High definition transcranial direct current stimulation modulates abnormal neurophysiological activity in post-stroke aphasia. Sci Rep 2020 Nov 12;10(1):19625
Date
11/14/2020Pubmed ID
33184382Pubmed Central ID
PMC7665190DOI
10.1038/s41598-020-76533-0Scopus ID
2-s2.0-85095958072 (requires institutional sign-in at Scopus site) 18 CitationsAbstract
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 JAuthor
Priyanka P. Shah PhD Assistant Professor in the Neurology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultAged
Aged, 80 and over
Aphasia
Female
Humans
Language
Magnetoencephalography
Male
Middle Aged
Severity of Illness Index
Stroke
Stroke Rehabilitation
Transcranial Direct Current Stimulation