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Find video protocols related to scientific articles indexed in Pubmed.
Cerebellar Transcranial Direct Current Stimulation (ctDCS): A Novel Approach to Understanding Cerebellar Function in Health and Disease.
Neuroscientist
PUBLISHED: 11-20-2014
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The cerebellum is critical for both motor and cognitive control. Dysfunction of the cerebellum is a component of multiple neurological disorders. In recent years, interventions have been developed that aim to excite or inhibit the activity and function of the human cerebellum. Transcranial direct current stimulation of the cerebellum (ctDCS) promises to be a powerful tool for the modulation of cerebellar excitability. This technique has gained popularity in recent years as it can be used to investigate human cerebellar function, is easily delivered, is well tolerated, and has not shown serious adverse effects. Importantly, the ability of ctDCS to modify behavior makes it an interesting approach with a potential therapeutic role for neurological patients. Through both electrical and non-electrical effects (vascular, metabolic) ctDCS is thought to modify the activity of the cerebellum and alter the output from cerebellar nuclei. Physiological studies have shown a polarity-specific effect on the modulation of cerebellar-motor cortex connectivity, likely via cerebellar-thalamocortical pathways. Modeling studies that have assessed commonly used electrode montages have shown that the ctDCS-generated electric field reaches the human cerebellum with little diffusion to neighboring structures. The posterior and inferior parts of the cerebellum (i.e., lobules VI-VIII) seem particularly susceptible to modulation by ctDCS. Numerous studies have shown to date that ctDCS can modulate motor learning, and affect cognitive and emotional processes. Importantly, this intervention has a good safety profile; similar to when applied over cerebral areas. Thus, investigations have begun exploring ctDCS as a viable intervention for patients with neurological conditions.
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Baseline Brain Activity Predicts Response to Neuromodulatory Pain Treatment.
Pain Med
PUBLISHED: 10-08-2014
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The objective of this study was to examine the associations between baseline electroencephalogram (EEG)-assessed brain oscillations and subsequent response to four neuromodulatory treatments. Based on available research, we hypothesized that baseline theta oscillations would prospectively predict response to hypnotic analgesia. Analyses involving other oscillations and the other treatments (meditation, neurofeedback, and both active and sham transcranial direct current stimulation) were viewed as exploratory, given the lack of previous research examining brain oscillations as predictors of response to these other treatments.
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Effects of tDCS on executive function in Parkinson's disease.
Neurosci. Lett.
PUBLISHED: 08-30-2014
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Non-motor symptoms in patients with Parkinson's disease (PD) are often poorly recognized, significantly impair quality of life and cause severe disability. Currently, there is limited evidence to guide treatment of associated psychiatric and cognitive problems. Non-invasive brain stimulation techniques have emerged as non-pharmacological alternatives to target cognitive symptoms without worsening motor function. In this context, we conducted a multicenter, sham controlled, double-blinded study to assess the immediate and long-term effects of ten consecutive sessions of transcranial direct current stimulation (tDCS) over the anode on the right dorsolateral prefrontal cortex (DLPFC) (n=5), left DLPFC (n=6) or sham (n=7). We assessed cognitive functions, depressive symptoms and motor functions in 18 PD patients at baseline, at the end of the 2-week stimulation sessions and at 1-month follow-up. Our results showed that active stimulation of both left and right DLPFC resulted in prolonged improvements in Trail Making Test B, an established test to measure executive function, compared to sham tDCS at the 1-month follow-up. These results suggest the existence of a beneficial long-term effect on executive functions in PD patients following active tDCS over the DLPFC. Thus, our findings encourage further investigation exploring tDCS as an adjuvant therapy for cognitive and behavioral treatment in PD.
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Effect of transcranial direct-current stimulation combined with treadmill training on balance and functional performance in children with cerebral palsy: a double-blind randomized controlled trial.
PLoS ONE
PUBLISHED: 08-29-2014
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Cerebral palsy refers to permanent, mutable motor development disorders stemming from a primary brain lesion, causing secondary musculoskeletal problems and limitations in activities of daily living. The aim of the present study was to determine the effects of gait training combined with transcranial direct-current stimulation over the primary motor cortex on balance and functional performance in children with cerebral palsy.
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Neural Markers of Neuropathic Pain Associated with Maladaptive Plasticity in Spinal Cord Injury.
Pain Pract
PUBLISHED: 08-28-2014
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Given the potential use of neural markers for the development of novel treatments in spinal cord pain, we aimed to characterize the most effective neural markers of neuropathic pain following spinal cord injury (SCI).
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Transcranial direct current stimulation modulates ERP-indexed inhibitory control and reduces food consumption.
Appetite
PUBLISHED: 08-13-2014
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Food craving can be defined as the "urge to eat a specific food". Previous findings suggest impairment of inhibitory control, specifically a regulatory deficit in the lateral prefrontal circuitry that is associated with a compulsion for food. As demonstrated by three previous studies, bilateral transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) (anode right/cathode left) reduces food craving and caloric intake. We designed the present study to evaluate the neural mechanisms that underlie these effects. We replicated the design of one of these previous studies but included electroencephalographic assessments to register evoked potentials in a Go/No-go task that contained pictures of food and furniture (a control visual stimulus). We collected data from nine women (mean age?=?23.4?±?2 years) in a crossover experiment. We observed that active DLPFC tDCS (anode right/cathode left), compared with sham stimulation, reduced the frontal N2 component and enhanced the P3a component of responses to No-go stimuli, regardless of the stimulus condition (food or furniture). Active tDCS was also associated with a reduction in caloric intake. We discuss our findings in the context of cortico-subcortical processing of craving and tDCS effects on inhibitory control neural circuitry.
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Transcranial direct current stimulation during treadmill training in children with cerebral palsy: a randomized controlled double-blind clinical trial.
Res Dev Disabil
PUBLISHED: 08-06-2014
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Impaired gait constitutes an important functional limitation in children with cerebral palsy (CP). Treadmill training has achieved encouraging results regarding improvements in the gait pattern of this population. Moreover, transcranial direct current stimulation (tDCS) is believed to potentiate the results achieved during the motor rehabilitation process. The aim of the present study was to determine the effect of the administration of tDCS during treadmill training on the gait pattern of children with spastic diparetic CP. A double-blind randomized controlled trial was carried out involving 24 children with CP allocated to either an experimental group (active anodal tDCS [1mA] over the primary motor cortex of the dominant hemisphere) or control group (placebo tDCS) during ten 20-min sessions of treadmill training. The experimental group exhibited improvements in temporal functional mobility, gait variables (spatiotemporal and kinematics variables). The results were maintained one month after the end of the intervention. There was a significant change in corticospinal excitability as compared to control group. In the present study, the administration of tDCS during treadmill training potentiated the effects of motor training in children with spastic diparetic CP.
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Intensity-dependent effects of transcranial pulsed current stimulation on interhemispheric connectivity: a high-resolution qEEG, sham-controlled study.
Neuroreport
PUBLISHED: 07-24-2014
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Defining optimal parameters for stimulation is a critical step in the development of noninvasive neuromodulation techniques. Transcranial pulsed current stimulation (tPCS) is emerging as another option in the field of neuromodulation; however, little is known about its mechanistic effects on electrical brain activity and how it can modulate its oscillatory patterns. The aim of this study was to identify the current intensity needed to exert an effect on quantitative electroencephalogram (qEEG) measurements. Forty healthy volunteers were randomized to receive a single session of sham or active stimulation at 0.2, 1, or 2?mA current intensity with a random frequency with an oscillatory pulsed range between 1 and 5?Hz. We conducted an exploratory frequency domain analysis to detect changes in absolute power for theta, alpha, and beta frequency bands and also interhemispheric coherence for alpha, theta, and four different sub-bands. Cognitive and nonspecific adverse effects were also recorded. Our results showed that both 1 and 2?mA can modulate interhemispheric coherence at the fronto-temporal areas for the theta band as compared with sham, while 2?mA also increased the low-beta and high-beta interhemispheric coherence at the same anatomical location. There were no group differences for adverse effects and participants could not guess correctly whether they received active versus sham stimulation. On the basis of our results, we conclude that tPCS is associated with an intensity-dependent facilitatory effect on interhemispheric connectivity. These results can guide future tPCS applications and will define its role as a neuromodulatory technique in the field.
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A randomized controlled trial of targeted prefrontal cortex modulation with tDCS in patients with alcohol dependence.
Int. J. Neuropsychopharmacol.
PUBLISHED: 07-10-2014
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Preliminary small studies have shown that transcranial direct current stimulation (tDCS) reduces craving in alcoholic subjects. It is unclear whether tDCS also leads to changes in clinically meaningful outcomes for alcohol dependence in a properly powered phase II randomized clinical trial. We aimed to investigate whether repetitive tDCS changes the risk of alcohol use relapse in severe alcoholics from outpatient services. Thirty-five subjects were randomized to receive active bilateral [left cathodal/right anodal over the dorsolateral prefrontal cortex (dlPFC)] repetitive (five consecutive days) tDCS (2 mA, 35 cm2, two times daily stimulation for 13 min with a 20-min interval) or sham-tDCS. There were two dropouts before treatment. From 33 alcoholic subjects, 17 (mean age 45.5±8.9 s.d., 16 males) were randomized to sham and 16 (44±7.8 s.d., 16 males) to real tDCS treatment. By the end of the six months of follow-up, two subjects treated with sham (11.8%) and eight treated with real tDCS (50%) were still alcohol-abstinent [p=0.02, Long-rank (Mantel-Cox) Test, HR=0.35 (95% CI, 0.14-0.85)]. No differences with regard to changes on scores of craving, frontal function, global mental status, depressive or anxiety symptoms were observed between groups. However, subjects from the tDCS group improved with regard to their overall perception of quality of life (p=0.02), and increased their scores in the environment domain (p=0.04) after treatment. Bilateral tDCS over dlPFC reduces relapse probability in severe alcoholic subjects and results in improved perception of quality of life.
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Effect of exercise on balance in persons with mild cognitive impairment.
NeuroRehabilitation
PUBLISHED: 07-04-2014
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Individuals with definite cognitive impairment and mild cognitive impairment (MCI) show motor dysfunction.
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Effect of a single session of transcranial direct-current stimulation on balance and spatiotemporal gait variables in children with cerebral palsy: A randomized sham-controlled study.
Braz J Phys Ther
PUBLISHED: 06-09-2014
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Transcranial direct-current stimulation (tDCS) has been widely studied with the aim of enhancing local synaptic efficacy and modulating the electrical activity of the cortex in patients with neurological disorders.
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Effect of a single session of transcranial direct-current stimulation on balance and spatiotemporal gait variables in children with cerebral palsy: A randomized sham-controlled study.
Braz J Phys Ther
PUBLISHED: 06-09-2014
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Background: Transcranial direct-current stimulation (tDCS) has been widely studied with the aim of enhancing local synaptic efficacy and modulating the electrical activity of the cortex in patients with neurological disorders. Objective: The purpose of the present study was to determine the effect of a single session of tDCS regarding immediate changes in spatiotemporal gait and oscillations of the center of pressure (30 seconds) in children with cerebral palsy (CP). Method: A randomized controlled trial with a blinded evaluator was conducted involving 20 children with CP between six and ten years of age. Gait and balance were evaluated three times: Evaluation 1 (before the stimulation), Evaluation 2 (immediately after stimulation), and Evaluation 3 (20 minutes after the stimulation). The protocol consisted of a 20-minute session of tDCS applied to the primary motor cortex at an intensity of 1 mA. The participants were randomly allocated to two groups: experimental group - anodal stimulation of the primary motor cortex; and control group - placebo transcranial stimulation. Results: Significant reductions were found in the experimental group regarding oscillations during standing in the anteroposterior and mediolateral directions with eyes open and eyes closed in comparison with the control group (p<0.05). In the intra-group analysis, the experimental group exhibited significant improvements in gait velocity, cadence, and oscillation in the center of pressure during standing (p<0.05). No significant differences were found in the control group among the different evaluations. Conclusion: A single session of tDCS applied to the primary motor cortex promotes positive changes in static balance and gait velocity in children with cerebral palsy.
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Clinical research in pediatric organ transplantation.
Clinics (Sao Paulo)
PUBLISHED: 05-27-2014
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Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments.
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State dependent effect of transcranial direct current stimulation (tDCS) on methamphetamine craving.
Int. J. Neuropsychopharmacol.
PUBLISHED: 05-14-2014
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Transcranial direct current stimulation (tDCS) has been shown to modulate subjective craving ratings in drug dependents by modification of cortical excitability in dorsolateral prefrontal cortex (DLPFC). Given the mechanism of craving in methamphetamine (meth) users, we aimed to test whether tDCS of DLPFC could also alter self-reported craving in abstinent meth users while being exposed to meth cues. In this double-blinded, crossover, sham-controlled study, thirty two right-handed abstinent male meth users were recruited. We applied 20 min 'anodal' tDCS (2 mA) or 'sham' tDCS over right DLPFC in a random sequence while subjects performed a computerized cue-induced craving task (CICT) starting after 10 min of stimulation. Immediate craving was assessed before the stimulation, after 10 min of tDCS, and after tDCS termination by visual analog scale (VAS) of 0 to 100. Anodal tDCS of rDLPFC altered craving ratings significantly. We found a significant reduction of craving at rest in real tDCS relative to the sham condition (p = 0.016) after 10 min of stimulation. On the other hand, cue-induced VAS craving was rated significantly higher in the real condition in comparison with sham stimulation (p = 0.012). Our findings showed a state dependent effect of tDCS: while active prefrontal tDCS acutely reduced craving at rest in the abstinent meth users, it increased craving during meth-related cue exposure. These findings reflect the important role of the prefrontal cortex in both cue saliency evaluation and urge to meth consumption.
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Transcranial direct current stimulation (tDCS) and the cardiovascular responses to acute pain in humans.
Clin Neurophysiol
PUBLISHED: 05-07-2014
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To determine if transcranial direct current stimulation (tDCS) reduces both acute pain perception and the resultant cardiovascular responses.
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Cognitive related electrophysiological changes induced by non-invasive cortical electrical stimulation in crack-cocaine addiction.
Int. J. Neuropsychopharmacol.
PUBLISHED: 04-28-2014
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Prefrontal dysfunction is a hallmark in drug addiction, yet interventions exploring modulation of prefrontal cortex function in drug addiction have not been fully investigated with regard to physiological alterations. We tested the hypothesis that non-invasive prefrontal stimulation would change neural activity in crack-cocaine addiction, investigating the effects of transcranial Direct Current Stimulation (tDCS) of Dorsolateral Prefrontal Cortex (DLPFC) induced cortical excitability modulation on the visual P3 Event Related Potentials (ERP) component under neutral and drug cue exposition in crack-cocaine addicts. Thirteen crack-cocaine users were randomly distributed to receive five applications (once a day, every other day) of bilateral (left cathodal/right anodal) tDCS (20 min, 2 mA, 35 cm2) or sham tDCS over the DLPFC. Brain activity was measured under crack-related or neutral visual-cued ERPs. There were significant differences in P3-related parameters when comparing group of stimulation (active vs. sham tDCS) and number of sessions (single vs. repetitive tDCS). After a single session of tDCS, P3 current intensity in the left DLPFC increased during neutral cues and decreased during crack-related cues. This effect was opposite to what was observed in the sham-tDCS group. In contrast, repetitive tDCS increased current density not only in the DLPFC, but also in a wider array of prefrontal areas, including presumably the frontopolar cortex (FPC) orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC), when subjects were visualizing crack-related cues. Thus, single and repetitive application of tDCS can impact cognitive processing of neutral and especially crack-related visual cues in prefrontal areas, which may be of importance for treatment of crack-cocaine addiction.
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Understanding tDCS effects in schizophrenia: a systematic review of clinical data and an integrated computation modeling analysis.
Expert Rev Med Devices
PUBLISHED: 04-22-2014
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Although recent clinical studies using transcranial direct current stimulation (tDCS) for schizophrenia showed encouraging results, several tDCS montages were employed and their current flow pattern has not been investigated. We performed a systematic review to identify clinical tDCS studies in schizophrenia. We then applied computer head modeling analysis for prediction of current flow. Out of 41 references, we identified 12 relevant studies. The most employed montage was anode and cathode over the left dorsolateral prefrontal and temporoparietal cortex, respectively. Computational model analysis predicted activation and under-activation under the anode and the cathode, respectively, occurring in areas respectively associated with negative and positive symptoms. We also identified tDCS-induced electrical currents in cortical areas between the electrodes (frontoparietal network) and, to a lesser extent, in deeper structures involved in schizophrenia pathophysiology. Mechanisms of tDCS effects in schizophrenia and the usefulness of computer modeling techniques for planning tDCS trials in schizophrenia are discussed.
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The appropriate use of neurostimulation: stimulation of the intracranial and extracranial space and head for chronic pain.
Neuromodulation
PUBLISHED: 04-17-2014
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The International Neuromodulation Society (INS) has identified a need for evaluation and analysis of the practice of neurostimulation of the brain and extracranial nerves of the head to treat chronic pain.
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Transcutaneous vagus and trigeminal nerve stimulation for neuropsychiatric disorders: a systematic review.
Arq Neuropsiquiatr
PUBLISHED: 04-15-2014
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We reviewed trigeminal nerve stimulation (TNS) and transcutaneous vagus nerve stimulation (tVNS). All techniques have shown preliminary promising results, although the results are mixed.
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Role of the primary motor cortex in the maintenance and treatment of pain in fibromyalgia.
Med. Hypotheses
PUBLISHED: 04-14-2014
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Fibromyalgia is a highly prevalent, debilitating disease, characterized by chronic widespread pain. The mechanisms underlying pain are not completely understood, but it is believed to be associated with important neuroplastic changes in pain-related neural circuits. Although the involvement of the pain matrix in fibromyalgia is well established, another area that has been found to play a role in the maintenance and treatment of chronic pain is the primary motor cortex (M1). Maladaptive plasticity of M1 is a common finding in patients with chronic pain and many studies in animal models and in human subjects have shown that modulation of the activity of this cortical area induces significant analgesic effects. Furthermore, studies in other chronic pain syndromes have found alterations in baseline characteristics of M1, including an increase in cortical excitability and an abnormally enhanced response to incoming sensory stimuli. Given these findings, we hypothesize that M1 is a major modulator of pain in fibromyalgia and therefore its baseline activity reflects this strong feedback between M1 and pain-related neural areas. However, the feedback loop between M1 and the pain matrix is not enough to decrease pain in fibromyalgia per se, thus increasing its modulatory effect by engaging this network through different behavioral and modulatory techniques is a potentially beneficial treatment for pain in fibromyalgia.
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Transcranial direct current stimulation for major depression: an updated systematic review and meta-analysis.
Int. J. Neuropsychopharmacol.
PUBLISHED: 04-08-2014
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Transcranial direct cranial stimulation (tDCS) is a promising non-pharmacological intervention for treating major depressive disorder (MDD). However, results from randomized controlled trials (RCTs) and meta-analyses are mixed. Our aim was to assess the efficacy of tDCS as a treatment for MDD. We performed a systematic review in Medline and other databases from the first RCT available until January 2014. The main outcome was the Hedges' g for continuous scores; secondary outcomes were the odds ratio (ORs) to achieve response and remission. We used a random-effects model. Seven RCTs (n = 259) were included, most with small sample sizes that assessed tDCS as either a monotherapy or as an add-on therapy. Active vs. sham tDCS was significantly superior for all outcomes (g = 0.37; 95% CI 0.04-0.7; ORs for response and remission were, respectively, 1.63; 95% CI = 1.26-2.12 and 2.50; 95% CI = 1.26-2.49). Risk of publication bias was low. No predictors of response were identified, possibly owing to low statistical power. In summary, active tDCS was statistically superior to sham tDCS for the acute depression treatment, although its role as a clinical intervention is still unclear owing to the mixed findings and heterogeneity of the reviewed studies. Further RCTs with larger sample sizes and assessing tDCS efficacy beyond the acute depressive episode are warranted.
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QEEG indexed frontal connectivity effects of transcranial pulsed current stimulation (tPCS): A sham-controlled mechanistic trial.
Neurosci. Lett.
PUBLISHED: 04-01-2014
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Transcranial pulsed current stimulation (tPCS) is a non-invasive brain stimulation technique that employs weak, pulsed current at different frequency ranges, inducing electrical currents that reach cortical and subcortical structures. Very little is known about its effects on brain oscillations and functional connectivity and whether these effects are dependent on the frequency of stimulation. Our aim was to evaluate the effects of tPCS with different frequency ranges in cortical oscillations indexed by high-resolution qEEG changes for power and interhemispheric coherence. Thirty-eight healthy subjects were enrolled and received a single 20-min session of either sham or active stimulation with 1 Hz, 100 Hz or random frequency (1-5 Hz). We conducted an exploratory analysis to detect changes in mean power for theta, alpha and beta, and interhemispheric coherence for alpha and theta and four different sub-bands cognitive and non-specific adverse effects were recorded. We found that active stimulation with a random frequency ranging between 1 and 5 Hz is able to significantly increase functional connectivity for the theta and low-alpha band as compared to sham and active stimulation with either 1 or 100 Hz. Based on these findings, we discuss the possible effects of tPCS on resting functional connectivity for low-frequency bands in fronto-temporal areas. Future studies should be conducted to investigate the potential benefit of these induced changes in pathologic states.
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Repetitive transcranial magnetic stimulation increases the corticospinal inhibition and the brain-derived neurotrophic factor in chronic myofascial pain syndrome: an explanatory double-blinded, randomized, sham-controlled trial.
J Pain
PUBLISHED: 03-25-2014
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Chronic myofascial pain syndrome has been related to defective descending inhibitory systems. Twenty-four females aged 19 to 65 years with chronic myofascial pain syndrome were randomized to receive 10 sessions of repetitive transcranial magnetic stimulation (rTMS) (n = 12) at 10 Hz or a sham intervention (n = 12). We tested if pain (quantitative sensory testing), descending inhibitory systems (conditioned pain modulation [quantitative sensory testing + conditioned pain modulation]), cortical excitability (TMS parameters), and the brain-derived neurotrophic factor (BDNF) would be modified. There was a significant interaction (time vs group) regarding the main outcomes of the pain scores as indexed by the visual analog scale on pain (analysis of variance, P < .01). Post hoc analysis showed that compared with placebo-sham, the treatment reduced daily pain scores by -30.21% (95% confidence interval = -39.23 to -21.20) and analgesic use by -44.56 (-57.46 to -31.67). Compared to sham, rTMS enhanced the corticospinal inhibitory system (41.74% reduction in quantitative sensory testing + conditioned pain modulation, P < .05), reduced the intracortical facilitation in 23.94% (P = .03), increased the motor evoked potential in 52.02% (P = .02), and presented 12.38 ng/mL higher serum BDNF (95% confidence interval = 2.32-22.38). No adverse events were observed. rTMS analgesic effects in chronic myofascial pain syndrome were mediated by top-down regulation mechanisms, enhancing the corticospinal inhibitory system possibly via BDNF secretion modulation.
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Modulation of smoking and decision-making behaviors with transcranial direct current stimulation in tobacco smokers: a preliminary study.
Drug Alcohol Depend
PUBLISHED: 03-24-2014
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Most tobacco smokers who wish to quit fail to reach their goal. One important, insufficiently emphasized aspect of addiction relates to the decision-making system, often characterized by dysfunctional cognitive control and a powerful drive for reward. Recent proof-of-principle studies indicate that transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) can transiently modulate processes involved in decision-making, and reduce substance intake and craving for various addictions. We previously proposed that this beneficial effect of stimulation for reducing addictive behaviors is in part mediated by more reflective decision-making. The goal of this study was to test whether nicotine intake and decision-making behaviors are modulated by tDCS over the DLPFC in tobacco smokers who wished to quit smoking.
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Association of anxiety with intracortical inhibition and descending pain modulation in chronic myofascial pain syndrome.
BMC Neurosci
PUBLISHED: 03-12-2014
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This study aimed to answer three questions related to chronic myofascial pain syndrome (MPS): 1) Is the motor cortex excitability, as assessed by transcranial magnetic stimulation parameters (TMS), related to state-trait anxiety? 2) Does anxiety modulate corticospinal excitability changes after evoked pain by Quantitative Sensory Testing (QST)? 3) Does the state-trait anxiety predict the response to pain evoked by QST if simultaneously receiving a heterotopic stimulus [Conditional Pain Modulation (CPM)]? We included females with chronic MPS (n = 47) and healthy controls (n = 11), aged 19 to 65 years. Motor cortex excitability was assessed by TMS, and anxiety was assessed based on the State-Trait Anxiety Inventory. The disability related to pain (DRP) was assessed by the Profile of Chronic Pain scale for the Brazilian population (B:PCP:S), and the psychophysical pain measurements were measured by the QST and CPM.
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Movement observation-induced modulation of pain perception and motor cortex excitability.
Clin Neurophysiol
PUBLISHED: 02-22-2014
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The observation of movements increases primary motor cortex (M1) excitability. This exploratory study examined the effects of movement observation on pressure pain threshold (PPT) and transcranial magnetic stimulation (TMS)-indexed corticospinal excitability bilaterally.
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Investigation of Central Nervous System Dysfunction in Chronic Pelvic Pain Using Magnetic Resonance Spectroscopy and Noninvasive Brain Stimulation.
Pain Pract
PUBLISHED: 02-10-2014
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Recent studies demonstrate that chronic pelvic pain is associated with altered afferent sensory input resulting in maladaptive changes in the neural circuitry of pain. To better understand the central changes associated with chronic pelvic pain, we investigated the contributions of critical pain-related neural circuits using single-voxel proton magnetic resonance spectroscopy (MRS) and transcranial direct current stimulation (tDCS).
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Combination of transcranial direct current stimulation and methylphenidate in subacute stroke.
Neurosci. Lett.
PUBLISHED: 02-04-2014
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Noninvasive transcranial direct current stimulation (tDCS) and methylphenidate (MP) are associated with motor recovery after stroke. Based on the potentially complementary mechanisms of these interventions, we examined whether there is an interactive effect between MP and tDCS. In this preliminary study, we randomized subacute stroke subjects to receive tDCS alone, MP alone or combination of tDCS and MP. A blinded rater measured safety, hand function, and cortical excitability before and after treatment. None of the treatments caused any major or severe adverse effects or induced significant differences in cortical excitability. Analysis of variance of gain score, as measured by Purdue pegboard test, showed a significant between-group difference (F(2,6)=12.167, p=0.008). Post hoc analysis showed that the combination treatment effected greater Purdue pegboard gain scores than tDCS alone (p=0.017) or MP alone (p=0.01). Our preliminary data with nine subjects shows an interesting dissociation between motor function improvement and lack of motor corticospinal plasticity changes as indexed by transcranial magnetic stimulation in subacute stroke subjects.
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Differences in methodological quality between positive and negative published clinical trials.
J Adv Nurs
PUBLISHED: 02-01-2014
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Comparison of methodological quality differences in nursing clinical trials with positive and negative findings.
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Transcranial Direct Current Stimulation Combined with Treadmill Gait Training in Delayed Neuro-psychomotor Development.
J Phys Ther Sci
PUBLISHED: 01-08-2014
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[Purpose] The aim of the present study was to describe the results of transcranial direct current stimulation combined with treadmill training in a child with delayed neuro-psychomotor development. [Subject and Methods] Transcranial direct current stimulation (intensity: 1 mA) was applied over the primary motor cortex for 20 minutes during simultaneous treadmill training (2.5?km/h) in ten sessions. [Results] Clinically significant improvement was found in motor development (fine motor subscale, 23 to 25; gross motor subscale, 32 to 41). Reductions in mean oscillation of the center of pressure were found in the anteroposterior (239.2 to 146.5?mm) and mediolateral (177.4 to 149.2?mm) directions. Increases occurred in cadence (106 to 123 steps/minute), step length (0.16 to 0.23 m), step width (0.09 to 0.14 m) and gait velocity with support (0.3 to 0.7 m/s). [Conclusion] After treatment, the child was able to initiate the standing position for the first time and walk without support.
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Chronic pain following physical and emotional trauma: the station nightclub fire.
Front Neurol
PUBLISHED: 01-01-2014
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The purpose of this study was to evaluate factors associated with chronic pain in survivors of a large fire, including those with and without burn injury.
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The reporting of blinding in physical medicine and rehabilitation randomized controlled trials: a systematic review.
J Rehabil Med
PUBLISHED: 12-16-2013
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To conduct a systematic review evaluating the reporting of blinding in randomized controlled trials published in the field of Physical Medicine and Rehabilitation over two time periods.
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Motor cortex-induced plasticity by noninvasive brain stimulation: a comparison between transcranial direct current stimulation and transcranial magnetic stimulation.
Neuroreport
PUBLISHED: 10-09-2013
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The aim of this study was to test and compare the effects of a within-subject design of repetitive transcranial magnetic stimulation (rTMS) [coupled with sham transcranial direct current stimulation (tDCS)] and tDCS (coupled with sham rTMS) on the motor cortex excitability and also compare the results against sham tDCS/sham rTMS. We conducted a double-blinded, randomized, sham-controlled, cross-over trial. Eleven right-handed, healthy individuals (five women, mean age: 39.8 years, SD 13.4) received the three interventions (cross-over design) in a randomized order: (a) high-frequency (HF) rTMS (+sham tDCS), (b) anodal tDCS (+sham rTMS), and (c) sham stimulation (sham rTMS+sham tDCS). Cortical excitability measurements [motor threshold, motor evoked potential (MEP), intracortical facilitation and inhibition, and transcallosal inhibition] and motor behavioral assessments were used as outcome measures. Between-group analysis of variance showed that MEP amplitude after HF rTMS was significantly higher than MEP amplitude after anodal tDCS (P=0.001). Post-hoc analysis showed a significant increase in MEP amplitude after HF rTMS (25.3%, P=0.036) and a significant decrease in MEP amplitude after anodal tDCS (-32.7%, P=0.001). There was a similar increase in motor function as indexed by Jebsen-Taylor Hand Function Test in the two active groups compared with sham stimulation. In conclusion, here, we showed that although both techniques induced similar motor gains, they induce opposing results in cortical excitability. HF rTMS is associated with an increase in corticospinal excitability, whereas 20 min of tDCS induces the opposite effect. We discuss potential implications of these results to future clinical experiments using rTMS or tDCS for motor function enhancement.
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Differential improvement in depressive symptoms for tDCS alone and combined with pharmacotherapy: an exploratory analysis from The Sertraline Vs. Electrical Current Therapy For Treating Depression Clinical Study.
Int. J. Neuropsychopharmacol.
PUBLISHED: 09-23-2013
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Transcranial direct current stimulation (tDCS) is a promising therapy for major depression treatment, although little is known of its effects in ameliorating distinct symptoms of depression. Thus, it is important, not only to increase knowledge of its antidepressant mechanisms, but also to guide its potential use in clinical practice. Using data from a recent factorial, double-blinded, placebo-controlled trial applying tDCS-alone and combined with sertraline to treat 120 depressed outpatients over 6 wk (Brunoni et al., 2013), we investigated the pattern of improvement in symptoms of depression from the Montgomery-Asberg depression scale (MADRS). First, we performed one multivariate analysis of variance with the score improvement of the 10 MADRS items as dependent variables. Significant (p < 0.05) results were further explored with follow-up analyses of variance. TDCS (alone and combined with sertraline) improved concentration difficulties and pessimistic and suicidal thoughts. The combined treatment also improved apparent and reported sadness, lassitude and inability to feel. Indeed, tDCS/sertraline significantly ameliorated all but the vegetative depression symptoms (inner tension, sleep and appetite items). We further discuss whether bifrontal tDCS over the dorsolateral prefrontal cortex could be associated with improvement in cognitive (concentration) and affective (pessimistic/suicidal thoughts) processing, while the combined treatment might have a more widespread antidepressant effect by simultaneously acting on different depression pathways. We also identified patterns of antidepressant improvement for tDCS that might aid in tailoring specific interventions for different subtypes of depressed patients, e.g. particularly those with suicidal ideation.
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Feasibility of Transcranial Direct Current Stimulation Use in Children Aged 5 to 12 Years.
J. Child Neurol.
PUBLISHED: 09-18-2013
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Transcranial direct current stimulation is a noninvasive brain stimulation technique that has been studied for the treatment of neuropsychiatric disorders in adults, with minimal side effects. The objective of this study is to report the feasibility, tolerability, and the short-term adverse effects of transcranial direct current stimulation in children from 5 to 12 years of age. It is a naturalistic study of 14 children who underwent 10 sessions of transcranial direct current stimulation as an alternative, off-label, and open-label treatment for various languages disorders. Frequency, intensity, adverse effects, and perception of improvement reported by parents were collected. The main side effects detected were tingling (28.6%) and itching (28.6%), acute mood changes (42.9%), and irritability (35.7%). Transcranial direct current stimulation is a feasible and tolerable technique in children, although studies regarding plastic and cognitive changes in children are needed to confirm its safety. In conclusion, this is a naturalistic report in which we considered transcranial direct current stimulation as feasible in children.
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Effect of transcranial direct current stimulation combined with gait and mobility training on functionality in children with cerebral palsy: study protocol for a double-blind randomized controlled clinical trial.
BMC Pediatr
PUBLISHED: 09-16-2013
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The project proposes three innovative intervention techniques (treadmill training, mobility training with virtual reality and transcranial direct current stimulation that can be safely administered to children with cerebral palsy. The combination of transcranial stimulation and physical therapy resources will provide the training of a specific task with multiple rhythmic repetitions of the phases of the gait cycle, providing rich sensory stimuli with a modified excitability threshold of the primary motor cortex to enhance local synaptic efficacy and potentiate motor learning.
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Effects of a Non-focal Plasticity Protocol on Apathy in Moderate Alzheimers Disease: A Randomized, Double-blind, Sham-controlled Trial.
Brain Stimul
PUBLISHED: 08-31-2013
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Apathy is the most common neuropsychiatric symptom in Alzheimers disease (AD) and it is associated with changes in prefrontal neural circuits involved with generation of voluntary actions. To date no effective treatment for apathy has been demonstrated.
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Technique and considerations in the use of 4x1 ring high-definition transcranial direct current stimulation (HD-tDCS).
J Vis Exp
PUBLISHED: 07-30-2013
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High-definition transcranial direct current stimulation (HD-tDCS) has recently been developed as a noninvasive brain stimulation approach that increases the accuracy of current delivery to the brain by using arrays of smaller "high-definition" electrodes, instead of the larger pad-electrodes of conventional tDCS. Targeting is achieved by energizing electrodes placed in predetermined configurations. One of these is the 4x1-ring configuration. In this approach, a center ring electrode (anode or cathode) overlying the target cortical region is surrounded by four return electrodes, which help circumscribe the area of stimulation. Delivery of 4x1-ring HD-tDCS is capable of inducing significant neurophysiological and clinical effects in both healthy subjects and patients. Furthermore, its tolerability is supported by studies using intensities as high as 2.0 milliamperes for up to twenty minutes. Even though 4x1 HD-tDCS is simple to perform, correct electrode positioning is important in order to accurately stimulate target cortical regions and exert its neuromodulatory effects. The use of electrodes and hardware that have specifically been tested for HD-tDCS is critical for safety and tolerability. Given that most published studies on 4x1 HD-tDCS have targeted the primary motor cortex (M1), particularly for pain-related outcomes, the purpose of this article is to systematically describe its use for M1 stimulation, as well as the considerations to be taken for safe and effective stimulation. However, the methods outlined here can be adapted for other HD-tDCS configurations and cortical targets.
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Very low levels of education and cognitive reserve: a clinicopathologic study.
Neurology
PUBLISHED: 07-19-2013
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We conducted a clinicopathologic study in a large population with very low levels of education to determine whether very few years of education could contribute to cognitive reserve and modify the relation of neuropathologic indices to dementia.
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Simultaneous EEG monitoring during transcranial direct current stimulation.
J Vis Exp
PUBLISHED: 07-16-2013
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Transcranial direct current stimulation (tDCS) is a technique that delivers weak electric currents through the scalp. This constant electric current induces shifts in neuronal membrane excitability, resulting in secondary changes in cortical activity. Although tDCS has most of its neuromodulatory effects on the underlying cortex, tDCS effects can also be observed in distant neural networks. Therefore, concomitant EEG monitoring of the effects of tDCS can provide valuable information on the mechanisms of tDCS. In addition, EEG findings can be an important surrogate marker for the effects of tDCS and thus can be used to optimize its parameters. This combined EEG-tDCS system can also be used for preventive treatment of neurological conditions characterized by abnormal peaks of cortical excitability, such as seizures. Such a system would be the basis of a non-invasive closed-loop device. In this article, we present a novel device that is capable of utilizing tDCS and EEG simultaneously. For that, we describe in a step-by-step fashion the main procedures of the application of this device using schematic figures, tables and video demonstrations. Additionally, we provide a literature review on clinical uses of tDCS and its cortical effects measured by EEG techniques.
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Heart rate variability is a trait marker of major depressive disorder: evidence from the sertraline vs. electric current therapy to treat depression clinical study.
Int. J. Neuropsychopharmacol.
PUBLISHED: 06-12-2013
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Decreased heart rate variability (HRV) is a cardiovascular predictor of mortality. Recent debate has focused on whether reductions in HRV in major depressive disorder (MDD) are a consequence of the disorder or a consequence of pharmacotherapy. Here we report on the impact of transcranial direct current stimulation (tDCS), a non-pharmacological intervention, vs. sertraline to further investigate this issue. The employed design was a double-blind, randomized, factorial, placebo-controlled trial. One hundred and eighteen moderate-to-severe, medication-free, low-cardiovascular risk depressed patients were recruited for this study and allocated to either active/sham tDCS (10 consecutive sessions plus two extra sessions every other week) or placebo/sertraline (50 mg/d) for 6 wk. Patients were age and gender-matched to healthy controls from a concurrent cohort study [the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)]. The impact of disorder, treatment and clinical response on HRV (root mean square of successive differences and high frequency) was examined. Our findings confirmed that patients displayed decreased HRV relative to controls. Furthermore, HRV scores did not change following treatment with either a non-pharmacological (tDCS) or pharmacological (sertraline) intervention, nor did HRV increase with clinical response to treatment. Based on these findings, we discuss whether reduced HRV is a trait-marker for MDD, which may predispose patients to a host of conditions and disease even after response to treatment. Our findings have important implications for our understanding of depression pathophysiology and the relationship between MDD, cardiovascular disorders and mortality.
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Comparison of blinding effectiveness between sham tDCS and placebo sertraline in a 6-week major depression randomized clinical trial.
Clin Neurophysiol
PUBLISHED: 06-01-2013
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To compare blinding integrity and associated factors for transcranial direct current stimulation (tDCS) vs. placebo-pill, the gold standard blinding method.
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Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study.
Sao Paulo Med J
PUBLISHED: 05-28-2013
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Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation.
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Therapeutic time window of noninvasive brain stimulation for pain treatment: inhibition of maladaptive plasticity with early intervention.
Expert Rev Med Devices
PUBLISHED: 05-15-2013
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Neuromodulatory effects of noninvasive brain stimulation (NIBS) have been extensively studied in chronic disorders such as major depression, chronic pain and stroke. However, few studies have explored the use of these techniques in acute conditions. A possible use of NIBS in acute disorders is to prevent or reverse ongoing maladaptive plastic alterations, seemingly responsible for treatment refractoriness and detrimental behavioral changes. In this review, the authors discuss the potential role of NIBS in blocking maladaptive plasticity using the transition of acute to chronic pain in conditions such as postsurgical pain, central poststroke pain, pain after spinal cord injury and pain after traumatic brain injury as a model. The authors also present suggestions for clinical trial design using NIBS in the acute stage of illnesses.
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Enhancement of Affective Processing Induced by Bifrontal Transcranial Direct Current Stimulation in Patients With Major Depression.
Neuromodulation
PUBLISHED: 04-10-2013
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OBJECTIVE: Our aim was to evaluate whether one single section of transcranial direct current stimulation (tDCS), a neuromodulatory technique that noninvasively modifies cortical excitability, could induce acute changes in the negative attentional bias in patients with major depression. SUBJECTS AND METHODS: Randomized, double-blind, sham-controlled, parallel design enrolling 24 age-, gender-matched, drug-free, depressed subjects. Anode and cathode were placed over the left and right dorsolateral prefrontal cortex. We performed a word Emotional Stroop Task collecting the response times (RTs) for positive-, negative-, and neutral-related words. The emotional Stroop effect for negative vs. neutral and vs. positive words was used as the measure of attentional bias. RESULTS: At baseline, RTs were significantly slower for negative vs. positive words. We found that active but not sham tDCS significantly modified the negative attentional bias, abolishing slower RT for negative words. CONCLUSION: Active but not sham tDCS significantly modified the negative attentional bias. These findings add evidence that a single tDCS session transiently induces potent changes in affective processing, which might be one of the mechanisms of tDCS underlying mood changes.
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Non-invasive brain stimulation and the autonomic nervous system.
Clin Neurophysiol
PUBLISHED: 03-11-2013
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Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are non-invasive methods of brain stimulation (NIBS) that can induce significant effects on cortical and subcortical neural networks. Both methods are relatively safe if appropriate guidelines are followed, and both can exert neuromodulatory effects that may be applied to the investigation of the autonomic nervous system (ANS). In addition, ANS measures can shed important light onto the neurobiologic mechanisms of NIBS. Here we present a systematic review on studies testing NIBS and ANS simultaneously. We structure our findings into four broad (not mutually exclusive) categories: (i) studies in which ANS function was modified by NIBS versus those in which it was not; (ii) studies in which NIBS was used to understand ANS function, (iii) studies in which ANS was used to understand NIBS mechanisms and (iv) NIBS/ANS studies conducted in healthy subjects versus those in patients with neuropsychiatric diseases. Forty-four articles were identified and no conclusive evidence of the effects of NIBS on ANS was observed, mainly because of the heterogeneity of included studies. Based on a comprehensive summary of this literature we propose how NIBS might be further developed to enhance our understanding of the cortical mechanisms of autonomic regulation and perhaps to modulate autonomic activity for therapeutic purposes.
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Motor and parietal cortex stimulation for phantom limb pain and sensations.
Pain
PUBLISHED: 03-09-2013
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Limb amputation may lead to chronic painful sensations referred to the absent limb, ie phantom limb pain (PLP), which is likely subtended by maladaptive plasticity. The present study investigated whether transcranial direct current stimulation (tDCS), a noninvasive technique of brain stimulation that can modulate neuroplasticity, can reduce PLP. In 2 double-blind, sham-controlled experiments in subjects with unilateral lower or upper limb amputation, we measured the effects of a single session of tDCS (2 mA, 15 min) of the primary motor cortex (M1) and of the posterior parietal cortex (PPC) on PLP, stump pain, nonpainful phantom limb sensations and telescoping. Anodal tDCS of M1 induced a selective short-lasting decrease of PLP, whereas cathodal tDCS of PPC induced a selective short-lasting decrease of nonpainful phantom sensations; stump pain and telescoping were not affected by parietal or by motor tDCS. These findings demonstrate that painful and nonpainful phantom limb sensations are dissociable phenomena. PLP is associated primarily with cortical excitability shifts in the sensorimotor network; increasing excitability in this system by anodal tDCS has an antalgic effect on PLP. Conversely, nonpainful phantom sensations are associated to a hyperexcitation of PPC that can be normalized by cathodal tDCS. This evidence highlights the relationship between the level of excitability of different cortical areas, which underpins maladaptive plasticity following limb amputation and the phenomenology of phantom limb, and it opens up new opportunities for the use of tDCS in the treatment of PLP.
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Effects of non-pharmacological pain treatments on brain states.
Clin Neurophysiol
PUBLISHED: 02-28-2013
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To (1) evaluate the effects of a single session of four non-pharmacological pain interventions, relative to a sham tDCS procedure, on pain and electroencephalogram- (EEG-) assessed brain oscillations, and (2) determine the extent to which procedure-related changes in pain intensity are associated with changes in brain oscillations.
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Classification of methods in transcranial electrical stimulation (tES) and evolving strategy from historical approaches to contemporary innovations.
J. Neurosci. Methods
PUBLISHED: 02-20-2013
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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.
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Focal modulation of the primary motor cortex in fibromyalgia using 4×1-ring high-definition transcranial direct current stimulation (HD-tDCS): immediate and delayed analgesic effects of cathodal and anodal stimulation.
J Pain
PUBLISHED: 02-14-2013
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Fibromyalgia is a prevalent chronic pain syndrome characterized by altered pain and sensory processing in the central nervous system, which is often refractory to multiple therapeutic approaches. Given previous evidence supporting analgesic properties of noninvasive brain stimulation techniques in this condition, this study examined the effects of a novel, more focal method of transcranial direct current stimulation (tDCS), using the 4×1-ring configuration of high-definition (HD)-tDCS, on overall perceived pain in fibromyalgia patients. In this patient- and assessor-blind, sham-controlled, crossover trial, 18 patients were randomized to undergo single 20-minute sessions of anodal, cathodal, and sham HD-tDCS at 2.0 mA in a counterbalanced fashion. The center electrode was positioned over the left primary motor cortex. Pain scales and sensory testing were assessed before and after each intervention. A finite element method brain model was generated to predict electric field distribution. We found that both active stimulation conditions led to significant reduction in overall perceived pain as compared to sham. This effect occurred immediately after cathodal HD-tDCS and was evident for both anodal and cathodal HD-tDCS 30 minutes after stimulation. Furthermore, active anodal stimulation induced a significant bilateral increase in mechanical detection thresholds. These interventions proved well tolerated in our patient population.
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Behavioral effects of transcranial Direct Current Stimulation (tDCS) induced dorsolateral prefrontal cortex plasticity in alcohol dependence.
J. Physiol. Paris
PUBLISHED: 01-31-2013
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Transcranial Direct Current Stimulation (tDCS) has been shown to reduce acute substance craving in drug addicts, and improve cognition in neuropsychiatric patients. Here we aimed to explore further tDCS induced behavioral and neurophysiological modulation including assessment of relapse rate over a prolonged time course in alcoholism. We examined the effects of repeated anodal tDCS (2mA, 35 cm(2), 20min) over the left dorsolateral prefrontal cortex (DLPFC) on relapse to the use of alcohol in alcoholics from outpatient services, who received additional routine clinical treatment. Furthermore, event related potentials (ERPs), cognitive and frontal executive processes, craving, depressive and anxiety symptoms were obtained before and after treatment. From thirteen alcoholic subjects, seven were randomized to sham-tDCS and six to real tDCS treatment (once a week for five consecutive weeks). Depressive symptoms and craving were reduced to a larger extent in the tDCS group compared to the sham group (p=0.005 and p=0.015, respectively). On the other hand, active tDCS was able to block the increase in neural activation triggered by alcohol related and neutral cues in prefrontal cortex (PFC) as indexed by ERP as seen in the sham-tDCS group. Finally, there was a trend for increased change in executive function in the tDCS group compared to the sham-tDCS group (p=0.082), and, similarly, a trend for more relapses in the tDCS group compared to sham tDCS (four alcoholic subjects (66.7%) vs. one (14.3%), p=0.053).These results confirm the previous findings of tDCS effects on craving in alcoholism and also extend these findings as we showed also tDCS-related mood improvement. However, potential increase in relapse is possible; thus the clinical value of an increase in craving and improvement in depression and executive function needs to be carefully assessed in further studies; including investigation of optimal parameters of stimulation.
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Impact of brain tissue filtering on neurostimulation fields: A modeling study.
Neuroimage
PUBLISHED: 01-29-2013
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Electrical neurostimulation techniques, such as deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), are increasingly used in the neurosciences, e.g., for studying brain function, and for neurotherapeutics, e.g., for treating depression, epilepsy, and Parkinsons disease. The characterization of electrical properties of brain tissue has guided our fundamental understanding and application of these methods, from electrophysiologic theory to clinical dosing-metrics. Nonetheless, prior computational models have primarily relied on ex-vivo impedance measurements. We recorded the in-vivo impedances of brain tissues during neurosurgical procedures and used these results to construct MRI guided computational models of TMS and DBS neurostimulatory fields and conductance-based models of neurons exposed to stimulation. We demonstrated that tissues carry neurostimulation currents through frequency dependent resistive and capacitive properties not typically accounted for by past neurostimulation modeling work. We show that these fundamental brain tissue properties can have significant effects on the neurostimulatory-fields (capacitive and resistive current composition and spatial/temporal dynamics) and neural responses (stimulation threshold, ionic currents, and membrane dynamics). These findings highlight the importance of tissue impedance properties on neurostimulation and impact our understanding of the biological mechanisms and technological potential of neurostimulatory methods.
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The sertraline versus electrical current therapy for treating depression clinical study (select-TDCS): results of the crossover and follow-up phases.
Depress Anxiety
PUBLISHED: 01-18-2013
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Transcranial direct current stimulation (tDCS) is a promising nonpharmacological therapy for major depression. In the Sertraline versus Electrical Current Therapy for Treating Depression Clinical Trial (SELECT-TDCS) trial, phase-I (Brunoni et al., JAMA Psychiatry, 2013) we found that tDCS is effective for the acute episode. Here, we describe tDCS effects during phases II (crossover) and III (follow-up) of this trial (NCTs: 01149889 and 01149213).
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The relationship between cortical excitability and pain catastrophizing in myofascial pain.
J Pain
PUBLISHED: 01-17-2013
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Pain catastrophizing regularly occurs in chronic pain patients. It has been suggested that pain catastrophizing is a stable, person-based construct. These findings highlight the importance of investigating catastrophizing in conceptualizing specific approaches for pain management. One important area of investigation is the mechanism underlying pain catastrophizing. Therefore, this study explored the relationship between a neurophysiological marker of cortical excitability, as assessed by transcranial magnetic stimulation, and catastrophizing, as assessed by the Brazilian Portuguese Pain Catastrophizing Scale, in patients with chronic myofascial pain syndrome. The Pain Catastrophizing Scale is a robust questionnaire used to examine rumination, magnification and helplessness that are associated with the experience of pain. We include 24 women with myofascial pain syndrome. The Brazilian Portuguese Pain Catastrophizing Scale and cortical excitability were assessed. Functional and behavioral aspects of pain were evaluated with a version of the Profile of Chronic Pain scale and by multiple pain measurements (eg, pain intensity, pressure pain threshold, and other quantitative sensory measurements). Intracortical facilitation was found to be significantly associated with pain catastrophizing (? = .63, P = .001). Our results did not suggest that these findings were influenced by other factors, such as age or medication use. Furthermore, short intracortical inhibition showed a significant association with pressure pain threshold (? = .44, P = .04). This study elaborates on previous findings indicating a relationship between cortical excitability and catastrophizing. The present findings suggest that glutamatergic activity may be associated with mechanisms underlying pain catastrophizing; thus, the results highlight the need to further investigate the neurophysiological mechanisms associated with pain and catastrophizing.
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Targeted therapies using electrical and magnetic neural stimulation for the treatment of chronic pain in spinal cord injury.
Neuroimage
PUBLISHED: 01-14-2013
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Chronic neuropathic pain is one of the most common and disabling symptoms in individuals with spinal cord injury (SCI). Over two-thirds of subjects with SCI suffer from chronic pain influencing quality of life, rehabilitation, and recovery. Given the refractoriness of chronic pain to most pharmacological treatments, the majority of individuals with SCI report worsening of this condition over time. Moreover, only 4-6% of patients in this cohort report improvement. Novel treatments targeting mechanisms associated with pain-maladaptive plasticity, such as electromagnetic neural stimulation, may be desirable to improve outcomes. To date, few, small clinical trials have assessed the effects of invasive and noninvasive nervous system stimulation on pain after SCI.
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Acute working memory improvement after tDCS in antidepressant-free patients with major depressive disorder.
Neurosci. Lett.
PUBLISHED: 01-14-2013
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Based on previous studies showing that transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that employs weak, direct currents to induce cortical-excitability changes, might be useful for working memory (WM) enhancement in healthy subjects and also in treating depressive symptoms, our aim was to evaluate whether tDCS could acutely enhance WM in depressed patients. Twenty-eight age- and gender-matched, antidepressant-free depressed subjects received a single-session of active/sham tDCS in a randomized, double-blind, parallel design. The anode was positioned over the left and the cathode over the right dorsolateral prefrontal cortex. The n-back task was used for assessing WM and it was performed immediately before and 15min after tDCS onset. We found that active vs. sham tDCS led to an increase in the rate of correct responses. We also used signal detection theory analyses to show that active tDCS increased both discriminability, i.e., the ability to discriminate signal (correct responses) from noise (false alarms), and response criterion, indicating a lower threshold to yield responses. All effect sizes were large. In other words, one session of tDCS acutely enhanced WM in depressed subjects, suggesting that tDCS can improve "cold" (non affective-loaded) working memory processes in MDD. Based on these findings, we discuss the effects of tDCS on WM enhancement in depression. We also suggest that the n-back task could be used as a biomarker in future tDCS studies investigating prefrontal activity in healthy and depressed samples.
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Safety of repeated transcranial direct current stimulation in impaired skin: a case report.
J ECT
PUBLISHED: 01-11-2013
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Transcranial direct current stimulation (tDCS) is a neuromodulatory technique based on the application of a weak, direct electric current via 2 or more electrodes (anode and cathode) over the scalp. One concern when applying tDCS is skin burn. It has been suggested that skin lesions are related to changes in the local dermal homeostasis, and therefore, caution is warranted in patients with skin diseases (Loo et al [Int J Neuropsychopharmacol. 2011;14:425-426]). In this context, we believe that it would be useful for this emerging field of tDCS to report the preliminary safety of repeated application of tDCS in a patient with vitiligo, an autoimmune disorder characterized by depigmentation sites of the skin or mucous membranes. We report the case of a 31-year-old male patient with schizophrenia who underwent 10-daily tDCS sessions. He has had generalized vitiligo since childhood, and despite previous treatment, no current dermatologic follow-up was being carried out. Depigmentation sites were evident in different areas, particularly under the anodal area. We found that repeated anodal tDCS in 1 patient did not lead to skin lesions when applied over a vitiligo skin area. Some of the procedures that we used to buffer changes in skin temperature may have contributed to prevent tDCS-induced skin damage. Nevertheless, the exact conditions that lead to skin lesion are still unknown. Given the growing use and testing of tDCS, continuous assessment and reporting of local adverse effects are still warranted especially in conditions with increased risk of skin lesions such as in dermatologic conditions, skin burns, and previous skin damage.
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A feasibility study assessing cortical plasticity in chronic neuropathic pain following burn injury.
J Burn Care Res
PUBLISHED: 01-08-2013
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The aim of this article is to evaluate the neuroplastic changes associated with chronic neuropathic pain following burn injury and modulation feasibility using transcranial direct current stimulation (tDCS). This is a crossover, double-blinded case series involving three patients with chronic neuropathic pain following burn injury. Participants were randomly assigned to undergo single sessions of both sham and active anodal tDCS over the primary motor cortex, contralateral to the most painful site. Excitability of the motor cortex was assessed before and after each stimulation session with the use of transcranial magnetic stimulation. An overall decrease in cortical excitability was seen after active tDCS only, as characterized by a decrease in intracortical facilitation and amplitude of motor evoked potentials and an increase in intracortical inhibition. Clinical outcomes did not change after a single session of tDCS. Results are consistent with previous studies showing that patients with chronic neuropathic pain have defective intracortical inhibition. This case series shows early evidence that chronic pain following burn injury may share similar central neural mechanisms, which could be modulated using tDCS.
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Effects of sensory behavioral tasks on pain threshold and cortical excitability.
PLoS ONE
PUBLISHED: 01-03-2013
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Transcutaneous electrical stimulation has been proven to modulate nervous system activity, leading to changes in pain perception, via the peripheral sensory system, in a bottom up approach. We tested whether different sensory behavioral tasks induce significant effects in pain processing and whether these changes correlate with cortical plasticity.
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Transcranial direct current stimulation reduces negative affect but not cigarette craving in overnight abstinent smokers.
Front Psychiatry
PUBLISHED: 01-01-2013
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Transcranial direct current stimulation (tDCS) can enhance cognitive control functions including attention and top-down regulation over negative affect and substance craving in both healthy and clinical populations, including early abstinent (?1.5?h) smokers. The aim of this study was to assess whether tDCS modulates negative affect, cigarette craving, and attention of overnight abstinent tobacco dependent smokers. In this study, 24 smokers received a real and a sham session of tDCS after overnight abstinence from smoking on two different days. We applied anode to the left dorsolateral prefrontal cortex and cathode to the right supra-orbital area for 20?min with a current of 2.0?mA. We used self-report questionnaires Profile of Mood States (POMS) to assess negative affect and Urge to Smoke (UTS) Scale to assess craving for cigarette smoking, and a computerized visual target identification task to assess attention immediately before and after each tDCS. Smokers reported significantly greater reductions in POMS scores of total mood disturbance and scores of tension-anxiety, depression-dejection, and confusion-bewilderment subscales after real relative to sham tDCS. Furthermore, this reduction in negative affect positively correlated with the level of nicotine dependence as assessed by Fagerström scale. However, reductions in cigarette craving after real vs. sham tDCS did not differ, nor were there differences in reaction time or hit rate change on the visual task. Smokers did not report significant side effects of tDCS. This study demonstrates the safety of tDCS and its promising effect in ameliorating negative affect in overnight abstinent smokers. Its efficacy in treating tobacco dependence deserves further investigation.
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Je pense donc je fais: transcranial direct current stimulation modulates brain oscillations associated with motor imagery and movement observation.
Front Hum Neurosci
PUBLISHED: 01-01-2013
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Motor system neural networks are activated during movement imagery, observation and execution, with a neural signature characterized by suppression of the Mu rhythm. In order to investigate the origin of this neurophysiological marker, we tested whether transcranial direct current stimulation (tDCS) modifies Mu rhythm oscillations during tasks involving observation and imagery of biological and non-biological movements. We applied tDCS (anodal, cathodal, and sham) in 21 male participants (mean age 23.8 ± 3.06), over the left M1 with a current of 2 mA for 20 min. Following this, we recorded the EEG at C3, C4, and Cz and surrounding C3 and C4 electrodes. Analyses of C3 and C4 showed significant effects for biological vs. non-biological movement (p = 0.005), and differential hemisphere effects according to the type of stimulation (p = 0.04) and type of movement (p = 0.02). Analyses of surrounding electrodes revealed significant interaction effects considering type of stimulation and imagery or observation of biological or non-biological movement (p = 0.03). The main findings of this study were (1) Mu desynchronization during biological movement of the hand region in the contralateral hemisphere after sham tDCS; (2) polarity-dependent modulation effects of tDCS on the Mu rhythm, i.e., anodal tDCS led to Mu synchronization while cathodal tDCS led to Mu desynchronization during movement observation and imagery (3) specific focal and opposite inter-hemispheric effects, i.e., contrary effects for the surrounding electrodes during imagery condition and also for inter-hemispheric electrodes (C3 vs. C4). These findings provide insights into the cortical oscillations during movement observation and imagery. Furthermore, it shows that tDCS can be highly focal when guided by a behavioral task.
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Cognitive, mood, and electroencephalographic effects of noninvasive cortical stimulation with weak electrical currents.
J ECT
PUBLISHED: 12-13-2011
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: The use of noninvasive cortical electrical stimulation with weak currents has significantly increased in basic and clinical human studies. Initial, preliminary studies with this technique have shown encouraging results; however, the safety and tolerability of this method of brain stimulation have not been sufficiently explored yet. The purpose of our study was to assess the effects of direct current (DC) and alternating current (AC) stimulation at different intensities in order to measure their effects on cognition, mood, and electroencephalogram.
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Assessment and treatment of pain with non-invasive cortical stimulation.
Restor. Neurol. Neurosci.
PUBLISHED: 11-30-2011
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There remains an unmet clinical need for the development of new therapeutic approaches for the treatment of pain. Recent findings have confirmed significant changes in the pain-related neural networks among patients with chronic pain, opening novel possibilities for investigation. Two non-invasive techniques (transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS)) have emerged as interesting, effective, and promising modalities for pain relief.
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Responding to unfair offers made by a friend: neuroelectrical activity changes in the anterior medial prefrontal cortex.
J. Neurosci.
PUBLISHED: 10-28-2011
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When receiving unfair monetary offers from another person, the most common response is punishment. Existing literature on the Ultimatum Game indicates that individuals frequently refuse unfair offers even when this results in a loss for themselves. Here, we present behavioral and neurophysiological evidence demonstrating that friendship substantially modifies this response. When the proposer was a friend rather than an unknown person, unfair offers were less frequently rejected and the medial frontal negativity (MFN) typically associated with unfair offers was reversed to positive polarity. The underlying generators were located in inferior-mesial and right inferior- and medial-lateral frontal regions (BA10 and BA11). These findings highlight the fundamental role of the anterior prefrontal cortex in interpersonal economic interaction and, particularly, present new evidence on the effects of social distance on the MFN.
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Non-invasive brain stimulation to assess and modulate neuroplasticity in Alzheimers disease.
Neuropsychol Rehabil
PUBLISHED: 09-26-2011
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Alzheimers disease (AD) is a neurodegenerative and progressive disease related to a gradual decline in cognitive functions such as memory, attention, perceptual-spatial abilities, language, and executive functions. Recent evidence has suggested that interventions promoting neural plasticity can induce significant cognitive gains especially in subjects at risk of or with mild AD. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are non-invasive techniques that can induce significant and long-lasting changes in focal and non-focal neuroplasticity. In this review, we present initial preliminary evidence that TMS and tDCS can enhance performance in cognitive functions typically impaired in AD. Also, we reviewed the initial six studies on AD that presented early findings showing cognitive gains such as in recognition memory and language associated with TMS and tDCS treatment. In addition, we showed that TMS has also been used to assess neuroplasticity changes in AD supporting the notion that cortical excitability is changed in AD due to the neurodegenerative process. Due to the safe profile, cost of these tools, and initial clinical trials results, further studies are warranted in order to replicate and extend the initial findings of rTMS and tDCS as cognitive enhancers in AD. Further trials should explore different targets of stimulation along with different paradigms of stimulation including combination with behavioural interventions.
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Atherosclerosis and dementia: a cross-sectional study with pathological analysis of the carotid arteries.
Stroke
PUBLISHED: 09-22-2011
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Previous ultrasound-based studies have shown an association between carotid artery atherosclerosis and dementia. Our aim was to investigate this association using postmortem examination.
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Translational research in transcranial direct current stimulation (tDCS): a systematic review of studies in animals.
Rev Neurosci
PUBLISHED: 08-09-2011
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Recent therapeutic human studies testing transcranial direct current stimulation (tDCS) has shown promising results, although many questions remain unanswered. Translational research with experimental animals is an appropriate framework for investigating its mechanisms of action that are still undetermined. Nevertheless, animal and human studies are often discordant. Our aim was to review tDCS animal studies, examining and comparing their main findings with human studies. We performed a systematic review in Medline and other databases, screening for animal studies in vivo that delivered tDCS. Studies in vitro and using other neuromodulatory techniques were excluded. We extracted data according to Animal Research: Reporting In Vivo Experiments (ARRIVE) guidelines for reporting in vivo animal research. Thus, we collected data on sample characteristics (size, gender, weight and specimen) and methodology (experimental procedures, experimental animals, housing and husbandry, as well as analysis). We also collected data on methods for delivering tDCS (location, size, current and current density of electrodes and electrode montage), experimental effects (polarity-, intensity- and after-effects) and safety. Only 12 of 48 potentially eligible studies met our inclusion criteria and were reviewed. Quality assessment reporting was only moderate and studies were heterogeneous regarding tDCS montage methodology, position of active and reference electrodes, and current density used. Nonetheless, almost all studies demonstrated that tDCS had positive immediate and long-lasting effects. Vis-à-vis human trials, animal studies applied higher current densities (34.2 vs. 0.4 A/m(2), respectively), preferred extra-cephalic positions for reference electrodes (60% vs. 10%, respectively) and used electrodes with different sizes more often. Potential implications for translational tDCS research are discussed.
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Neurophysiological and behavioral effects of tDCS combined with constraint-induced movement therapy in poststroke patients.
Neurorehabil Neural Repair
PUBLISHED: 07-29-2011
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Recovery of motor function after stroke may depend on a balance of activity in the neural network involving the affected and the unaffected motor cortices.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.