Posts Tagged TMS

[WEB SITE] What is neurohacking and can it actually rewire your brain?

Marc Bordons / Stocksy

What is neurohacking and can it actually rewire your brain?

Although at one point, “hack” referred to a creative solution to a tech problem, the term can apply to pretty much anything now. There are kitchen hacks, productivity hacks, personal finance hacks. Brain hacks, or neurohacks, are among the buzziest, though, thanks largely to the Silicon Valley techies who often swear by them as a way to boost their cognitive function, focus, and creativity. Mic asked a neuroscientist to explain neurohacking, which neurohacking methods are especially promising, which are mostly hype, and how to make neurohacking work for you.

First things first: Neurohacking, is a broad umbrella term that encompasses anything that involves “manipulating brain function or structure to improve one’s experience of the world,” says neuroscientist Don Vaughn of Santa Clara University and the University of California, Los Angeles. Like the other myriad forms of hacking, neurohacking uses an engineering approach, treating the brain as a piece of hardware that can be systematically modified and upgraded.

Neurohacking techniques can fall under a number of categories — here are a few of the most relevant ones, as well as the thinking behind them.

Brain stimulation

This involves applying an electric or magnetic field to certain regions of the brain in non-neurotypical people to make their activity more closely resemble that seen in a neurotypical brain. In 2008, the Food and Drug Administration approved transcranial magnetic stimulation (TMS) — a noninvasive form of brain stimulation which delivers magnetic pulses to the brain in a noninvasive manner — for major depression. Since then, the FDA has also approved TMS for pain associated with migraines with auras, as well as obsessive-compulsive disorder. Established brain stimulation techniques (such as TMS or electroconvulsive therapy) performed by an expert provider, such as a psychiatrist or neuroscientist, are generally safe, Vaughn says.

Neurofeedback

This one involves using a device that measures brain activity, such as an electroencephalogram (EEG) or a functional magnetic resonance imaging (fMRI) machine. People with neuropsychological disorders receive feedback on their own brain activity — often in the form of images or sound — and focus on trying to make it more closely resemble the brain activity in a healthy person, Vaughn says. This could happen through changing their thought patterns, Vaughn says. Another possibility is that the feedback itself, or the person’s thoughts about the feedback, may somehow lead to a change in their brain’s wiring.

Reducing cognitive load

This means minimizing how much apps, devices, and other tech compete for your attention. Doing so can sharpen and sustain your focus, or what Vaughn refers to as your attention quotient (AQ). To boost his AQ, Vaughn listens to brown noise, which he likens to “white noise, but deeper.” (Think the low rush of a waterfall versus pure static.) He also chews gum, which he says provides an outlet for his restless “monkey mind” while still allowing him to focus on the task at hand.

Reducing cognitive load can also deepen your connection with others. Vaughn uses Voicea, an app based on an AI assistant that takes and store notes of meetings, whether over the phone or in-person, allowing him to focus solely on the conversation, not on recording it. “If we can quell those disruptions that occur because of the way work is done these days, it will allow us to focus and be more empathic with each other,” he says.

Monitoring sleep

Tracking your sleep patterns and adjusting them accordingly. Every night, you go through around five or so stages of sleep, each one deeper than the last. “People are less groggy and make fewer errors when they wake up in a lighter stage of sleep,” Vaughn says. He uses Sleep Cycle, an app that tracks your sleep patterns based on your movements in bed to rouse you during your lightest sleep stage.

Andrey Popov / Shutterstock

Microdosing

Microdosing is the routinely consumption of teensy doses of psychedelics like LSD, ecstasy, or magic mushrooms. Many who practice microdosing follow the regimen recommended by James Fadiman, psychologist and author of The Psychedelic Explorer’s Guide: Safe, Therapeutic, and Sacred Journeys: a twentieth to a tenth of a regular dose, once every three days for about a month. While a regular dose may make you trip, a microdose has subtler effects, with some users reporting, for instance, enhanced energy and focus, per The Cut.

Nootropics

These are OTC supplements or drugs taken to enhance cognitive function. They range from everyday caffeine and vitamin B12 (B12 deficiency has been associated with cognitive decline) to prescription drugs like Ritalin and Adderall, used to treat ADHD and narcolepsy, as well as Provigil (modafinil), used to treat extreme drowsiness resulting from narcolepsy and other sleep disorder. (All three of these drugs promote wakefulness.) The science behind nootropic supplements in particular remains rather murky, though.

Does neurohacking work, though?

Vaughn finds microdosing, neurostimulation, and neurofeedback especially promising for neuropsychological disorders. Although studies suggest that larger doses of psychedelics could help with disorders such as PTSD and treatment-resistant major depression, there are few studies on microdosing psychedelics. “The little science that has been done…is mixed—perhaps slightly positive,” Vaughn says. “Microdosing is promising mainly because of anecdotal evidence.” Meanwhile, neurostimulation can be used noninvasively in some cases, and TMS has already received FDA approval for a handful of conditions. Neurofeedback is not only non-invasive, but offers immediate feedback, and studies suggest it could be effective for PTSD and addiction.

But it’s important to note that just because these methods could positively alter brain function in people with neuropsychological disorders, that “doesn’t mean it’s going to take a normal system and make it superhuman,” Vaughn says. “I think there are lots of small hacks to be done that could add up to something big,” rather than huge hacks that can vastly upgrade cognitive function, a la Limitless. Thanks to millions of years of evolution, the human brain is already pretty damn optimized. “I just don’t know how much more we can tweak it to make it better,” Vaughn says.

As far as enhancements for neurotypical brains, he says that “you’ll probably see a much greater improvement” from removing distractions in your environment to reduce cognitive load than say, increasing your B12 intake — which brings us to an important disclaimer about nootropic supplements in particular. As with all supplements, they aren’t FDA-regulated, meaning that companies that sell them don’t need to provide evidence that they’re safe or effective. Vaughn recommends trying nootropics that research has shown to be safe and effective, like B12 or caffeine.

How can I start neurohacking?

As tempting as it is, adopting every neurohack under the sun is “not the answer,” Vaughn says. Remember, everyone is different. While your best friend may gush about how much her mood has improved since she began microdosing shrooms, your brain might not respond to microdosing—or maybe taking psychedelics just doesn’t align with your ethics.

Start by exploring different neurohacks, and of course, be skeptical of any product that makes outrageous claims. Since neurofeedback isn’t a common medical treatment, talk to your doctor about enrolling in academic studies on neurofeedback, or companies that offer it if you’re interested, Vaughn says. You should also talk to your doctor if you want to try brain stimulation. A doctor can prescribe you Adderall, Ritalin, or Provigil but only for their indicated medical uses, not for cognitive enhancement.

Ultimately, neurohacks are tools, Vaughn says. “You have to find the one that works for you.” If anything, taking this DIY approach to improving your brain function will leave you feeling empowered, a benefit that probably rivals anything a supplement or sleep tracking app could offer.

 

via What is neurohacking and can it actually rewire your brain?

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[Abstract] Role of Interhemispheric Cortical Interactions in Poststroke Motor Function

Background/Objective. We investigated interhemispheric interactions in stroke survivors by measuring transcranial magnetic stimulation (TMS)–evoked cortical coherence. We tested the effect of TMS on interhemispheric coherence during rest and active muscle contraction and compared coherence in stroke and older adults. We evaluated the relationships between interhemispheric coherence, paretic motor function, and the ipsilateral cortical silent period (iSP).

Methods. Participants with (n = 19) and without (n = 14) chronic stroke either rested or maintained a contraction of the ipsilateral hand muscle during simultaneous recordings of evoked responses to TMS of the ipsilesional/nondominant (i/ndM1) and contralesional/dominant (c/dM1) primary motor cortex with EEG and in the hand muscle with EMG. We calculated pre- and post-TMS interhemispheric beta coherence (15-30 Hz) between motor areas in both conditions and the iSP duration during the active condition.

Results. During active i/ndM1 TMS, interhemispheric coherence increased immediately following TMS in controls but not in stroke. Coherence during active cM1 TMS was greater than iM1 TMS in the stroke group. Coherence during active iM1 TMS was less in stroke participants and was negatively associated with measures of paretic arm motor function. Paretic iSP was longer compared with controls and negatively associated with clinical measures of manual dexterity. There was no relationship between coherence and. iSP for either group. No within- or between-group differences in coherence were observed at rest.

Conclusions. TMS-evoked cortical coherence during hand muscle activation can index interhemispheric interactions associated with poststroke motor function and potentially offer new insights into neural mechanisms influencing functional recovery.

 

via Role of Interhemispheric Cortical Interactions in Poststroke Motor Function – Jacqueline A. Palmer, Lewis A. Wheaton, Whitney A. Gray, Mary Alice Saltão da Silva, Steven L. Wolf, Michael R. Borich, 2019

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[Abstract] Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke

Background. Upper-limb chronic stroke hemiplegia was once thought to persist because of disproportionate amounts of inhibition imposed from the contralesional on the ipsilesional hemisphere. Thus, one rehabilitation strategy involves discouraging engagement of the contralesional hemisphere by only engaging the impaired upper limb with intensive unilateral activities. However, this premise has recently been debated and has been shown to be task specific and/or apply only to a subset of the stroke population. Bilateral rehabilitation, conversely, engages both hemispheres and has been shown to benefit motor recovery. To determine what neurophysiological strategies bilateral therapies may engage, we compared the effects of a bilateral and unilateral based therapy using transcranial magnetic stimulation.

Methods. We adopted a peripheral electrical stimulation paradigm where participants received 1 session of bilateral contralaterally controlled functional electrical stimulation (CCFES) and 1 session of unilateral cyclic neuromuscular electrical stimulation (cNMES) in a repeated-measures design. In all, 15 chronic stroke participants with a wide range of motor impairments (upper extremity Fugl-Meyer score: 15 [severe] to 63 [mild]) underwent single 1-hour sessions of CCFES and cNMES. We measured whether CCFES and cNMES produced different effects on interhemispheric inhibition (IHI) to the ipsilesional hemisphere, ipsilesional corticospinal output, and ipsilateral corticospinal output originating from the contralesional hemisphere.

Results. CCFES reduced IHI and maintained ipsilesional output when compared with cNMES. We found no effect on ipsilateral output for either condition. Finally, the less-impaired participants demonstrated a greater increase in ipsilesional output following CCFES.

Conclusions. Our results suggest that bilateral therapies are capable of alleviating inhibition on the ipsilesional hemisphere and enhancing output to the paretic limb.

 

via Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke – David A. Cunningham, Jayme S. Knutson, Vishwanath Sankarasubramanian, Kelsey A. Potter-Baker, Andre G. Machado, Ela B. Plow, 2019

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[ARTICLE] Paired Associative Stimulation as a Tool to Assess Plasticity Enhancers in Chronic Stroke – Full Text

Background and Purpose: The potential for adaptive plasticity in the post-stroke brain is difficult to estimate, as is the demonstration of central nervous system (CNS) target engagement of drugs that show promise in facilitating stroke recovery. We set out to determine if paired associative stimulation (PAS) can be used (a) as an assay of CNS plasticity in patients with chronic stroke, and (b) to demonstrate CNS engagement by memantine, a drug which has potential plasticity-modulating effects for use in motor recovery following stroke.

Methods: We examined the effect of PAS in fourteen participants with chronic hemiparetic stroke at five time-points in a within-subjects repeated measures design study: baseline off-drug, and following a week of orally administered memantine at doses of 5, 10, 15, and 20 mg, comprising a total of seventy sessions. Each week, MEP amplitude pre and post-PAS was assessed in the contralesional hemisphere as a marker of enhanced or diminished plasticity. Strength and dexterity were recorded each week to monitor motor-specific clinical status across the study period.

Results: We found that MEP amplitude was significantly larger after PAS in baseline sessions off-drug, and responsiveness to PAS in these sessions was associated with increased clinical severity. There was no observed increase in MEP amplitude after PAS with memantine at any dose. Motor threshold (MT), strength, and dexterity remained unchanged during the study.

Conclusion: Paired associative stimulation successfully induced corticospinal excitability enhancement in chronic stroke subjects at the group level. However, this response did not occur in all participants, and was associated with increased clinical severity. This could be an important way to stratify patients for future PAS-drug studies. PAS was suppressed by memantine at all doses, regardless of responsiveness to PAS off-drug, indicating CNS engagement.

Introduction

The capacity of the brain to make structural, physiological, and genetic adaptations following stroke, otherwise known as plasticity, is likely to be critical for improving sensorimotor impairments and functional activities. Promotion of adaptive plasticity in the central nervous system (CNS) leading to sustained functional improvement is of paramount importance, given the personal suffering and cost associated with post-stroke disability (Ma et al., 2014). In addition to rehabilitation therapies to retrain degraded motor skills, animal and human studies have tried to augment recovery with neuropharmacologic interventions. Unfortunately, few if any have had a notable effect in patients or have come into routine use (Martinsson et al., 2007Chollet et al., 2011Cramer, 2015Simpson et al., 2015). Methods to screen drugs based on their presumed mechanism of action on plasticity in human motor systems could speed translation to patients. However, there is currently no accepted method in stroke patients for evaluating the potential effectiveness or individual responsiveness to putative “plasticity enhancing” drugs in an efficient, low-cost, cross-sectional manner, in order to establish target engagement in humans and to avoid the extensive time and cost of protracted clinical trials.

Paired associative stimulation (PAS) is a safe, painless, and non-invasive technique known to result in short-term modulation of corticospinal excitability in the adult human motor system, lasting ∼90 min (Stefan et al., 2000Wolters et al., 2003). Post-PAS excitability enhancement has been considered an LTP-like response thought to relate to transient changes in synaptic efficacy in the glutamatergic system at the N-methyl-D-aspartate (NMDA) receptor, since both human NMDA receptor deficiency (Volz et al., 2016) and pharmacological manipulation with dextromethorphan (Stefan et al., 2002) can block the effect. While PAS has been explored as a potential therapeutic intervention in patients with residual motor deficits after stroke (Jayaram and Stinear, 2008Castel-Lacanal et al., 2009), it has not previously been investigated for its potential use as an assay of motor system plasticity in this context. Prior studies have suggested that motor practice and PAS share the same neuronal substrates, modulating LTP and LTD-like plasticity in the human motor system (Ziemann et al., 2004Jung and Ziemann, 2009); therefore, as an established non-invasive human neuromodulation method (Suppa et al., 2017), we reasoned that PAS would be a suitable assay in the present study to examine the effect of a drug on motor system plasticity.

Here, we examine the effect of memantine, a drug used for treatment of Alzheimer’s disease, on the PAS response in patients with chronic stroke. Memantine is described pharmacologically as a low affinity, voltage dependent, non-competitive, NMDA antagonist (Rogawski and Wenk, 2003). At high concentrations, like other NMDA-R antagonists, it can inhibit synaptic plasticity. At lower, clinically relevant concentrations, memantine can, under some circumstances, promote synaptic plasticity by selectively inhibiting extra-synaptic glutamate receptor activity while sparing normal synaptic transmission, and hence may have clinical utility for rehabilitation (Xia et al., 2010). Interest in specifically using the drug for its interaction with stroke pathophysiology stems from animal models of both prevention (Trotman et al., 2015), in which pre-conditioning reduced infarct size, as well as for functional recovery, in which chronic oral administration starting >2 h post-stroke resulted in improved function through a non-neuroprotective mechanism (López-Valdés et al., 2014). In humans, memantine taken over multiple days has been used to demonstrate that the NMDA receptor is implicated in specific transcranial magnetic paired-pulse measures (Schwenkreis et al., 1999), and short-term training-induced motor map reorganization (Schwenkreis et al., 2005). In studies of neuromodulation, memantine blocked the facilitatory effect of intermittent theta-burst stimulation (iTBS) (Huang et al., 2007). Similarly, LTP-like plasticity induced by associative pairing of painful laser stimuli and TMS over primary motor cortex (M1) can also be blocked by memantine (Suppa et al., 2013). The effects of memantine on the PAS response have not yet been demonstrated, including examination of potential dose-response effects, which would be important for the potential clinical application of memantine for stroke recovery.

In our study, we set out to determine whether PAS might be a useful tool to probe the potential for plasticity after stroke in persons with chronic hemiparesis and apply PAS as an assay to look at drug effects on motor system plasticity using memantine. We hypothesized that (a) PAS would enhance corticospinal excitability in the contralesional hemisphere of stroke patients, and that (b) since PAS-induced plasticity is thought to involve a short-term change in glutamatergic synaptic efficacy, memantine would have a dose-dependent effect on PAS response. We predicted that at low doses, memantine would enhance PAS-induced plasticity through selective blockade of extrasynaptic NMDA receptors, whereas higher doses would inhibit PAS-induced plasticity.[…]

 

Continue —> Frontiers | Paired Associative Stimulation as a Tool to Assess Plasticity Enhancers in Chronic Stroke | Neuroscience

Figure 1. Axial MR/CT images for individual patients illustrating the stroke lesion. Images are displayed in radiological convention. Images are labeled by participant number.

 

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[Abstract] Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke

Background. Upper-limb chronic stroke hemiplegia was once thought to persist because of disproportionate amounts of inhibition imposed from the contralesional on the ipsilesional hemisphere. Thus, one rehabilitation strategy involves discouraging engagement of the contralesional hemisphere by only engaging the impaired upper limb with intensive unilateral activities. However, this premise has recently been debated and has been shown to be task specific and/or apply only to a subset of the stroke population. Bilateral rehabilitation, conversely, engages both hemispheres and has been shown to benefit motor recovery. To determine what neurophysiological strategies bilateral therapies may engage, we compared the effects of a bilateral and unilateral based therapy using transcranial magnetic stimulation.

Methods. We adopted a peripheral electrical stimulation paradigm where participants received 1 session of bilateral contralaterally controlled functional electrical stimulation (CCFES) and 1 session of unilateral cyclic neuromuscular electrical stimulation (cNMES) in a repeated-measures design. In all, 15 chronic stroke participants with a wide range of motor impairments (upper extremity Fugl-Meyer score: 15 [severe] to 63 [mild]) underwent single 1-hour sessions of CCFES and cNMES. We measured whether CCFES and cNMES produced different effects on interhemispheric inhibition (IHI) to the ipsilesional hemisphere, ipsilesional corticospinal output, and ipsilateral corticospinal output originating from the contralesional hemisphere.

Results. CCFES reduced IHI and maintained ipsilesional output when compared with cNMES. We found no effect on ipsilateral output for either condition. Finally, the less-impaired participants demonstrated a greater increase in ipsilesional output following CCFES.

Conclusions. Our results suggest that bilateral therapies are capable of alleviating inhibition on the ipsilesional hemisphere and enhancing output to the paretic limb.

via Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke – David A. Cunningham, Jayme S. Knutson, Vishwanath Sankarasubramanian, Kelsey A. Potter-Baker, Andre G. Machado, Ela B. Plow,

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[Abstract] Publication trends in transcranial magnetic stimulation: A 30-year panorama

Highlights

  • This study uses a systematic, bibliometric approach to assess the TMS literature base.
  • Annual TMS research output has increased dramatically over the period 1988–2017.
  • The top disease entities studied to date have been stroke and depression.

 

Abstract

Background

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulatory technique that has broad diagnostic and therapeutic potential across a range of neurological and psychiatric diseases.

Objective

This study utilises a bibliometric approach to systematically and comprehensively evaluate the literature on TMS from the last three decades.

Methods

The Scopus citation database was used to identify all peer-reviewed journal articles concerning TMS over the period 1988–2017. Frequency-distribution, cross-tabulation and keyword analyses were performed to determine the most prolific researchers, institutions, nations, journals and the foremost studied disease entities within the TMS field. Given recent heightened awareness of gender bias across many fields of biomedicine, female representation among the most prolific authors was determined. Open-access publication rates and types of study design utilised were also quantified.

Results

17,492 TMS-related articles were published during the study period 1988–2017. The annual TMS research output has increased dramatically over this time, despite a recent levelling-off of publications per year. The most prolific institutions were based in the United Kingdom, the United States and Canada. The top disease entities studied were stroke, depression and Parkinson’s disease. Only 4/52 of the most productive researchers during the study period were female. A minority (4.81%) of publications were published as gold open-access.

Conclusion

This study implemented a systematic, bibliometric approach to quantitively assess the breadth of the TMS literature base and identify temporal publication and authorship trends. Drawing on these insights may aid understanding of historical progress in TMS over the last 30 years and help identify into unmet needs and opportunities to improve scientific and publishing practices to contribute to the future health of the field. These findings are likely to be relevant to researchers, clinicians, funders, industry collaborators and other stakeholders.

 

via Publication trends in transcranial magnetic stimulation: A 30-year panorama – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation

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[WEB SITE] Transcranial Magnetic Stimulation for the Recovery of Gait and Balance in Stroke Patients – BrainPost

Post by Thomas Brown

What’s the science?

The permanent brain damage which occurs following ischemic stroke makes functional recovery difficult. While physiotherapy can result in improved voluntary motor recovery, the improvement of balance and gait can be harder. Issues with balance pose a safety risk for stroke patients, who may be more likely to fall. Ultimately, problems with balance can mean reduced independence for patients. The cerebellum, a structure located at the back of the brain, is known to regulate movement, gait and balance. Deficits to the cerebellum often result in ataxia and widened gaits, making this area a prime target for functional recovery analysis. This week in JAMA Neurology Koch and colleagues demonstrate in a phase IIa clinical trial, an increase in gait and balance in hemiparetic stroke patients, up to three weeks after physiotherapy supplemented with transcranial magnetic stimulation of the cerebellum.

How did they do it?

A group of 36 hemiparetic (one side affected) stroke patients were randomly assigned to one of two age-matched groups; control or experimental. The experimental group was treated with intermittent theta-burst magnetic stimulation (TBS) of the cerebellar region ipsilateral (same side) to their motor issues. Intermittent TBS is a process by which bursts of magnetic energy are applied to the scalp over an area of interest. TBS was administered in conjunction with physiotherapy to the experimental group for three weeks. The control group still received physiotherapy, but received sham (fake) TBS. Patients were assessed using a wide range of balance and gait analysis tests to determine the degree of recovery. The authors relied primarily on the Berg Balance Scale, which is a series of 14 tests that determine the ability of an individual to balance without aid. Gait analysis was also performed, in which patients were asked to walk while a machine measured their gait (the space between each foot while walking). Neural activity was measured with electroencephalography while transcranial magnetic stimulation was applied simultaneously (EEG-TMS). This technique was used to measure neural activity changes in motor regions of the brain following activation of the motor cortex using a different TMS paradigm than the one used for treatment.

What did they find?

The authors found that after three weeks of the last treatment with either sham or cerebellar TBS, there was an average increase in the Berg Balance Scale score in those treated with TBS compared to controls. They also showed a reduction in gait width; a wide gait is often associated with the body’s attempt to compensate for problems with balance. This finding was supported by correlational analysis which found that a reduction is step width was associated with an improvement in Berg Balance Scale score. Interestingly, three weeks after treatment there was also an increase in neural activity in the motor (M1) region of the brain in the hemispheres affected by the stoke, in treated patients compared to controls. This area of the cortex is associated with the movement execution. Altogether these findings suggest that there were significant balance, gait and motor cortex activity improvements following treatment with TBS. Critically, no adverse effects were observed following treatment with TBS during the clinical trial.

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What’s the impact?

These findings suggest that theta-burst stimulation may be an effective way of supplementing physiotherapy in those suffering with balance and gait deficits following stroke. Theta-burst stimulation in conjunction with physiotherapy, was able to improve both balance and gait in stroke patients. Treatment with theta-burst stimulation could reduce the chance of falling and improve independence in stroke patients.

stroke_quote.png

Koch et al. Effect of Cerebellar Stimulation on Gait and Balance Recovery
in Patients With Hemiparetic Stroke. JAMA Neurology (2018).Access the original scientific publication here

 

via Weekly BrainPost — BrainPost

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[Abstract] Bilateral Motor Cortex Plasticity in Individuals With Chronic Stroke, Induced by Paired Associative Stimulation

Background: In the chronic phase after stroke, cortical excitability differs between the cerebral hemispheres; the magnitude of this asymmetry depends on degree of motor impairment. It is unclear whether these asymmetries also affect capacity for plasticity in corticospinal tract excitability or whether hemispheric differences in plasticity are related to chronic sensorimotor impairment.

Methods: Response to paired associative stimulation (PAS) was assessed bilaterally in 22 individuals with chronic hemiparesis. Corticospinal excitability was measured as the area under the motor-evoked potential (MEP) recruitment curve (AUC) at baseline, 5 minutes, and 30 minutes post-PAS. Percentage change in contralesional AUC was calculated and correlated with paretic motor and somatosensory impairment scores.

Results: PAS induced a significant increase in AUC in the contralesional hemisphere (P = .041); in the ipsilesional hemisphere, there was no significant effect of PAS (P = .073). Contralesional AUC showed significantly greater change in individuals without an ipsilesional MEP (P = .029). Percentage change in contralesional AUC between baseline and 5 m post-PAS correlated significantly with FM score (r = −0.443; P = .039) and monofilament thresholds (r = 0.444, P = .044).

Discussion: There are differential responses to PAS within each cerebral hemisphere. Contralesional plasticity was increased in individuals with more severe hemiparesis, indicated by both the absence of an ipsilesional MEP and a greater degree of motor and somatosensory impairment. These data support a body of research showing compensatory changes in the contralesional hemisphere after stroke; new therapies for individuals with chronic stroke could exploit contralesional plasticity to help restore function.

 

via Bilateral Motor Cortex Plasticity in Individuals With Chronic Stroke, Induced by Paired Associative Stimulation – Jennifer K. Ferris, Jason L. Neva, Beatrice A. Francisco, Lara A. Boyd, 2018

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[WEB SITE] What effect does transcranial magnetic stimulation have on the brain?

The procedure facilitates reorganization of connections between neurons which could be useful for therapies

Date: June 5, 2018
Source: Ruhr-University Bochum
Summary:
Researchers have gained new insights on the question of how transcranial magnetic stimulation (TMS) effects functional interconnectivity of neurons. For visualization, they employed fluorescent dyes which provide information on the activity of neurons by light. Using this technique, they showed in an animal model that TMS predisposes neuronal connections in the visual cortex of the brain for processes of reorganization.
 
FULL STORY

Researchers of the Ruhr-Universität Bochum have gained new insights on the question of how transcranial magnetic stimulation (TMS) effects functional interconnectivity of neurons. For visualisation, they employed fluorescent dyes which provide information on the activity of neurons by light. Using this technique, they showed in an animal model that TMS predisposes neuronal connections in the visual cortex of the brain for processes of reorganisation.

TMS is being used as a treatment for a number of brain diseases such as depression, Alzheimer’s disease and schizophrenia, but there has been little research on how exactly TMS works. The team of associate professor Dr Dirk Jancke of the Optical Imaging Lab in Bochum describes its new discoveries in the journal Proceedings of the National Academy of Science (PNAS).

Examining the effects on cortical maps in the visual cortex

The researchers have investigated how TMS affects the organisation of so-called orientation maps in the visual part of the brain. Those maps are partly genetically determined and partly shaped by the interaction with our surroundings. In the visual cortex, for example, neurons respond to contrast edges of certain orientations, which typically constitute boundaries of objects. Neurons that preferably respond to edges of a specific orientation are closely grouped while clusters of neurons with other orientation preferences are gradually located further away, altogether forming a systematic map across all orientations.

The team employed high frequency TMS and compared the behaviour of neurons to visual stimuli with a specific angular orientation before and after the procedure. The result: After the magnetic stimulation the neurons responded more variable, that is, their preference for a particular orientation was less pronounced than before the TMS. “You could say that after the TMS the neurons were somewhat undecided and hence, potentially open to new tasks,” explains Dirk Jancke. “Therefore, we reasoned that the treatment provides us with a time window for the induction of plastic processes during which neurons can change their functional preference.”

A short visual training remodels the maps

The team then looked into the impact of a passive visual training after TMS treatment. 20-minutes of exposure to images of a specific angular orientation led to enlargement of those areas of the brain representing the trained orientation. “Thus, the map in the visual cortex has incorporated the bias in information content of the preceding visual stimulation by changing its layout within a short time,” says Jancke. “Such a procedure — that is a targeted sensory or motor training after TMS to modify the brain’s connectivity pattern — might be a useful approach to therapeutic interventions as well as for specific forms of sensory-motor training,” explains Dirk Jancke.

Methodological challenges

Transcranial magnetic stimulation is a non-invasive painless procedure: A solenoid is being positioned above the head and the brain area in question can be activated or inhibited by means of magnetic waves. So far little is known about the impact of the procedure on a cellular network level, because the strong magnetic field of the TMS superimposes signals that are used by researchers in order to monitor the neuronal effects of the TMS. The magnetic pulse interferes in particular with electrical measurement techniques, such as EEG. In addition, other procedures used in human participants, e.g. functional magnetic resonance imaging, are too slow or their spatial resolution is too low.

Dirk Jancke’s team used voltage dependent fluorescent dyes, embedded in the membranes of the neurons, in order to measure the brain’s activity after the TMS with high spatiotemporal resolution. As soon as a neuron’s activity is modulated, the dye molecules change emission intensity. Light signals therefore provide information about immediate changes in activity of groups of neurons.

Story Source: Materials provided by Ruhr-University BochumNote: Content may be edited for style and length.


Journal Reference:

  1. Vladislav Kozyrev, Robert Staadt, Ulf T. Eysel, Dirk Jancke. TMS-induced neuronal plasticity enables targeted remodeling of visual cortical mapsProceedings of the National Academy of Sciences, 2018; 201802798 DOI: 10.1073/pnas.1802798115

 

via What effect does transcranial magnetic stimulation have on the brain? The procedure facilitates reorganization of connections between neurons which could be useful for therapies — ScienceDaily

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[WEB SITE] Cognitive Behavioral Therapy (CBT) and Transcranial Magnetic Stimulation (TMS): What Are These Therapies and How Are They Used?

Published 7 Feb 2018  – Reviewed 7 Feb 2018 – Author Melissa Galinato  – Source BrainFacts/SfN

When you have a cold, you might have a runny nose, a headache, and a cough. You may take different medications to treat each symptom to soothe your throat or ease your sneezing. Like treating a cold with multiple symptoms, there are different types of therapies to treat the multiple symptoms of depressive disorder, widely known as depression. Cognitive Behavioral Therapy (CBT) and Transcranial Magnetic Stimulation (TMS) are two therapy types that address specific symptoms of depression.

More than 300 million people around the world have depression, which is a common mental illness with multiple symptoms such as persistent sadness, irritability, a feeling of worthlessness, and loss of interest in activities—especially in things that previously brought joy or excitement.

With Cognitive Behavioral Therapy (CBT), a therapist helps a patient with depression to focus on understanding how three things – thoughts, feelings, and behavior – affect each other. “The goal of CBT for depression is to start targeting problematic thoughts and actions that are occurring in the present – as opposed to looking back in the past for a cause – teaching patients skills that they can use to become more aware of their negative thoughts, evaluate their validity and, when not accurate, replace them with more realistic/balanced ways of thinking,” says Simon Rego, Chief Psychologist at Montefiore Medical Center/Albert Einstein College of Medicine in New York.

“At the same time, the other goal of CBT is to help patients change maladaptive patterns of behavior, gradually increasing activities of pleasure and accomplishment, which are known to enhance mood. Taken together, changing how you think and what you do can have a powerful positive impact on your mood.”

Imagine setting a goal – like running a marathon for the first time. A running coach could help you reach that goal by giving you tips and developing a training to slowly build up your strength. In CBT, the therapist acts like a coach and helps people identify goals such as driving a car or giving a speech. Then the therapist helps to figure out actions to reach those goals such as practicing thinking strategies, writing in journals, and doing homework assignments between appointments. Doing these activities in CBT can help people learn coping skills, build self-confidence, and have a sense of control, and a growing number of studies show that CBT works very well for treating depression and several other mental health conditions.

“CBT is an effective treatment for depression because it targets the two main areas where people with depression struggle: negative thoughts and unhelpful behaviors,” said Rego. “The main theory in CBT is that how we feel is directly influenced by how we think and what we do (or don’t do). In the case of depression, we know that people tend to have many negative thoughts about themselves, the world, and the future (e.g., I am a failure, I’ll never get better, no one cares about me, I don’t have the energy to do anything, etc.) which only serve to perpetuate their negative mood.”

Another therapy called Transcranial Magnetic Stimulation (TMS) can be used for some patients with depression who do not get better with antidepressant medications or other treatments. “In our experience, TMS is an appropriate treatment for major depressive disorder, moderate in severity and who are still functioning in the home, community, and who have failed multiple antidepressant medications,” said Ananda Pandurangi, medical director and chair of inpatient psychiatry in the Department of Psychiatry at Virginia Commonwealth University School of Medicine. “It is not appropriate for patients with either “mild” depression or those with severe depression including those with psychosis or catatonia,” said Pandurangi, noting that psychotherapy and medications may be more appropriate for patients with mild to severe depression.

TMS aims to alter brain circuitry. Using an electromagnetic coil, called a stimulator, to affect brain activity and treat depression, TMS treatment involves a doctor placing the stimulator near the forehead against the scalp. This activates brain cells in an area of the brain that includes the prefrontal cortex and controls mood and depression.

Sessions typically use repetitive TMS (rTMS) where recurrent magnetic pulses stimulate the brain. In 2008, the FDA approved rTMS for depression treatment after several research studies showed this TMS treatment lowers signs of depression and improves mood in people with treatment-resistant depression.

REFERENCES

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Depression. National Alliance on Mental Illness. Accessed 2/7/2018.

Depression. World Health Organization. February 2017.

Dobson D, Dobson KS. Evidence-based practice of cognitive-behavioral therapy. Guilford Publications. 2016. 

Gaynes BN, Lloyd SW, Lux L, Gartlehner G, Hansen RA, et al. Repetitive transcranial magnetic stimulation for treatment-resistant depression: a systematic review and meta-analysis. The Journal of Clinical Psychiatry. 75(5), 477-89 (2014).

Huguet A, Rao S, McGrath PJ, Wozney L, Wheaton M, et al. A systematic review of cognitive behavioral therapy and behavioral activation apps for depression. PLoS One. 11(5), e0154248 (2016). 

Lefaucheur JP, André-Obadia N, Antal A, Ayache SS, et al. Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS). Clinical Neurophysiology. 125(11), 2150-2206 (2014). 

Levkovitz Y, Isserles M, Padberg F, Lisanby SH, Bystritsky A, et al. Efficacy and safety of deep transcranial magnetic stimulation for major depression: a prospective multicenter randomized controlled trial. World Psychiatry. 14(1), 64-73 (2015). 

Pascual-Leone A, Rubio B, Pallardó F, Catalá MD. Rapid-rate transcranial magnetic stimulation of left dorsolateral prefrontal cortex in drug-resistant depression. The Lancet. 348(9022), 233-237 (1996). 

Psychotherapy. National Alliance on Mental Illness. Accessed 2/7/2018.

Wassermann EM, Williams WA, Callahan A, Ketter TA, Basser P, et al. Daily repetitive transcranial magnetic stimulation (rTMS) improves mood in. Neuroreport. 6, 1853-1856 (1995). 

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