title: Effects of noninvasive brain stimulation on cognitive function in healthy aging and Alzheimer's disease: a systematic review and meta-analysis.
abstract: The study aimed to evaluate the effects of noninvasive brain stimulation on cognitive function in healthy older adults and patients with Alzheimer's disease. A comprehensive literature search was performed on noninvasive stimulation studies published from January 1990 to November 2014 in Pubmed and Web of Science. Fourteen articles with a total of 331 participants were identified as studies with healthy older adults, and the mean effect size and 95% confidence interval were estimated. A significant effect size of 0.42 was found for the cognitive outcome. Further subgroup analyses demonstrated more prominent effects for studies delivering the stimulation before the execution of the task and studies applying multiple sessions of stimulation. To assess the effects of stimulation on Alzheimer's disease patients, 11 studies with a total of 200 patients were included in the analysis. A significant effect size of 1.35 was found for the cognitive outcomes. Subgroup analyses indicated more pronounced effects for studies applying the stimulation during the execution of the task compared with studies delivering the stimulation before the execution of the task. Noninvasive brain stimulation has a positive effect on cognitive function in physiological and pathological aging.
authors.affiliation: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Hsu
authors.affiliation: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Key Laboratory of Brain Functional Genomics, Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics, Institue of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Ku
authors.affiliation: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Theodore P
authors.initials: TP
authors.lastname: Zanto
authors.affiliation: Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Department of Physiology and Psychiatry, University of California, San Francisco, San Francisco, CA, USA. Electronic address: adam.gazzaley@ucsf.edu.
authors.forename: Adam
authors.initials: A
authors.lastname: Gazzaley
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D000544:Alzheimer Disease / Q000523:psychology* / Q000628:therapy*; D003071:Cognition; D016206:Databases, Bibliographic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D065908:Transcranial Direct Current Stimulation; D050781:Transcranial Magnetic Stimulation; D016896:Treatment Outcome
keywords: Aging; Alzheimer's disease (AD); Cognitive function; Meta-analysis; Neuronal plasticity; Repetitive transcranial magnetic stimulation (rTMS); Transcranial direct current stimulation (tDCS)