Journal Article

Efficacy of non-invasive brain stimulation on cognitive functioning in brain disorders: a meta-analysis

Aleman, André, Ćurčić-Blake, Branislava, Begemann, Marieke J., Brand, Bodyl A., Sommer, Iris E.

2020

Overview

Cognition is commonly affected in brain disorders. Non-invasive brain stimulation (NIBS) may have procognitive effects, with high tolerability. This meta-analysis evaluates the efficacy of transcranial magnetic stimulation (TMS) and transcranial Direct Current Stimulation (tDCS) in improving cognition, in schizophrenia, depression, dementia, Parkinson's disease, stroke, traumatic brain injury, and multiple sclerosis. A PRISMA systematic search was conducted for randomized controlled trials. Hedges' g was used to quantify effect sizes (ES) for changes in cognition after TMS/tDCS v. sham. As different cognitive functions may have unequal susceptibility to TMS/tDCS, we separately evaluated the effects on: attention/vigilance, working memory, executive functioning, processing speed, verbal fluency, verbal learning, and social cognition. We included 82 studies (n = 2784). For working memory, both TMS (ES = 0.17, p = 0.015) and tDCS (ES = 0.17, p = 0.021) showed small but significant effects. Age positively moderated the effect of TMS. TDCS was superior to sham for attention/vigilance (ES = 0.20, p = 0.020). These significant effects did not differ across the type of brain disorder. Results were not significant for the other five cognitive domains. Our results revealed that both TMS and tDCS elicit a small trans-diagnostic effect on working memory, tDCS also improved attention/vigilance across diagnoses. Effects on the other domains were not significant. Observed ES were small, yet even slight cognitive improvements may facilitate daily functioning. While NIBS can be a well-tolerated treatment, its effects appear domain specific and should be applied only for realistic indications (i.e. to induce a small improvement in working memory or attention).

• Publisher: Cambridge University Press
• Subject: Age differences / Alzheimer's disease / Attention / Brain / Brain damage / Brain Diseases - therapy / Chronic illnesses / Clinical trials / Cognition / Cognition & reasoning / Cognitive ability / Cognitive functioning / Dementia / Dementia disorders / Disorders / Efficacy / Executive function / Fluency / Humans / Information processing / Medical research / Memory / Memory, Short-Term / Mental disorders / Meta-analysis / Movement disorders / Multiple sclerosis / Neurodegenerative diseases / Neurological disorders / Non-invasive / Parkinson's disease / Patients / Randomized Controlled Trials as Topic / Review / Schizophrenia / Short term memory / Social cognition / Social discrimination learning / Social interactions / Social perception / Stimuli / Stroke / Susceptibility / Systematic review / Transcranial direct current stimulation / Transcranial Direct Current Stimulation - methods / Transcranial magnetic stimulation / Transcranial Magnetic Stimulation - methods / Trauma / Traumatic brain injury / Verbal learning / Vigilance