Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis
Background: Transcranial direct-current stimulation (tDCS) facilitates cognitive improvement in healthy and pathological populations. It has been increasingly used in cases of mild cognitive impairment (MCI) and dementia. Our research question is: Can tDCS serve as a clinical intervention for improv...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-10-01
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| Series: | Frontiers in Human Neuroscience |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fnhum.2018.00416/full |
| _version_ | 1811215013907529728 |
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| author | Pablo Cruz Gonzalez Kenneth N. K. Fong Kenneth N. K. Fong Raymond C. K. Chung Kin-Hung Ting Lawla L. F. Law Ted Brown |
| author_facet | Pablo Cruz Gonzalez Kenneth N. K. Fong Kenneth N. K. Fong Raymond C. K. Chung Kin-Hung Ting Lawla L. F. Law Ted Brown |
| author_sort | Pablo Cruz Gonzalez |
| collection | DOAJ |
| description | Background: Transcranial direct-current stimulation (tDCS) facilitates cognitive improvement in healthy and pathological populations. It has been increasingly used in cases of mild cognitive impairment (MCI) and dementia. Our research question is: Can tDCS serve as a clinical intervention for improving the cognitive functions of persons with MCI (PwMCI) and dementia (PwD)?Objective: This systematic review evaluated the evidence to determine the efficacy of tDCS in improving cognitive outcomes in PwD and PwMCI.Methods: A systematic review was conducted of studies published up to November 2017 involving tDCS in cases of MCI and dementia. Studies were ranked according to the level of evidence (Oxford Center for Evidence-Based Medicine) and assessed for methodological quality (Risk of Bias Tool in the Cochrane Handbook for Systematic Reviews of Interventions). Data was extracted on all protocol variables to establish a reference framework for clinical interventions. Different modalities, tDCS alone or combined with cognitive training, compared with sham tDCS were examined in both short and long-term effects. Four randomized control trials (RCTs) with memory outcomes were pooled using the fixed-effect model for the meta-analysis.Results: Twelve studies with 195 PwD and four with 53 PwMCI met the inclusion criteria. Eleven articles were ranked as Level 1b. The results on the meta-analysis on pooled effects of memory indicated a statistically significant medium effect size of 0.39 (p = 0.04) for immediate effects. This improvement was not maintained in the long term 0.15 (p = 0.44).Conclusion: tDCS improves memory in PwD in the short term, it also seems to have a mild positive effect on memory and language in PwMCI. However, there is no conclusive advantage in coupling tDCS with cognitive training. More rigorous evidence is needed to establish whether tDCS can serve as an evidence-based intervention for both populations. |
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| format | Article |
| id | doaj.art-ad8288bba65e46aead31c2ae08062c6b |
| institution | Directory Open Access Journal |
| issn | 1662-5161 |
| language | English |
| last_indexed | 2024-04-12T06:15:09Z |
| publishDate | 2018-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Human Neuroscience |
| spelling | doaj.art-ad8288bba65e46aead31c2ae08062c6b2022-12-22T03:44:32ZengFrontiers Media S.A.Frontiers in Human Neuroscience1662-51612018-10-011210.3389/fnhum.2018.00416398142Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-AnalysisPablo Cruz Gonzalez0Kenneth N. K. Fong1Kenneth N. K. Fong2Raymond C. K. Chung3Kin-Hung Ting4Lawla L. F. Law5Ted Brown6Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong KongDepartment of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong KongUniversity Research Facility in Behavioral and Systems Neuroscience, The Hong Kong Polytechnic University, Kowloon, Hong KongDepartment of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong KongUniversity Research Facility in Behavioral and Systems Neuroscience, The Hong Kong Polytechnic University, Kowloon, Hong KongSchool of Medical and Health Sciences, Tung Wah College, Kowloon, Hong KongDepartment of Occupational Therapy, Monash University, Melbourne, VIC, AustraliaBackground: Transcranial direct-current stimulation (tDCS) facilitates cognitive improvement in healthy and pathological populations. It has been increasingly used in cases of mild cognitive impairment (MCI) and dementia. Our research question is: Can tDCS serve as a clinical intervention for improving the cognitive functions of persons with MCI (PwMCI) and dementia (PwD)?Objective: This systematic review evaluated the evidence to determine the efficacy of tDCS in improving cognitive outcomes in PwD and PwMCI.Methods: A systematic review was conducted of studies published up to November 2017 involving tDCS in cases of MCI and dementia. Studies were ranked according to the level of evidence (Oxford Center for Evidence-Based Medicine) and assessed for methodological quality (Risk of Bias Tool in the Cochrane Handbook for Systematic Reviews of Interventions). Data was extracted on all protocol variables to establish a reference framework for clinical interventions. Different modalities, tDCS alone or combined with cognitive training, compared with sham tDCS were examined in both short and long-term effects. Four randomized control trials (RCTs) with memory outcomes were pooled using the fixed-effect model for the meta-analysis.Results: Twelve studies with 195 PwD and four with 53 PwMCI met the inclusion criteria. Eleven articles were ranked as Level 1b. The results on the meta-analysis on pooled effects of memory indicated a statistically significant medium effect size of 0.39 (p = 0.04) for immediate effects. This improvement was not maintained in the long term 0.15 (p = 0.44).Conclusion: tDCS improves memory in PwD in the short term, it also seems to have a mild positive effect on memory and language in PwMCI. However, there is no conclusive advantage in coupling tDCS with cognitive training. More rigorous evidence is needed to establish whether tDCS can serve as an evidence-based intervention for both populations.https://www.frontiersin.org/article/10.3389/fnhum.2018.00416/fulltDCS (transcranial direct-current stimulation)neuromodulationMCI (mild cognitive impairment)dementiacognitive rehabilitationcognitive training |
| spellingShingle | Pablo Cruz Gonzalez Kenneth N. K. Fong Kenneth N. K. Fong Raymond C. K. Chung Kin-Hung Ting Lawla L. F. Law Ted Brown Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis Frontiers in Human Neuroscience tDCS (transcranial direct-current stimulation) neuromodulation MCI (mild cognitive impairment) dementia cognitive rehabilitation cognitive training |
| title | Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis |
| title_full | Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis |
| title_fullStr | Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis |
| title_full_unstemmed | Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis |
| title_short | Can Transcranial Direct-Current Stimulation Alone or Combined With Cognitive Training Be Used as a Clinical Intervention to Improve Cognitive Functioning in Persons With Mild Cognitive Impairment and Dementia? A Systematic Review and Meta-Analysis |
| title_sort | can transcranial direct current stimulation alone or combined with cognitive training be used as a clinical intervention to improve cognitive functioning in persons with mild cognitive impairment and dementia a systematic review and meta analysis |
| topic | tDCS (transcranial direct-current stimulation) neuromodulation MCI (mild cognitive impairment) dementia cognitive rehabilitation cognitive training |
| url | https://www.frontiersin.org/article/10.3389/fnhum.2018.00416/full |
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