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High definition transcranial direct current stimulation modulates abnormal neurophysiological activity in post-stroke aphasia. Sci Rep 2020 Nov 12;10(1):19625

Date

11/14/2020

Pubmed ID

33184382

Pubmed Central ID

PMC7665190

DOI

10.1038/s41598-020-76533-0

Scopus ID

2-s2.0-85095958072 (requires institutional sign-in at Scopus site)   18 Citations

Abstract

Recent findings indicate that measures derived from resting-state magnetoencephalography (rsMEG) are sensitive to cortical dysfunction in post-stroke aphasia. Spectral power and multiscale entropy (MSE) measures show that left-hemispheric areas surrounding the stroke lesion (perilesional) exhibit pathological oscillatory slowing and alterations in signal complexity. In the current study, we tested whether individually-targeted high-definition transcranial direct current stimulation (HD-tDCS) can reduce MEG abnormalities and transiently improve language performance. In eleven chronic aphasia survivors, we devised a method to localize perilesional areas exhibiting peak MSE abnormalities, and subsequently targeted these areas with excitatory/anodal-tDCS, or targeted the contralateral homolog areas with inhibitory/cathodal-tDCS, based on prominent theories of stroke recovery. Pathological MEG slowing in these patients was correlated with aphasia severity. Sentence/phrase repetition accuracy was assessed before and after tDCS. A delayed word reading task was administered inside MEG to assess tDCS-induced neurophysiological changes in relative power and MSE computed on the pre-stimulus and delay task time windows. Results indicated increases in repetition accuracy, decreases in contralateral theta (4-7 Hz) and coarse-scale MSE (slow activity), and increases in perilesional low-gamma (25-50 Hz) and fine-scale MSE (fast activity) after anodal-tDCS, indicating reversal of pathological abnormalities. RsMEG may be a sensitive measure for guiding therapeutic tDCS.

Author List

Shah-Basak PP, Sivaratnam G, Teti S, Francois-Nienaber A, Yossofzai M, Armstrong S, Nayar S, Jokel R, Meltzer J

Author

Priyanka P. Shah PhD Assistant Professor in the Neurology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Adult
Aged
Aged, 80 and over
Aphasia
Female
Humans
Language
Magnetoencephalography
Male
Middle Aged
Severity of Illness Index
Stroke
Stroke Rehabilitation
Transcranial Direct Current Stimulation