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Updated: Jan 25, 2026

Modulating Cognition Using Transcranial Direct Current Stimulation of the Cerebellum
Published on: February 15, 2015
Transcranial Direct Current Stimulation Improves Cognitive Function in Mild to Moderate Alzheimer Disease: A
Mengjie Cai1, Zhiwei Guo1, Guoqiang Xing1,2
1Department of Radiology & Imaging Institute of Rehabilitation and Development of Brain Function, The Second Clinical Medical College of North Sichuan Medical College Nanchong Central Hospital, Nanchong.
Objective:
The purpose of this meta-analysis was to evaluate the therapeutic effect of transcranial direct current stimulation (tDCS) on mild to moderate Alzheimer disease (AD) patients.
Materials And Methods:
PubMed, Embase, Web of Science, and Cochrane Library were searched until April 2018. The primary cognitive outcomes were extracted from included articles. A crude standardized mean difference with 95% CI was calculated by using fixed or random effect models.
Results:
Seven studies with 146 patients were included in this meta-analysis. The pooled result showed that tDCS significantly improved cognitive function of AD patients (standardized mean difference=0.37; 95% CI, 0.09-0.65; P=0.01). Subgroup analyses showed that: a single session of tDCS was significantly effective (P<0.05) whereas repeated sessions of tDCS was not lower current density (0.06 mA/cm) (P>0.05) but not higher current density (0.08 mA/cm) significantly improved cognitive performance; stimulating the temporal cortex (P<0.05) but not the left dorsal lateral prefrontal cortex significantly improved cognitive function of AD patients; and improved cognitive function occurred in the group with higher education (P<0.05) but not in the group with lower education.
Conclusions:
Current evidence suggests that tDCS has a beneficial effect in mild to moderate AD patients. We must be cautious about the results of subgroup analysis given small sample sizes, and further well-designed studies with larger sample size are required to verify these results.
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