Efficacy of semantic–phonological treatment combined with tDCS for verb retrieval in a patient with aphasia

Recent studies reported enhanced performance on language tasks induced by transcranial direct current stimulation (tDCS) in patients with aphasia. One chronic patient with non-fluent aphasia received 20 sessions of a verb anomia training combined with off-line bihemispheric tDCS applied to the dorsolateral prefrontal cortex (DLPFC) – anodal tDCS over left DLPFC plus cathodal tDCS over right DLPFC. A significant improvement in verb naming was observed at all testing times (4, 12, 24, and 48 weeks from post-entry/baseline testing) for treated and untreated verbs. Our findings show beneficial effects of verb anomia training in combination with tDCS in chronic aphasic patient, suggesting a long-lasting effect of this treatment.     

Stress and depression scales in aphasia: relation between the aphasia depression rating scale,stroke aphasia depression questionnaire-10, and the perceived stress scale

Background: Assessment and diagnosis of post-stroke depression (PSD) among patients with aphasia presents unique challenges. A gold standard assessment of PSD among this population has yet to be identified.

Objectives: The first aim was to investigate the association between two depression scales developed for assessing depressive symptoms among patients with aphasia. The second aim was to evaluate the relation between these scales and a measure of perceived stress.

Method: Twenty-five (16 male; 9 female) individuals with history of left hemisphere cerebrovascular accident (CVA) were assessed for depression and perceived stress using the Stroke Aphasic Depression Questionnaire-10 (SADQ-10), the Aphasia Depression Rating Scale (ADRS), and the Perceived Stress Scale (PSS).

Results: SADQ-10 and ADRS ratings were strongly correlated with each other (r = 0.708, p < 0.001). SADQ-10 ratings were strongly correlated with PSS ratings (r = 0.620, p = 0.003), while ADRS ratings were moderately correlated (r = 0.492, p = 0.027). Item analysis of each scale identified items which increased both inter-scale correlation and intra-scale consistency when excluded.

Conclusions: The SADQ-10 and ADRS appear to be acceptable measures of depressive symptoms in aphasia patients. Measurements of perceived stress may also be an important factor in assessment of depressive symptoms.     

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.     

Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS)

A group of European experts was commissioned by the European Chapter of the International Federation of Clinical Neurophysiology to gather knowledge about the state of the art of the therapeutic use of transcranial direct current stimulation (tDCS) from studies published up until September 2016, regarding pain, Parkinson’s disease, other movement disorders, motor stroke, poststroke aphasia, multiple sclerosis, epilepsy, consciousness disorders, Alzheimer’s disease, tinnitus, depression, schizophrenia, and craving/addiction. The evidence-based analysis included only studies based on repeated tDCS sessions with sham tDCS control procedure; 25 patients or more having received active treatment was required for Class I, while a lower number of 10–24 patients was accepted for Class II studies. Current evidence does not allow making any recommendation of Level A (definite efficacy) for any indication. Level B recommendation (probable efficacy) is proposed for: (i) anodal tDCS of the left primary motor cortex (M1) (with right orbitofrontal cathode) in fibromyalgia; (ii) anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episode without drug resistance; (iii) anodal tDCS of the right DLPFC (with left DLPFC cathode) in addiction/craving. Level C recommendation (possible efficacy) is proposed for anodal tDCS of the left M1 (or contralateral to pain side, with right orbitofrontal cathode) in chronic lower limb neuropathic pain secondary to spinal cord lesion. Conversely, Level B recommendation (probable inefficacy) is conferred on the absence of clinical effects of: (i) anodal tDCS of the left temporal cortex (with right orbitofrontal cathode) in tinnitus; (ii) anodal tDCS of the left DLPFC (with right orbitofrontal cathode) in drug-resistant major depressive episode. It remains to be clarified whether the probable or possible therapeutic effects of tDCS are clinically meaningful and how to optimally perform tDCS in a therapeutic setting. In addition, the easy management and low cost of tDCS devices allow at home use by the patient, but this might raise ethical and legal concerns with regard to potential misuse or overuse. We must be careful to avoid inappropriate applications of this technique by ensuring rigorous training of the professionals and education of the patients.     

Treatment of chronic tinnitus with repeated sessions of prefrontal transcranial direct current stimulation: outcomes from an open-label pilot study

Tinnitus is the perception of sound in the absence of an environmental sound source. Abnormal activity in central auditory pathways is considered as the neuronal correlate of tinnitus. However, there is increasing evidence from neuroimaging studies for an additional involvement of the frontal cortex in the pathophysiology of tinnitus, especially concerning its attentional and emotional aspects. Recently, in a subgroup of tinnitus patients, temporary reduction of tinnitus intensity and tinnitus-related distress has been reported after bifrontal tDCS with the anode over the right and the cathode over the left dorsolateral prefrontal cortex (DLPFC). The aim of this study was to investigate whether repeated application of bifrontal tDCS results in longer-lasting reduction of tinnitus and may represent a potential treatment approach. Thirty-two patients with chronic and treatment-resistant tinnitus received six sessions of bifrontal tDCS (1.5 mA, 30 min, two sessions per week) with the anode over the right and the cathode over the left DLPFC. Treatment outcome was assessed with several standardized tinnitus questionnaires, numeric rating scales, and a depression scale. In the entire group, beneficial effects of bifrontal tDCS on tinnitus were found for numeric rating scores of loudness, unpleasantness, and discomfort, but not in tinnitus or depression scales. Exploratory analysis revealed an effect of gender on treatment effects with female patients demonstrating a better response in several scores. Our open-label pilot study suggests some beneficial effect of bifrontal tDCS (anode right and cathode left) in the treatment of severe tinnitus, warranting further controlled studies.     

Effects of transcranial direct current stimulation on cognitive dysfunction in multiple sclerosis

BackgroundAround 40%–70% of patients with multiple sclerosis (MS) may experience cognitive impairments during the course of their disease with detrimental effects on social and occupational activities. Transcranial direct current stimulation (tDCS has been investigated in pain, fatigue, and mood disorders related to MS, but to date, few studies have examined effects of tDCS on cognitive performance in MS.ObjectiveThe current study aimed to investigate the effects of a multi-session tDCS protocol on cognitive performance and resting-state brain electrical activities in patients with MS.MethodsTwenty-four eligible MS patients were randomly assigned to real (anodal) or sham tDCS groups. Before and after 8 consecutive daily tDCS sessions over the left dorsolateral prefrontal cortex (DLPFC), patients’ cognitive performance was assessed using the Cambridge Brain Sciences-Cognitive Platform (CBS-CP). Cortical electrical activity was also evaluated using quantitative electroencephalography (QEEG) analysis at baseline and after the intervention.ResultsCompared to the sham condition, significant improvement in reasoning and executive functions of the patients in the real tDCS group was observed. Attention was also improved considerably but not statistically significantly following real tDCS. However, no significant changes in resting-state brain activities were observed after stimulation in either group.ConclusionAnodal tDCS over the left DLPFC appears to be a promising therapeutic option for cognitive dysfunction in patients with MS. Larger studies are required to confirm these findings and to investigate underlying neuronal mechanisms.     

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.     

The effect of transcranial direct stimulation as an add-on treatment to conventional physical therapy on pain intensity and functional ability in individuals with knee osteoarthritis: A randomized controlled trial

ObjectiveTo investigate the effect of adding transcranial direct current stimulation (tDCS) to conventional physiotherapy treatment (PT) on pain and performance of individuals with knee osteoarthritis (KOA).MethodsEighty people suffering from chronic KOA participated in this study. They were randomly divided into four treatment groups, including PT combined with tDCS over the primary motor cortex (M1), PT combined with tDCS over the primary sensory cortex (S1), PT combined with tDCS over the dorsolateral prefrontal cortex (DLPFC), and PT combined with sham tDCS. A visual analog scale (VAS) for pain intensity, the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire for knee-related disability, and several performance tests (stepping 15 s, chair stand test in 30 s, and walking 4 × 10 m) were used for assessment following 10 sessions of tDCS (T1), and one month after the last session of tDCS (T2).ResultsDifferential effects on pain intensity, knee-related disability, and performance were found between groups. Compared to sham tDCS: (i) tDCS over M1 improved VAS pain score, KOOS disability score, and performance tests at T1 and T2; (ii) tDCS over S1 improved VAS pain score at T1 and T2 and KOOS disability score and performance tests at T2; (iii) tDCS over the DLPFC improved VAS pain score at T1 and performance tests at T1 and T2.ConclusiontDCS could be a beneficial add-on treatment to conventional PT for pain relief, disability reduction and functional improvement in patients with KOA.     

Transcranial direct current stimulation (tDCS) for depression in pregnancy: A pilot randomized controlled trial

BackgroundDepression in pregnancy negatively affects maternal-child health. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation treatment for depression, has not been evaluated in pregnancy.ObjectiveTo conduct a pilot randomized controlled trial (RCT) to evaluate tDCS for antenatal depression.MethodsIn this pilot RCT in Toronto, Ontario (October 2014 to December 2016), adult pregnant women 14–32 weeks gestation with major depressive disorder who had declined antidepressant medication were considered for inclusion. Participants were randomly assigned 1:1 to tDCS or sham-control. Active tDCS comprised 30-min sessions of 2 mAmp direct current delivered over the dorsolateral prefrontal cortex, 5 days per week, for 3 weeks. Sham was administered similarly, but with current turned off after 30 s. Main outcomes were feasibility, acceptability, and protocol adherence. Maternal Montgomery Asperg Depression Rating Scale (MADRS) was measured post-treatment and at 4 and 12 weeks postpartum.ResultsOf 20 women randomized, 16 completed treatment and provided data (124 tDCS, 122 sham sessions). Views of treatment were positive with no serious adverse events. Post-treatment estimated marginal mean MADRS scores were 11.8 (standard error, SE 2.66) for tDCS and 15.4 (SE 2.51) for sham (p = 0.34). At 4 weeks postpartum, 75.0% of tDCS women were remitted versus 12.5% sham-control (p = 0.04).ConclusionsResults support proceeding to a definitive RCT to evaluate tDCS for antenatal depression. The preliminary efficacy estimates immediately post-treatment and in the postpartum, are encouraging with respect to the potential use of tDCS to improve treatment rates in this population. The trial was registered at: clinical trials.gov (NCT02116127).     

Antidepressant effects of tDCS are associated with prefrontal gray matter volumes at baseline: Evidence from the ELECT-TDCS trial

BackgroundTranscranial direct current stimulation (tDCS) is a promising intervention for major depression. However, its clinical effects are heterogeneous. We investigated, in a subsample of the randomized, clinical trial Escitalopram versus Electrical Direct Current Therapy for Depression Study (ELECT-TDCS), whether the volumes of left and right prefrontal cortex (PFC) and anterior cingulate cortex (ACC) were associated with prefrontal tDCS response.MethodsBaseline structural T1 weighted MRI data were analyzed from 52 patients (15 males). Patients were randomized to the following conditions: escitalopram 20 mg/day, bifrontal tDCS (2 mA, 30min, 22 sessions), or placebo. Antidepressant outcomes were assessed over a treatment period of 10 weeks. Voxel-based gray matter volumes of PFC and ACC were determined using state-of-the-art parcellation approaches.ResultsAccording to our a priori hypothesis, in the left dorsal PFC, larger gray matter volumes were associated with depression improvement in the tDCS group (n = 15) compared to sham (n = 21) (Cohen's d = 0.3, 95% confidence interval [0.01; 0.6], p = 0.04). Neither right PFC nor ACC volumes were associated with depression improvement. Exploratory analyses of distinct PFC subregions were performed, but no area was associated with tDCS response after correction for multiple comparisons.ConclusionLeft PFC baseline gray matter volume was associated with tDCS antidepressant effects. This brain region and its subdivisions should be investigated further as a potential neurobiological predictor for prefrontal tDCS treatment in depression and might be correlated with tDCS antidepressant mechanisms of action.     

Concurrent Cognitive Control Training Augments the Antidepressant Efficacy of tDCS: A Pilot Study

BackgroundMajor depressive disorder (MDD) is frequently associated with underactivity of the dorsolateral prefrontal cortex (DLPFC) which has led to this brain region being identified as an important target for the development of neurobiological treatments. Transcranial direct current stimulation (tDCS) administered to the DLPFC has antidepressant efficacy, however the magnitude of antidepressant outcomes are limited. Concurrent cognitive activity has been shown to enhance tDCS induced stimulation effects. Cognitive control training (CCT) is a new cognitive therapy for MDD that aims to enhance DLPFC activity via behavioral methods.HypothesisWe tested the hypothesis that co-administration of DLPFC tDCS and CCT would result in a greater reduction in depressive symptomology than administration of tDCS or CCT alone.Methods27 adult participants with MDD were randomized into a three-arm sham-controlled between-groups pilot study comparing the efficacy of 2 mA tDCS + CCT, sham tDCS + CCT and sham CCT + 2 mA tDCS (5 sessions administered on consecutive working days). Blinded assessments of depression severity and cognitive control were conducted at baseline, end of treatment and a three week follow up review.ResultsAll three treatment conditions were associated with a reduction in depression severity at the end of five treatment sessions. However, only administration of tDCS + CCT resulted in sustained antidepressant response at follow up, the magnitude of which was greater than that observed immediately following conclusion of the treatment course.ConclusionsThe results provide preliminary evidence that concurrent CCT enhances antidepressant outcomes from tDCS. In the current sample, participants receiving concurrent tDCS and CCT continued to improve following cessation of treatment. The clinical superiority of a combined therapeutic approach was apparent even in a small sample and following a relatively short treatment course.     

Transcranial Direct Current Stimulation (tDCS) paired with a decision-making task reduces risk-taking in a clinically impulsive sample

Background

Impulsivity is a multidimensional personality trait observed across a variety of psychiatric disorders. Transcranial direct current stimulation (tDCS) applied over dorsolateral prefrontal cortex (DLPFC) has shown promise as an intervention to reduce impulsivity.

Improving working memory: Exploring the effect of transcranial random noise stimulation and transcranial direct current stimulation on the dorsolateral prefrontal cortex

Objective

The aim of this study was to determine if working memory (WM) performance is significantly improved after the delivery of transcranial random noise stimulation (tRNS) to the left dorsolateral prefrontal cortex (DLPFC), compared to an active comparator or sham.

Methods

Ten participants undertook three experimental sessions in which they received 10 min of anodal tDCS (active comparator), tRNS or sham tDCS whilst performing the Sternberg WM task. Intra-stimulation engagement in a WM task was undertaken as this has been previously shown to enhance the effects of tDCS. Experimental sessions were separated by a minimum of 1 week. Immediately prior to and after each stimulation session the participants were measured on speed and accuracy of performance on an n-back task.

Results

There was significant improvement in speed of performance following anodal tDCS on the 2-back WM task; this was the only significant finding.

Conclusions

The results do not provide support for the hypothesis that tRNS improves WM. However, the study does provide confirmation of previous findings that anodal tDCS enhances some aspects of DLPFC functioning. Methodological limitations that may have contributed to the lack of significant findings following tRNS are discussed.

Significance

Anodal tDCS may have significant implications for WM remediation in psychiatric conditions, particularly schizophrenia.     

Site‐specific effects of mental practice combined with transcranial direct current stimulation on motor learning

Mental practice can induce significant neural plasticity and result in motor performance improvement if associated with motor imagery tasks. Given the effects of transcranial direct current stimulation (tDCS) on neuroplasticity, the current study tested whether tDCS, using different electrode montages, can increase the neuroplastic effects of mental imagery on motor learning. Eighteen healthy right‐handed adults underwent a randomised sham‐controlled crossover experiment to receive mental training combined with either sham or active anodal tDCS of the right primary motor cortex (M1), right supplementary motor area, right premotor area, right cerebellum or left dorsolateral prefrontal cortex (DLPFC). Motor performance was assessed by a blinded rater using: non‐dominant handwriting time and legibility, and mentally trained task at baseline (pre) and immediately after (post) mental practice combined with tDCS. Active tDCS significantly enhances the motor‐imagery‐induced improvement in motor function as compared with sham tDCS. There was a specific effect for the site of stimulation such that effects were only observed after M1 and DLPFC stimulation during mental practice. These findings provide new insights into motor imagery training and point out that two cortical targets (M1 and DLPFC) are significantly associated with the neuroplastic effects of mental imagery on motor learning. Further studies should explore a similar paradigm in patients with brain lesions.     

Top down prefrontal affective modulation of tinnitus with multiple sessions of tDCS of dorsolateral prefrontal cortex

Most forms of tinnitus are attributable to reorganization and hyperactivity in the auditory central nervous system with coactivation of nonauditory brain structures. One such nonauditory brain area is the dorsolateral prefrontal cortex (DLPFC), which is important for the integration of sensory and emotional aspects of tinnitus. Based on extensive evidence that transcranial direct current stimulation can induce significant effects on DLPFC-related cognitive function, we aimed to investigate whether left or right anodal DLFPC tDCS is associated with modulation of tinnitus. We conducted a double-blind, placebo-controlled cross-over study in which 15 subjects with tinnitus were randomly assigned to receive active and sham anodal tDCS over left (n = 8) or right DLPFC (n = 7) for six sessions in a counterbalanced order; the cathode electrode was placed in the contralateral DLPFC. The results demonstrate that both active conditions-irrespective of the anodal position-can decrease tinnitus annoyance but it is not associated with improvements in tinnitus intensity when comparing pre-tDCS versus post-tDCS as well as comparing sham-tDCS versus real tDCS. Also, we show that the anode electrode placed over the left DLPFC modulates depression when comparing pre-tDCS versus post-tDCS as well as comparing sham-tDCS versus real tDCS. In addition, we also show that the anode electrode placed over the right DLPFC modulates anxiety when comparing pre-tDCS versus post-tDCS. This latter effect does not remain when we compare sham-tDCS versus real tDCS. This study further supports the involvement of the prefrontal cortex in the neural network associated with tinnitus, and also provides initial evidence for a potential brain stimulation site for tinnitus treatment in association with other treatments that can reduce tinnitus intensity.     

Repeated stimulation of the dorsolateral-prefrontal cortex improves executive dysfunctions and craving in drug addiction: A randomized,double-blind,parallel-group study

BackgroundAccording to the neurocognitive model of addiction, the development and maintenance of drug addiction is associated with cognitive control deficits, as well as decreased activity of prefrontal regions, especially the dorsolateral prefrontal cortex (DLPFC). This study investigated how improving executive functions (EFs) impacts methamphetamine-use disorder, which has been less explored compared to craving, but might be a central aspect for the therapeutic efficacy of DLPFC stimulation in drug addiction.MethodsWe assessed the efficacy of 10 repeated sessions of transcranial direct current stimulation (tDCS) over the DLPFC on executive dysfunctions in methamphetamine-use disorder, and its association with craving alterations. 39 of 50 initially recruited individuals with methamphetamine-use disorder who were in the abstinent-course treatment were randomly assigned to “active” and “sham” stimulation groups in a randomized, double-blind parallel-group study. They received active (2 mA, 20 min) or sham tDCS for 10 sessions over 5 weeks. Performance on major EF tasks (e.g., working memory, inhibitory control, cognitive flexibility, and risk-taking behaviour) and craving were measured before, immediately after, and 1 month following the intervention. Participants reported abstinence from drug consumption throughout the experiment, verified by regular urine tests during the course of the study up to the follow-up measurement.ResultsThe group which received active DLPFC tDCS showed significantly improved task performance across all EFs immediately after and 1 month following the intervention, when compared to both pre-stimulation baseline and individuals who received sham tDCS. Similarly, a significant reduction in craving was observed immediately after and 1 month following the intervention in the active, but not sham stimulation group. A significant correlation between cognitive control improvement and craving reduction was found as well.ConclusionsImprovement of cognitive control functions is closely associated with reduced craving. Repeated DLPFC stimulation in order to improve executive control could be a promising approach for therapeutic interventions in drug addiction. However, the observed findings require further confirmation by studies that measure relapse/consumption of the respective substances over longer follow-up measurements.     

Effects of transcranial direct current stimulation on performance and recovery sleep during acute sleep deprivation: a pilot study

BackgroundPrevious studies claimed that transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) improves cognition in neuropsychiatric patients with cognitive impairment, schizophrenia, organic hypersomnia, etc, but few studies evaluated the effects of tDCS on cognitive improvement following sleep deprivation. The objective of this study was to determine whether tDCS (anode on the left DLPFC and cathode on the right DLPFC with a 2-mA current for 30 min) improves cognition following sleep deprivation.MethodsSeven participants received active tDCS and eight participants received sham tDCS when their cognition declined during at least 30 h of sleep deprivation. All participants completed the psychomotor vigilance task, Trail Making Tests A and B, digit cancellation test, Stroop color word test, the Brief Visuospatial Memory Test-Revised and a procedural game every 2 h during the sleep deprivation and after recovery sleep.ResultsCompared to the sham stimulation, active tDCS (anode on the left DLPFC and cathode on the right DLPFC at a 2-mA current for 30 min) had beneficial effects on attention, memory, executive function, processing speed, and the ability to inhibit cognitive interference, and improved in subjective drowsiness and fatigue following sleep deprivation. The lasting effect of a single tDCS on cognition during sleep deprivation was greater than 2 h. In all participants, tDCS did not disturb recovery sleep, and cognitive performance recovered to the baseline levels after recovery sleep.ConclusionsThe study results indicate that tDCS can improve cognition following sleep deprivation and does not disturb recovery sleep or cognitive performance after recovery sleep. The possible pathophysiological mechanisms might be related to the modulation of the corticothalamic pathway. We believe that tDCS can be applied in the treatment of sleep disorders involving sleepiness.Trial registration numberChiCTR2000029420.Date of registration2020-1-31.     

Differential effects of cathodal transcranial direct current stimulation of prefrontal,motor and somatosensory cortices on cortical excitability and pain perception – a double‐blind randomised sham‐controlled study

The primary aim of this study was to assess the effects of cathodal transcranial direct current stimulation (c‐tDCS) over cortical regions of the pain neuromatrix, including the primary motor (M1), sensory (S1) and dorsolateral prefrontal (DLPFC) cortices on M1/S1 excitability, sensory (STh), and pain thresholds (PTh) in healthy adults. The secondary aim was to evaluate the placebo effects of c‐tDCS on induced cortical and behavioural changes. Before, immediately after and 30 min after c‐tDCS the amplitude of N20–P25 components of somatosensory evoked potentials (SEPs) and peak‐to‐peak amplitudes of motor evoked potentials (MEPs) were measured under four different experimental conditions. STh and PTh for peripheral electrical and mechanical stimulation were also evaluated. c‐tDCS of 0.3 mA was applied for 20 min. A blinded assessor evaluated all outcome measures. c‐tDCS of M1, S1 and DLPFC significantly decreased the corticospinal excitability of M1 (P < 0.05) for at least 30 min. Following the application of c‐tDCS over S1, M1 and DLPFC, the amplitude of the N20–P25 component of SEPs decreased for at least 30 min (P < 0.05). Compared with baseline values, significant STh and PTh increases were observed after c‐tDCS of these three sites. Decreasing the level of S1 and M1 excitability, following S1, M1 and DLPFC stimulation, confirmed the functional connectivities between these cortical sites involved in pain processing. Furthermore, increasing the level of STh/PTh after c‐tDCS of these sites indicated that stimulation of not only M1 but also S1 and DLPFC could be considered a technique to decrease the level of pain in patients.     

Modulation of emotions associated with images of human pain using anodal transcranial direct current stimulation (tDCS)

Viewing images of other humans in pain elicits a variety of responses including distress, anxiety, and a sensation that is similar to pain. We aimed to evaluate whether transcranial direct current stimulation (tDCS) could be effective in modulating the emotional aspects of pain as to further explore mechanisms of tDCS in pain relief. Twenty-three healthy subjects rated images with respect to unpleasantness and discomfort/pain (baseline), and then received stimulation with tDCS under four different conditions of stimulation: anodal tDCS of the left primary motor cortex (M1), dorsolateral prefrontal cortex (DLPFC), occipital cortex (V1); and sham tDCS. The order of conditions was randomized and counterbalanced across subjects. During each stimulation session (after 3 min of stimulation), subjects were shown a new set of aversive images and were again asked to rate the images with respect to unpleasantness and discomfort/pain. The results showed that ratings of unpleasantness and discomfort/pain were significantly decreased during DLPFC tDCS only, as compared to baseline and sham tDCS. The other conditions of stimulation (M1 and V1 tDCS) did not result in any significant changes. These results support the notion that DLPFC is a critical area for the emotional processing of pain and also suggests that DLPFC may be a potential target of stimulation for alleviation of pain with a significant emotional-affective component. Our results also suggest that the mechanism of tDCS in modulating emotional pain involve pathways that are independent of those modulating the somatosensory perception of pain.     

Depressive symptoms in acute stroke: A cross-sectional study of their association with sociodemographics and clinical factors

The aim of the study was to estimate the prevalence of post-stroke depression (PSD) in the acute phase following first-ever stroke, and to identify its sociodemographic and clinical correlates. Data were collected in a cross-sectional correlational study from face-to-face interviews using structured questionnaires and patients' medical records. The sample consisted of 109 patients with first-ever stroke. Depressive symptoms after stroke were measured with Beck Depression Inventory II. Mild, moderate or severe depressive symptoms were reported by 27% of the participants. PSD was uniquely associated with post-stroke fatigue, sleep latency and sleep disturbance. Patients with PSD also reported slightly more bodily pain. Stroke type, stroke location, and the sociodemographic characteristics we examined were unrelated to PSD. Further research is needed to assess the role sleep changes, fatigue and bodily pain might have in relation to depression in the acute phase after stroke.