cause in many cases remains unknown. It has historically been treated with a variety methodologies including baclofen pumps, Botox injection, peripheral denervation, and stereotactic surgery. Deep brain stimulation (DBS) is emerging as a viable treatment option for selected patients with dystonia. Results of DBS for dystonia appear to be more consistently superior in patients with primary versus secondary forms of the disorder. Patients with secondary dystonia, due to a variety of causes, may still be candidates for DBS surgery, although the results may not be as consistently good. The procedure is relatively safe with a small likelihood of morbidity and mortality. A randomized trial is needed to determine who are the best patients and when it is best to proceed with surgery. PMID:22084748

  19. Effects of thalamic deep brain stimulation on spontaneous language production.

    PubMed

    Ehlen, Felicitas; Vonberg, Isabelle; Kühn, Andrea A; Klostermann, Fabian

    2016-08-01

    The thalamus is thought to contribute to language-related processing, but specifications of this notion remain vague. An assessment of potential effects of thalamic deep brain stimulation (DBS) on spontaneous language may help to delineate respective functions. For this purpose, we analyzed spontaneous language samples from thirteen (six female / seven male) patients with essential tremor treated with DBS of the thalamic ventral intermediate nucleus (VIM) in their respective ON vs. OFF conditions. Samples were obtained from semi-structured interviews and examined on multidimensional linguistic levels. In the VIM-DBS ON condition, participants used a significantly higher proportion of paratactic as opposed to hypotactic sentence structures. This increase correlated negatively with the change in the more global cognitive score, which in itself did not change significantly. In conclusion, VIM-DBS appears to induce the use of a simplified syntactic structure. The findings are discussed in relation to concepts of thalamic roles in language-related cognitive behavior. PMID:27267813

  20. Clustered Desynchronization from High-Frequency Deep Brain Stimulation.

    PubMed

    Wilson, Dan; Moehlis, Jeff

    2015-12-01

    While high-frequency deep brain stimulation is a well established treatment for Parkinson's disease, its underlying mechanisms remain elusive. Here, we show that two competing hypotheses, desynchronization and entrainment in a population of model neurons, may not be mutually exclusive. We find that in a noisy group of phase oscillators, high frequency perturbations can separate the population into multiple clusters, each with a nearly identical proportion of the overall population. This phenomenon can be understood by studying maps of the underlying deterministic system and is guaranteed to be observed for small noise strengths. When we apply this framework to populations of Type I and Type II neurons, we observe clustered desynchronization at many pulsing frequencies. PMID:26713619

  1. Analgesic effects of noninvasive brain stimulation in rodent animal models: A systematic review of translational findings

    PubMed Central

    Volz, Magdalena Sarah; Volz, Theresa Sophie; Brunoni, Andre Russowsky; de Oliveira, João Paulo Vaz Tostes Ribeiro; Fregni, Felipe

    2014-01-01

    Objectives Noninvasive brain stimulation (NIBS) interventions have demonstrated promising results in the clinical treatment of pain, according to several preliminary trials, although the results have been mixed. The limitations of clinical research on NIBS are the insufficient understanding of its mechanisms of action, a lack of adequate safety data, and several disparities with regard to stimulation parameters, which have hindered the generalizability of such studies. Thus, experimental animal research that allows the use of more invasive interventions and creates additional control of independent variables and confounders is desirable. To this end, we systematically reviewed animal studies investigating the analgesic effects of NIBS. In addition we also explored the investigation of NIBS in animal models of stroke as to compare these findings with NIBS animal pain research. Methods Of 1916 articles that were found initially, we identified 15 studies (stroke and pain studies) per our eligibility criteria that used NIBS methods, such as transcranial direct current stimulation (tDCS), paired associative stimulation (PAS), transcranial magnetic stimulation (TMS), and transcranial electrostimulation (TES). We extracted the main outcomes on stroke and pain, as well as the methods and electrical parameters of each technique. Results NIBS techniques are effective in alleviating pain. Similar beneficial clinical effects are observed in stroke. The main insights from these animal studies are: (i) combination of NIBS with analgesic drugs has a synergistic effect; (ii) effects are dependent on the parameters of stimulation, and in fact, not necessarily the strongest stimulation parameter (i.e., the largest intensity of stimulation) is associated with the largest benefit; (iii) pain studies show an overall good quality as indexed by ARRIVE guidelines of the reporting of animal experiments, but insufficient with regard to the reporting of safety data for brain stimulation; (iv

  2. Chaotic Synchronization of Multi-neurons in External Electrical Stimulation.

    PubMed

    Jiang, Wang; Dengbin; Xiangyang, Fei; Feng, Dong

    2005-01-01

    The synchronization of n(n≥3) neurons coupled with gap junction in external electrical stimulation is investigated. In this paper, the coupled model is established on the basis of nonlinear cable model, and then the relation of coupling strength of the gap junction and the synchronization is discussed in detail. The sufficient condition of complete synchronization is attained from rigorously mathematical derivation. The synchronizations of periodic neurons and chaotic neurons are studied respectively. PMID:17282643

  3. A Computational Framework for Electrical Stimulation of Vestibular Nerve.

    PubMed

    Marianelli, Prisca; Capogrosso, Marco; Bassi Luciani, Lorenzo; Panarese, Alessandro; Micera, Silvestro

    2015-09-01

    The vestibular organs are very important to generate reflexes critical for stabilizing gaze and body posture. Vestibular diseases significantly reduce the quality of life of people who are affected by them. Some research groups have recently started developing vestibular neuroprostheses to mitigate these symptoms. However, many scientific and technological issues need to be addressed to optimise their use in clinical trials. We developed a computational model able to mimic the response of human vestibular nerves and which can be exploited for "in-silico" testing of new strategies to design implantable vestibular prostheses. First, a digital model of the vestibular system was reconstructed from anatomical data. Monopolar stimulation was delivered at different positions and distances from ampullary nerves. The electrical potential induced by the injected current was computed through finite-element methods and drove extra-cellular stimulation of fibers in the vestibular, facial, and cochlear nerves. The electrical activity of vestibular nerves and the resulting eye movements elicited by different stimulation protocols were investigated. A set of electrode configurations was analyzed in terms of selectivity at increasing injected current. Electrode position along the nerve plays a major role in producing undesired activity in other nontargeted nerves, whereas distance from the fiber does not significantly affect selectivity. Indications are provided to minimize misalignment in nonoptimal electrode locations. Eye movements elicited by the different stimulation protocols are calculated and compared to experimental values, for the purpose of model validation. PMID:25751868

  4. The Effect of Surface Electrical Stimulation on Vocal Fold Position

    PubMed Central

    Humbert, Ianessa A.; Poletto, Christopher J.; Saxon, Keith G.; Kearney, Pamela R.; Ludlow, Christy L.

    2008-01-01

    Objectives/Hypothesis Closure of the true and false vocal folds is a normal part of airway protection during swallowing. Individuals with reduced or delayed true vocal fold closure can be at risk for aspiration and benefit from intervention to ameliorate the problem. Surface electrical stimulation is currently used during therapy for dysphagia, despite limited knowledge of its physiological effects. Design Prospective single effects study. Methods The immediate physiological effect of surface stimulation on true vocal fold angle was examined at rest in 27 healthy adults using ten different electrode placements on the submental and neck regions. Fiberoptic nasolaryngoscopic recordings during passive inspiration were used to measure change in true vocal fold angle with stimulation. Results Vocal fold angles changed only to a small extent during two electrode placements (p ≤ 0.05). When two sets of electrodes were placed vertically on the neck the mean true vocal fold abduction was 2.4 degrees; while horizontal placements of electrodes in the submental region produced a mean adduction of 2.8 degrees (p=0.03). Conclusions Surface electrical stimulation to the submental and neck regions does not produce immediate true vocal fold adduction adequate for airway protection during swallowing and one position may produce a slight increase in true vocal fold opening. PMID:18043496

  5. Self-Triggered Functional Electrical Stimulation During Swallowing

    PubMed Central

    Burnett, Theresa A.; Mann, Eric A.; Stoklosa, Joseph B.; Ludlow, Christy L.

    2006-01-01

    Hyolaryngeal elevation is essential for airway protection during swallowing and is mainly a reflexive response to oropharyngeal sensory stimulation. Targeted intramuscular electrical stimulation can elevate the resting larynx and, if applied during swallowing, may improve airway protection in dysphagic patients with inadequate hyolaryngeal motion. To be beneficial, patients must synchronize functional electrical stimulation (FES) with their reflexive swallowing and not adapt to FES by reducing the amplitude or duration of their own muscle activity. We evaluated the ability of nine healthy adults to manually synchronize FES with hyolaryngeal muscle activity during discrete swallows, and tested for motor adaptation. Hooked-wire electrodes were placed into the mylo- and thyrohyoid muscles to record electromyographic activity from one side of the neck and deliver monopolar FES for hyolaryngeal elevation to the other side. After performing baseline swallows, volunteers were instructed to trigger FES with a thumb switch in synchrony with their swallows for a series of trials. An experimenter surreptitiously disabled the thumb switch during the final attempt, creating a foil. From the outset, volunteers synchronized FES with the onset of swallow-related thyrohyoid activity (~225 ms after mylohyoid activity onset), preserving the normal sequence of muscle activation. A comparison between average baseline and foil swallows failed to show significant adaptive changes in the amplitude, duration, or relative timing of activity for either muscle, indicating that the central pattern generator for hyolaryngeal elevation is immutable with short term stimulation that augments laryngeal elevation during the reflexive, pharyngeal phase of swallowing. PMID:16107520

  6. A clinical exercise system for paraplegics using functional electrical stimulation.

    PubMed

    Bremner, L A; Sloan, K E; Day, R E; Scull, E R; Ackland, T

    1992-09-01

    A low cost clinical exercise system was developed for the spinal cord injured, based on a bicycle ergometer and electrical stimulation. A pilot project was conducted, using the system, to examine the effects of stimulation induced cycling in long term paraplegics. The project comprised 2 phases of exercise, a strengthening phase involving a 12 week programme of electrical stimulation to the quadriceps and hamstrings and a 12 week cycling phase. Physiological, morphological and biochemical parameters were measured for each subject, at the beginning of the programme and following each phase. Results showed that a programme of stimulation induced lower limb exercise increased the exercise tolerance of all patients, as determined by a progressive increase in exercise time, cycling rate and exercise load. The enhanced exercise tolerance was a result of increases in local muscle strength and endurance. Increases in thigh muscle area and joint range of motion were recorded and all incomplete subjects reported an improvement in functional capabilities and general wellbeing. PMID:1408342

  7. Peripheral electrical stimulation triggered by self-paced detection of motor intention enhances motor evoked potentials.

    PubMed

    Niazi, Imran Khan; Mrachacz-Kersting, Natalie; Jiang, Ning; Dremstrup, Kim; Farina, Dario

    2012-07-01

    This paper proposes the development and experimental tests of a self-paced asynchronous brain-computer interfacing (BCI) system that detects movement related cortical potentials (MRCPs) produced during motor imagination of ankle dorsiflexion and triggers peripheral electrical stimulations timed with the occurrence of MRCPs to induce corticospinal plasticity. MRCPs were detected online from EEG signals in eight healthy subjects with a true positive rate (TPR) of 67.15 ± 7.87% and false positive rate (FPR) of 22.05 ±9.07%. The excitability of the cortical projection to the target muscle (tibialis anterior) was assessed before and after the intervention through motor evoked potentials (MEP) using transcranial magnetic stimulation (TMS). The peak of the evoked potential significantly (P=0.02) increased after the BCI intervention by 53 ± 43% (relative to preintervention measure), although the spinal excitability (tested by stretch reflexes) did not change. These results demonstrate for the first time that it is possible to alter the corticospinal projections to the tibialis anterior muscle by using an asynchronous BCI system based on online motor imagination that triggered peripheral stimulation. This type of repetitive proprioceptive feedback training based on self-generated brain signal decoding may be a requirement for purposeful skill acquisition in intact humans and in the rehabilitation of persons with brain damage. PMID:22547461

  8. Water diffusion reveals networks that modulate multiregional morphological plasticity after repetitive brain stimulation

    PubMed Central

    Abe, Mitsunari; Fukuyama, Hidenao; Mima, Tatsuya

    2014-01-01

    Repetitive brain stimulation protocols induce plasticity in the stimulated site in brain slice models. Recent evidence from network models has indicated that additional plasticity-related changes occur in nonstimulated remote regions. Despite increasing use of brain stimulation protocols in experimental and clinical settings, the neural substrates underlying the additional effects in remote regions are unknown. Diffusion-weighted MRI (DWI) probes water diffusion and can be used to estimate morphological changes in cortical tissue that occur with the induction of plasticity. Using DWI techniques, we estimated morphological changes induced by application of repetitive transcranial magnetic stimulation (rTMS) over the left primary motor cortex (M1). We found that rTMS altered water diffusion in multiple regions including the left M1. Notably, the change in water diffusion was retained longest in the left M1 and remote regions that had a correlation of baseline fluctuations in water diffusion before rTMS. We conclude that synchronization of water diffusion at rest between stimulated and remote regions ensures retention of rTMS-induced changes in water diffusion in remote regions. Synchronized fluctuations in the morphology of cortical microstructures between stimulated and remote regions might identify networks that allow retention of plasticity-related morphological changes in multiple regions after brain stimulation protocols. These results increase our understanding of the effects of brain stimulation-induced plasticity on multiregional brain networks. DWI techniques could provide a tool to evaluate treatment effects of brain stimulation protocols in patients with brain disorders. PMID:24619090

  9. Moving Forward by Stimulating the Brain: Transcranial Direct Current Stimulation in Post-Stroke Hemiparesis

    PubMed Central

    Peters, Heather T.; Edwards, Dylan J.; Wortman-Jutt, Susan; Page, Stephen J.

    2016-01-01

    Stroke remains a leading cause of disability worldwide, with a majority of survivors experiencing long term decrements in motor function that severely undermine quality of life. While many treatment approaches and adjunctive strategies exist to remediate motor impairment, many are only efficacious or feasible for survivors with active hand and wrist function, a population who constitute only a minority of stroke survivors. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, has been increasingly utilized to increase motor function following stroke as it is able to be used with stroke survivors of varying impairment levels, is portable, is relatively inexpensive and has few side effects and contraindications. Accordingly, in recent years the number of studies investigating its efficacy when utilized as an adjunct to motor rehabilitation regimens has drastically increased. While many of these trials have reported positive and promising efficacy, methodologies vary greatly between studies, including differences in stimulation parameters, outcome measures and the nature of physical practice. As such, an urgent need remains, centering on the need to investigate these methodological differences and synthesize the most current evidence surrounding the application of tDCS for post-stroke motor rehabilitation. Accordingly, the purpose of this paper is to provide a detailed overview of the most recent tDCS literature (published 2014-2015), while highlighting these variations in methodological approach, as well to elucidate the mechanisms associated with tDCS and post-stroke motor re-learning and neuroplasticity. PMID:27555811

  10. Moving Forward by Stimulating the Brain: Transcranial Direct Current Stimulation in Post-Stroke Hemiparesis.

    PubMed

    Peters, Heather T; Edwards, Dylan J; Wortman-Jutt, Susan; Page, Stephen J

    2016-01-01

    Stroke remains a leading cause of disability worldwide, with a majority of survivors experiencing long term decrements in motor function that severely undermine quality of life. While many treatment approaches and adjunctive strategies exist to remediate motor impairment, many are only efficacious or feasible for survivors with active hand and wrist function, a population who constitute only a minority of stroke survivors. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, has been increasingly utilized to increase motor function following stroke as it is able to be used with stroke survivors of varying impairment levels, is portable, is relatively inexpensive and has few side effects and contraindications. Accordingly, in recent years the number of studies investigating its efficacy when utilized as an adjunct to motor rehabilitation regimens has drastically increased. While many of these trials have reported positive and promising efficacy, methodologies vary greatly between studies, including differences in stimulation parameters, outcome measures and the nature of physical practice. As such, an urgent need remains, centering on the need to investigate these methodological differences and synthesize the most current evidence surrounding the application of tDCS for post-stroke motor rehabilitation. Accordingly, the purpose of this paper is to provide a detailed overview of the most recent tDCS literature (published 2014-2015), while highlighting these variations in methodological approach, as well to elucidate the mechanisms associated with tDCS and post-stroke motor re-learning and neuroplasticity. PMID:27555811

  11. A Review of Brain Stimulation Treatments for Late-Life Depression

    PubMed Central

    Hsu, Jonathan H.; Daskalakis, Zafiris J.

    2016-01-01

    Opinion Statement Recurrence, relapse and resistance to first-line therapies are common and pervasive issues in the treatment of depression in older adults. As a result, brain stimulation modalities are essential treatment options in this population. The majority of data for the effectiveness of brain stimulation modalities comes from electroconvulsive therapy (ECT) studies. Current ECT trials are focused on prolonging response after a successful course and mitigating the cognitive adverse effects. Newer forms of brain stimulation have emerged; unfortunately, as with most advances in medicine older adults have not been systematically included in clinical trials. Repetitive transcranial magnetic stimulation has demonstrated efficacy in younger adults and there is emerging data to support its use in late-life depression (LLD). It will be imperative that older adults be included in future transcranial direct current stimulation and magnetic seizure therapy clinical trials. Unclear efficacy results are a concern for both vagus nerve stimulation and deep brain stimulation. PMID:27398288

  12. How does transcranial magnetic stimulation modify neuronal activity in the brain? - Implications for studies of cognition

    PubMed Central

    Siebner, Hartwig R.; Hartwigsen, Gesa; Kassuba, Tanja; Rothwell, John

    2010-01-01

    Transcranial magnetic stimulation (TMS) uses a magnetic field to “carry” a short lasting electrical current pulse into the brain where it stimulates neurones, particularly in superficial regions of cerebral cortex. TMS can interfere with cognitive functions in two ways. A high intensity TMS pulse causes a synchronised high frequency burst of discharge in a relatively large population of neurones that is terminated by a long lasting GABAergic inhibition. The combination of artificial synchronisation of activity followed by depression effectively disrupts perceptual, motor and cognitive processes in the human brain. This transient neurodisruption has been termed a “virtual lesion”. Smaller intensities of stimulation produce less activity; in such cases, cognitive operations can probably continue but are disrupted because of the added noisy input from the TNS pulse. It is usually argued that if a TMS pulse affects performance, then the area stimulated must provide an essential contribution to behaviour being studied. However, there is one exception to this: the pulse could be applied to an area that is not involved in the task but which has projections to the critical site. Activation of outputs from the site of stimulation could potentially disrupt processing at the distant site, interfering with behaviour without having any involvement in the task. A final important feature of the response to TMS is “context dependency”, which indicates that the response depends on how excitable the cortex is at the time the stimulus is applied: if many neurones are close to firing threshold then the more of them are recruited by the pulse than at rest. Many studies have noted this context-dependent modulation. However, it is often assumed that the excitability of an area has a simple relationship to activity in that area. We argue that this is not necessarily the case. Awareness of the problem may help resolve some apparent anomalies in the literature. PMID:19371866

  13. Transcutaneous Electrical Acupoint Stimulation in Children with Autism and Its Impact on Plasma Levels of Arginine-Vasopressin and Oxytocin: A Prospective Single-Blinded Controlled Study

    ERIC Educational Resources Information Center

    Zhang, Rong; Jia, Mei-Xiang; Zhang, Ji-Sui; Xu, Xin-Jie; Shou, Xiao-Jing; Zhang, Xiu-Ting; Li, Li; Li, Ning; Han, Song-Ping; Han, Ji-Sheng

    2012-01-01

    Acupuncture increases brain levels of arginine-vasopressin (AVP) and oxytocin (OXT), which are known to be involved in the modulation of mammalian social behavior. Transcutaneous electrical acupoint stimulation (TEAS) is often used clinically to produce a similar stimulation to that of acupuncture on the acupoints. In the present study, TEAS was…

  14. Laparoscopic insertion of gastric electrodes for electrical stimulation.

    PubMed

    Brody, Fred; Nam, Arthur; Drenon, Elizabeth; Ali, Aamir; Soffer, Edy

    2007-02-01

    Gastric electrical stimulation can provide symptomatic relief for patients with refractory gastroparesis. Traditionally, these wires are placed through a midline laparotomy. This paper describes and illustrates, in detail, the laparoscopic technique for successful implantation. Thirty-one consecutive patients from October 2003 to March 2005 underwent laparoscopic insertion of gastric stimulating wires for gastroparesis. Twenty-six patients were female. Four laparoscopic ports were used to insert a pair of electrodes. Anterior, cephalad retraction of the gastric wall is critical for accurate seromuscular placement of gastric leads. Intraoperative endoscopy was used to verify the seromuscular placement of the leads. Both leads were secured to a subcutaneous generator and electrical parameters were immediately established in the operating room. Patient demographics, operative details, and postoperative morbidities were recorded. All procedures were completed laparoscopically. The mean operative time was 114.4 +/- 20.9 minutes (range, 95-140). No perioperative mortality occurred. Two patients developed cellulitis at the generator site postoperatively and oral antibiotics were prescribed for one week postoperatively. No hardware was removed. Two patients had their generators repositioned due to pain at the pocket site. Gastric electrical stimulation is a novel treatment modality for patients with refractory gastroparesis and can be accomplished safely via laparoscopy. Laparoscopic insertion is successful even in patients with prior surgery and intact gastrointestinal tubes. Long-term follow-up and the current prospective multicenter trial continue to assess the efficacy of this treatment modality. PMID:17362169

  15. Choosing electrodes for deep brain stimulation experiments--electrochemical considerations.

    PubMed

    Gimsa, Jan; Habel, Beate; Schreiber, Ute; van Rienen, Ursula; Strauss, Ulf; Gimsa, Ulrike

    2005-03-30

    Deep brain stimulation (DBS) is a therapy of movement disorders including Parkinson's disease (PD). Commercially available electrodes for animal models of Parkinson's disease vary in geometry and material. We characterized such electrodes and found a drift in their properties within minutes and up to about 60 h after immersion in cell culture medium, both with and without a stimulation signal. Electrode properties could largely be restored by proteolytic treatment for platinum/iridium electrodes but not for stainless steel ones. Short-term drift and irreversible aging could be followed by impedance measurements. Aging was accompanied by metal corrosion and erosion of the plastic insulation. For both materials, the degradation rates depended on the current density at the electrode surfaces. Fourier analysis of the DBS pulse (60 micros, repetition rate 130 Hz) revealed harmonic frequencies spanning a band of more than three decades, with significant harmonics up to the MHz range. The band is located in a window imposed by electrode processes and capacitive cell membrane bridging at the low and high frequency ends, respectively. Even though electrode processes are reduced at higher frequencies they only vanish above 1 MHz and cannot be avoided. Therefore, the use of inert electrode materials is of special importance. The neurotoxicity of iron makes avoiding stainless steel electrodes imperative. Future developments need to avoid the use of corrosive materials and current density hot spots at the electrode surface, and to reduce low frequency components in the DBS pulses in order to diminish electrode processes. PMID:15698665

  16. Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology.

    PubMed

    Ho, Allen L; Erickson-Direnzo, Elizabeth; Pendharkar, Arjun V; Sung, Chih-Kwang; Halpern, Casey H

    2015-06-01

    Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors' knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach. PMID:26030706

  17. Deep brain stimulation in the globus pallidus externa promotes sleep.

    PubMed

    Qiu, M H; Chen, M C; Wu, J; Nelson, D; Lu, J

    2016-05-13

    The basal ganglia, a network of subcortical structures, play a critical role in movements, sleep and mental behavior. Basal ganglia disorders such as Parkinson's disease and Huntington's disease affect sleep. Deep brain stimulation (DBS) to treat motor symptoms in Parkinson's disease can ameliorate sleep disturbances. Our series of previous studies lead the hypothesis that dopamine, acting on D2 receptors on the striatopallidal terminals, enhances activity in the globus pallidus externa (GPe) and promotes sleep. Here, we tested if DBS in the GPe promotes sleep in rats. We found that unilateral DBS (180Hz at 100μA) in the GPe in rats significantly increased both non-rapid eye movement and rapid eye movement sleep compared to sham DBS stimulation. The EEG power spectrum of sleep induced by DBS was similar to that of the baseline sleep, and sleep latency was not affected by DBS. The GPe is potentially a better site for DBS to treat both insomnia and motor disorders caused by basal ganglia dysfunction. PMID:26917269

  18. Calcium imaging of infrared-stimulated activity in rodent brain.

    PubMed

    Cayce, Jonathan Matthew; Bouchard, Matthew B; Chernov, Mykyta M; Chen, Brenda R; Grosberg, Lauren E; Jansen, E Duco; Hillman, Elizabeth M C; Mahadevan-Jansen, Anita

    2014-04-01

    Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain. PMID:24674600

  19. Deep brain stimulation for severe autism: from pathophysiology to procedure.

    PubMed

    Sinha, Saurabh; McGovern, Robert A; Sheth, Sameer A

    2015-06-01

    Autism is a heterogeneous neurodevelopmental disorder characterized by early-onset impairment in social interaction and communication and by repetitive, restricted behaviors and interests. Because the degree of impairment may vary, a spectrum of clinical manifestations exists. Severe autism is characterized by complete lack of language development and potentially life-threatening self-injurious behavior, the latter of which may be refractory to medical therapy and devastating for affected individuals and their caretakers. New treatment strategies are therefore needed. Here, the authors propose deep brain stimulation (DBS) of the basolateral nucleus of the amygdala (BLA) as a therapeutic intervention to treat severe autism. The authors review recent developments in the understanding of the pathophysiology of autism. Specifically, they describe the genetic and environmental alterations that affect neurodevelopment. The authors also highlight the resultant microstructural, macrostructural, and functional abnormalities that emerge during brain development, which create a pattern of dysfunctional neural networks involved in socioemotional processing. They then discuss how these findings implicate the BLA as a key node in the pathophysiology of autism and review a reported case of BLA DBS for treatment of severe autism. Much progress has been made in recent years in understanding the pathophysiology of autism. The BLA represents a logical neurosurgical target for treating severe autism. Further study is needed that considers mechanistic and operative challenges. PMID:26030703

  20. Calcium imaging of infrared-stimulated activity in rodent brain

    PubMed Central

    Cayce, Jonathan Matthew; Bouchard, Matthew B.; Chernov, Mykyta M.; Chen, Brenda R.; Grosberg, Lauren E.; Jansen, E. Duco; Hillman, Elizabeth M. C.; Mahadevan-Jansen, Anita

    2014-01-01

    Summary Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain. PMID:24674600

  1. Safety of Noninvasive Brain Stimulation in Children and Adolescents

    PubMed Central

    Krishnan, Chandramouli; Santos, Luciana; Peterson, Mark D.; Ehinger, Margaret

    2015-01-01

    Background Noninvasive brain stimulation (NIBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (tCS) have the potential to mitigate a variety of symptoms associated with neurological and psychiatric conditions, including stroke, cerebral palsy, autism, depression, and Tourette syndrome. While the safety of these modalities has been established in adults, there is a paucity of research assessing the safety of NIBS among children. Objective To examine the existing literature regarding the safety of NIBS techniques in children and adolescents with neurologic and neuropsychiatric disorders. Methods An electronic search was performed on online databases for studies using NIBS in individuals less than 18 years of age. Non-English publications, diagnostic studies, electroconvulsive therapy, single/dual pulse TMS studies, and reviews were excluded. Adverse events reported in the studies were carefully examined and synthesized to understand the safety and tolerability of NIBS among children and adolescents. Results The data from 48 studies involving more than 513 children/adolescents (2.5–17.8 years of age) indicate that the side-effects of NIBS were, in general, mild and transient [TMS: headache (11.5%), scalp discomfort (2.5%), twitching (1.2%), mood changes (1.2%), fatigue (0.9%), tinnitus (0.6%); tCS: tingling (11.5%), itching (5.8%), redness (4.7%), scalp discomfort (3.1%)] with relatively few serious adverse events. Conclusion Our findings indicate that both repetitive TMS and tCS are safe modalities in children and adolescents with various neurological conditions, especially when safety guidelines are followed. The incidence of adverse events appears to be similar to that observed in adults; however, further studies with longer treatment and follow-up periods are needed to better understand the benefits and tolerance of long-term use of NIBS in children. PMID:25499471

  2. Direct and reflex responses in perineal muscles on electrical stimulation.

    PubMed Central

    Vodusek, D B; Janko, M; Lokar, J

    1983-01-01

    Responses in the external anal and urethral sphincters as well as in the bulbocavernosus muscle have been evoked by supramaximal electrical stimulation of the penis (or clitoris), perineum and the peri-anal region and recorded electromyographically in 82 male subjects 5 to 73 years old and in nine female subjects 18 to 55 years old, who had no systemic diseases or demonstrable sacral nervous system lesion. On perineal stimulation (including the penis or clitoris) reflex responses with a typical latency of 33 ms and which exhibit no habituation were obtained in all muscles examined. Stimulation of the peri-anal region gave habituating reflex responses with a typical latency of 55 ms in all muscles examined. On perineal, and sometimes also peri-anal stimulation, stable short latency responses with typical latencies of 5 and 13 ms were recorded; both were considered to be direct responses. The different evoked muscle responses obtained by stimulation in the perineal and peri-anal region have to be distinguished when the bulbocavernosus and anal reflexes are recorded for evaluation of sacral nervous system lesions. PMID:6842203

  3. Chronic Spinal Cord Electrical Stimulation Protects Against 6-hydroxydopamine Lesions

    NASA Astrophysics Data System (ADS)

    Yadav, Amol P.; Fuentes, Romulo; Zhang, Hao; Vinholo, Thais; Wang, Chi-Han; Freire, Marco Aurelio M.; Nicolelis, Miguel A. L.

    2014-01-01

    Although L-dopa continues to be the gold standard for treating motor symptoms of Parkinson's disease (PD), it presents long-term complications. Deep brain stimulation is effective, but only a small percentage of idiopathic PD patients are eligible. Based on results in animal models and a handful of patients, dorsal column stimulation (DCS) has been proposed as a potential therapy for PD. To date, the long-term effects of DCS in animal models have not been quantified. Here, we report that DCS applied twice a week in rats treated with bilateral 6-OHDA striatal infusions led to a significant improvement in symptoms. DCS-treated rats exhibited a higher density of dopaminergic innervation in the striatum and higher neuronal cell count in the substantia nigra pars compacta compared to a control group. These results suggest that DCS has a chronic therapeutical and neuroprotective effect, increasing its potential as a new clinical option for treating PD patients.

  4. Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases.

    PubMed

    Fox, Michael D; Buckner, Randy L; Liu, Hesheng; Chakravarty, M Mallar; Lozano, Andres M; Pascual-Leone, Alvaro

    2014-10-14

    Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the ideal stimulation site for a given technique is often ambiguous, limiting optimization of the stimulation and its application in further disorders. In this article, we identify diseases treated with both types of stimulation, list the stimulation sites thought to be most effective in each disease, and test the hypothesis that these sites are different nodes within the same brain network as defined by resting-state functional-connectivity MRI. Sites where DBS was effective were functionally connected to sites where noninvasive brain stimulation was effective across diseases including depression, Parkinson's disease, obsessive-compulsive disorder, essential tremor, addiction, pain, minimally conscious states, and Alzheimer's disease. A lack of functional connectivity identified sites where stimulation was ineffective, and the sign of the correlation related to whether excitatory or inhibitory noninvasive stimulation was found clinically effective. These results suggest that resting-state functional connectivity may be useful for translating therapy between stimulation modalities, optimizing treatment, and identifying new stimulation targets. More broadly, this work supports a network perspective toward understanding and treating neuropsychiatric disease, highlighting the therapeutic potential of targeted brain network modulation. PMID:25267639

  5. Resting-state networks link invasive and noninvasive brain stimulation across diverse psychiatric and neurological diseases

    PubMed Central

    Fox, Michael D.; Buckner, Randy L.; Liu, Hesheng; Chakravarty, M. Mallar; Lozano, Andres M.; Pascual-Leone, Alvaro

    2014-01-01

    Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the ideal stimulation site for a given technique is often ambiguous, limiting optimization of the stimulation and its application in further disorders. In this article, we identify diseases treated with both types of stimulation, list the stimulation sites thought to be most effective in each disease, and test the hypothesis that these sites are different nodes within the same brain network as defined by resting-state functional-connectivity MRI. Sites where DBS was effective were functionally connected to sites where noninvasive brain stimulation was effective across diseases including depression, Parkinson's disease, obsessive-compulsive disorder, essential tremor, addiction, pain, minimally conscious states, and Alzheimer’s disease. A lack of functional connectivity identified sites where stimulation was ineffective, and the sign of the correlation related to whether excitatory or inhibitory noninvasive stimulation was found clinically effective. These results suggest that resting-state functional connectivity may be useful for translating therapy between stimulation modalities, optimizing treatment, and identifying new stimulation targets. More broadly, this work supports a network perspective toward understanding and treating neuropsychiatric disease, highlighting the therapeutic potential of targeted brain network modulation. PMID:25267639

  6. Central thalamic deep brain stimulation to support anterior forebrain mesocircuit function in the severely injured brain.

    PubMed

    Schiff, Nicholas D

    2016-07-01

    This integrative review frames a general rationale for the use of central thalamic deep brain stimulation (CT-DBS) to support arousal regulation mechanisms in the severely injured brain. The organizing role of the anterior forebrain mesocircuit in recovery mechanisms following widespread deafferentation produced by multi-focal structural brain injuries is emphasized. The mesocircuit model provides the conceptual foundation for the key role of the central thalamus as a privileged node for neuromodulation to support forebrain arousal regulation. In this context, cellular mechanisms arising at the neocortical, striatal, and thalamic population level are considered in the assessment of an individual patient's capacity for harboring underlying reserve that could be recruited for further recovery. Recent preclinical studies and pilot clinical results are compared to frame the detailed rationale for CT-DBS. Application of CT-DBS across the range of outcomes following severe-to-moderate brain injuries is discussed with the aim of improving consciousness and cognition in patients with non-progressive brain injuries. PMID:27113938

  7. The facilitation of motor actions by acoustic and electric stimulation.

    PubMed

    Marinovic, Welber; Milford, Magdalene; Carroll, Timothy; Riek, Stephan

    2015-12-01

    The presentation of a loud acoustic stimulus during the preparation of motor actions can both speed movement initiation and increase response vigor. Several recent studies have explored this phenomenon as a means to investigate the mechanisms and neural correlates of movement preparation. Here, we sought to determine the generality of this effect across sensory modalities, and in particular whether unexpected somatosensory stimulation can facilitate movements in a manner similar to loud sounds. We show that electric and acoustic stimuli can be similarly effective in inducing the early release of motor actions, in both reaction time and anticipatory timing tasks. Consistent with recent response activation models of motor preparation, we also demonstrate that increasing the intensity of electric stimuli induces both progressive decreases in reaction time and increases in response vigor. Additionally, we show that the early release of motor actions can be induced by electric stimuli targeting predominantly either muscle afferents or skin afferents. Finally, we show that simultaneous acoustic and electric stimulation leads to earlier releases of anticipatory actions than either unimodal stimulus. These findings may lead to new avenues for experimental and clinical exploitation of the effects of accessory sensory information on movement preparation and initiation. PMID:26338375

  8. Electrical Stimulation of Microbial PCB Degradation in Sediment

    PubMed Central

    Chun, Chan Lan; Payne, Rayford B.; Sowers, Kevin R.; May, Harold D.

    2012-01-01

    Bioremediation of polychlorinated biphenyls (PCBs) has been precluded in part by the lack of a cost-effective method to stimulate microbial degradation in situ. A common limitation is the lack of an effective method of providing electron donors and acceptors to promote in situ PCB biodegradation. Application of an electric potential to soil/sediment could be an effective means of providing electron-donors/-acceptors to PCB dechlorinating and degrading microorganisms. In this study, electrical stimulation of microbial PCB dechlorination/ degradation was examined in sediment maintained under simulated in situ conditions. Voltage was applied to open microcosms filled with PCB-impacted (Aroclor 1242) freshwater sediment from a Superfund site (Fox River, WI). The effect of applied low voltages (1.5 to 3.0V) on the microbial transformation of PCBs was determined with: 1) spiked PCBs, and 2) indigenous weathered PCBs. The results indicate that both oxidative and reductive microbial transformation of the spiked PCBs was stimulated but oxidation was dominant and most effective with higher voltage. Chlorobenzoates were produced as oxidation metabolites of the spiked PCBs, but increasing voltage enhanced chlorobenzoate consumption, indicating that overall degradation was enhanced. In the case of weathered PCBs, the total concentration decreased 40–60% in microcosms exposed to electric current while no significant decrease of PCB concentration was observed in control reactors (0 V or sterilized). Single congener analysis of the weathered PCBs showed significant loss of di- to penta-chlorinated congeners, indicating that microbial activity was not limited to anaerobic dechlorination of only higher chlorinated congeners. Degradation was most apparent with the application of only 1.5 V where anodic O2 was not generated, indicating a mechanism of degradation independent of electrolytic O2. Low voltage stimulation of the microbial degradation of weathered PCBs observed in this

  9. Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields

    PubMed Central

    Ruffini, Giulio; Fox, Michael D.; Ripolles, Oscar; Miranda, Pedro Cavaleiro; Pascual-Leone, Alvaro

    2014-01-01

    Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result of abnormality in one isolated brain region but represent alterations in brain networks. In this paper we describe a method for optimizing the configuration of multifocal tCS for stimulation of brain networks, represented by spatially extended cortical targets. We show how, based on fMRI, PET, EEG or other data specifying a target map on the cortical surface for excitatory, inhibitory or neutral stimulation and a constraint of the maximal number of electrodes, a solution can be produced with the optimal currents and locations of the electrodes. The method described here relies on a fast calculation of multifocal tCS electric fields (including components normal and tangential to the cortical boundaries) using a five layer finite element model of a realistic head. Based on the hypothesis that the effects of current stimulation are to first order due to the interaction of electric fields with populations of elongated cortical neurons, it is argued that the optimization problem for tCS stimulation can be defined in terms of the component of the electric field normal to the cortical surface. Solutions are found using constrained least squares to optimize current intensities, while electrode number and their locations are selected using a genetic algorithm. For direct current tCS (tDCS) applications, we provide some examples of this technique using an available tCS system providing 8 small Ag/AgCl stimulation electrodes. We demonstrate the approach both for localized and spatially extended targets defined using rs-fcMRI and PET data, with clinical applications in stroke and depression. Finally, we extend these ideas to more general

  10. Electrical stimulation vs thermal effects in a complex electromagnetic environment.

    PubMed

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Sánchez, Miguel

    2009-08-01

    Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10(-4)) than that based on thermal considerations (exposure quotient 0.16 10(-4)). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects. PMID:19481236

  11. Intra-operative recording of motor tract potentials at the cervico-medullary junction following scalp electrical and magnetic stimulation of the motor cortex.

    PubMed

    Thompson, P D; Day, B L; Crockard, H A; Calder, I; Murray, N M; Rothwell, J C; Marsden, C D

    1991-07-01

    Activity in descending motor pathways after scalp electrical and magnetic brain stimulation of the motor cortex was recorded from the exposed cervico-medullary junction in six patients having trans-oral surgery of the upper cervical spine. Recordings during deep anaesthesia without muscle paralysis revealed an initial negative potential (D wave) at about 2 ms with electrical stimulation in five of the six patients. This was followed by a muscle potential which obscured any later waveforms. Magnetic stimulation produced clear potentials in only one patient. The earliest wave to magnetic stimulation during deep anaesthesia was 1-2 ms later than the earliest potential to electrical stimulation. Following lightening of the anaesthetic and the administration of muscle relaxants a series of later negative potentials (I waves) were more clearly seen to both electrical and magnetic stimulation. More I waves were recorded to magnetic stimulation during light anaesthesia than during deep anaesthesia. Increasing the intensity of electrical stimulation also produced an extra late I wave. At the highest intensity of magnetic stimulation the latency of the earliest potential was comparable to the D wave to electrical stimulation. The intervals between these various D and I waves corresponded to those previously described for the timing of single motor unit discharge after cortical stimulation. PMID:1654395

  12. 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).

  13. Electromagnetic Field Modeling of Transcranial Electric and Magnetic Stimulation: Targeting, Individualization, and Safety of Convulsive and Subconvulsive Applications

    NASA Astrophysics Data System (ADS)

    Deng, Zhi-De

    The proliferation of noninvasive transcranial electric and magnetic brain stimulation techniques and applications in recent years has led to important insights into brain function and pathophysiology of brain-based disorders. Transcranial electric and magnetic stimulation encompasses a wide spectrum of methods that have developed into therapeutic interventions for a variety of neurological and psychiatric disorders. Although these methods are at different stages of development, the physical principle underlying these techniques is the similar. Namely, an electromagnetic field is induced in the brain either via current injection through scalp electrodes or via electromagnetic induction. The induced electric field modulates the neuronal transmembrane potentials and, thereby, neuronal excitability or activity. Therefore, knowledge of the induced electric field distribution is key in the design and interpretation of basic research and clinical studies. This work aims to delineate the fundamental physical limitations, tradeoffs, and technological feasibility constraints associated with transcranial electric and magnetic stimulation, in order to inform the development of technologies that deliver safer, and more spatially, temporally, and patient specific stimulation. Part I of this dissertation expounds on the issue of spatial targeting of the electric field. Contrasting electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) configurations that differ markedly in efficacy, side effects, and seizure induction efficiency could advance our understanding of the principles linking treatment parameters and therapeutic outcome and could provide a means of testing hypotheses of the mechanisms of therapeutic action. Using the finite element method, we systematically compare the electric field characteristics of existing forms of ECT and MST. We introduce a method of incorporating a modality-specific neural activation threshold in the electric field models that can

  14. Two is More Than One: How to Combine Brain Stimulation Rehabilitative Training for Functional Recovery?

    PubMed Central

    Koganemaru, Satoko; Fukuyama, Hidenao; Mima, Tatsuya

    2015-01-01

    A number of studies have shown that non-invasive brain stimulation has an additional effect in combination with rehabilitative therapy to enhance functional recovery than either therapy alone. The combination enhances use-dependent plasticity induced by repetitive training. The neurophysiological mechanism of the effects of this combination is based on associative plasticity. However, these effects were not reported in all cases. We propose a list of possible strategies to achieve an effective association between rehabilitative training with brain stimulation for plasticity: (1) control of temporal aspect between stimulation and task execution; (2) the use of a shaped task for the combination; (3) the appropriate stimulation of neuronal circuits where use-dependent plastic changes occur; and (4) phase synchronization between rhythmically patterned brain stimulation and task-related patterned activities of neurons. To better utilize brain stimulation in neuro-rehabilitation, it is important to develop more effective techniques to combine them. PMID:26617497

  15. The Impact of Deep Brain Stimulation on Sleep and Olfactory Function in Parkinson’s Disease

    PubMed Central

    Breen, David P; Low, Hu Liang; Misbahuddin, Anjum

    2015-01-01

    Objective: Relatively little is known about the effects of deep brain stimulation on non-motor symptoms. The aim of this pilot study was to assess the impact of deep brain stimulation on sleep and olfactory function in Parkinson’s disease. Methods: Subjective sleep quality and olfactory testing were performed on 11 consecutive Parkinson’s disease patients (eight men and three women) undergoing bilateral subthalamic nucleus stimulation. All patients consented to undergo clinical assessments prior to the procedure, and at regular intervals afterwards. Results: Subjective sleep quality improved at six months following deep brain stimulation and this benefit was sustained in the majority of patients at later follow-up assessments. There was no significant change in olfactory function following deep brain stimulation. Conclusions: In addition to having beneficial effects on motor function and quality of life, bilateral subthalamic nucleus stimulation improves subjective sleep quality in Parkinson’s disease. PMID:26535069

  16. Using independent component analysis to remove artifacts in visual cortex responses elicited by electrical stimulation of the optic nerve

    NASA Astrophysics Data System (ADS)

    Lu, Yiliang; Cao, Pengjia; Sun, Jingjing; Wang, Jing; Li, Liming; Ren, Qiushi; Chen, Yao; Chai, Xinyu

    2012-04-01

    In visual prosthesis research, electrically evoked potentials (EEPs) can be elicited by one or more biphasic current pulses delivered to the optic nerve (ON) through penetrating electrodes. Multi-channel EEPs recorded from the visual cortex usually contain large stimulus artifacts caused by instantaneous electrotonic current spread through the brain tissue. These stimulus artifacts contaminate the EEP waveform and often make subsequent analysis of the underlying neural responses difficult. This is particularly serious when investigating EEPs in response to electrical stimulation with long duration and multi-pulses. We applied independent component analysis (ICA) to remove these electrical stimulation-induced artifacts during the development of a visual prosthesis. Multi-channel signals were recorded from visual cortices of five rabbits in response to ON electrical stimulation with various stimulus parameters. ON action potentials were then blocked by lidocaine in order to acquire cortical potentials only including stimulus artifacts. Correlation analysis of reconstructed artifacts by ICA and artifacts recorded after blocking the ON indicates successful removal of artifacts from electrical stimulation by the ICA method. This technique has potential applications in studies designed to optimize the electrical stimulation parameters used by visual prostheses.

  17. 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. PMID:26420473

  18. Modulating Human Auditory Processing by Transcranial Electrical Stimulation

    PubMed Central

    Heimrath, Kai; Fiene, Marina; Rufener, Katharina S.; Zaehle, Tino

    2016-01-01

    Transcranial electrical stimulation (tES) has become a valuable research tool for the investigation of neurophysiological processes underlying human action and cognition. In recent years, striking evidence for the neuromodulatory effects of transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial random noise stimulation has emerged. While the wealth of knowledge has been gained about tES in the motor domain and, to a lesser extent, about its ability to modulate human cognition, surprisingly little is known about its impact on perceptual processing, particularly in the auditory domain. Moreover, while only a few studies systematically investigated the impact of auditory tES, it has already been applied in a large number of clinical trials, leading to a remarkable imbalance between basic and clinical research on auditory tES. Here, we review the state of the art of tES application in the auditory domain focussing on the impact of neuromodulation on acoustic perception and its potential for clinical application in the treatment of auditory related disorders. PMID:27013969

  19. Modulating Human Auditory Processing by Transcranial Electrical Stimulation.

    PubMed

    Heimrath, Kai; Fiene, Marina; Rufener, Katharina S; Zaehle, Tino

    2016-01-01

    Transcranial electrical stimulation (tES) has become a valuable research tool for the investigation of neurophysiological processes underlying human action and cognition. In recent years, striking evidence for the neuromodulatory effects of transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial random noise stimulation has emerged. While the wealth of knowledge has been gained about tES in the motor domain and, to a lesser extent, about its ability to modulate human cognition, surprisingly little is known about its impact on perceptual processing, particularly in the auditory domain. Moreover, while only a few studies systematically investigated the impact of auditory tES, it has already been applied in a large number of clinical trials, leading to a remarkable imbalance between basic and clinical research on auditory tES. Here, we review the state of the art of tES application in the auditory domain focussing on the impact of neuromodulation on acoustic perception and its potential for clinical application in the treatment of auditory related disorders. PMID:27013969

  20. Habituation to Experimentally Induced Electrical Pain during Voluntary-Breathing Controlled Electrical Stimulation (BreEStim)

    PubMed Central

    Li, Shengai; Hu, Tracy; Beran, Maria A.; Li, Sheng

    2014-01-01

    Objective Painful peripheral electrical stimulation to acupuncture points was found to cause sensitization if delivered randomly (EStim), but induced habituation if triggered by voluntary breathing (BreEStim). The objective was to systematically compare the effectiveness of BreEStim and EStim and to investigate the possible mechanisms mediating the habituation effect of BreEStim. Methods Eleven pain-free, healthy subjects (6 males, 5 females) participated in the study. Each subject received the BreEStim and EStim treatments in a random order at least three days apart. Both treatments consisted of 120 painful but tolerable stimuli to the ulnar nerve at the elbow on the dominant arm. BreEStim was triggered by voluntary breathing while EStim was delivered randomly. Electrical sensation threshold (EST) and electrical pain threshold (EPT) were measured from the thenar and hypothenar eminences on both hands at pre-intervention and 10-minutes post-intervention. Results There was no difference in the pre-intervention baseline measurement of EST and EPT between BreEStim and EStim. BreEStim increased EPT in all tested sites on both hands, while EStim increased EPT in the dominant hypothenar eminence distal to the stimulating site and had no effect on EPT in other sites. There was no difference in the intensity of electrical stimulation between EStim and BreEStim. Conclusion Our findings support the important role human voluntary breathing plays in the systemic habituation effect of BreEStim to peripheral painful electrical stimulation. PMID:25153077

  1. "Sexy stimulants": the interaction between psychomotor stimulants and sexual behavior in the female brain.

    PubMed

    Guarraci, Fay A; Bolton, Jessica L

    2014-06-01

    Research indicates gender differences in sensitivity to psychomotor stimulants. Preclinical work investigating the interaction between drugs of abuse and sex-specific behaviors, such as sexual behavior, is critical to our understanding of such gender differences in humans. A number of behavioral paradigms can be used to model aspects of human sexual behavior in animal subjects. Although traditional assessment of the reflexive, lordosis posture of the female rat has been used to map the neuroanatomical and neurochemical systems that contribute to uniquely female copulatory behavior, the additional behavioral paradigms discussed in the current review have helped us expand our description of the appetitive and consummatory patterns of sexual behavior in the female rat. Measuring appetitive behavior is particularly important for assessing sexual motivation, the equivalent of "desire" in humans. By investigating the effects of commonly abused drugs on female sexual motivation, we are beginning to elucidate the role of dopaminergic neurotransmission, a neural system also known to be critical to the neurobiology of drug addiction, in female sexual motivation. A better understanding of the nexus of sex and drugs in the female brain will help advance our understanding of motivation in general and explain how psychomotor stimulants affect males and females differently. PMID:24269964

  2. Transcranial Magnetic Stimulation and Deep Brain Stimulation in the treatment of alcohol dependence

    PubMed Central

    Alba-Ferrara, L.; Fernandez, F.; Salas, R.; de Erausquin, G. A.

    2013-01-01

    Alcohol dependence is a major social, economic, and public health problem. Alcoholism can lead to damage of the gastrointestinal, nervous, cardiovascular, and respiratory systems and it can be lethal, costing hundreds of billions to the health care system. Despite the existence of cognitive-behavioral therapy, psychosocial interventions, and spiritually integrated treatment to treat it, alcohol dependence has a high relapse rate and poor prognosis, albeit with high interindividual variability. In this review, we discuss the use of two neuromodulation techniques, namely repetitive transcranial magnetic stimulation (rTMS) and deep brain stimulation (DBS), and their advantages and disadvantages compared to first-line pharmacological treatment for alcohol dependence. We also discuss rTMS and DBS targets for alcohol dependence treatment, considering experimental animal and human evidence, with careful consideration of methodological issues preventing the identification of feasible targets for neuromodulation treatments, as well as inter-individual variability factors influencing alcoholism prognosis. Lastly, we anticipate future research aiming to tailor the treatment to each individual patient by combining neurofunctional, neuroanatomical and neurodisruptive techniques optimizing the outcome. PMID:25598743

  3. A Comparison of Two Electric Taste Stimulation Devices

    PubMed Central

    McClure, Scott T.; Lawless, Harry T.

    2016-01-01

    Electrical stimulation of the tongue, commonly used in clinical evaluations of taste dysfunction, can produce a variety of sensations including reports of metallic taste. Two studies compared responses to a fabricated electrical stimulator (a 1.6 V battery, anode side exposed) and a clinical electrogustometer (Rion TR-06). Batteries placed on the anterior dorsal tongue surface produced sensations similar in intensity and quality to those produced by the clinical electrogustometer, with equal intensity on the tongue tip for the 1.6 V battery in the range of 33 – 56 µA from the electrogustometer. A second study examined responses on three areas of the tongue on each side. Responses declined for areas lower in fungiform papillae for both devices, but at different rates. Higher current levels were required to match the battery in lower density areas, indicating spatial summation for the larger battery surface area. A consistent pattern of lateral differences was seen in only one subject. Quality descriptions were similar in frequency whether or not a word list was provided, with metallic, sour, pain and bitter being the most frequently mentioned words for both electric stimuli. Similarities in response to the battery device and electrogustometer were evident in intensity, qualities evoked, lack of a laterality effect and decreasing response in areas with lower fungiform papillae density. The battery device may provide an inexpensive portable alternative to an electrogustometer for use in clinical testing of taste. PMID:17573078

  4. Generation of Electrical Power from Stimulated Muscle Contractions Evaluated

    NASA Technical Reports Server (NTRS)

    Lewandowski, Beth; Kilgore, Kevin; Ercegovic, David B.

    2004-01-01

    This project is a collaborative effort between NASA Glenn Research Center's Revolutionary Aeropropulsion Concepts (RAC) Project, part of the NASA Aerospace Propulsion and Power Program of the Aerospace Technology Enterprise, and Case Western Reserve University's Cleveland Functional Electrical Stimulation (FES) Center. The RAC Project foresees implantable power requirements for future applications such as organically based sensor platforms and robotics that can interface with the human senses. One of the goals of the FES Center is to develop a totally implantable neural prosthesis. This goal is based on feedback from patients who would prefer a system with an internal power source over the currently used system with an external power source. The conversion system under investigation would transform the energy produced from a stimulated muscle contraction into electrical energy. We hypothesize that the output power of the system will be greater than the input power necessary to initiate, sustain, and control the electrical conversion system because of the stored potential energy of the muscle. If the system can be made biocompatible, durable, and with the potential for sustained use, then the biological power source will be a viable solution.

  5. Deep brain stimulation for psychiatric diseases: what are the risks?

    PubMed

    Saleh, Christian; Fontaine, Denys

    2015-05-01

    Despite the application of deep brain stimulation (DBS) as an efficient treatment modality for psychiatric disorders, such as obsessive-compulsive disorder (OCD), Gilles de la Tourette Syndrome (GTS), and treatment refractory major depression (TRD), few patients are operated or included in clinical trials, often for fear of the potential risks of an approach deemed too dangerous. To assess the surgical risks, we conducted an analysis of publications on DBS for psychiatric disorders. A PubMed search was conducted on reports on DBS for OCD, GTS, and TRD. Forty-nine articles were included. Only reports on complications related to DBS were selected and analyzed. Two hundred seventy-two patients with a mean follow-up of 22 months were included in our analysis. Surgical mortality was nil. The overall mortality was 1.1 %: two suicides were unrelated to DBS and one death was reported to be unlikely due to DBS. The majority of complications were transient and related to stimulation. Long-term morbidity occurred in 16.5 % of cases. Three patients had permanent neurological complications due to intracerebral hemorrhage (2.2 %). Complications reported in DBS for psychiatric diseases appear to be similar to those reported for DBS in movement disorders. But class I evidence is lacking. Our analysis was based mainly on small non-randomized studies. A significant number of patients (approximately 150 patients) who were treated with DBS for psychiatric diseases had to be excluded from our analysis as no data on complications was available. The exact prevalence of complications of DBS in psychiatric diseases could not be established. DBS for psychiatric diseases is promising, but remains an experimental technique in need of further evaluation. A close surveillance of patients undergoing DBS for psychiatric diseases is mandatory. PMID:25795265

  6. Uncommon Applications of Deep Brain Stimulation in Hyperkinetic Movement Disorders

    PubMed Central

    Smith, Kara M.; Spindler, Meredith A.

    2015-01-01

    Background In addition to the established indications of tremor and dystonia, deep brain stimulation (DBS) has been utilized less commonly for several hyperkinetic movement disorders, including medication-refractory myoclonus, ballism, chorea, and Gilles de la Tourette (GTS) and tardive syndromes. Given the lack of adequate controlled trials, it is difficult to translate published reports into clinical use. We summarize the literature, draw conclusions regarding efficacy when possible, and highlight concerns and areas for future study. Methods A Pubmed search was performed for English-language articles between January 1980 and June 2014. Studies were selected if they focused primarily on DBS to treat the conditions of focus. Results We identified 49 cases of DBS for myoclonus-dystonia, 21 for Huntington's disease, 15 for choreacanthocytosis, 129 for GTS, and 73 for tardive syndromes. Bilateral globus pallidus interna (GPi) DBS was the most frequently utilized procedure for all conditions except GTS, in which medial thalamic DBS was more common. While the majority of cases demonstrate some improvement, there are also reports of no improvement or even worsening of symptoms in each condition. The few studies including functional or quality of life outcomes suggest benefit. A limited number of studies included blinded on/off testing. There have been two double-blind controlled trials performed in GTS and a single prospective double-blind, uncontrolled trial in tardive syndromes. Patient characteristics, surgical target, stimulation parameters, and duration of follow-up varied among studies. Discussion Despite these extensive limitations, the literature overall supports the efficacy of DBS in these conditions, in particular GTS and tardive syndromes. For other conditions, the preliminary evidence from small studies is promising and encourages further study. PMID:25713746

  7. Photoacoustic microscopy of microvascular responses to cortical electrical stimulation

    NASA Astrophysics Data System (ADS)

    Tsytsarev, Vassiliy; Hu, Song; Yao, Junjie; Maslov, Konstantin; Barbour, Dennis L.; Wang, Lihong V.

    2011-07-01

    Advances in the functional imaging of cortical hemodynamics have greatly facilitated the understanding of neurovascular coupling. In this study, label-free optical-resolution photoacoustic microscopy (OR-PAM) was used to monitor microvascular responses to direct electrical stimulations of the mouse somatosensory cortex through a cranial opening. The responses appeared in two forms: vasoconstriction and vasodilatation. The transition between these two forms of response was observed in single vessels by varying the stimulation intensity. Marked correlation was found between the current-dependent responses of two daughter vessels bifurcating from the same parent vessel. Statistical analysis of twenty-seven vessels from three different animals further characterized the spatial-temporal features and the current dependence of the microvascular response. Our results demonstrate that OR-PAM is a valuable tool to study neurovascular coupling at the microscopic level.

  8. Calcium Activation Profile In Electrically Stimulated Intact Rat Heart Cells

    NASA Astrophysics Data System (ADS)

    Geerts, Hugo; Nuydens, Rony; Ver Donck, Luc; Nuyens, Roger; De Brabander, Marc; Borgers, Marcel

    1988-06-01

    Recent advances in fluorescent probe technology and image processing equipment have made available the measurement of calcium in living systems on a real-time basis. We present the use of the calcium indicator Fura-2 in intact normally stimulated rat heart cells for the spatial and dynamic measurement of the calcium excitation profile. After electric stimulation (1 Hz), the activation proceeds from the center of the myocyte toward the periphery. Within two frame times (80 ms), the whole cell is activated. The activation is slightly faster in the center of the cell than in the periphery. The mean recovery time is 200-400 ms. There is no difference along the cell's long axis. The effect of a beta-agonist and of a calcium antagonist is described.

  9. Technical Rebuilding of Movement Function Using Functional Electrical Stimulation

    NASA Astrophysics Data System (ADS)

    Gföhler, Margit

    To rebuild lost movement functions, neuroprostheses based on functional electrical stimulation (FES) artificially activate skeletal muscles in corresponding sequences, using both residual body functions and artificial signals for control. Besides the functional gain, FES training also brings physiological and psychological benefits for spinal cord-injured subjects. In this chapter, current stimulation technology and the main components of FES-based neuroprostheses including enhanced control systems are presented. Technology and application of FES cycling and rowing, both approaches that enable spinal cord-injured subjects to participate in mainstream activities and improve their health and fitness by exercising like able-bodied subjects, are discussed in detail, and an overview of neuroprostheses that aim at restoring movement functions for daily life as walking or grasping is given.

  10. Functional results of electrical cortical stimulation of the lower sensory strip.

    PubMed

    Tanriverdi, Taner; Al-Jehani, Hosam; Poulin, Nicole; Olivier, Andre

    2009-09-01

    The aim of this paper is to provide functional results obtained from electrical cortical stimulation of the lower postcentral gyrus in patients who underwent either lesional or non-lesional epilepsy surgery. Group I (n=393) included those patients with gliosis or normal tissue and Group II (n=107) included patients with space-occupying lesions. For cortical stimulation, a unipolar voltage-controlled electrode was used. The tongue, lip, and hand/finger sequences over the lower postcentral gyrus lateromedially in both groups were in agreement with classic teaching. The presence of structural lesions, such as tumors and dysplasia, did not affect the vertical representation of the body parts on the lower sensory strip. Individual variations, which included mosaicism over the sensory strip, were frequent. Whether the functional variability and mosaicism within the sensory cortex result from a pathological condition or not remains to be elucidated in healthy humans using advanced non-invasive brain mapping techniques. PMID:19497753

  11. Behavioural and physiological effects of electrical stimulation in the nucleus accumbens: a review.

    PubMed

    van Kuyck, K; Gabriëls, L; Cosyns, P; Arckens, L; Sturm, V; Rasmussen, S; Nuttin, B

    2007-01-01

    Electrical stimulation (ES) in the brain is becoming a new treatment option in patients with treatment-resistant obsessive-compulsive disorder (OCD). A possible brain target might be the nucleus accumbens (NACC). This review aims to summarise the behavioural and physiological effects of ES in the NACC in humans and in animals and to discuss these findings with regard to neuroanatomical, electrophysiological and behavioural insights. The results clearly demonstrate that ES in the NACC has an effect on reward, activity, fight-or-flight, exploratory behaviour and food intake, with evidence for only moderate physiological effects. Seizures were rarely observed. Finally, the results of ES studies in patients with treatment-resistant OCD and in animal models for OCD are promising. PMID:17691326

  12. Non-invasive brain stimulation can induce paradoxical facilitation. Are these neuroenhancements transferable and meaningful to security services?

    PubMed Central

    Levasseur-Moreau, Jean; Brunelin, Jerome; Fecteau, Shirley

    2013-01-01

    For ages, we have been looking for ways to enhance our physical and cognitive capacities in order to augment our security. One potential way to enhance our capacities may be to externally stimulate the brain. Methods of non-invasive brain stimulation (NIBS), such as repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (tES), have been recently developed to modulate brain activity. Both techniques are relatively safe and can transiently modify motor and cognitive functions outlasting the stimulation period. The purpose of this paper is to review data suggesting that NIBS can enhance motor and cognitive performance in healthy volunteers. We frame these findings in the context of whether they may serve security purposes. Specifically, we review studies reporting that NIBS induces paradoxical facilitation in motor (precision, speed, strength, acceleration endurance, and execution of daily motor task) and cognitive functions (attention, impulsive behavior, risk-taking, working memory, planning, and deceptive capacities). Although transferability and meaningfulness of these NIBS-induced paradoxical facilitations into real-life situations are not clear yet, NIBS may contribute at improving training of motor and cognitive functions relevant for military, civil, and forensic security services. This is an enthusiastic perspective that also calls for fair and open debates on the ethics of using NIBS in healthy individuals to enhance normal functions. PMID:23966923

  13. New Perspectives in Edema Control via Electrical Stimulation

    PubMed Central

    Mendel, Frank C.; Fish, Dale R.

    1993-01-01

    Clinicians commonly use electrical stimulation (ES) to control acute edema. But, except for anecdotal reports, there is little evidence to support that practice. We recently conducted a series of controlled, blinded studies on several nonhuman animal models to determine the efficacy of several forms of ES, but high-voltage pulsed current (HVPC) in particular, in controlling acute posttraumatic edema. We observed that acute posttraumatic edema is curbed by HVPC when certain protocols are used. Results of these studies suggest to us that wave form, polarity, treatment schedule, intensity and frequency of pulses all influence ES, and that clinical protocols need revision. PMID:16558209

  14. Neuronal excitability level transition induced by electrical stimulation

    NASA Astrophysics Data System (ADS)

    Florence, G.; Kurths, J.; Machado, B. S.; Fonoff, E. T.; Cerdeira, H. A.; Teixeira, M. J.; Sameshima, K.

    2014-12-01

    In experimental studies, electrical stimulation (ES) has been applied to induce neuronal activity or to disrupt pathological patterns. Nevertheless, the underlying mechanisms of these activity pattern transitions are not clear. To study these phenomena, we simulated a model of the hippocampal region CA1. The computational simulations using different amplitude levels and duration of ES revealed three states of neuronal excitability: burst-firing mode, depolarization block and spreading depression wave. We used the bifurcation theory to analyse the interference of ES in the cellular excitability and the neuronal dynamics. Understanding this process would help to improve the ES techniques to control some neurological disorders.

  15. Disease-specific longevity of impulse generators in deep brain stimulation and review of the literature.

    PubMed

    van Riesen, Christoph; Tsironis, Georg; Gruber, Doreen; Klostermann, Fabian; Krause, Patricia; Schneider, Gerd Helge; Kupsch, Andreas

    2016-06-01

    Deep brain stimulation (DBS) represents an established and internationally approved therapy for movement disorders. In the present retrospective analysis, we evaluated disease-specific longevity of dual channel impulse generators (IPG) used in different movement disorders. We correlated the battery lifetime with electrical stimulation settings, "total electrical energy delivered" (TEED), stimulation modi (monopolar, double monopolar and bipolar) and targets. Specifically, we reviewed the longevity and stimulation settings of 464 IPGs implanted between 1996 until 2011 in a single university center. Disease entities comprised Parkinson's disease (PD, n = 257), dystonia (n = 130) and essential tremor (ET, n = 50). Further subanalyses aimed at assessing differential longevity in different subtypes of PD and dystonia. The main finding relates to longer IPG longevity in ET (thalamic DBS) and PD (subthalamic DBS) vs. dystonia (pallidal DBS; 71.9 ± 6.7 vs. 51.5 ± 2.3 vs. 37 ± 2 months). In PD the tremor-dominant type was associated with a significant shorter battery survival than in the akinetic-rigid type without tremor or the "balanced" type with tremor, bradykinesia and rigidity (38.8 ± 3.9 vs. 53.6 ± 3.4 vs. 58.8 ± 4.1 months), while there were no significant differences in longevity between the subtypes of dystonia. Frequency, amplitude, pulse widths and TEED correlated inversely with battery lifetime. Pallidal DBS in dystonia is associated with a shorter lifetime of IPGs than subthalamic or thalamic DBS for PD or ET. The present results may contribute to the rapidly evolving refinement of DBS devices. Future studies that assess energy consumption both in patients with and without IPG replacement could help to avoid potential underestimation of longevity of IPGs. PMID:27198700

  16. Deep brain stimulation for Parkinson's disease - patient selection.

    PubMed

    Pollak, Pierre

    2013-01-01

    Proper selection of patients who will reliably benefit from deep brain stimulation (DBS) is critical to its success. This requires careful evaluation that should be delivered by an expert multidisciplinary team involving a movement disorder neurologist, a neurosurgeon, a neuropsychologist, and a psychiatrist. The most suitable candidates for DBS suffer from Parkinson's disease with motor fluctuations and/or dyskinesias that are not adequately controlled with optimized medical therapy, or with medication-refractory tremor. During the best on-motor periods, gait difficulties, instability, and speech problems should be minimal, reflecting an excellent response to levodopa in the ideal candidate. The cognitive, psychiatric, and behavioral status must be normal or minimally affected, with the exception of dopamine agonist drug-induced impulse control disorders, which are usually improved after successful surgery and drug withdrawal. Moreover, the patients have no serious comorbidities. Most patients corresponding to this profile suffer from a relatively young onset of Parkinson's disease, and are aged less than 70 years at the time of surgery. Indeed, most patients fall outside this ideal description, and the medical art is to appreciate for each patient the extent to which the alterations of these features can be accepted. Eventually, patients make their own decision from detailed information of their individualized risks and benefits of DBS. Patient expectations, cooperation, and familial support are also important considerations. PMID:24112888

  17. Deep Brain Stimulation Can Preserve Working Status in Parkinson's Disease

    PubMed Central

    Deli, Gabriella; Balás, István; Dóczi, Tamás; Janszky, József; Karádi, Kázmér; Aschermann, Zsuzsanna; Nagy, Ferenc; Makkos, Attila; Kovács, Márton; Bosnyák, Edit; Kovács, Norbert; Komoly, Sámuel

    2015-01-01

    Objectives. Our investigation aimed at evaluating if bilateral subthalamic deep brain stimulation (DBS) could preserve working capability in Parkinson's disease (PD). Materials. We reviewed the data of 40 young (<60 year-old) PD patients who underwent DBS implantation and had at least 2 years of follow-up. Patients were categorized based on their working capability at time of surgery: “active job” group (n = 20) and “no job” group (n = 20). Baseline characteristics were comparable. Quality of life (EQ-5D) and presence of active job were evaluated preoperatively and 2 years postoperatively. Results. Although similar (approximately 50%) improvement was achieved in the severity of motor and major nonmotor symptoms in both groups, the postoperative quality of life was significantly better in the “active job” group (0.687 versus 0.587, medians, p < 0.05). Majority (80%) of “active job” group members were able to preserve their job 2 years after the operation. However, only a minimal portion (5%) of the “no job” group members was able to return to the world of active employees (p < 0.01). Conclusions. Although our study has several limitations, our results suggest that in patients with active job the appropriately “early” usage of DBS might help preserve working capability and gain higher improvement in quality of life. PMID:26295005

  18. Presurgical Rehearsals for Patients Considering "Awake" Deep Brain Stimulation.

    PubMed

    Falconer, Ramsey A; Rogers, Sean L; Brewer, Cristie M; Piscitani, Franco; Shenai, Mahesh B

    2016-01-01

    Simulated surgical environments are rapidly gaining adoption in training students, residents, and members of specialized surgical teams. However, minimal attention has been given to the use of simulated surgical environments to educate patients on surgical processes, particularly procedures that require the active participation of the patient. "Awake" neurosurgery provides a unique situation in which patients openly participate in their operation. We describe a case report, in which a 62-year-old male was referred for "awake" deep brain stimulation implantation, in relation to medically refractory Parkinson's disease. The patient had significant concerns regarding anxiety and claustrophobia, and toleration of the "awake" procedure. Consequently, we designed a simulated OR environment and process, to recreate the physical experience of the procedure, with minimal cost or risk. This experience was crucial in determining the care plan, as after this experience, the patient opted for an "asleep" alternative. Thus, in certain settings, presurgical rehearsals may have a dramatic impact in the overall course of care. PMID:27532036

  19. Deep brain stimulation for dystonia: review of the literature.

    PubMed

    Mehdorn, Hubertus M

    2016-06-01

    Deep brain stimulation (DBS) has become one of the major therapy options for movement disorders including dystonia. This article should give a review of the current literature from a neurosurgical perspective. Since dystonia is a rare disease, only few studies on larger cohorts have been published, and very few randomized controlled studies are avaialable in the international literature. Our experiences gained treating 134 patients with various types of dystonia, between 1999 and 2015, will serve a guide to interpret the current literature. Symptoms of dystonia are due to a variety of medical conditions. A careful and extensive neurological evaluation is mandatory before medical and surgical treatment options are considered, since the clinical benefits of more aggressive treatment e.g. by DBS depend to a large extent on the etiology of the disease. Diagnostic steps should include also magnetic resonance imaging (MRI) and possibly genetic evaluation. Therapy consists of physiotherapy, medical therapy including botulinum toxin injections in focal dystonia and DBS. This neurosurgical therapy is considered a highly effective therapy in well selected patients, which should be discussed, depending on the etiology, early in the patient's career. Patients with primary dystonia will benefit the most from DBS to the ventromediolateral part of the globus pallidus internus (GPi) with acceptable low complication rates; in order to optimize longterm results in these groups of patient, they will require an interdisciplinary individualized approach both pre- and postoperatively as well as longterm care adjusting to their needs. PMID:26977634

  20. The use of deep brain stimulation in Tourette's syndrome.

    PubMed

    Rotsides, Janine; Mammis, Antonios

    2013-11-01

    Tourette's syndrome (TS) is a childhood neuropsychiatric disorder characterized by multiple involuntary motor and vocal tics. It is commonly associated with other behavioral disorders including attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety, depression, and self-injurious behaviors. Tourette's syndrome can be effectively managed with psychobehavioral and pharmacological treatments, and many patients experience an improvement in tics in adulthood. However, symptoms may persist and cause severe impairment in a small subset of patients despite available therapies. In recent years, deep brain stimulation (DBS) has been shown to be a promising treatment option for such patients. Since the advent of its use in 1999, multiple targets have been identified in DBS for TS, including the medial thalamus, globus pallidus internus, globus pallidus externus, anterior limb of the internal capsule/nucleus accumbens, and subthalamic nucleus. While the medial thalamus is the most commonly reported trajectory, the optimal surgical target for TS is still a topic of much debate. This paper provides a review of the available literature regarding the use of DBS for TS. PMID:24175864

  1. Deep brain stimulation in the treatment of depression

    PubMed Central

    Delaloye, Sibylle; Holtzheimer, Paul E.

    2014-01-01

    Major depressive disorder is a worldwide disease with debilitating effects on a patient's life. Common treatments include pharmacotherapy, psychotherapy, and electroconvulsive therapy. Many patients do not respond to these treatments; this has led to the investigation of alternative therapeutic modalities. Deep brain stimulation (DBS) is one of these modalities. It was first used with success for treating movement disorders and has since been extended to the treatment of psychiatric disorders. Although DBS is still an emerging treatment, promising efficacy and safety have been demonstrated in preliminary trials in patients with treatment-resistant depression (TRD). Further, neuroimaging has played a pivotal role in identifying some DBS targets and remains an important tool for evaluating the mechanism of action of this novel intervention. Preclinical animal studies have broadened knowledge about the possible mechanisms of action of DBS for TRD, Given that DBS involves neurosurgery in patients with severe psychiatric impairment, ethical questions concerning capacity to consent arise; these issues must continue to be carefully considered. PMID:24733973

  2. Personality Changes after Deep Brain Stimulation in Parkinson's Disease

    PubMed Central

    Pham, Uyen; Solbakk, Anne-Kristin; Skogseid, Inger-Marie; Pripp, Are Hugo; Konglund, Ane Eidahl; Andersson, Stein; Haraldsen, Ira Ronit; Aarsland, Dag; Dietrichs, Espen; Malt, Ulrik Fredrik

    2015-01-01

    Objectives. Deep brain stimulation of the subthalamic nucleus (STN-DBS) is a recognized therapy that improves motor symptoms in advanced Parkinson's disease (PD). However, little is known about its impact on personality. To address this topic, we have assessed personality traits before and after STN-DBS in PD patients. Methods. Forty patients with advanced PD were assessed with the Temperament and Character Inventory (TCI): the Urgency, Premeditation, Perseverance, Sensation Seeking impulsive behaviour scale (UPPS), and the Neuroticism and Lie subscales of the Eysenck Personality Questionnaire (EPQ-N, EPQ-L) before surgery and after three months of STN-DBS. Collateral information obtained from the UPPS was also reported. Results. Despite improvement in motor function and reduction in dopaminergic dosage patients reported lower score on the TCI Persistence and Self-Transcendence scales, after three months of STN-DBS, compared to baseline (P = 0.006; P = 0.024). Relatives reported significantly increased scores on the UPPS Lack of Premeditation scale at follow-up (P = 0.027). Conclusion. STN-DBS in PD patients is associated with personality changes in the direction of increased impulsivity. PMID:25705545

  3. Deep brain stimulation for levodopa-refractory benign tremulous parkinsonism.

    PubMed

    Konno, Takuya; Ross, Owen A; Wharen, Robert E; Uitti, Ryan J; Wszolek, Zbigniew K

    2016-01-01

    Benign tremulous parkinsonism (BTP) is characterized by prominent resting tremor combined with action and postural components, and with only subtle rigidity and bradykinesia. This tremor is frequently disabling and poorly responsive to therapy with levodopa. Thus, BTP could be considered either as a distinct clinical disorder or a variant of PD. We present a case of a 57-year-old man who had a 3-year history of severe and functionally disabling resting tremor with action and postural features bilaterally but with left dominant hand predominance. There was only very mild rigidity and bradykinesia and no postural instability. His tremor was refractory to dopaminergic therapy, including carbidopa/levodopa. The dopamine transporter (DAT) imaging showed reduced tracer uptake in the putamen bilaterally, more so on the right side. He was treated with deep brain stimulation (DBS) targeting the right ventral intermediate nucleus of the thalamus. His tremor resolved immediately after procedure. The DAT imaging abnormalities indicate the presynaptic dopamine deficiency. In some autopsied BTP cases classic alpha-synuclein pathology of PD was observed. Thus, despite the lack of levodopa responsiveness BTP likely represents a variant of PD and not a distinct neurodegenerative disorder. DBS should be considered for patients with BTP PD variant despite their poor responsiveness to levodopa treatment. PMID:27591066

  4. Electrical stimulation of the lateral habenula produces an inhibitory effect on sucrose self-administration.

    PubMed

    Friedman, Alexander; Lax, Elad; Dikshtein, Yahav; Abraham, Lital; Flaumenhaft, Yakov; Sudai, Einav; Ben-Tzion, Moshe; Yadid, Gal

    2011-01-01

    The lateral habenula (LHb) plays a role in prediction of negative reinforcement, punishment and aversive responses. In the current study, we examined the role that the LHb plays in regulation of negative reward responses and aversion. First, we tested the effect of intervention in LHb activity on sucrose reinforcing behavior. An electrode was implanted into the LHb and rats were trained to self-administer sucrose (20%; 16 days) until at least three days of stable performance were achieved (as represented by the number of active lever presses in self-administration cages). Rats subsequently received deep brain stimulation (DBS) of the LHb, which significantly reduced sucrose self-administration levels. In contrast, lesion of the LHb increased sucrose-seeking behavior, as demonstrated by a delayed extinction response to substitution of sucrose with water. Furthermore, in a modified non-rewarding conditioned-place-preference paradigm, DBS of the LHb led to aversion to the context associated with stimulation of this brain region. We postulate that electrical stimulation of the LHb attenuates positive reward-associated reinforcement by natural substances. PMID:20955718

  5. Programmed acute electrical stimulation of ventral tegmental area alleviates depressive-like behavior.

    PubMed

    Friedman, Alexander; Frankel, Michael; Flaumenhaft, Yakov; Merenlender, Avia; Pinhasov, Albert; Feder, Yuval; Taler, Michal; Gil-Ad, Irit; Abeles, Moshe; Yadid, Gal

    2009-03-01

    Depressive disorders affect approximately 5% of the population in any given year. Antidepressants may require several weeks to produce their clinical effects. Despite progress being made in this area there is still room and a need to explore additional therapeutic modes to increase treatment effectiveness and responsiveness. Herein, we examined a new method for intervention in depressive states based on deep brain stimulation of the ventral tegmental area (VTA) as a source of incentive motivation and hedonia, in comparison to chemical antidepressants. The pattern of stimulation was fashioned to mimic the firing pattern of VTA neurons in the normal rat. Behavioral manifestations of depression were then monitored weekly using a battery of behavioral tests. The results suggest that treatment with programmed acute electrical stimulation of the VTA substantially alleviates depressive behavior, as compared to chemical antidepressants or electroconvulsive therapy, both in onset time and longitudinal effect. These results were also highly correlated with increases in brain-derived neurotrophic factor mRNA levels in the prefrontal cortex. PMID:18843267

  6. Glioma localization and excision using direct electrical stimulation for language mapping during awake surgery

    PubMed Central

    LI, TIANDONG; BAI, HONGMIN; WANG, GUOLIANG; WANG, WEIMIN; LIN, JIAN; GAO, HAN; WANG, LIMIN; XIA, LIHUI; XIE, XUEMIN

    2015-01-01

    The aim of this study was to investigate the method and significance of the application of direct electrical stimulation (DES) to the brain mapping of language functions during glioma surgery. A retrospective analysis of clinical data was performed for 91 cases of brain functional area glioma surgery under DES from January 2003 until January 2012. Following cortical electrical stimulation, 88 patients exhibited seizures involving facial or hand movements and 91 cases experienced language disorders such as counting interruption, naming errors or anomia. The most commonly observed areas of counting interruption were distributed on the posterior part of the left anterior central gyrus (47.7%), the operculum of the left inferior frontal gyrus (24.4%) and the triangular part of the left inferior frontal gyrus (12.8%). Postoperative magnetic resonance imaging demonstrated that overall excision was achieved in 53 cases and sub-overall excision was performed in 31 cases. A total of 42 cases (46.2%) exhibited no postoperative neurological dysfunction, 39 cases (42.9%) exhibited brief language dysfunction, 27 cases (29.7%) experienced brief limb movement disorder, and one case appeared to have permanent neurological dysfunction. DES was indicated to be a reliable and noninvasive method for the intraoperative positioning of language areas, and was able to resect gliomas in the language area with maximal safety. PMID:26136923

  7. 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

  8. Pallidal Deep Brain Stimulation Improves Higher Control of the Oculomotor System in Parkinson's Disease.

    PubMed

    Antoniades, Chrystalina A; Rebelo, Pedro; Kennard, Christopher; Aziz, Tipu Z; Green, Alexander L; FitzGerald, James J

    2015-09-23

    The frontal cortex and basal ganglia form a set of parallel but mostly segregated circuits called cortico-basal ganglia loops. The oculomotor loop controls eye movements and can direct relatively simple movements, such as reflexive prosaccades, without external help but needs input from "higher" loops for more complex behaviors. The antisaccade task requires the dorsolateral prefrontal cortex, which is part of the prefrontal loop. Information flows from prefrontal to oculomotor circuits in the striatum, and directional errors in this task can be considered a measure of failure of prefrontal control over the oculomotor loop. The antisaccadic error rate (AER) is increased in Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has no effect on the AER, but a previous case suggested that DBS of the globus pallidus interna (GPi) might. Our aim was to compare the effects of STN DBS and GPi DBS on the AER. We tested eye movements in 14 human DBS patients and 10 controls. GPi DBS substantially reduced the AER, restoring lost higher control over oculomotor function. Interloop information flow involves striatal neurons that receive cortical input and project to pallidum. They are normally silent when quiescent, but in PD they fire randomly, creating noise that may account for the degradation in interloop control. The reduced AER with GPi DBS could be explained by retrograde stimulation of striatopallidal axons with consequent activation of inhibitory collaterals and reduction in background striatal firing rates. This study may help explain aspects of PD pathophysiology and the mechanism of action of GPi DBS. Significance statement: Parkinson's disease causes symptoms including stiffness, slowness of movement, and tremor. Electrical stimulation of specific areas deep in the brain can effectively treat these symptoms, but exactly how is not fully understood. Part of the cause of such symptoms may be impairments in the way information flows

  9. Pallidal Deep Brain Stimulation Improves Higher Control of the Oculomotor System in Parkinson's Disease

    PubMed Central

    Rebelo, Pedro; Kennard, Christopher; Aziz, Tipu Z.; Green, Alexander L.

    2015-01-01

    The frontal cortex and basal ganglia form a set of parallel but mostly segregated circuits called cortico-basal ganglia loops. The oculomotor loop controls eye movements and can direct relatively simple movements, such as reflexive prosaccades, without external help but needs input from “higher” loops for more complex behaviors. The antisaccade task requires the dorsolateral prefrontal cortex, which is part of the prefrontal loop. Information flows from prefrontal to oculomotor circuits in the striatum, and directional errors in this task can be considered a measure of failure of prefrontal control over the oculomotor loop. The antisaccadic error rate (AER) is increased in Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has no effect on the AER, but a previous case suggested that DBS of the globus pallidus interna (GPi) might. Our aim was to compare the effects of STN DBS and GPi DBS on the AER. We tested eye movements in 14 human DBS patients and 10 controls. GPi DBS substantially reduced the AER, restoring lost higher control over oculomotor function. Interloop information flow involves striatal neurons that receive cortical input and project to pallidum. They are normally silent when quiescent, but in PD they fire randomly, creating noise that may account for the degradation in interloop control. The reduced AER with GPi DBS could be explained by retrograde stimulation of striatopallidal axons with consequent activation of inhibitory collaterals and reduction in background striatal firing rates. This study may help explain aspects of PD pathophysiology and the mechanism of action of GPi DBS. SIGNIFICANCE STATEMENT Parkinson's disease causes symptoms including stiffness, slowness of movement, and tremor. Electrical stimulation of specific areas deep in the brain can effectively treat these symptoms, but exactly how is not fully understood. Part of the cause of such symptoms may be impairments in the way information

  10. Microelectrode Guided Implantation of Electrodes into the Subthalamic Nucleus of Rats for Long-term Deep Brain Stimulation.

    PubMed

    Fluri, Felix; Bieber, Micheal; Volkmann, Jens; Kleinschnitz, Christoph

    2015-01-01

    Deep brain stimulation (DBS) is a widely used and effective therapy for several neurologic disorders, such as idiopathic Parkinson's disease, dystonia or tremor. DBS is based on the delivery of electrical stimuli to specific deep anatomic structures of the central nervous system. However, the mechanisms underlying the effect of DBS remain enigmatic. This has led to an interest in investigating the impact of DBS in animal models, especially in rats. As DBS is a long-term therapy, research should be focused on molecular-genetic changes of neural circuits that occur several weeks after DBS. Long-term DBS in rats is challenging because the rats move around in their cage, which causes problems in keeping in place the wire leading from the head of the animal to the stimulator. Furthermore, target structures for stimulation in the rat brain are small and therefore electrodes cannot easily be placed at the required position. Thus, a set-up for long-lasting stimulation of rats using platinum/iridium electrodes with an impedance of about 1 MΩ was developed for this study. An electrode with these specifications allows for not only adequate stimulation but also recording of deep brain structures to identify the target area for DBS. In our set-up, an electrode with a plug for the wire was embedded in dental cement with four anchoring screws secured onto the skull. The wire from the plug to the stimulator was protected by a stainless-steel spring. A swivel was connected to the circuit to prevent the wire from becoming tangled. Overall, this stimulation set-up offers a high degree of free mobility for the rat and enables the head plug, as well as the wire connection between the plug and the stimulator, to retain long-lasting strength. PMID:26485522

  11. Potential predictors for the amount of intra-operative brain shift during deep brain stimulation surgery

    NASA Astrophysics Data System (ADS)

    Datteri, Ryan; Pallavaram, Srivatsan; Konrad, Peter E.; Neimat, Joseph S.; D'Haese, Pierre-François; Dawant, Benoit M.

    2011-03-01

    A number of groups have reported on the occurrence of intra-operative brain shift during deep brain stimulation (DBS) surgery. This has a number of implications for the procedure including an increased chance of intra-cranial bleeding and complications due to the need for more exploratory electrodes to account for the brain shift. It has been reported that the amount of pneumocephalus or air invasion into the cranial cavity due to the opening of the dura correlates with intraoperative brain shift. Therefore, pre-operatively predicting the amount of pneumocephalus expected during surgery is of interest toward accounting for brain shift. In this study, we used 64 DBS patients who received bilateral electrode implantations and had a post-operative CT scan acquired immediately after surgery (CT-PI). For each patient, the volumes of the pneumocephalus, left ventricle, right ventricle, third ventricle, white matter, grey matter, and cerebral spinal fluid were calculated. The pneumocephalus was calculated from the CT-PI utilizing a region growing technique that was initialized with an atlas-based image registration method. A multi-atlas-based image segmentation method was used to segment out the ventricles of each patient. The Statistical Parametric Mapping (SPM) software package was utilized to calculate the volumes of the cerebral spinal fluid (CSF), white matter and grey matter. The volume of individual structures had a moderate correlation with pneumocephalus. Utilizing a multi-linear regression between the volume of the pneumocephalus and the statistically relevant individual structures a Pearson's coefficient of r = 0.4123 (p = 0.0103) was found. This study shows preliminary results that could be used to develop a method to predict the amount of pneumocephalus ahead of the surgery.

  12. Dopamine Dysregulation Syndrome and Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson's Disease

    PubMed Central

    De la Casa-Fages, Beatriz; Grandas, Francisco

    2011-01-01

    Dopamine dysregulation syndrome is a complication of the dopaminergic treatment in Parkinson's disease that may be very disabling due to the negative impact that compulsive medication use may have on patients' social, psychological, and physical functioning. The relationship between subthalamic nucleus deep brain stimulation and dopamine dysregulation syndrome in patients with Parkinson's disease remains unclear. Deep brain stimulation may improve, worsen, or have no effect on preoperative dopamine dysregulation syndrome. Moreover, dopamine dysregulation syndrome may appear for the first time after deep brain stimulation of the subthalamic nucleus. The outcome of postoperative dopamine dysregulation syndrome is poor despite stimulation and medication adjustments. Here we review the phenomenology and neurobiology of this disorder, discuss possible mechanisms that may underlie the diverse outcomes of dopamine dysregulation syndrome after subthalamic nucleus deep brain stimulation, and propose management strategies. PMID:22135744

  13. A Low Power Micro Deep Brain Stimulation Device for Murine Preclinical Research

    PubMed Central

    Abulseoud, Osama A.; Tye, Susannah J.; Hosain, Md Kamal; Berk, Michael

    2013-01-01

    Deep brain stimulation has emerged as an effective medical procedure that has therapeutic efficacy in a number of neuropsychiatric disorders. Preclinical research involving laboratory animals is being conducted to study the principles, mechanisms, and therapeutic effects of deep brain stimulation. A bottleneck is, however, the lack of deep brain stimulation devices that enable long term brain stimulation in freely moving laboratory animals. Most of the existing devices employ complex circuitry, and are thus bulky. These devices are usually connected to the electrode that is implanted into the animal brain using long fixed wires. In long term behavioral trials, however, laboratory animals often need to continuously receive brain stimulation for days without interruption, which is difficult with existing technology. This paper presents a low power and lightweight portable microdeep brain stimulation device for laboratory animals. Three different configurations of the device are presented as follows: 1) single piece head mountable; 2) single piece back mountable; and 3) two piece back mountable. The device can be easily carried by the animal during the course of a clinical trial, and that it can produce non-stop stimulation current pulses of desired characteristics for over 12 days on a single battery. It employs passive charge balancing to minimize undesirable effects on the target tissue. The results of bench, in-vitro, and in-vivo tests to evaluate the performance of the device are presented. PMID:27170861

  14. A Low Power Micro Deep Brain Stimulation Device for Murine Preclinical Research.

    PubMed

    Kouzani, Abbas Z; Abulseoud, Osama A; Tye, Susannah J; Hosain, M D Kamal; Berk, Michael

    2013-01-01

    Deep brain stimulation has emerged as an effective medical procedure that has therapeutic efficacy in a number of neuropsychiatric disorders. Preclinical research involving laboratory animals is being conducted to study the principles, mechanisms, and therapeutic effects of deep brain stimulation. A bottleneck is, however, the lack of deep brain stimulation devices that enable long term brain stimulation in freely moving laboratory animals. Most of the existing devices employ complex circuitry, and are thus bulky. These devices are usually connected to the electrode that is implanted into the animal brain using long fixed wires. In long term behavioral trials, however, laboratory animals often need to continuously receive brain stimulation for days without interruption, which is difficult with existing technology. This paper presents a low power and lightweight portable microdeep brain stimulation device for laboratory animals. Three different configurations of the device are presented as follows: 1) single piece head mountable; 2) single piece back mountable; and 3) two piece back mountable. The device can be easily carried by the animal during the course of a clinical trial, and that it can produce non-stop stimulation current pulses of desired characteristics for over 12 days on a single battery. It employs passive charge balancing to minimize undesirable effects on the target tissue. The results of bench, in-vitro, and in-vivo tests to evaluate the performance of the device are presented. PMID:27170861

  15. Comparison of cervical magnetic stimulation and bilateral percutaneous electrical stimulation of the phrenic nerves in normal subjects.

    PubMed

    Wragg, S; Aquilina, R; Moran, J; Ridding, M; Hamnegard, C; Fearn, T; Green, M; Moxham, J

    1994-10-01

    Cervical magnetic stimulation is a new technique for stimulating the phrenic nerves, and may offer an alternative to percutaneous electrical stimulation for assessing diaphragmatic strength in normal subjects and patients in whom electrical stimulation is technically difficult or poorly tolerated. We compared cervical magnetic stimulation with conventional supramaximal bilateral percutaneous electrical stimulation in nine normal subjects. We measured oesophageal pressure (Poes), gastric pressure (Pgas) and transdiaphragmatic pressure (Pdi). The maximal relaxation rate (MRR) was also measured. The mean magnetic twitch Pdi was 36.5 cmH2O (range 27-48 cmH2O), significantly larger than electrical twitch Pdi, mean 29.7 cmH2O (range 22-40 cmH2O). The difference in twitch Pdi was explained entirely by twitch Poes, and it is possible that the magnetic technique stimulates some of the nerves to the upper chest wall muscles as well as the phrenic nerves. We compared bilateral, rectified, integrated, diaphragm surface electromyographic (EMG) responses in three subjects and found results within 10% in each subject, indicating similar diaphragmatic activation. The within occasion coefficient of variation, i.e. same subject/same session, was 6.7% both for magnetic and electrical twitch Pdi. The between occasion coefficient of variation, i.e. same subject/different days, was 6.6% for magnetic stimulation and 8.8% for electrical. There was no difference between relaxation rates measured with either technique. We conclude that magnetic stimulation is a reproducible and acceptable technique for stimulating the phrenic nerves, and that it provides a potentially useful alternative to conventional electrical stimulation as a nonvolitional test of diaphragm strength. PMID:7828686

  16. Nonmotor Symptoms and Subthalamic Deep Brain Stimulation in Parkinson’s Disease

    PubMed Central

    Kim, Han-Joon; Jeon, Beom S.; Paek, Sun Ha

    2015-01-01

    Subthalamic deep brain stimulation (STN DBS) is an established treatment for the motor symptoms in patients with advanced Parkinson’s disease (PD). In addition to improvements in motor symptoms, many studies have reported changes in various nonmotor symptoms (NMSs) after STN DBS in patients with PD. Psychiatric symptoms, including depression, apathy, anxiety, and impulsivity, can worsen or improve depending on the electrical stimulation parameters, the locations of the stimulating contacts within the STN, and changes in medications after surgery. Global cognitive function is not affected by STN DBS, and there is no increase in the incidence of dementia after STN DBS compared to that after medical treatment, although clinically insignificant declines in verbal fluency have been consistently reported. Pain, especially PD-related pain, improves with STN DBS. Evidence regarding the effects of STN DBS on autonomic symptoms and sleep-related problems is limited and remains conflicting. Many symptoms of nonmotor fluctuations, which are occasionally more troublesome than motor fluctuations, improve with STN DBS. Although it is clear that NMSs are not target symptoms for STN DBS, NMSs have a strong influence on the quality of life of patients with PD, and clinicians should thus be aware of these NMSs when deciding whether to perform surgery and should pay attention to changes in these symptoms after STN DBS to ensure the optimal care for patients. PMID:26090080

  17. Emerging technology: electrical stimulation in obstructive sleep apnoea

    PubMed Central

    Steier, Joerg

    2015-01-01

    Electrical stimulation (ES) of the upper airway (UAW) dilator muscles for patients with obstructive sleep apnoea (OSA) has been used for several decades, but in recent years research in this field has experienced a renaissance; the results of several studies have triggered a steady rise in the interest in this topic. Prospective trials, although still lacking a sham-controlled and randomised approach, have revealed the potential of ES. Hypoglossal nerve stimulation (HNS) leads to a significant reduction in the apnoea-hypopnoea index and the oxygen desaturation index (ODI). There are similar results published from feasibility studies for transcutaneous ES. A limitation of HNS remains the invasive procedure, the costs involved and severe adverse events, while for the non-invasive approach complications are rare and limited. The limiting step for transcutaneous ES is to deliver a sufficient current without causing arousal from sleep. Despite the progress up to date, numerous variables including optimal stimulation settings, different devices and procedures remain to be further defined for the invasive and the non-invasive method. Further studies are required to identify which patients respond to this treatment. ES of the UAW dilator muscles in OSA has the potential to develop into a clinical alternative to continuous positive airway pressure (CPAP) therapy. It could benefit selected patients who fail standard therapy due to poor long-term compliance. It is likely that international societies will need to review and update their existing guidance on the use of ES in OSA. PMID:26380757

  18. Optic nerve evoked potentials elicited by electrical stimulation.

    PubMed

    Kikuchi, Yasuhiro; Sasaki, Tatsuya; Matsumoto, Masato; Oikawa, Tomoyoshi; Itakura, Takeshi; Kodama, Namio

    2005-07-01

    This study investigated whether the optic nerve evoked potential (ONEP) elicited by electrical stimulation of the optic nerve can serve as a reliable intraoperative indicator of visual function. In the experimental study, two silver-ball stimulating electrodes were placed on the dog optic nerve adjacent to the apex of the orbit and one recording electrode was placed on the optic nerve near the chiasm. The nerve was stimulated with 0.1 to 10 mA rectangular pulses. Stable and reproducible ONEPs were obtained. The ONEPs were not influenced by electromyographic potentials and were recorded more clearly on the optic nerve than on the surrounding tissue. Stepwise incremental transection of the thickness of the nerve resulted in incremental amplitude reduction proportional to the transected area. No response was recorded after complete sectioning of the nerve. In the clinical study, recordings were obtained from 15 patients after craniotomy to treat parasellar tumors or cerebral aneurysms. Reproducible ONEPs were recorded intraoperatively from the electrode placed on the optic nerve near the chiasm in 14 of 15 patients. In the remaining patient, the ONEP, recorded only after tumor removal because the optic nerve was stretched and extremely thin, was remarkably small and the patient developed unilateral blindness postoperatively. These experimental and clinical results suggest the possibility of intraoperative monitoring of visual function in patients undergoing craniotomy for the treatment of lesions near the optic nerve. PMID:16041180

  19. Electrical stimulation to optimize cardioprotective exosomes from cardiac stem cells.

    PubMed

    Campbell, C R; Berman, A E; Weintraub, N L; Tang, Y L

    2016-03-01

    Injured or ischemic cardiac tissue has limited intrinsic capacity for regeneration. While stem cell transplantation is a promising approach to stimulating cardiac repair, its success in humans has thus far been limited. Harnessing the therapeutic benefits of stem cells requires a better understanding of their mechanisms of action and methods to optimize their function. Cardiac stem cells (CSC) represent a particularly effective cellular source for cardiac repair, and pre-conditioning CSC with electrical stimulation (EleS) was demonstrated to further enhance their function, although the mechanisms are unknown. Recent studies suggest that transplanted stem cells primarily exert their effects through communicating with endogenous tissues via the release of exosomes containing cardioprotective molecules such as miRNAs, which upon uptake by recipient cells may stimulate survival, proliferation, and angiogenesis. Exosomes are also effective therapeutic agents in isolation and may provide a feasible alternative to stem cell transplantation. We hypothesize that EleS enhances CSC-mediated cardiac repair through its beneficial effects on production of cardioprotective exosomes. Moreover, we hypothesize that the beneficial effects of biventricular pacing in patients with heart failure may in part result from EleS-induced preconditioning of endogenous CSC to promote cardiac repair. With future research, our hypothesis may provide applications to optimize stem cell therapy and augment current pacing protocols, which may significantly advance the treatment of patients with heart disease. PMID:26880625

  20. Programmable and on-demand drug release using electrical stimulation

    PubMed Central

    Yi, Y. T.; Sun, J. Y.; Lu, Y. W.; Liao, Y. C.

    2015-01-01

    Recent advancement in microfabrication has enabled the implementation of implantable drug delivery devices with precise drug administration and fast release rates at specific locations. This article presents a membrane-based drug delivery device, which can be electrically stimulated to release drugs on demand with a fast release rate. Hydrogels with ionic model drugs are sealed in a cylindrical reservoir with a separation membrane. Electrokinetic forces are then utilized to drive ionic drug molecules from the hydrogels into surrounding bulk solutions. The drug release profiles of a model drug show that release rates from the device can be electrically controlled by adjusting the stimulated voltage. When a square voltage wave is applied, the device can be quickly switched between on and off to achieve pulsatile release. The drug dose released is then determined by the duration and amplitude of the applied voltages. In addition, successive on/off cycles can be programmed in the voltage waveforms to generate consistent and repeatable drug release pulses for on-demand drug delivery. PMID:25825612

  1. [The transition of deep brain stimulation from disease specific to symptom specific indications].

    PubMed

    Okun, Michael S

    2012-01-01

    The success of chronic deep brain stimulation (DBS) and electrical neuro-network modulation (ENM) to address neurological and neuropsychiatric disorders has led the Food and Drug Administration (FDA), and also other worldwide regulatory agencies to grant approval for the use of DBS in specific disorders. In the United States, DBS is FDA approved for the treatment of advanced Parkinson's disease (PD), essential tremor (ET), obsessive compulsive disorder (OCD), and for dystonia. OCD and dystonia have been approved under a mechanism referred to as a humanitarian device exemption (HDE). However, as the field of DBS and ENM evolve there has been a shift in practice patterns from targeting diseases to targeting specific and disabling symptoms. This shift has been driving interdisciplinary DBS boards to collect, and to address symptom profiles in all potential DBS candidates. Based on a specific symptom profile, a strategic and personalized medicine approach can be undertaken. The personalized approach will take into consideration the brain target, a unilateral versus a bilateral procedure, and the potential for use of more than one DBS lead per brain hemisphere. Additionally, a personalized approach to DBS will also facilitate improved pre-operative medication adjustments, as well as optimal post-operative medication, behavioral, and device management. PMID:23196455

  2. Electromagnetic Field Modeling of Transcranial Electric and Magnetic Stimulation: Targeting, Individualization, and Safety of Convulsive and Subconvulsive Applications

    NASA Astrophysics Data System (ADS)

    Deng, Zhi-De

    The proliferation of noninvasive transcranial electric and magnetic brain stimulation techniques and applications in recent years has led to important insights into brain function and pathophysiology of brain-based disorders. Transcranial electric and magnetic stimulation encompasses a wide spectrum of methods that have developed into therapeutic interventions for a variety of neurological and psychiatric disorders. Although these methods are at different stages of development, the physical principle underlying these techniques is the similar. Namely, an electromagnetic field is induced in the brain either via current injection through scalp electrodes or via electromagnetic induction. The induced electric field modulates the neuronal transmembrane potentials and, thereby, neuronal excitability or activity. Therefore, knowledge of the induced electric field distribution is key in the design and interpretation of basic research and clinical studies. This work aims to delineate the fundamental physical limitations, tradeoffs, and technological feasibility constraints associated with transcranial electric and magnetic stimulation, in order to inform the development of technologies that deliver safer, and more spatially, temporally, and patient specific stimulation. Part I of this dissertation expounds on the issue of spatial targeting of the electric field. Contrasting electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) configurations that differ markedly in efficacy, side effects, and seizure induction efficiency could advance our understanding of the principles linking treatment parameters and therapeutic outcome and could provide a means of testing hypotheses of the mechanisms of therapeutic action. Using the finite element method, we systematically compare the electric field characteristics of existing forms of ECT and MST. We introduce a method of incorporating a modality-specific neural activation threshold in the electric field models that can

  3. Transcranial magnetic stimulation: studying the brain-behaviour relationship by induction of 'virtual lesions'.

    PubMed Central

    Pascual-Leone, A; Bartres-Faz, D; Keenan, J P

    1999-01-01

    Transcranial magnetic stimulation (TMS) provides a non-invasive method of induction of a focal current in the brain and transient modulation of the function of the targeted cortex. Despite limited understanding about focality and mechanisms of action, TMS provides a unique opportunity of studying brain-behaviour relations in normal humans. TMS can enhance the results of other neuroimaging techniques by establishing the causal link between brain activity and task performance, and by exploring functional brain connectivity. PMID:10466148

  4. [Non-invasive brain stimulation in neurology : Transcranial direct current stimulation to enhance cognitive functioning].

    PubMed

    Antonenko, D; Flöel, A

    2016-08-01

    Transcranial direct current stimulation (tDCS) has been successfully used in neuroscientific research to modulate cognitive functions. Recent studies suggested that improvement of behavioral performance is associated with tDCS-induced modulation of neuronal activity and connectivity. Thus, tDCS may also represent a promising tool for reconstitution of cognitive functions in the context of memory decline related to Alzheimer's disease or aphasia following stroke; however, evidence from randomized sham-controlled clinical trials is still scarce. Initial results of tDCS-induced behavioral improvement in patients with Alzheimer's dementia and its precursors indicated that an intense memory training combined with tDCS may be effective. Early interventions in the stage of mild cognitive impairment could be crucial but further evidence is needed to substantiate this. In patients with aphasia following stroke tDCS was applied to the left and right hemispheres, with varying results depending on the severity of the symptoms and polarity of the stimulation. Patients with mild aphasia can benefit from tDCS of the language dominant hemisphere while in patients with severe aphasia tDCS of right hemispheric homologous brain language areas may be particularly relevant. Moreover, recent studies suggested that an intervention in the subacute phase of aphasia could be most promising. In summary, tDCS could provide the exciting possibility to reconstitute cognitive functions in patients with neurological disorders. Future studies have to elucidate whether tDCS can be used in the clinical routine to prevent further cognitive decline in neurodegenerative diseases and whether beneficial effects from experimental studies translate into long-term improvement in activities of daily life. PMID:27167887

  5. Noninvasive transcranial focused ultrasonic-magnetic stimulation for modulating brain oscillatory activity

    NASA Astrophysics Data System (ADS)

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-02-01

    A novel technique, transcranial focused ultrasonic-magnetic stimulation (tFUMS), has been developed for noninvasive brain modulation in vivo. tFUMS has a higher spatial resolution (<2 mm) and a higher penetration depth than other noninvasive neuromodulation methods. The in vivo animal experimental results show that tFUMS can not only increase the power of local field potentials and the firing rate of the neurons, but also enhance the effect of transcranial focused ultrasound stimulation on the neuromodulation. The results demonstrate that tFUMS can modulate brain oscillatory activities by stimulating brain tissues.

  6. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton.

    PubMed

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  7. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton

    PubMed Central

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  8. Influence of electrical stimulation on hip joint adductor muscle activity during maximum effort

    PubMed Central

    Nakano, Sota; Wada, Chikamune

    2016-01-01

    [Purpose] This study investigated whether hip adductor activity was influenced by electrical stimulation of the tensor fascia lata muscle. [Subjects and Methods] The subjects were 16 nondisabled males. Each subject was asked to adduct the hip joint with maximum effort. The electromyogram of the adductor longus was recorded under two experimental conditions, with and without electrical stimulation of the tensor fascia lata. [Results] In the presence of electrical stimulation, muscle activity decreased to 72.9% (57.8–89.3%) of that without stimulation. [Conclusion] These results suggested that inactivation of the adductor group was promoted by electrical stimulation of the tensor fascia lata. PMID:27313387

  9. 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

  10. Analysis of deep brain stimulation electrode characteristics for neural recording

    NASA Astrophysics Data System (ADS)

    Kent, Alexander R.; Grill, Warren M.

    2014-08-01

    Objective. Closed-loop deep brain stimulation (DBS) systems have the potential to optimize treatment of movement disorders by enabling automatic adjustment of stimulation parameters based on a feedback signal. Evoked compound action potentials (ECAPs) and local field potentials (LFPs) recorded from the DBS electrode may serve as suitable closed-loop control signals. The objective of this study was to understand better the factors that influence ECAP and LFP recording, including the physical presence of the electrode, the geometrical dimensions of the electrode, and changes in the composition of the peri-electrode space across recording conditions. Approach. Coupled volume conductor-neuron models were used to calculate single-unit activity as well as ECAP responses and LFP activity from a population of model thalamic neurons. Main results. Comparing ECAPs and LFPs measured with and without the presence of the highly conductive recording contacts, we found that the presence of these contacts had a negligible effect on the magnitude of single-unit recordings, ECAPs (7% RMS difference between waveforms), and LFPs (5% change in signal magnitude). Spatial averaging across the contact surface decreased the ECAP magnitude in a phase-dependent manner (74% RMS difference), resulting from a differential effect of the contact on the contribution from nearby or distant elements, and decreased the LFP magnitude (25% change). Reductions in the electrode diameter or recording contact length increased signal energy and increased spatial sensitivity of single neuron recordings. Moreover, smaller diameter electrodes (500 µm) were more selective for recording from local cells over passing axons, with the opposite true for larger diameters (1500 µm). Changes in electrode dimensions had phase-dependent effects on ECAP characteristics, and generally had small effects on the LFP magnitude. ECAP signal energy and LFP magnitude decreased with tighter contact spacing (100 µm), compared to

  11. A Gastrointestinal Electrical Stimulation System Based on Transcutaneous Power Transmission Technology

    PubMed Central

    Zhu, Bingquan; Wang, Yongbing; Yan, Guozheng; Jiang, Pingping; Liu, Zhiqiang

    2014-01-01

    Electrical