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1.
Transcranial Magnetic Stimulation as Treatment in Multiple Neurologic Conditions.
Iglesias, AH
Current neurology and neuroscience reports. 2020;(1):1
Abstract
PURPOSE OF REVIEW Transcranial magnetic stimulation (TMS) is a method of Non-Invasive Brain Stimulation that is based on electro-physical principles discovered by Michael Faraday. A TMS device is made of one or two copper coils, positioned superficially to a site of interest in the brain, to non-invasively produce a brief magnetic pulse to an estimated depth from the surface of the scalp with the following axonal depolarization. This axonal depolarization activates cortical and subcortical networks with multiple effects. There are different methods of TMS used, all with different mechanisms of action. TMS is well tolerated with very few side effects. RECENT FINDINGS TMS is now approved for major depression disorder and obsessive-compulsive disorder. There is significant data to consider approval of TMS for many neurological disorders. This is a review of the uses of TMS in diverse neurological conditions, including stroke and spasticity, migraine, and dementia. TMS is a device that utilizes non-invasive brain stimulation, and it has shown promising results with objective clinical and basic science data. Its ability to trigger neuronal plasticity and potentiating synaptic transmission gives it incredible therapeutic potential. There are diverse mechanisms of action, and this could be troublesome in elaborating clinical trials and standardization of therapy.
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2.
Effects of Noninvasive Brain Stimulation on Food Cravings and Consumption: A Meta-Analytic Review.
Lowe, CJ, Vincent, C, Hall, PA
Psychosomatic medicine. 2017;(1):2-13
Abstract
OBJECTIVE The primary aim of this review was to evaluate the effectiveness of noninvasive brain stimulation to the dorsolateral prefrontal cortex (dlPFC) for modulating appetitive food cravings and consumption in laboratory (via meta-analysis) and therapeutic (via systematic review) contexts. METHODS Keyword searches of electronic databases (PubMed, Scopus, Web of Science, PsychoInfo, and EMBASE) and searches of previous quantitative reviews were used to identify studies (experimental [single-session] or randomized trials [multi-session]) that examined the effects of neuromodulation to the dlPFC on food cravings (n = 9) and/or consumption (n = 7). Random-effects models were employed to estimate the overall and method-specific (repetitive transcranial magnetic stimulation [rTMS] and transcranial direct current stimulation [tDCS]) effect sizes. Age and body mass index were examined as potential moderators. Two studies involving multisession therapeutic stimulation were considered in a separate systematic review. RESULTS Findings revealed a moderate-sized effect of modulation on cravings across studies (g, -0.516; p = .037); this effect was subject to significant heterogeneity (Q, 33.086; p < .001). Although no statistically significant moderators were identified, the stimulation effect on cravings was statistically significant for rTMS (g, -0.834; p = .008) but not tDCS (g, -0.252; p = .37). There was not sufficient evidence to support a causal effect of neuromodulation and consumption in experimental studies; therapeutic studies reported mixed findings. CONCLUSIONS Stimulation of the dlPFC modulates cravings for appetitive foods in single-session laboratory paradigms; when estimated separately, the effect size is only significant for rTMS protocols. Effects on consumption in laboratory contexts were not reliable across studies, but this may reflect methodological variability in delivery of stimulation and assessment of eating behavior. Additional single- and multi-session studies assessing eating behavior outcomes are needed.
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3.
UNANSWERED QUESTIONS IN THE TRANSCRANIAL MAGNETIC STIMULATION TREATMENT OF PATIENTS WITH DEPRESSION.
Morvai, S, Nagy, A, Kovács, A, Móre, CE, Berecz, R, Frecska, E
Ideggyogyaszati szemle. 2016;(1-2):4-11
Abstract
According to the WHO fact sheet depression is a common mental disorder affecting 350 million people of all ages worldwide. Transcranial Magnetic Stimulation (TMS) is a technique which allows the investigator to stimulate and study cortical functions in healthy subjects and patients suffering from various mental and neurological disorders. In the early 1990s, studies revealed that it is possible to evoke long term mood changes in healthy volunteers by rapid rate repetitive, TMS (rTMS) over the frontal cortex. Subsequent studies involving depressed patients found frontal cortical rTMS administered daily to be clinically effective. In the past two decades, numerous trials examined the therapeutic potential of rTMS application in the treatment of mood disorders with constantly evolving treatment protocols. The aim of this paper is to review the literature of the past two decades, focusing on trials addressing the efficacy and safety of rTMS in depressed patients. Our primary goal is to evaluate the results in order to direct future studies which may help investigators in the development of treatment protocols suitable in hospital settings. The time is not far when TMS devices will be used routinely by practitioners primarily for therapeutic purpose rather than clinical research. To our knowledge, a widely accepted "gold standard" that would offer the highest efficacy, with the best tolerability has not been established yet. In order to approach this goal, the most important factors to be addressed by further studies are: localization, frequency, intensity, concurrent medication, maintenance treatments, number of pulses, trains, unilateral, or bilateral mode of application.
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4.
Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity.
Val-Laillet, D, Aarts, E, Weber, B, Ferrari, M, Quaresima, V, Stoeckel, LE, Alonso-Alonso, M, Audette, M, Malbert, CH, Stice, E
NeuroImage. Clinical. 2015;:1-31
Abstract
Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain-behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of these non-invasive neuromodulation strategies to study basic mechanisms underlying eating behavior and to treat its disorders. Both of these approaches will be compared in light of recent work in this field, while addressing technical and practical questions. The third part of this review will be dedicated to invasive neuromodulation strategies, such as vagus nerve stimulation (VNS) and deep brain stimulation (DBS). In combination with neuroimaging approaches, these techniques are promising experimental tools to unravel the intricate relationships between homeostatic and hedonic brain circuits. Their potential as additional therapeutic tools to combat pharmacorefractory morbid obesity or acute eating disorders will be discussed, in terms of technical challenges, applicability and ethics. In a general discussion, we will put the brain at the core of fundamental research, prevention and therapy in the context of obesity and eating disorders. First, we will discuss the possibility to identify new biological markers of brain functions. Second, we will highlight the potential of neuroimaging and neuromodulation in individualized medicine. Third, we will introduce the ethical questions that are concomitant to the emergence of new neuromodulation therapies.
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5.
TMS-induced motor evoked potentials in Wilson's disease: a systematic literature review.
Bembenek, JP, Kurczych, K, Członkowska, A
Bioelectromagnetics. 2015;(4):255-66
Abstract
Wilson's disease (WD) is a metabolic brain disease resulting from improper copper metabolism. Although pyramidal symptoms are rarely observed, subclinical injury is highly possible as copper accumulates in all brain structures. The usefulness of motor evoked potentials (MEPs) in pyramidal tracts damage evaluation still appears to be somehow equivocal. We searched for original papers assessing the value of transcranial magnetic stimulation elicited MEPs with respect to motor function of upper and lower extremity in WD. We searched PubMed for original papers evaluating use of MEPs in WD using key words: "motor evoked potentials Wilson's disease" and "transcranial magnetic stimulation Wilson's disease." We found six articles using the above key words. One additional article and one case report were found while viewing the references lists. Therefore, we included eight studies. Number of patients in studies was low and their clinical characteristic was variable. There were also differences in methodology. Abnormal MEPs were confirmed in 20-70% of study participants. MEPs were not recorded in 7.6-66.7% of patients. Four studies reported significantly increased cortical excitability (up to 70% of patients). Prolonged central motor conduction time was observed in four studies (30-100% of patients). One study reported absent or prolonged central motor latency in 66.7% of patients. Although MEPs may be abnormal in WD, this has not been thoroughly assessed. Hence, further studies are indispensable to evaluate MEPs' usefulness in assessing pyramidal tract damage in WD.
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6.
Interaction between electrical modulation of the brain and pharmacotherapy to control pharmacoresistant epilepsy.
Rocha, L
Pharmacology & therapeutics. 2013;(2):211-28
Abstract
In spite of the high success rate of many surgical procedures for pharmacoresistant epilepsy, a substantial number of patients do not become seizure-free. Different strategies for electrical modulation of the brain such as Deep Brain Stimulation, Vagal Nerve Stimulation and Transcraneal Magnetic Stimulation have gained considerable interest in the last decade as alternative therapies for patients with medically refractory epilepsy. Research into the mechanism of action of the strategies for electrical modulation of the brain suggests a crucial role of different molecules and channels such as glutamate, γ-aminobutyric acid, adenosine, brain-derived neurotrophic factor, calcium channels, sodium channels as well as extracellular potassium. Electrical modulation of the brain may reduce the overexpression of P-glycoprotein, a drug efflux transporter that reduces the absorption of antiepileptic drugs. Electrical modulation of the brain induces long-term effects associated with beneficial consequences on clinical symptoms observed during the postictal state. In addition, electrical modulation of the brain might also promote the neurogenesis in subjects with pharmacoresistant epilepsy in whom this process is decreased. Targeting the regulatory pathways in charge of the effects of electrical modulation of the brain is discussed as a means to improve its efficacy. Electrical modulation of the brain combined with pharmacotherapy may represent an innovative approach to avoid epileptogenesis, reduce seizure activity, induce beneficial effects during the postictal state, diminish the amount of antiepileptic drugs, and improve alertness, memory and mood in pharmacoresistant epilepsy.