Posts Tagged Brain stimulation

[Abstract] The treatment of fatigue by non-invasive brain stimulation

Summary

The use of non-invasive brain neurostimulation (NIBS) techniques to treat neurological or psychiatric diseases is currently under development. Fatigue is a commonly observed symptom in the field of potentially treatable pathologies by NIBS, yet very little data has been published regarding its treatment. We conducted a review of the literature until the end of February 2017 to analyze all the studies that reported a clinical assessment of the effects of NIBS techniques on fatigue. We have limited our analysis to repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). We found only 15 studies on this subject, including 8 tDCS studies and 7 rTMS studies. Of the tDCS studies, 6 concerned patients with multiple sclerosis while 6 rTMS studies concerned fibromyalgia or chronic fatigue syndrome. The remaining 3 studies included patients with post-polio syndrome, Parkinson’s disease and amyotrophic lateral sclerosis. Three cortical regions were targeted: the primary sensorimotor cortex, the dorsolateral prefrontal cortex and the posterior parietal cortex. In all cases, tDCS protocols were performed according to a bipolar montage with the anode over the cortical target. On the other hand, rTMS protocols consisted of either high-frequency phasic stimulation or low-frequency tonic stimulation. The results available to date are still too few, partial and heterogeneous as to the methods applied, the clinical profile of the patients and the variables studied (different fatigue scores) in order to draw any conclusion. However, the effects obtained, especially in multiple sclerosis and fibromyalgia, are really carriers of therapeutic hope.

Source: The treatment of fatigue by non-invasive brain stimulation

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[Abstract] Bilateral sequential motor cortex stimulation and skilled task performance with non-dominant hand

Highlights

  • Both, contralateral M1 iTBS and ipsilateral M1 cTBS improved non-dominant skilled-task performance.
  • Bilateral sequential M1 TBS (contralateral cTBS followed by ipsilateral iTBS) improved skilled-task performance more than unilateral or sham TBS.
  • Bilateral sequential M1 TBS may be particularly effective in improving motor learning, also in the neurorehabilitation setting.

Abstract

Objective

To check whether bilateral sequential stimulation (BSS) of M1 with theta burst stimulation (TBS), using facilitatory protocol over non-dominant M1 followed by inhibitory one over dominant M1, can improve skilled task performance with non-dominant hand more than either of the unilateral stimulations do. Both, direct motor cortex (M1) facilitatory non-invasive brain stimulation (NIBS) and contralateral M1 inhibitory NIBS were shown to improve motor learning.

Methods

Forty right-handed healthy subjects were divided into 4 matched groups which received either ipsilateral facilitatory (intermittent TBS [iTBS] over non-dominant M1), contralateral inhibitory (continuous TBS [cTBS] over dominant M1), bilateral sequential (contralateral cTBS followed by ipsilateral iTBS), or placebo stimulation. Performance was evaluated by Purdue peg-board test (PPT), before (T0), immediately after (T1), and 30 min after (T2) an intervention.

Results

In all groups and for both hands, the PPT scores increased at T1 and T2 in comparison to T0, showing clear learning effect. However, for the target non-dominant hand only, immediately after BSS (at T1) the PPT scores improved significantly more than after either of unilateral interventions or placebo.

Conclusion

M1 BSS TBS is an effective intervention for improving motor performance.

Significance

M1 BSS TBS seems as a promising tool for motor learning improvement with potential uses in neurorehabilitation.

Source: Bilateral sequential motor cortex stimulation and skilled task performance with non-dominant hand – Clinical Neurophysiology

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[WEB SITE] Electrical brain stimulation could boost benefits of stroke rehabilitation. | Science | The Guardian

Research indicates that transcranial direct current stimulation (tCDS) during rehabilitation therapy might help stroke patients recover more movement

Scans showing the effects of hemorrhagic and ischemic stroke.

Scans showing the effects of hemorrhagic and ischemic stroke on the brain. Photograph: Alamy

Electrical brain stimulation could benefit stroke patients by boosting the effects of rehabilitation therapy, new research suggests.

Writing in the journal Science Translational Medicine, the authors reveal that patients who were given electrical brain stimulation during a rehabilitation programme performed better on a range of tasks than those taking part in the rehabilitation programme.

“It is an exciting message because there is so much frustration about people not reaching their true recovery potential,” said Professor Heidi Johansen-Berg, an author of the study from the University of Oxford, highlighting the fact that the cost of programmes and limited availability of therapists often restricts the amount of rehabilitation offered to patients.

To probe the effects of brain stimulation, the researchers chose 24 patients who had experienced a stroke at least six months before, and who had difficulties with moving one hand. The participants were then split into two groups.

The first group underwent nine consecutive days of rehabilitation training, with each session lasting an hour. For the first 20 minutes, the patients had two electrodes placed on their heads and a direct current applied, a process known as anodal transcranial direct current stimulation (tDCS). This is stimulation is thought to prime the brain for learning.

The second group also underwent the nine-day programme, but while they too had electrodes placed on their head for the first 20 minutes, the current was turned off after the first 10 seconds, leading to a placebo trial.

The results indicate that brain stimulation bolstered the effect of the rehabilitation therapy, with patients who underwent the stimulation scoring appreciably higher on two of the tests – those related to carrying out particular tasks with the hand such as picking up a paper-clip – in assessments carried out three months after the therapy. For third test, which measured effects such as the strength of grip, brain stimulation was not linked to improvements.

“If we take at face value what the results are telling us, it is that the stimulation doesn’t completely change the way that the brain can produce a movement, in that it doesn’t make you stronger, but it makes the brain better at being able to carry out a particular task like lifting up an object,” said Johansen-Berg.

However not everyone is convinced. Jane Burridge, professor of restorative neuroscience at the University of Southampton, who was not involved with the study, said the smaller effect for the third test could simply be down to the small size of the study. “You do need to have bigger trials to be certain of the results,” she said.

The research also found that patients who underwent the brain stimulation had larger increases in activity in regions of the brain associated with movement than those who had been given the placebo treatment – an effect that was seen from fMRI scans taken immediately after the nine-day programme and one month later.

“What is particularly important about [the study] is that it does relate the functional improvements with the neuroimaging changes – and that is very encouraging,” said Burridge.

But Burridge also cautions that the results should not be taken as a sign that brain stimulation will benefit all stroke patients. “One has to remember that this is one quite small study,” she said. “The overall view at the moment of when we put all the data [from many studies] together is that there is no clear benefit.”

Johansen-Berg also admits the new research has its limitations. “One thing it doesn’t allow us to do at all is get at the question of variability ,” she says. “We wouldn’t expect this to work for everybody, there will be some people it will work well for and some people who it won’t and we haven’t got anything like the numbers you’d need to tease that apart.”

The results were welcomed by health charities. “This study is an important step toward larger trials to test the effectiveness of non-invasive, electrical brain stimulation to improve the motor recovery of stroke survivors and support their rehabilitation after stroke,” said Dr Shamim Quadir of the Stroke Association. “Stroke is one of the largest causes of disability, and more than half of stroke survivors are left dependent on others for help with everyday activities. It is crucial that we find alternative ways to help improve the recovery rates from this devastating condition.”

But Dr Nick Ward from University College London warns that the study is unlikely to lead to a change in treatment programmes any time soon. “I would call this a proof of principle study,” he said. “This is not something that you can translate into the NHS or any other clinical service immediately.”

For Ward, the most interesting revelation is the level of improvement shown by the patients who did not receive brain stimulation, calling the results “dramatic”. While he cautions that the size of the effect might be down to the very selective nature of the group, if shown to apply more generally it would support the idea that “doing more physical therapy is a good thing.”

Johansen-Berg also believes the research offers a wider message of hope. “With the two weeks of intense therapy, both groups show significant improvement, it is just that they are slightly boosting that with the tDCS,” she said. “ What this shows is if you do two weeks of intensive practice with your bad hand, you will get much better.”

Source: Electrical brain stimulation could boost benefits of stroke rehabilitation | Science | The Guardian

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[Abstract] Enhancement of motor relearning and functional recovery in stroke patients: non-invasive strategies for modulating the central nervous system. – PubMed

INTRODUCTION: Most of the stroke survivors do not recover the basal state of the affected upper limb, suffering from a severe disability which remains during the chronic phase of the illness. This has an extremely negative impact in the quality of life of these patients. Hence, neurorehabilitation strategies aim at the minimization of the sensorimotor dysfunctions associated to stroke, by promoting neuroplasticity in the central nervous system.

DEVELOPMENT: Brain reorganization can facilitate motor and functional recovery in stroke subjects. None-theless, after the insult, maladaptive neuroplastic changes can also happen, which may lead to the appearance of certain sensori-motor disorders such as spasticity. Noninvasive brain stimulation strategies, like transcranial direct current stimulation or transcranial magnetic stimulation, are widely used techniques that, when applied over the primary motor cortex, can modify neural networks excitability, as well as cognitive functions, both in healthy subjects and individuals with neurological disorders. Similarly, brain-machine-interface systems also have the potential to induce a brain reorganization by the contingent and simultaneous association between the brain activation and the peripheral stimulation.

CONCLUSION: This review describes the positive effects of the previously mentioned neurorehabilitation strategies for the enhancement of cortical reorganization after stroke, and how they can be used to alleviate the symptoms of the spasticity syndrome.

Source: [Enhancement of motor relearning and functional recovery in stroke patients: non-invasive strategies for modulating the central nervous system]. – PubMed – NCBI

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[ARTICLE] Underlying neural mechanisms of mirror therapy: Implications for motor rehabilitation in stroke. – Full Text 

Abstract

Mirror therapy (MT) is a valuable method for enhancing motor recovery in poststroke hemiparesis. The technique utilizes the mirror-illusion created by the movement of sound limb that is perceived as the paretic limb. MT is a simple and economical technique than can stimulate the brain noninvasively. The intervention unquestionably has neural foundation. But the underlying neural mechanisms inducing motor recovery are still unclear. In this review, the neural-modulation due to MT has been explored. Multiple areas of the brain such as the occipital lobe, dorsal frontal area and corpus callosum are involved during the simple MT regime. Bilateral premotor cortex, primary motor cortex, primary somatosensory cortex, and cerebellum also get reorganized to enhance the function of the damaged brain. The motor areas of the lesioned hemisphere receive visuo-motor processing information through the parieto-occipital lobe. The damaged motor cortex responds variably to the MT and may augment true motor recovery. Mirror neurons may also play a possible role in the cortico-stimulatory mechanisms occurring due to the MT.

Introduction

The science of mirror therapy (MT) is getting due attention in the management of half-sided paresis due to stroke. The technique was first introduced by Ramachandran and Roger-Ramachandran to manage phantom sensations among the subjects with a unilateral amputation.[1]

Figure 1: Illustrates the arrangement of mirror therapy regime; the affected upper extremity (left) is placed inside the box (shown as dotted line) while the sound limb (right) is facing the mirror

Figure 1: Illustrates the arrangement of mirror therapy regime; the affected upper extremity (left) is placed inside the box (shown as dotted line) while the sound limb (right) is facing the mirror

The characteristic property of a mirror that reflects an image after altering its right-left orientation is a commonly known fact. In humans, the movement of right side of the body is primarily controlled by the left brain, and vice versa. The mirror feature and the brain behaviour collectively form the concept of MT. The paradigm allows an individual to perform the movements of an unaffected body part in front of the arranged mirror-box while hiding the affected part. The technique induces a visual illusion that appears to mimic the movement of the paretic part [Figure 1]. The perception, more than being a simple feedback mechanism, has been found to enhance motor recovery of the impaired body side.[2],[3],[4] The neural mechanisms leading to the favourable improvement are components of a complex phenomenon that need to be explored and comprehended…

Continue —> Underlying neural mechanisms of mirror therapy: Implications for motor rehabilitation in stroke Arya KN Neurol India

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[WEB SITE] Novel Brain Stimulation May Boost Creativity, Treat Depression

Application of a weak electric current to the frontal areas of the brain boosts creativity and may lead to a novel method of treating depression, a new proof-of-concept study suggests.

Applying 10 Hz of stimulation via electrodes to healthy individuals, the team was able to increase alpha oscillations in the brain and improve performance on a commonly used measure of creativity.

They now hope to use the findings as a springboard to improve alpha oscillations in individuals with depression and so improve symptoms.

Explaining how alpha oscillations may mediate creativity, coauthor Flavio Frohlich, PhD, assistant professor at the University of North Carolina (UNC) School of Medicine, Chapel Hill, said in a release, “For a long time, people thought alpha waves represented the brain idling.”

“But over the past 20 years, we’ve developed much better insight. Our brains are not wasting energy, creating these patterns for nothing. When the brain is decoupled from the environment, it still does important things.”

The team believes that the stimulation may also enhance phase synchronization between the frontal regions, further boosting creativity.

The research is published in the June issue of Cortex.

Continue —> Novel Brain Stimulation May Boost Creativity, Treat Depression.

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[WEB SITE] #MindGames Forever – Where is NeuroGaming headed? — Blog Neuroelectrics

…WHAT IS NEUROGAMING?

Well to start with NeuroGaming refers to combining a videogame with physiological (ECG, GSR, etc.) and neurophysiological (EEG, NIRS, etc.) monitoring. In this context the signals obtained affect the game specifically by moving objects or creating movement, or generally by adjusting the game difficulty and other general parameters. Additionally, recently, brain stimulation such as transcranial current stimulation (tCS) has been added to the NeuroGaming definition as it increases brain plasticity during game play…

Continue–> #MindGames Forever – Where is NeuroGaming headed? | Blog Neuroelectrics.

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[ARTICLE] A Combined Therapeutic Approach in Stroke Rehabilitation: A Review on Non-Invasive Brain Stimulation plus Pharmacotherapy -Full Text PDF

Abstract

Stroke is a leading cause of disability in the United States. Available treatments for stroke have only a modest effect on motor rehabilitation and about 50-60% of stroke patients remain with some degree of motor impairment after standard treatment.

Non-invasive brain stimulation (NIBS) techniques have been proposed as adjuvant treatments to physical therapy for motor recovery after stroke. High frequency rTMS and anodal tDCS can be delivered over the affected motor cortex in order to increase cortical excitability and induce brain plasticity with the intention to enhance motor learning and achieve functional goals in stroke patients. Similarly, low frequency rTMS and cathodal tDCS can be delivered to the unaffected motor cortex to reduce interhemispheric inhibition and hinder maladaptive plasticity.

The use of several drugs such as amphetamines, selective serotonin reuptake inhibitors (SSRIs), levodopa and cholinergic agents have been also proposed to enhance the motor function. Given that both NIBS and pharmacotherapy might provide some treatment effect independently for motor rehabilitation in stroke and with the rationale that they could work in a synergistic fashion, we believe that a combined therapy- NIBS plus pharmacotherapy- can lead to better outcomes than one or the other alone. In this paper we review the literature that support the potential use of a combined approach in stroke recovery and present the studies that have already investigated this idea

Full Text PDF

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[ARTICLE] Brain–machine interfaces in neurorehabilitation of stroke – Full Text HTML

Abstract

Stroke is among the leading causes of long-term disabilities leaving an increasing number of people with cognitive, affective and motor impairments depending on assistance in their daily life. While function after stroke can significantly improve in the first weeks and months, further recovery is often slow or non-existent in the more severe cases encompassing 30–50% of all stroke victims.

The neurobiological mechanisms underlying recovery in those patients are incompletely understood. However, recent studies demonstrated the brain’s remarkable capacity for functional and structural plasticity and recovery even in severe chronic stroke. As all established rehabilitation strategies require some remaining motor function, there is currently no standardized and accepted treatment for patients with complete chronic muscle paralysis.

The development of brain–machine interfaces (BMIs) that translate brain activity into control signals of computers or external devices provides two new strategies to overcome stroke-related motor paralysis.

  • First, BMIs can establish continuous high-dimensional brain-control of robotic devices or functional electric stimulation (FES) to assist in daily life activities (assistive BMI).
  • Second, BMIs could facilitate neuroplasticity, thus enhancing motor learning and motor recovery (rehabilitative BMI).

Advances in sensor technology, development of non-invasive and implantable wireless BMI-systems and their combination with brain stimulation, along with evidence for BMI system’s clinical efficacy suggest that BMI-related strategies will play an increasing role in neurorehabilitation of stroke…

Full Text HTML –> Brain–machine interfaces in neurorehabilitation of stroke.

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[ARTICLE] Clinical Research with Transcranial Direct Current Stimulation (tDCS): Challenges and Future Directions – Full Text HTML

Abstract

Background: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past ten years, tDCS physiological mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodological, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them.

Methods: We convened a workgroup of researchers in the field to review, discuss and provide updates and key challenges of neuromodulation use for clinical research.

Main Findings/Discussion: We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (i) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (ii) methodological aspects related to the clinical research of tDCS as divided according to study phase (i.e., preclinical, phase I, phase II and phase III studies); (iii) ethical and regulatory concerns; (iv) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS.

Full Text HTML –> Clinical Research with Transcranial Direct Current Stimulation (tDCS): Challenges and Future Directions.

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