Cognitive functioning before and after repetitive transcranial magnetic stimulation (rTMS): A quantitative meta-analysis in healthy adults.

Author: Patel R1, Silla F2, Pierce S2, Theule J2, Girard TA3
Affiliation:
1Department of Clinical Health Psychology, Max Rady College of Medicine, University of Manitoba, Canada. Electronic address: rpatel4@exchange.hsc.mb.ca.
2Department of Psychology, University of Manitoba, Canada.
3Department of Psychology, Ryerson University, Canada.
Conference/Journal: Neuropsychologia.
Date published: 2020 Mar 3
Other: Volume ID: 107395 , Special Notes: doi: 10.1016/j.neuropsychologia.2020.107395. [Epub ahead of print] , Word Count: 269


Repetitive transcranial magnetic stimulation (rTMS) is thought to modulate brain function through methods of electromagnetic induction. Over the last few decades, a large body of studies have investigated the clinical applications of rTMS in a variety of patient populations for a diverse range of symptoms from depressive symptomology to post-stroke motor functioning. There is still no clear consensus, however, on how rTMS influences cognitive functioning in the healthy brain. We conducted a quantitative meta-analysis in order to evaluate whether offline rTMS (the delivery of rTMS when not actively engaged in a cognitive task) influences cognition in healthy adults. More specifically, we examined studies that applied rTMS to the dorsal lateral prefrontal cortex (DLFPC) and that tracked cognitive outcomes both before and after a prescribed period of rTMS. Fifteen studies met our inclusion criteria. Cognitive performance was pooled and examined across studies for four cognitive domains (working memory, executive functioning, episodic memory, and visual perception) and under two types of stimulation conditions (excitatory and inhibitory rTMS). Whereas excitatory rTMS was associated with statistically reliable effects for improving executive functioning, inhibitory rTMS was associated with statistically reliable effects for improving episodic memory and visual perception. However, the magnitude of these effects was small and no other significant effects were observed. Though future studies are still needed, our findings suggest that offline forms of rTMS may have limited utility in affecting cognitive functioning when applied to the DLPFC in healthy adults, irrespective of cognitive domain or stimulation type.

Copyright © 2020. Published by Elsevier Ltd.

KEYWORDS: Cognition; Executive functioning; Healthy adults; Memory; Offline rTMS; Repetitive transcranial magnetic stimulation; Working memory

PMID: 32142730 DOI: 10.1016/j.neuropsychologia.2020.107395

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