scholarly journals Investigating the Effects of Cerebellar Transcranial Direct Current Stimulation on Post-Stroke Overground Gait Performance: a partial least-squares regression approach

2020 ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Partial Least Squares Regression ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Post Stroke ◽  
Wilcoxon Rank Sum Test ◽  
The Mean

Abstract Background Stroke often results in impaired gait, which can limit community ambulation and the quality of life. Recent works have shown the feasibility of transcranial Direct Current Stimulation (tDCS) as an adjuvant treatment to facilitate gait rehabilitation. Since the cerebellum plays an essential role in balance and movement coordination, which is crucial for independent overground ambulation, so, we investigated the effects of cerebellar tDCS (ctDCS) on the post-stroke overground gait performance in chronic stroke survivors. Methods Fourteen chronic post-stroke male subjects were recruited based on convenience sampling at the collaborating hospitals where ten subjects finally participated in the ctDCS gait study. We evaluated the effects of two ctDCS montages with 2 mA direct current, a) optimized configuration for dentate stimulation with 3.14 cm2 disc anode at PO10h (10/5 EEG system) and 3.14 cm2 disc cathode at PO9h (10/5 EEG system), and b) optimized configuration for leg lobules VII-IX stimulation with 3.14 cm2 disc anode at Exx8 (electrodes defined by ROAST) and 3.14 cm2 disc cathode at Exx7. Two-sided Wilcoxon rank-sum test was performed at the 5% significance level on the percent normalized change measures in the overground gait performance. Results We found ctDCS to be acceptable by all the exposed subjects. The ctDCS intervention had an effect on the 'Normalised Step length Affected side' (p = 0.1) and 'Gait Stability Ratio' (p = 0.0569), which was found using Wilcoxon signed-rank test at 10% significance level. Also, ctDCS montage specific effect was found using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p = 0.0257) and '%Stance Time Unaffected Leg' (p = 0.0376). Moreover, the changes in the quantitative gait parameters across both the montages were found to be correlated to the mean electric field strength in the lobules based on partial least squares regression analysis (R2 statistic = 0.6574) where the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsilesional IX, Vermis IX, Ipsilesional X, had the most loading. Conclusion Our feasibility study indicated the potential of a single session of ctDCS to contribute to the immediate improvement in the balance and gait performance in terms of gait-related indices and clinical gait measures.

scholarly journals Investigating the Effects of Cerebellar Transcranial Direct Current Stimulation on Post-Stroke Overground Gait Performance: A Partial Least-Squares Regression Approach

2020 ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Partial Least Squares Regression ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Post Stroke ◽  
The Mean

Stroke often results in impaired gait, which can limit community ambulation and the quality of life. Recent works have shown the feasibility of transcranial Direct Current Stimulation (tDCS) as an adjuvant treatment to facilitate gait rehabilitation. Since the cerebellum plays an essential role in balance and movement coordination, which is crucial for independent overground ambulation, so, we investigated the effects of cerebellar tDCS (ctDCS) on the post-stroke overground gait performance in chronic stroke survivors. Fourteen chronic post-stroke male subjects were recruited based on convenience sampling at the collaborating hospitals where ten subjects finally participated in the ctDCS study. We evaluated the effects of two ctDCS montages with 2mA direct current, a) optimized configuration for dentate stimulation with 3.14cm2 disc anode at PO10h (10/5 EEG system) and 3.14cm2 disc cathode at PO9h (10/5 EEG system), and b) optimized configuration for leg lobules VII-IX stimulation with 3.14cm2 disc anode at Exx8 (electrodes defined by ROAST) and 3.14cm2 disc cathode at Exx7. We found ctDCS to be acceptable by all the exposed subjects. The ctDCS intervention had an effect on the 'Normalised Step length Affected side' (p=0.1) and 'Gait Stability Ratio' (p=0.0569), which was found using Wilcoxon signed-rank test at 10% significance level. Also, ctDCS montage specific effect was found using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p=0.0257) and '%Stance Time Unaffected Leg' (p=0.0376). Moreover, the changes in the quantitative gait parameters across both the montages were found to be correlated to the mean electric field strength in the lobules based on partial least squares regression analysis (R2 statistic = 0.6574) where the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsilesional IX, Vermis IX, Ipsilesional X, had the most loading. In conclusion, our feasibility study indicated the potential of a single session of ctDCS to contribute to the immediate improvement in the balance and gait performance in terms of gait-related indices and clinical gait measures.

scholarly journals Investigating the Feasibility of Cerebellar Transcranial Direct Current Stimulation to facilitate Post-Stroke Overground Gait Performance in Chronic Stroke: a partial least-squares regression approach

2020 ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Post Stroke ◽  
Wilcoxon Rank Sum Test ◽  
Gait Parameters ◽  
The Mean

Abstract Background: Cerebellar transcranial Direct Current Stimulation (ctDCS) has been shown to be promising as an adjuvant treatment to facilitate post-stroke gait rehabilitation; however, investigation of lobule-specific electric field effects on overground gait performance has not been performed. Methods: Ten chronic post-stroke male subjects participated in this repeated-measure single-blind crossover study, where we evaluated the single-session effects of two bilateral ctDCS montages that applied 2mA via 3.14cm 2 disc electrodes for 15 minutes targeting a) dentate nuclei (also, anterior and posterior lobes), and b) lower-limb representations (lobules VIIb-IX). A two-sided Wilcoxon rank-sum test was performed at 5% significance level on the percent normalized change measures in the overground gait performance. Partial least squares regression (PLSR) analysis was performed on the quantitative gait parameters as response variables to the mean lobular electric field strength as the predictors. Clinical assessments were performed with the Ten-Meter walk test (TMWT), Timed Up & Go (TUG), and the Berg Balance Scale based on minimal clinically important differences (MCID). Results: The ctDCS montage specific effect was found significant using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p=0.0257) and '%Stance Time Unaffected Leg' (p=0.0376). The changes in the quantitative gait parameters were found to be correlated to the mean electric field strength in the lobules based on PLSR analysis ( R 2 statistic = 0.6574). Here, the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsi-lesional IX, Vermis IX, Ipsi-lesional X, had the most loading, and were positively related to the 'Step Time Affected Leg' and '%Stance Time Unaffected Leg,' and negatively related to the '%Swing Time Unaffected Leg,' '%Single Support Time Affected Leg.' Clinical assessments found similar improvement in the TMWT (MCID: 0.10m/sec), TUG (MCID: 8sec), and BBS score (MCID: 12.5 points) for both the ctDCS montages. Conclusion: Our feasibility study found an association between the lobular mean electric field strength and the changes in the quantitative gait parameters following a single ctDCS session in chronic stroke. Both the ctDCS montages improved the clinical outcome measures that should be investigated with a larger sample size for clinical validation.

scholarly journals Investigating the feasibility of cerebellar transcranial direct current stimulation to facilitate post-stroke overground gait performance in chronic stroke: a partial least-squares regression approach

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Chronic Stroke ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Wilcoxon Rank Sum Test ◽  
Gait Parameters ◽  
The Mean

Abstract Background Investigation of lobule-specific electric field effects of cerebellar transcranial direct current stimulation (ctDCS) on overground gait performance has not been performed, so this study aimed to investigate the feasibility of two lobule-specific bilateral ctDCS montages to facilitate overground walking in chronic stroke. Methods Ten chronic post-stroke male subjects participated in this repeated-measure single-blind crossover study, where we evaluated the single-session effects of two bilateral ctDCS montages that applied 2 mA via 3.14 cm2 disc electrodes for 15 min targeting (a) dentate nuclei (also, anterior and posterior lobes), and (b) lower-limb representations (lobules VIIb-IX). A two-sided Wilcoxon rank-sum test was performed at a 5% significance level on the percent normalized change measures in the overground gait performance. Partial least squares regression (PLSR) analysis was performed on the quantitative gait parameters as response variables to the mean lobular electric field strength as the predictors. Clinical assessments were performed with the Ten-Meter walk test (TMWT), Timed Up & Go (TUG), and the Berg Balance Scale based on minimal clinically important differences (MCID). Results The ctDCS montage specific effect was found significant using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p = 0.0257) and '%Stance Time Unaffected Leg' (p = 0.0376). The changes in the quantitative gait parameters were found to be correlated to the mean electric field strength in the lobules based on PLSR analysis (R2 statistic = 0.6574). Here, the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsi-lesional IX, Vermis IX, Ipsi-lesional X, had the most loading and were positively related to the 'Step Time Affected Leg' and '%Stance Time Unaffected Leg,' and negatively related to the '%Swing Time Unaffected Leg,' '%Single Support Time Affected Leg.' Clinical assessments found similar improvement in the TMWT (MCID: 0.10 m/s), TUG (MCID: 8 s), and BBS score (MCID: 12.5 points) for both the ctDCS montages. Conclusion Our feasibility study found an association between the lobular mean electric field strength and the changes in the quantitative gait parameters following a single ctDCS session in chronic stroke. Both the ctDCS montages improved the clinical outcome measures that should be investigated with a larger sample size for clinical validation. Trial registration: Being retrospectively registered.

scholarly journals Investigating the Feasibility of Cerebellar Transcranial Direct Current Stimulation to facilitate Post-Stroke Overground Gait Performance in Chronic Stroke: a partial least-squares regression approach

2020 ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Chronic Stroke ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Wilcoxon Rank Sum Test ◽  
Gait Parameters ◽  
The Mean

Abstract Background: Investigation of lobule-specific electric field effects of cerebellar transcranial direct current stimulation (ctDCS) on overground gait performance has not been performed, so this study aimed to investigate the feasibility of two lobule-specific bilateral ctDCS montages to facilitate overground walking in chronic stroke. Methods: Ten chronic post-stroke male subjects participated in this repeated-measure single-blind crossover study, where we evaluated the single-session effects of two bilateral ctDCS montages that applied 2mA via 3.14cm2 disc electrodes for 15 minutes targeting a) dentate nuclei (also, anterior and posterior lobes), and b) lower-limb representations (lobules VIIb-IX). A two-sided Wilcoxon rank-sum test was performed at a 5% significance level on the percent normalized change measures in the overground gait performance. Partial least squares regression (PLSR) analysis was performed on the quantitative gait parameters as response variables to the mean lobular electric field strength as the predictors. Clinical assessments were performed with the Ten-Meter walk test (TMWT), Timed Up & Go (TUG), and the Berg Balance Scale based on minimal clinically important differences (MCID).Results: The ctDCS montage specific effect was found significant using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p=0.0257) and '%Stance Time Unaffected Leg' (p=0.0376). The changes in the quantitative gait parameters were found to be correlated to the mean electric field strength in the lobules based on PLSR analysis (R2 statistic = 0.6574). Here, the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsi-lesional IX, Vermis IX, Ipsi-lesional X, had the most loading and were positively related to the 'Step Time Affected Leg' and '%Stance Time Unaffected Leg,' and negatively related to the '%Swing Time Unaffected Leg,' '%Single Support Time Affected Leg.' Clinical assessments found similar improvement in the TMWT (MCID: 0.10m/sec), TUG (MCID: 8sec), and BBS score (MCID: 12.5 points) for both the ctDCS montages. Conclusion: Our feasibility study found an association between the lobular mean electric field strength and the changes in the quantitative gait parameters following a single ctDCS session in chronic stroke. Both the ctDCS montages improved the clinical outcome measures that should be investigated with a larger sample size for clinical validation.

scholarly journals Deep Cerebellar Transcranial Direct Current Stimulation of the Dentate Nucleus to Facilitate Standing Balance in Chronic Stroke Survivors

2019 ◽  
Author(s):  
Zeynab Rezaee ◽  
Surbhi Kaura ◽  
Dhaval Solanki ◽  
Adyasha Dash ◽  
M V Padma Srivastava ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Lower Limb ◽  
Standing Balance ◽  
Stroke Survivors ◽  
Post Stroke ◽  
Functional Reach

Objective: Cerebrovascular accidents are the second leading cause of death and the third leading cause of disability worldwide. We hypothesized that cerebellar transcranial direct current stimulation (ctDCS) of the dentate nuclei and the lower-limb representations in the cerebellum can improve standing balance functional reach in chronic (> 6 months’ post-stroke) stroke survivors. Materials and Methods: Magnetic resonance imaging(MRI) based subject-specific electric field was computed across 10 stroke survivors and one healthy MRI template to find an optimal bipolar bilateral ctDCS montage to target dentate nuclei and lower-limb representations (lobules VII-IX). Then, in a repeated-measure crossover study on 5 stroke survivors, we compared 15minutes of 2mA ctDCS based on the effects on successful functional reach(%) during standing balance task. Three-way ANOVA investigated the factors of interest– brain regions, montages, stroke participants, and their interactions.Results: “One-size-fits-all” ctDCS montage for the clinical study was found to be bipolar PO9h – PO10h for dentate nuclei and bipolar Exx7–Exx8 for lobules VII-IX with contalesional anode. Bipolar PO9h–PO10h ctDCS performed significantly (alpha=0.05) better in facilitating successful functional reach (%) when compared to bipolar Exx7–Exx8 ctDCS. Furthermore, a linear relationship between successful functional reach (%) and electric field strength was found where bipolar PO9h–PO10h montage resulted in a significantly (alpha=0.05) higher electric field strength when compared to bipolar Exx7–Exx8 montage for the same 2mA current. Conclusion: We presented a rational neuroimaging based approach to optimize deep ctDCS of the dentate nuclei and lower limb representations in the cerebellum for post-stroke balance rehabilitation.

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.

Mood and cognitive effects of transcranial direct current stimulation in post-stroke depression

Neurocase ◽  
2011 ◽  
Vol 17 (4) ◽  
pp. 318-322 ◽  
Author(s):  
Viviane F. Bueno ◽  
Andre R. Brunoni ◽  
Paulo S. Boggio ◽  
Isabela M. Bensenor ◽  
Felipe Fregni
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cognitive Effects ◽  
Direct Current Stimulation ◽  
Post Stroke ◽  
Post Stroke Depression

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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