Corticospinal excitability enhancement with simultaneous transcranial near-infrared stimulation and anodal direct current stimulation of motor cortex

ObjectivesNon-invasive brain stimulation (NIBS) is beneficial to many neurological and psychiatric disorders by modulating neuroplasticity and cortical excitability. However, recent studies evidence that single type of NIBS such as transcranial direct current stimulation (tDCS) does not have meaningful clinical therapeutic responses due to their small effect size. Transcranial near-infrared stimulation (tNIRS) is a novel form of NIBS. Both tNIRS and tDCS implement its therapeutic effects by modulating cortical excitability but with different mechanisms. We hypothesized that simultaneous tNIRS and tDCS is superior to single stimulation, leading to a greater cortical excitability.MethodsSixteen healthy subjects participated in a double-blind, sham-controlled, cross-over designed study. Motor evoked potentials (MEPs) were used to measure motor cortex excitability. The changes of MEP were calculated and compared in the sham condition, tDCS stimulation condition, tNIRS condition and the simultaneous tNIRS and anodal tDCS condition.ResultstDCS alone and tNIRS alone both elicited higher MEP after stimulation, while the MEP amplitude in the simultaneous tNIRS and tDCS condition was significantly higher than either tNIRS alone or tDCS alone. The enhancement lasted up to at least 30 minutes after stimulation, indicating simultaneous 820 nm tNIRS with 2 mA anodal tDCS have a synergistic effect on cortical plasticity.ConclusionsSimultaneous application of tNIRS with tDCS produces a stronger cortical excitability effect.SignificanceThe simultaneous tNIRS and tDCS is a promising technology with exciting potential as a means of treatment, neuro-enhancement, or neuro-protection.     

Prefrontal cortex and impulsivity: Interest of noninvasive brain stimulation

IntroductionImpulsivity has been reported in many psychiatric conditions and includes deficits in several cognitive functions such as attention, inhibitory control, risk taking, delay discounting and planning. Many studies have shown that noninvasive brain stimulation (NIBS) techniques modulate the activity of the prefrontal cortex and the functions involved in impulsivity.ObjectiveThis article aims to review the literature on the effect of NIBS on impulsivity in healthy subjects aged 18–65 years old, and to highlight research avenues to develop therapeutic alternatives for such disorders.MethodWe performed a systematic review of the literature in the PubMed database following PRISMA method with “transcranial magnetic stimulation”, “repetitive transcranial magnetic stimulation”, “transcranial direct current stimulation”, “inhibition”, “risk”, “impulsive behavior”, “attention”, “reward”, “delay discounting”, “delay task”, “planning”, “prefrontal cortex” as key words.ResultsWe selected fifty-six studies showing modulation of the cognitive functions involved in impulsivity through NIBS.ConclusionsThe data led us to consider new therapeutic alternatives in impulsive disorders by modulating prefrontal cortex activity through NIBS.     

Non-invasive brain stimulation in Parkinson’s disease: Exploiting crossroads of cognition and mood

Cognitive impairments and depression are common non-motor manifestations in Parkinson’s disease (PD). Recent evidence suggests that both partially arise via the same frontostriatal network, opening the opportunity for concomitant treatment with non-invasive brain stimulation (NIBS) techniques such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS).In this systematic review, we evaluate the effects of NIBS on cognition and/or mood in 19 placebo-controlled studies involving 561 PD patients. Outcomes depended on the area stimulated and the technique used. rTMS over the dorsolateral-prefrontal cortex (DLPFC) resulted in significant reductions in scores of depressive symptoms with moderate to large effect sizes along with increased performance in several tests of cognitive functions. tDCS over the DLPFC improved performance in several cognitive measures, including executive functions with large effect sizes. Additional effects of tDCS on mood were not detectable; however, only non-depressed patients were assessed. Further confirmatory research is needed to clarify the contribution that NIBS could make in the care of PD patients.     

Implications from translational cross-validation of clinical assessment tools for diagnosis and treatment in psychiatry

Traditional therapeutic methods in psychiatry, such as psychopharmacology and psychotherapy help many people suffering from mental disorders, but in the long-term prove to be effective in a relatively small proportion of those affected. Therapeutically, resistant forms of mental disorders such as schizophrenia, major depressive disorder, and bipolar disorder lead to persistent distress and dysfunction in personal, social, and professional aspects. In an effort to address these problems, the translational approach in neuroscience has initiated the inclusion of novel or modified unconventional diagnostic and therapeutic techniques with promising results. For instance, neuroimaging data sets from multiple modalities provide insight into the nature of pathophysiological mechanisms such as disruptions of connectivity, integration, and segregation of neural networks, focusing on the treatment of mental disorders through instrumental biomedical methods such as electro-convulsive therapy (ECT), transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS) and deep brain stimulation (DBS). These methodologies have yielded promising results that have yet to be understood and improved to enhance the prognosis of the severe and persistent psychotic and affective disorders. The current review is focused on the translational approach in the management of schizophrenia and mood disorders, as well as the adaptation of new transdisciplinary diagnostic tools such as neuroimaging with concurrently administered psychopathological questionnaires and integration of the results into the therapeutic framework using various advanced instrumental biomedical tools such as ECT, TMS, tDCS and DBS.     

Efectos de la estimulación transcraneal por corriente directa y de la estimulación magnética transcraneal en pacientes con fibromialgia. Revisión sistemática

IntroductionFibromyalgia syndrome (FM) is a chronic pathology characterized by widespread pain commonly associated with psychological distress affecting quality of life. In recent years, transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) have been investigated to treat chronic pain. The aim of the current review is to determine the effects of tDCS and TMS on the main symptoms of patients with FM.DevelopmentA systematic review based on PRISMA guidelines was carried out. The search strategy was performed in Medline, Scopus, PEDro and Cochrane Library. Randomized controlled trials based on the effects of tDCS and TMS on pain, pressure pain threshold, fatigue, anxiety and depression, catastrophizing and quality of life in patients with FM were analysed. Fourteen studies were included.ConclusionsThe application of tDCS to the motor cortex is the only intervention shown to decrease pain in the short and medium-term in patients with FM. The application of both interventions showed improvements in pressure pain threshold, catastrophizing and quality of life when applied to the motor cortex, and in fatigue when applied to the dorsolateral prefrontal cortex. The effects of these interventions on anxiety and depression are unclear.     

Guidelines for TMS/tES clinical services and research through the COVID-19 pandemic

BackgroundThe COVID-19 pandemic has broadly disrupted biomedical treatment and research including non-invasive brain stimulation (NIBS). Moreover, the rapid onset of societal disruption and evolving regulatory restrictions may not have allowed for systematic planning of how clinical and research work may continue throughout the pandemic or be restarted as restrictions are abated. The urgency to provide and develop NIBS as an intervention for diverse neurological and mental health indications, and as a catalyst of fundamental brain research, is not dampened by the parallel efforts to address the most life-threatening aspects of COVID-19; rather in many cases the need for NIBS is heightened including the potential to mitigate mental health consequences related to COVID-19.ObjectiveTo facilitate the re-establishment of access to NIBS clinical services and research operations during the current COVID-19 pandemic and possible future outbreaks, we develop and discuss a framework for balancing the importance of NIBS operations with safety considerations, while addressing the needs of all stakeholders. We focus on Transcranial Magnetic Stimulation (TMS) and low intensity transcranial Electrical Stimulation (tES) - including transcranial Direct Current Stimulation (tDCS) and transcranial Alternating Current Stimulation (tACS).MethodsThe present consensus paper provides guidelines and good practices for managing and reopening NIBS clinics and laboratories through the immediate and ongoing stages of COVID-19. The document reflects the analysis of experts with domain-relevant expertise spanning NIBS technology, clinical services, and basic and clinical research – with an international perspective. We outline regulatory aspects, human resources, NIBS optimization, as well as accommodations for specific demographics.ResultsA model based on three phases (early COVID-19 impact, current practices, and future preparation) with an 11-step checklist (spanning removing or streamlining in-person protocols, incorporating telemedicine, and addressing COVID-19-associated adverse events) is proposed. Recommendations on implementing social distancing and sterilization of NIBS related equipment, specific considerations of COVID-19 positive populations including mental health comorbidities, as well as considerations regarding regulatory and human resource in the era of COVID-19 are outlined. We discuss COVID-19 considerations specifically for clinical (sub-)populations including pediatric, stroke, addiction, and the elderly. Numerous case-examples across the world are described.ConclusionThere is an evident, and in cases urgent, need to maintain NIBS operations through the COVID-19 pandemic, including anticipating future pandemic waves and addressing effects of COVID-19 on brain and mind. The proposed robust and structured strategy aims to address the current and anticipated future challenges while maintaining scientific rigor and managing risk.     

Effects of cerebellar neuromodulation in movement disorders: A systematic review

Background

The cerebellum is involved in the pathophysiology of many movement disorders and its importance in the field of neuromodulation is growing.

Repetitive transcranial magnetic stimulation (rTMS) versus transcranial direct current stimulation (tDCS) in the management of patients with fibromyalgia: A randomized controlled trial

ObjectivesThe aim of this study was to compare the effects of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) on pain and quality of life in patients with fibromyalgia.MethodsThirty participants were randomized into two groups of 15 patients, to receive 3 sessions of either high-frequency (10 Hz) rTMS or 2 mA, 20 min anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex (DLPFC) over 1 week. Pain was assessed using a Visual Analog Scale (VAS) before treatment, immediately after treatment, 6 and 12 weeks later. Quality of life was evaluated using the Revised Fibromyalgia Impact Questionnaire (FIQR) and psychiatric symptoms were measured using the Depression Anxiety Stress Scale-21 Item (DASS-21) before treatment, and 6 and 12 weeks after treatment.ResultsFor the VAS there was a significant time-group interaction, showing that the behavior of two groups differed regarding changes of VAS in favor of the RTMS group (df = 1.73, F = 4.80, p = <0.016). Time-group interaction effect on DASS-21 and FIQR was not significant. 66.6% of patients in rTMS group and 26.6% of patients in tDCS group experienced at least a 30% reduction of VAS from baseline to last follow-up (p = 0.028).DiscussionWith the methodology used in this study, both rTMS and tDCS were safe modalities and three sessions of rTMS over DLPFC had greater and longer lasting analgesic effects compared to tDCS in patients with FM. However, considering the limitations of this study, further studies are needed to explore the most effective modality.     

Transcranial electrical stimulation motor threshold can estimate individualized tDCS dosage from reverse-calculation electric-field modeling

BackgroundUnique amongst brain stimulation tools, transcranial direct current stimulation (tDCS) currently lacks an easy or widely implemented method for individualizing dosage.ObjectiveWe developed a method of reverse-calculating electric-field (E-field) models based on Magnetic Resonance Imaging (MRI) scans that can estimate individualized tDCS dose. We also evaluated an MRI-free method of individualizing tDCS dose by measuring transcranial magnetic stimulation (TMS) motor threshold (MT) and single pulse, suprathreshold transcranial electrical stimulation (TES) MT and regressing it against E-field modeling. Key assumptions of reverse-calculation E-field modeling, including the size of region of interest (ROI) analysis and the linearity of multiple E-field models were also tested.MethodsIn 29 healthy adults, we acquired TMS MT, TES MT, and anatomical T1-weighted MPRAGE MRI scans with a fiducial marking the motor hotspot. We then computed a “reverse-calculated tDCS dose” of tDCS applied at the scalp needed to cause a 1.00 V/m E-field at the cortex. Finally, we examined whether the predicted E-field values correlated with each participant’s measured TMS MT or TES MT.ResultsWe were able to determine a reverse-calculated tDCS dose for each participant using a 5 × 5 x 5 voxel grid region of interest (ROI) approach (average = 6.03 mA, SD = 1.44 mA, range = 3.75–9.74 mA). The Transcranial Electrical Stimulation MT, but not the Transcranial Magnetic Stimulation MT, significantly correlated with the ROI-based reverse-calculated tDCS dose determined by E-field modeling (R² = 0.45, p < 0.001).ConclusionsReverse-calculation E-field modeling, alone or regressed against TES MT, shows promise as a method to individualize tDCS dose. The large range of the reverse-calculated tDCS doses between subjects underscores the likely need to individualize tDCS dose. Future research should further examine the use of TES MT to individually dose tDCS as an MRI-free method of dosing tDCS.     

Treating Post-traumatic Stress Disorder with Neuromodulation Therapies: Transcranial Magnetic Stimulation,Transcranial Direct Current Stimulation,and Deep Brain Stimulation

Post-traumatic stress disorder (PTSD) is a prevalent and debilitating illness. While standard treatment with pharmacotherapy and psychotherapy may be effective, approximately 20 to 30% of patients remain symptomatic. These individuals experience depression, anxiety, and elevated rates of suicide. For treatment-resistant patients, there is a growing interest in the use of neuromodulation therapies, including transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS). We conducted a systematic review on the use of neuromodulation strategies for PTSD and pooled 13 randomized clinical trials (RCTs), 11 case series, and 6 case reports for analysis. Overall, most studies reported favorable outcomes in alleviating both PTSD and depressive symptoms. Although several RCTs described significant differences when active and sham stimulations were compared, others found marginal or nonsignificant differences between groups. Also positive were studies comparing PTSD symptoms before and after treatment. The side effect profile with all 3 modalities was found to be low, with mostly mild adverse events being reported. Despite these encouraging data, several aspects remain unknown. Given that PTSD is a highly heterogeneous condition that can be accompanied by distinct psychiatric diagnoses, defining a unique treatment for this patient population can be quite challenging. There has also been considerable variation across trials regarding stimulation parameters, symptomatic response, and the role of adjunctive psychotherapy. Future studies are needed to address these issues.Electronic supplementary materialThe online version of this article (10.1007/s13311-020-00871-0) contains supplementary material, which is available to authorized users.Key Words: Post-traumatic stress disorder (PTSD), neuromodulation, transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS)     

Pinging the brain with transcranial magnetic stimulation reveals cortical reactivity in time and space

BackgroundSingle-pulse transcranial magnetic stimulation (TMS) elicits an evoked electroencephalography (EEG) potential (TMS-evoked potential, TEP), which is interpreted as direct evidence of cortical reactivity to TMS. Thus, combining TMS with EEG can be used to investigate the mechanism underlying brain network engagement in TMS treatment paradigms. However, controversy remains regarding whether TEP is a genuine marker of TMS-induced cortical reactivity or if it is confounded by responses to peripheral somatosensory and auditory inputs. Resolving this controversy is of great significance for the field and will validate TMS as a tool to probe networks of interest in cognitive and clinical neuroscience.ObjectiveHere, we delineated the cortical origin of TEP by spatially and temporally localizing successive TEP components, and modulating them with transcranial direct current stimulation (tDCS) to investigate cortical reactivity elicited by single-pulse TMS and its causal relationship with cortical excitability.MethodsWe recruited 18 healthy participants in a double-blind, cross-over, sham-controlled design. We collected motor-evoked potentials (MEPs) and TEPs elicited by suprathreshold single-pulse TMS targeting the left primary motor cortex (M1). To causally test cortical and corticospinal excitability, we applied tDCS to the left M1.ResultsWe found that the earliest TEP component (P25) was localized to the left M1. The following TEP components (N45 and P60) were largely localized to the primary somatosensory cortex, which may reflect afferent input by hand-muscle twitches. The later TEP components (N100, P180, and N280) were largely localized to the auditory cortex. As hypothesized, tDCS selectively modulated cortical and corticospinal excitability by modulating the pre-stimulus mu-rhythm oscillatory power.ConclusionTogether, our findings provide causal evidence that the early TEP components reflect cortical reactivity to TMS.     

Behavioural facilitation following brain stimulation: implications for neurorehabilitation

Studies showing facilitation of behavioural performance by transcranial magnetic stimulation (TMS), and transcranial direct current stimulation (tDCS) in sensory and perceptual domains, spatial attention, working memory, and executive and emotional tasks are reviewed. In these domains the performance of neurologically unimpaired participants may be modulated, with behavioural facilitation or interference, by TMS, and by tDCS. The mapping of the frequency-dependent effects of TMS, and of the polarity-dependent effects of tDCS on behaviour does not systematically and mechanistically result in an increase or decrease of behavioural performance. Factors such as the parameters of the cerebral stimulation (localisation, duration, intensity), and the features of the task (complexity, phase of training) contribute to determine the final net effect on the participants' performance. Non-invasive brain stimulation (NIBS), which modulates learning, and appears to have, under some conditions, long lasting effects, is a promising tool to be used in the rehabilitation of a variety of neurological and cognitive disorders, that typically involve repeated behavioural training sessions.     

Transcranial Magnetic and Direct Current Stimulation in Children

Promising results in adult neurologic and psychiatric disorders are driving active research into transcranial brain stimulation techniques, particularly transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), in childhood and adolescent syndromes. TMS has realistic utility as an experimental tool tested in a range of pediatric neuropathologies such as perinatal stroke, depression, Tourette syndrome, and autism spectrum disorder (ASD). tDCS has also been tested as a treatment for a number of pediatric neurologic conditions, including ASD, attention-deficit/hyperactivity disorder, epilepsy, and cerebral palsy. Here, we complement recent reviews with an update of published TMS and tDCS results in children, and discuss developmental neuroscience considerations that should inform pediatric transcranial stimulation.     

A Negative Pilot Study of Daily Bimodal Transcranial Direct Current Stimulation in Schizophrenia

BackgroundA small number of studies conducted to date have suggested that transcranial direct current stimulation (tDCS) applied to the temporoparietal cortex may reduce auditory hallucinations in patients with schizophrenia. Prefrontal brain stimulation with other methods, has also been shown to potentially improve the negative symptoms of this disorder.ObjectiveTo investigate the therapeutic potential of daily bimodal tDCS: anodal stimulation to the prefrontal cortex and cathodal stimulation to the temporoparietal junction in patients with persistent hallucinations and negative symptoms of schizophrenia.MethodsWe conducted two small randomized double-blind controlled trials comparing bimodal tDCS to sham stimulation. In one study, stimulation was provided unilaterally, in the second study it was provided bilaterally.ResultsNeither unilateral nor bilateral tDCS resulted in a substantial change in either hallucinations or negative symptoms. Stimulation was well tolerated without side-effects.ConclusionDaily tDCS does not appear to have substantial potential in the treatment of hallucinations or negative symptoms and further research should investigate higher doses of stimulation or more frequently applied treatment schedules.     

Multi-modal investigation of transcranial ultrasound-induced neuroplasticity of the human motor cortex

IntroductionThere is currently a gap in accessibility to neuromodulation tools that can approximate the efficacy and spatial resolution of invasive methods. Low intensity transcranial focused ultrasound stimulation (TUS) is an emerging technology for non-invasive brain stimulation (NIBS) that can penetrate cortical and deep brain structures with more focal stimulation compared to existing NIBS modalities. Theta burst TUS (tbTUS, TUS delivered in a theta burst pattern) is a novel repetitive TUS protocol that can induce durable changes in motor cortex excitability, thereby holding promise as a novel neuromodulation tool with durable effects.ObjectiveThe aim of the present study was to elucidate the neurophysiologic effects of tbTUS motor cortical excitability, as well on local and global neural oscillations and network connectivity.MethodsAn 80-s train of active or sham tbTUS was delivered to the left motor cortex in 15 healthy subjects. Motor cortical excitability was investigated through transcranial magnetic stimulation (TMS)-elicited motor-evoked potentials (MEPs), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF) using paired-pulse TMS. Magnetoencephalography (MEG) recordings during resting state and an index finger abduction-adduction task were used to assess oscillatory brain responses and network connectivity. The correlations between the changes in neural oscillations and motor cortical excitability were also evaluated.ResultstbTUS to the motor cortex results in a sustained increase in MEP amplitude and decreased SICI, but no change in ICF. MEG spectral power analysis revealed TUS-mediated desynchronization in alpha and beta spectral power. Significant changes in alpha power were detected within the supplementary motor cortex (Right > Left) and changes in beta power within bilateral supplementary motor cortices, right basal ganglia and parietal regions. Coherence analysis revealed increased local connectivity in motor areas. MEP and SICI changes correlated with both local and inter-regional coherence.ConclusionThe findings from this study provide novel insights into the neurophysiologic basis of TUS-mediated neuroplasticity and point to the involvement of regions within the motor network in mediating this sustained response. Future studies may further characterize the durability of TUS-mediated neuroplasticity and its clinical applications as a neuromodulation strategy for neurological and psychiatric disorders.     

The use of tDCS and CVS as methods of non-invasive brain stimulation

Transcranial direct current stimulation (tDCS) and caloric vestibular stimulation (CVS) are safe methods for selectively modulating cortical excitability and activation, respectively, which have recently received increased interest regarding possible clinical applications. tDCS involves the application of low currents to the scalp via cathodal and anodal electrodes and has been shown to affect a range of motor, somatosensory, visual, affective and cognitive functions. Therapeutic effects have been demonstrated in clinical trials of tDCS for a variety of conditions including tinnitus, post-stroke motor deficits, fibromyalgia, depression, epilepsy and Parkinson's disease. Its effects can be modulated by combination with pharmacological treatment and it may influence the efficacy of other neurostimulatory techniques such as transcranial magnetic stimulation. CVS involves irrigating the auditory canal with cold water which induces a temperature gradient across the semicircular canals of the vestibular apparatus. This has been shown in functional brain-imaging studies to result in activation in several contralateral cortical and subcortical brain regions. CVS has also been shown to have effects on a wide range of visual and cognitive phenomena, as well as on post-stroke conditions, mania and chronic pain states. Both these techniques have been shown to modulate a range of brain functions, and display potential as clinical treatments. Importantly, they are both inexpensive relative to other brain stimulation techniques such as electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS).     

Site-Dependent Effects of tDCS Uncover Dissociations in the Communication Network Underlying the Processing of Visual Search

BackgroundThe right posterior parietal cortex (rPPC) and the right frontal eye field (rFEF) form part of a network of brain areas involved in orienting spatial attention. Previous studies using transcranial magnetic stimulation (TMS) have demonstrated that both areas are critically involved in the processing of conjunction visual search tasks, since stimulation of these sites disrupts performance.ObjectiveThis study investigated the effects of long term neuronal modulation to rPPC and rFEF using transcranial direct current stimulation (tDCS) with the aim of uncovering sharing of these resources in the processing of conjunction visual search tasks.MethodsParticipants completed four blocks of conjunction search trials over the course of 45 min. Following the first block they received 15 min of either cathodal or anodal stimulation to rPPC or rFEF, or sham stimulation.ResultsA significant interaction between block and stimulation condition was found, indicating that tDCS caused different effects according to the site (rPPC or rFEF) and type of stimulation (cathodal, anodal, or sham). Practice resulted in a significant reduction in reaction time across the four blocks in all conditions except when cathodal tDCS was applied to rPPC.ConclusionsThe effects of cathodal tDCS over rPPC are subtler than those seen with TMS, and no effect of tDCS was evident at rFEF. This suggests that rFEF has a more transient role than rPPC in the processing of conjunction visual search and is robust to longer-term methods of neuro-disruption. Our results may be explained within the framework of functional connectivity between these, and other, areas.     

The effects of repeated transcranial direct current stimulation on sleep quality and depression symptoms in patients with major depression and insomnia

ImportanceAlthough several strategies using transcranial direct current stimulation (tDCS) have been investigated to treat major depressive disorder (MDD), the efficacy of this treatment for patients with MDD who also have insomnia is unclear.ObjectiveTo observe the effects of tDCS on sleep quality and depressive symptoms in patients with MDD who have insomnia.MethodsWe conducted a randomized, double-blinded study involving adults with major depression and insomnia. We randomly assigned patients to either add tDCS or to sham tDCS to their regular treatment. After randomization, we treated a total of 90 patients at the Kangning Hospital, Ningbo, China. We allocated 47 patients to the tDCS group and 43 to the sham tDCS group. The tDCS treatment procedure included 20 sessions of 2-mA stimulation of the dorsolateral prefrontal cortex (DLPFC) for 30 min, which was followed by four weekly treatments. The anode and cathode electrodes were placed on the left and right DLPFC, respectively. We recorded the Self-rating Depression Scale (SDS), Self-rating Anxiety Scale (SAS), Pittsburgh Sleep Quality Inventory (PSQI), and Polysomnography (PSG) at Day 1 and Day 28.ResultsCompared with the sham tDCS group, the active tDCS group showed improved total scores of SAS and SDS. PSQI total score and all PSQI sub-divisions, except for “sleep duration and sleep efficiency,” significantly improved after treatment. We also observed that tDCS affected sleep architecture, by increasing total sleep time and improving sleep efficiency through PSG.ConclusionsOur study demonstrated the effect of tDCS on sleep quality and depressive symptoms in patients with MDD and insomnia. These results suggested that tDCS stimulation not only improved symptoms of depression and anxiety but also had a positive effect on sleep quality in patients with MDD. For patients with depression and insomnia, tDCS stimulation could be a good supplement to drugs.     

Exploring Patient Perceptions of Noninvasive Brain Stimulation: A Systematic Review

ObjectiveTo synthesize and critically appraise literature exploring patient perceptions regarding the therapeutic use of noninvasive brain stimulation.Material and MethodsA systematic search of CINHAL, PUBMED, Web of Science, and Medline was performed. Reference lists of relevant articles were also screened. Studies exploring participant perceptions regarding the therapeutic use of noninvasive brain stimulation were eligible for inclusion. Perceptions were divided into three domains: knowledge, experience, and attitudes. Noninvasive brain stimulation was defined as any neuromodulation technique that alters brain activity but does not require invasive methods such as surgery. No restrictions were placed upon study design or participant population. Two reviewers performed data extraction and risk of bias assessment. Data relating to methodological characteristics, participant demographics, type of noninvasive brain stimulation, and nature of perceptions (knowledge, experience, or attitudes) were extracted.ResultsFour studies comprising data from 163 participants met the inclusion criteria. All studies investigated perceptions of repetitive transcranial magnetic stimulation (rTMS) in psychiatric populations. Most participants perceived rTMS to be safe and beneficial, demonstrated low levels of fear, and were willing to recommend the intervention to others. No studies were found investigating patient perception of transcranial direct current stimulation (tDCS).ConclusionThe findings from this review suggest that rTMS is well accepted as a therapeutic treatment among psychiatric populations, providing support for its clinical utility. Future work is needed to determine if similar findings exist for other conditions (eg, chronic pain) and for other therapeutic forms of brain stimulation (eg, tDCS).     

A perfect match: noninvasive brain stimulation and psychotherapy

One out of four patients with a psychiatric disorder does not tolerate or sufficiently respond to standard treatments, leading to impaired quality of life, significant morbidity and mortality, as well as high socioeconomic costs. There is increasing evidence that—apart from psychopharmacologic and psychotherapeutic interventions—targeted modulation of neural networks by brain stimulation techniques might serve as a third treatment modality. In the whole spectrum of treatment modalities, combined approaches are often used for difficult-to-treat patients. They may be superior strategies compared to monotherapy and could possible also include brain stimulation interventions. However, systematic research is lacking for the latter issue. Particularly, noninvasive brain stimulation (NIBS), e.g., transcranial direct current stimulation (tDCS) can be easily combined with psychotherapy approaches. Here, we introduce NIBS techniques for priming and augmenting psychotherapy, review preliminary data and propose a future research strategy. Interestingly, this strategy parallels the promising development in neurology and neurorehabilitation where tDCS is currently combined with functional training tasks to enhance motor or cognitive performance.