scholarly journals Impact of Psychosocial Occupational Therapy Combined with Anodal Transcranial Direct Current Stimulation to the Left Dorsolateral Prefrontal Cortex on the Cognitive Performance of Patients with Schizophrenia: A Randomized Controlled Trial

2021 ◽  
pp. 156918612110651
Author(s):  
Elahe Fathi Azar ◽  
Samaneh Hosseinzadeh ◽  
Masoud Nosrat Abadi ◽  
Mohamad Sayad Nasiri ◽  
Hojjat Allah Haghgoo
Keyword(s):  
Prefrontal Cortex ◽  
Occupational Therapy ◽  
Cognitive Performance ◽  
Direct Current ◽  
Cognitive Functions ◽  
Visual Memory ◽  
Dorsolateral Prefrontal Cortex ◽  
Anodal Tdcs ◽  
Learning Abilities ◽  
Dorsolateral Prefrontal

Background The most common cognitive dysfunctions in patients with schizophrenia are information processing, memory, and learning. Based on the hypothesis of rehabilitation and brain stimulation in memory and learning, adding a form of neuromodulation to conventional rehabilitation might increase the effectiveness of treatments. Aims To explore the effects of psychosocial occupational therapy combined with anodal Transcranial Direct Current Stimulation (tDCS) on cognitive performance in patients with Schizophrenia. Methods Twenty-four patients diagnosed with schizophrenia were randomized into the experimental and control groups. We used The Cambridge Neuropsychological Test Automated Battery (CANTAB) and the Loewenstein Occupational Therapy Cognitive Assessment battery (LOTCA) to assess spatial recognition, attention, visual memory, learning abilities, and high-level cognitive functions like problem-solving. All participants received customized psychosocial occupational therapy activities. Furthermore, the experimental group received 12 sessions of active anodal tDCS for 20 minutes with 2 mA intensity on the left dorsolateral prefrontal cortex (DLPFC) while the patients in the sham group received sham tDCS. Results Combining tDCS to conventional psychosocial occupational therapy resulted in a significant increase in spatial memory, visual learning, and attention. Conclusions Anodal tDCS on the left DLPFC improved visual memory, attention, and learning abilities. Contrary to our expectations, we could not find any changes in complex and more demanding cognitive functions.

scholarly journals Efficiency of Repetitive Transcranial Direct Current Stimulation of the Dorsolateral Prefrontal Cortex in Disorders of Consciousness: A Randomized Sham-Controlled Study

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Min Wu ◽  
Yamei Yu ◽  
Lunjie Luo ◽  
Yuehao Wu ◽  
Jian Gao ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Disorders Of Consciousness ◽  
Anodal Tdcs ◽  
Direct Current Stimulation ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
Stimulation Of

Conventional transcranial direct current stimulation (tDCS) targeting the left dorsolateral prefrontal cortex (DLPFC) could improve arousal in disorders of consciousness (DOC). However, the comparative effectiveness of anodal stimulation of the left DLPFC and the electrophysiological effect of tDCS are yet to be determined. In this randomized sham-controlled design, patients were separated into three groups (left/right anodal tDCS, sham). Data on the clinical assessments and EEG were collected at baseline and after 2 weeks of tDCS. The outcome at 3-month follow-up was evaluated using the Glasgow Outcome Scale-Extended. Results showed that sessions of the left tDCS facilitated the excitability of the prefrontal cortex, whereas only one patient had a positive outcome. Targeting the right DLPFC was less effective, merely leading to activation of the stimulation site, with no effect on the state of arousal. Moreover, sham stimulation had minimal or no effect on any of the outcomes. These results provide evidence for a hemispheric asymmetry of tDCS effects in patients with DOC. Left anodal tDCS might be more effective for modulating cortical excitability compared to tDCS on the right DLPFC. However, future studies with large sample sizes are needed to confirm these findings. This trial is registered with NCT03809936.

scholarly journals CAN TRANSCRANIAL DIRECT CURRENT STIMULATION OVER THE DORSOLATERAL PREFRONTAL CORTEX ENHANCE PROPRIOCEPTION?

2019 ◽  
Author(s):  
Eric N. Beck ◽  
Sankirtana Shankar Narayanan ◽  
Rian McDermott ◽  
Alice G. Witney
Keyword(s):  
Prefrontal Cortex ◽  
Direct Current ◽  
Sensorimotor Cortex ◽  
Motor Performance ◽  
Significant Interaction ◽  
Dorsolateral Prefrontal Cortex ◽  
Anodal Tdcs ◽  
Target Task ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal

ABSTRACTIntroductionProprioception (perception of one’s limb position) is critical for accurate and consistent movement, and is processed by the sensorimotor cortex. Increased prefrontal activity is associated with improved proprioception and motor performance. Anodal transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex (DLPFC) has been found to increase activity of the sensorimotor cortex. Thus, this study aimed to investigate whether anodal tDCS of the DLPFC may enhance proprioception measured with a target task. It was hypothesized that tDCS over the left DLPFC would improve motor performance (error and variability) on a target task completed without vision.DesignSingle blind, within-participant, sham-controlled trial.MethodsFifteen healthy young adults (M:F=6:9, age=23.3 years) completed 18 trials of a computerized target task (manipulating a mouse) with their non-dominant upper-limb, with and without vision, before and after (pre/post assessment) 20-minutes of stimulation (anodal tDCS of the left DLPFC) and sham conditions. Averages and coefficient of variation (CV, variability between trials) of spatio-temporal parameters associated with the movement were measured. Stimulation/ sham sessions were counterbalanced (stimulation first session, n=8), with each session separated by one week. Repeated-measures ANOVA and pairwise comparisons (95% confidence intervals [CI]) were conducted.ResultsRegarding distance travelled CV, a significant interaction between condition and assessment (F(1,14)=5.09, p=0.041) demonstrated that variability was significantly less post-stimulation compared to pre (p=0.003). A significant interaction between assessment and vision (F(1,14)=30.08, p<0.001) regarding distance travelled CV showed that without vision, variability was significantly less at post compared to pre (p<0.001), and this decrease was found after the stimulation condition only (95% CI = Δ 7.4 +/− 1.6 [4.0 to 10.9]).ConclusionSince variability of distance travelled during the target task without vision was lower post-stimulation compared to pre, consistency of movement without vision, and therefore proprioception, may have been enhanced by anodal tDCS of the DLPFC. This improvement could be due to modulation of fronto-striatal-thalamic circuits. These findings may be the first step in developing tDCS methods as an effective adjunct therapy for dysfunctional proprioception in various disorders, such as Parkinson’s disease.

scholarly journals Acute effects of a single dose of 2 mA of anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex on executive functions in patients with schizophrenia—A randomized controlled trial

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254695
Author(s):  
Thomas M. Schilling ◽  
Magdalena Bossert ◽  
Miriam König ◽  
Gustav Wirtz ◽  
Matthias Weisbrod ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Prefrontal Cortex ◽  
Executive Functions ◽  
Patient Group ◽  
Direct Current ◽  
Response Inhibition ◽  
Transcranial Direct Current Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Anodal Tdcs ◽  
Dorsolateral Prefrontal

Objective Cognitive impairments are a frequent and difficult to treat symptom in patients with schizophrenia and the strongest predictor for a successful reintegration in occupational and everyday life. Recent research suggests transcranial direct current stimulation (tDCS) to enhance cognition in this patient group. However, the question regarding its acute effectiveness on executive functions remains largely unanswered. Here, we examined in a randomized, double blind, sham-controlled repeated-measures design the impact of tDCS on performance in several executive functions in patients with schizophrenia, schizoaffective disorder or acute transient psychotic disorder. Methods Patients (N = 48) were tested twice using standardized, well-constructed and clinically validated neuropsychological tests assessing verbal working memory, response inhibition, mental flexibility and problem solving. In session 1 they solely underwent the neuropsychological assessment, whereas in session 2 they additionally received 2 mA of anodal tDCS stimulation over the left dorsolateral prefrontal cortex (DLPFC), cathode right supraorbital ridge, or sham stimulation for 20 minutes. Results Patients of both groups were not able to correctly discriminate the type of stimulation received confirming the success of the blinding procedure. However, analyzing the whole sample the change in performance from session 1 to session 2 was the same in the verum as in the sham condition (all p >.5). Moreover, a subsequent exploratory analysis showed that performance in the response inhibition task was worse for patients that engaged in the task within 20 minutes after the end of the verum stimulation. Conclusion Hence, 2 mA of anodal tDCS applied over the left DLPFC did not acutely enhance executive functions in patients with schizophrenia or related disorders but impaired performance in the response inhibition task shortly after. Future studies should continue to seek for effective stimulation configurations for this patient group. Clinical trial registration The study is registered in the “Deutsches Register Klinischer Studien DRKS”, German Clinical Trial Register and has been allocated the following number: DRKS00022126.

scholarly journals Involvement of the Right Dorsolateral Prefrontal Cortex in Numerical Rule Induction: A Transcranial Direct Current Stimulation Study

2020 ◽  
Vol 14 ◽  
Author(s):  
Yuzhao Yao ◽  
Xiuqin Jia ◽  
Jun Luo ◽  
Feiyan Chen ◽  
Peipeng Liang
Keyword(s):  
Prefrontal Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Critical Role ◽  
Inductive Reasoning ◽  
Anodal Tdcs ◽  
Direct Current Stimulation ◽  
Dorsolateral Prefrontal ◽  
The Right

Numerical inductive reasoning has been considered as one of the most important higher cognitive functions of the human brain. Importantly, previous behavioral studies have consistently reported that one critical component of numerical inductive reasoning is checking, which often occurs when a discrepant element is discovered, and reprocessing is needed to determine whether the discrepancy is an error of the original series. However, less is known about the neural mechanism underlying the checking process. Given that the checking effect involves cognitive control processes, such as the incongruent resolution, that are linked to the right dorsolateral prefrontal cortex (DLPFC), this study hypothesizes that the right DLPFC may play a specific role in the checking process. To test the hypothesis, this study utilized the transcranial direct current stimulation (tDCS), a non-invasive brain stimulation method that could modulate cortical excitability, and examined whether and how the stimulation of the right DLPFC via tDCS could modulate the checking effect during a number-series completion problem task. Ninety healthy participants were allocated to one of the anodal, cathodal, and sham groups. Subjects were required to verify whether number sequences formed rule-based series, and checking effect was assessed by the difference in performance between invalid and valid conditions. It was found that significantly longer response times (RTs) were exhibited in invalid condition compared with valid condition in groups of anodal, cathodal, and sham tDCS. Furthermore, the anodal tDCS significantly shortened the checking effect than those of the cathodal and sham groups, whereas no significantly prolonged checking effect was detected in the cathodal group. The current findings indicated that anodal tDCS affected the process of checking, which suggested that the right DLPFC might play a critical role in the checking process of numerical inductive reasoning by inhibiting incongruent response.

Comparing the effects of multi-session anodal trans-cranial direct current stimulation of primary motor and dorsolateral prefrontal cortices on fatigue and quality of life in patients with multiple sclerosis: a double-blind, randomized, sham-controlled trial

2020 ◽  
Vol 34 (8) ◽  
pp. 1103-1111
Author(s):  
Marzieh Mortezanejad ◽  
Fatemeh Ehsani ◽  
Nooshin Masoudian ◽  
Maryam Zoghi ◽  
Shapour Jaberzadeh
Keyword(s):  
Quality Of Life ◽  
Multiple Sclerosis ◽  
Prefrontal Cortex ◽  
Direct Current ◽  
Dorsolateral Prefrontal Cortex ◽  
Fatigue Severity Scale ◽  
Severity Scale ◽  
Dorsolateral Prefrontal ◽  
Fatigue Severity

Objective: To compare the effects of anodal trans-cranial direct current stimulation (a-tDCS) over primary motor and dorsolateral prefrontal cortices on Fatigue Severity Scale and its lasting effect on fatigue reduction and improvement in quality of life in patients with multiple sclerosis. Design: A randomized, double-blinded, sham-controlled parallel clinical trial study. Setting: Neurological physiotherapy clinics. Subjects: Thirty-nine participants were randomly assigned to three groups: dorsolateral prefrontal cortex a-tDCS, primary motor a-tDCS (experimental groups) and sham a-tDCS. Finally, 36 participants completed the whole study ( n = 12 in each group). Interventions: Participants in the experimental groups received six-session a-tDCS (1.5 mA, 20 minutes) during two weeks (three sessions per week). The sham group received six sessions of 20-minute sham stimulation. Main measures: The Fatigue Severity Scale and quality of life were assessed before, immediately and four weeks after the intervention. Results: Findings indicated a significant reduction in the Fatigue Severity Scale and a significant increase in the quality of life in both experimental groups, immediately after the intervention ( P < 0.001), while Fatigue Severity Scale and quality of life changes were not significant in the sham a-tDCS group ( P > 0.05). In addition, improvement of the variables remained four weeks after the intervention in dorsolateral prefrontal cortex a-tDCS (mean differences (95% confidence interval): 0.03 (−0.63 to 0.68) as compared to primary motor (−0.62 (−0.11 to −1.14) and sham a-tDCS groups (−0.47 (−1.37 to 0.43)). Conclusion: Both primary motor and dorsolateral prefrontal cortex a-tDCS as compared to sham intervention can immediately improve fatigue and quality of life. However, the effects last up to four weeks only by the dorsolateral prefrontal cortex a-tDCS.

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