Effect of Transcranial Brain Stimulation for the Treatment of Alzheimer Disease: A Review

Available pharmacological treatments for Alzheimer disease (AD) have limited effectiveness, are expensive, and sometimes induce side effects. Therefore, alternative or complementary adjuvant therapeutic strategies have gained increasing attention. The development of novel noninvasive methods of brain stimulation has increased the interest in neuromodulatory techniques as potential therapeutic tool for cognitive rehabilitation in AD. In particular, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are noninvasive approaches that induce prolonged functional changes in the cerebral cortex. Several studies have begun to therapeutically use rTMS or tDCS to improve cognitive performances in patients with AD. However, most of them induced short-duration beneficial effects and were not adequately powered to establish evidence for therapeutic efficacy. Therefore, TMS and tDCS approaches, seeking to enhance cognitive function, have to be considered still very preliminary. In future studies, multiple rTMS or tDCS sessions might also interact, and metaplasticity effects could affect the outcome

Neuroplastic Changes Following Brain Ischemia and their Contribution to Stroke Recovery: Novel Approaches in Neurorehabilitation

Ischemic damage to the brain triggers substantial reorganization of spared areas and pathways, which is associated with limited, spontaneous restoration of function. A better understanding of this plastic remodeling is crucial to develop more effective strategies for stroke rehabilitation. In this review article, we discuss advances in the comprehension of post-stroke network reorganization in patients and animal models. We first focus on rodent studies that have shed light on the mechanisms underlying neuronal remodeling in the perilesional area and contralesional hemisphere after motor cortex infarcts. Analysis of electrophysiological data has demonstrated brain-wide alterations in functional connectivity in both hemispheres, well beyond the infarcted area. We then illustrate the potential use of non-invasive brain stimulation (NIBS) techniques to boost recovery. We finally discuss rehabilitative protocols based on robotic devices as a tool to promote endogenous plasticity and functional restoration

Time since onset might be of essence: a recommendation to assess the effects of combination of non-pharmacological neuromodulatory approaches at early stage since symptoms onset

In the past decade researchers began to assess the potential beneficial effects of non-invasive brain stimulation (NIBS) combined with a behavioral task as a treatment approach for various medical conditions. Transcranial direct current stimulation (tDCS) applied to the motor cortex combined with another treatment approach has been assessed as analgesic treatment in neuropathic and non-neuropathic pain conditions, and was found to exert only modest pain relief. Our group results show that combined tDCS and mirror therapy dramatically reduced acute phantom limb pain intensity with long-lasting effects, potentially preventing pain chronification. A review of the scientific literature indicates that our approach differs from that of others: We applied the intervention at the acute stage of the disease, whereas other studies applied the intervention in patients whose disease had already been established. We suggest that the timing of administration of the combined intervention is critical. Unlike in patients with chronic painful condition, in which the maladaptive plasticity associated with pain chronification and chronicity is well-consolidated, early treatment at the acute pain stage may be more successful in counterbalancing the not-yet consolidated maladaptive plasticity. We encourage the research community to test our hypothesis, both in the treatment of pain, and beyond.info:eu-repo/semantics/publishedVersio

Cortical mapping of the neuronal circuits modulating the muscle tone. Introduction to the electrophysiological treatment of the spastic hand

L'objectiu d'aquest estudi es investigar l'organització cortical junt amb la connectivitat còrtico-subcortical en subjectes sans, com a estudi preliminar. Els mapes corticals s'han fet per TMS navegada, i els punts motors obtinguts s'han exportant per estudi tractogràfic i anàlisi de las seves connexions. El coneixement precís de la localització de l'àrea cortical motora primària i les seves connexions es la base per ser utilitzada en estudis posteriors de la reorganització cortical i sub-cortical en pacients amb infart cerebral. Aquesta reorganització es deguda a la neuroplasticitat i pot ser influenciada per els efectes neuromoduladors de la estimulació cerebral no invasiva.The purpose of this study is to investigate the motor cortex organisation together with the cortico-subcortical connectivity in healthy subjects, as a preliminary study. Cortical maps have been performed by navigated TMS and the motor points have been exported to DTI to study their subcortical connectivity. The precise knowledge of localization of the primary motor cortex area and its connectivity is the base to be used in later studies of cortical and subcortical re-organisation in stroke patients. This re-organisation is due to the neuroplascity and can be influenced by the neuromodulation effects of the non-invasive cerebral stimulation therapy by TMS

Noninvasive Brain Stimulation and Noninvasive Peripheral Stimulation for Neglect Syndrome Following Acquired Brain Injury

OBJECTIVE: Hemispatial neglect is a frequent condition usually following nondominant hemispheric brain injury. It strongly affects rehabilitation strategies and everyday life activities. It is associated with behavioral and cognitive disability with a strong impact on patient's life. METHODS: We reviewed the published literature on the use of noninvasive brain stimulation, including repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), and of noninvasive peripheral muscle stimulation, as therapeutic strategies for rehabilitation of neglect after acquired brain injury, such as in stroke or in traumatic injuries. The studies were grouped as controlled or uncontrolled studies in each stimulation techniques. RESULTS: Thirty-four studies were identified and 16 on rTMS, 10 on tDCS, and 8 on vibration. All studies were conducted in adult patients who suffered a stroke, except for one that was conducted in a patient suffering traumatic acquired brain injury and another that was conducted in a patient with brain tumor. In spite of significant variability in treatment protocols, patients' features and assessment of neglect, improvement was reported in almost all studies with no side-effects. CONCLUSIONS: Noninvasive brain stimulation and neuromuscular vibration are promising therapeutic neuromodulatory approaches for neglect. Further randomized-controlled studies are needed to corroborate their effectiveness as separate and combined techniques

Neural signature of tDCS, tPCS and their combination: Comparing the effects on neural plasticity

Transcranial pulsed current stimulation (tPCS) and transcranial direct current stimulation (tDCS) are two noninvasive neuromodulatory brain stimulation techniques whose effects on human brain and behavior have been studied individually. In the present study we aimed to quantify the effects of tDCS and tPCS, individually and in combination, on cortical activity, sensitivity and pain-related assessments in healthy individuals in order to understand their neurophysiological mechanisms and potential applications in clinical populations. A total of 48 healthy individuals participated in this randomized double blind sham controlled study. Participants were randomized to receive a single stimulation session of either: active or sham tPCS and active or sham tDCS. Quantitative electroencephalography (qEEG), sensitivity and pain assessments were used before and after each stimulation session. We observed that tPCS had a higher effect on power, as compared to tDCS, in several bandwidths on various cortical regions: the theta band in the parietal region (p = 0.021), the alpha band in the temporal (p=0.009), parietal (p = 0.0063), and occipital (p < 0.0001) regions. We found that the combination of tPCS and tDCS significantly decreased power in the low beta bandwidth of the frontal (p = 0.0006), central (p = 0.0001), and occipital (p = 0.0003) regions, when compared to sham stimulation. Additionally, tDCS significantly increased power in high beta over the temporal (p = 0.0015) and parietal (p = 0.0007) regions, as compared to sham. We found no effect on sensitivity or pain-related assessments. We concluded that tPCS and tDCS have different neurophysiological mechanisms, elicit distinct signatures, and that the combination of the two leads to no effect or a decrease on qEEG power. Further studies are required to examine the effects of these techniques on clinical populations in which EEG signatures have been found altered. (C) 2016 Published by Elsevier Ireland Ltd.This research was supported by Labuschagne Foundation. Dr. Thibaut was founded by the Belgian American Educational Foundation (BAEF) and the Duesberg Foundation. Dr. Morales-Quezada received funding support from an Institutional National Research Service Award from the National Center for Complementary and Integrative Health grant T32AT000051, the Ryoichi Sasakawa Fellowship Fund, and by the Program in Placebo Studies at Beth Israel Deaconess Medical Center. Deitos, A. was founded by the Coordination for the Improvement of Higher Education Personnel - CAPES, International Cooperation General Program - PGCI (no 023/11). Prof. Fregni has been supported by NIH RO1 grant (1R01HD082302-01A1)