scholarly journals Investigation of the Influence of Phonological Awareness Intervention and Transcranial Direct Current Stimulation on the Enhancement of Rapid Automatized Naming and Verbal Short Term Memory in Developmental Dyslexia: A Randomized Controlled Trial

2021 ◽  
Author(s):  
Seyyedeh Samaneh Mirahadi ◽  
Reyhane Mohamadi ◽  
Bahar Arshi ◽  
Jamile Abolghasemi
Keyword(s):  
Phonological Awareness ◽  
Outcome Measures ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Short Term Memory ◽  
Rapid Automatized Naming ◽  
Short Term ◽  
Term Memory ◽  
Direct Current Stimulation ◽  
The Mean

Abstract Phonological deficits include phonological awareness (PA), rapid automatized naming (RAN) and verbal short term memory (VSTM). PA is defined as a conscious manipulation of the word subunits in word structure. Recently, transcranial direct current stimulation (tDCS) has been used as a complementary treatment with PA intervention in the dyslexia treatment. In this trial we had both a PA intervention group and a PA + tDCS group in which the tDCS is applied over the left parieto-temporal area. It was hypothesized that the PA + tDCS treatment can improve RAN and VSTM. A randomized, double-blind, sham-controlled clinical trial was conducted to evaluate the influence of PA + tDCS intervention in improving RAN and VSTM. Twenty-eight participants were randomly allocated to the active (PA + anodal tDCS) or sham (PA + sham tDCS) groups. Each dyslexic student participated in 15 intervention sessions. RAN and VSTM sub-tests were assessed at the baseline, at the end of the fifth, tenth, and final treatment sessions and finally 6 weeks after the treatment. In both groups, mean scores of RAN sub-tests significantly decreased and the mean scores of the VSTM sub-tests significantly increased during, immediately and also 6 weeks after intervention. There was no significant difference between the two groups in the mean scores of the outcome measures. PA intervention leads to improvement in RAN and VSTM abilities in dyslexic students for a longer period of time. Combined intervention (PA + tDCS) had no further effect on outcome measures than PA intervention alone.

scholarly journals Gender-specific modulation of short-term neuroplasticity in the visual cortex induced by transcranial direct current stimulation

2008 ◽  
Vol 25 (1) ◽  
pp. 77-81 ◽  
Author(s):  
LEILA CHAIEB ◽  
ANDREA ANTAL ◽  
WALTER PAULUS
Keyword(s):  
Sex Differences ◽  
Visual Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cortical Excitability ◽  
Gonadal Hormones ◽  
Study Data ◽  
Short Term ◽  
Direct Current Stimulation ◽  
Significant Difference

Transcranial direct current stimulation (tDCS) is a non-invasive method of modulating levels of cortical excitability. In this study, data gathered over a number of previously conducted experiments before and after tDCS, has been re-analyzed to investigate correlations between sex differences with respect to neuroplastic effects. Visual evoked potentials (VEPs), phosphene thresholds (PTs), and contrast sensitivity measurements (CSs) are used as indicators of the excitability of the primary visual cortex. The data revealed that cathodally induced excitability effects 10 min post stimulation with tDCS, showed no significant difference between genders. However, stimulation in the anodal direction revealed sex-specific effects: in women, anodal stimulation heightened cortical excitability significantly when compared to the age-matched male subject group. There was no significant difference between male and female subjects immediately after stimulation. These results indicate that sex differences exist within the visual cortex of humans, and may be subject to the influences of modulatory neurotransmitters or gonadal hormones which mirror short-term neuroplastic effects.

scholarly journals Functional Network Alterations as Markers for Predicting the Treatment Outcome of Cathodal Transcranial Direct Current Stimulation in Focal Epilepsy

2021 ◽  
Vol 15 ◽  
Author(s):  
Jiaxin Hao ◽  
Wenyi Luo ◽  
Yuhai Xie ◽  
Yu Feng ◽  
Wei Sun ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Prediction Model ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Path Length ◽  
Focal Epilepsy ◽  
Functional Network ◽  
Functional Networks ◽  
Direct Current Stimulation ◽  
The Mean

Background and PurposeTranscranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique for focal epilepsy. Because epilepsy is a disease affecting the brain network, our study was aimed to evaluate and predict the treatment outcome of cathodal tDCS (ctDCS) by analyzing the ctDCS-induced functional network alterations.MethodsEither the active 5-day, −1.0 mA, 20-min ctDCS or sham ctDCS targeting at the most active interictal epileptiform discharge regions was applied to 27 subjects suffering from focal epilepsy. The functional networks before and after ctDCS were compared employing graph theoretical analysis based on the functional magnetic resonance imaging (fMRI) data. A support vector machine (SVM) prediction model was built to predict the treatment outcome of ctDCS using the graph theoretical measures as markers.ResultsOur results revealed that the mean clustering coefficient and the global efficiency decreased significantly, as well as the characteristic path length and the mean shortest path length at the stimulation sites in the fMRI functional networks increased significantly after ctDCS only for the patients with response to the active ctDCS (at least 20% reduction rate of seizure frequency). Our prediction model achieved the mean prediction accuracy of 68.3% (mean sensitivity: 70.0%; mean specificity: 67.5%) after the nested cross validation. The mean area under the receiver operating curve was 0.75, which showed good prediction performance.ConclusionThe study demonstrated that the response to ctDCS was related to the topological alterations in the functional networks of epilepsy patients detected by fMRI. The graph theoretical measures were promising for clinical prediction of ctDCS treatment outcome.

Abstract P200: Transcranial Direct Current Stimulation in Post-Stroke Chronic Aphasia: A Double Blind Randomized Controlled Study

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Caroline Schnakers ◽  
Zhong Sheng Zheng ◽  
Henry Millan ◽  
Sharon Lee ◽  
Melissa Howard ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Superior Cerebellar Peduncle ◽  
Double Blind ◽  
Verbal Comprehension ◽  
Direct Current Stimulation ◽  
Post Stroke ◽  
Chronic Aphasia ◽  
Cerebellar Peduncle

Background: There is growing evidence even amongst those with chronic aphasia that transcranial direct current stimulation (tDCS) combined with behavioral speech therapy could boost language. However, current findings do not allow making strong recommendations for using tDCS in order to improve language in post-stroke aphasia. The efficacy of tDCS therefore still needs to be established using double-blind controlled randomized trials in large samples. Intervention: In this ongoing double-blind randomized placebo controlled trial study, participants were randomly assigned either to the tDCS group or to the sham group. Both groups had five consecutive days of 20 minutes session, using a FDA approved tDCS device (soterixmedical.com). Behavioral and neuroimaging data were performed the week before/after tDCS/sham intervention and again 3 months following treatment. Participants: 42 post-stroke patients with chronic aphasia (32 males; age: 61±11y; 0.9-18years post-injury; 32 ischemic stroke; 19 non-fluent aphasia). Eighteen patients were in the tDCS group. Main Outcome Measures: The Western Aphasia Battery-Revised (WAB-R), Communication Outcomes after Stroke, patient and family report (COAST). MRI Diffusion Tensor Imaging data (64 dir) were also collected. Statistical Analyses: Anova with repeated measures was used on the behavioral outcome measures with aphasia severity, age and time since injury as covariates in SPSS. The average fractional anisotropy (FA) and mean diffusivity (MD) were extracted per ROI from each participant and timepoint. Main Results: a) Behavioral. Groups differed, pre/post intervention, on the WAB-R total score, for the Auditory-Verbal Comprehension and Repetition subscores; b) Neuroimaging. Change in Spontaneous Speech and Auditory Verbal Comprehension negatively correlated with change in mean MD and FA, respectively, in Superior Cerebellar Peduncle for tDCS, but not sham. Conclusion: Our preliminary findings show a higher improvement in language functions (for both receptive and expressive language skills) in response to treatment (vs. sham). Neuroplasticity was observed in superior cerebellar peduncle in response to tDCS mediated language improvement.

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