AUTHOR=Chang Won Kee , Park Jihong , Lee Ji-Young , Cho Sungmin , Lee Jongseung , Kim Won-Seok , Paik Nam-Jong 

TITLE=Functional Network Changes After High-Frequency rTMS Over the Most Activated Speech-Related Area Combined With Speech Therapy in Chronic Stroke With Non-fluent Aphasia

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.690048

DOI=10.3389/fneur.2022.690048

ISSN=1664-2295

ABSTRACT=Objective: High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) to the lesional hemisphere requires prudence in selecting the appropriate stimulation spot. Functional near-infrared spectroscopy (fNIRS) can be used in both selecting the stimulation spot and assessing the changes of brain network. This study aimed to evaluate the effect of HF-rTMS on the most activated spot identified with fNIRS and assess the changes of brain functional network in the post-stroke aphasia patients.

Methods: Five patients received HF-rTMS to the most activated area on the lesional hemisphere, followed by 30 minutes of speech therapy for 10 days. Korean Western aphasia battery (K-WAB) and fNIRS evaluation were done one day before the treatment, one day and one month after the last treatment session. Changes of K-WAB and paired cortical interaction and brain network analysis using graph theory were assessed.

Results: Aphasia quotient in K-WAB significantly increased after the treatment (P=0.043). The correlation analysis of cortical interactions showed increased connectivity between language production and processing areas. Clustering coefficients of the left hemisphere were increased over a sparsity range between 0.45–0.58 (0.015 < p < 0.031), whereas the clustering coefficients of the right hemisphere, decreased over a sparsity range 0.15–0.87 (0.063 < p < 0.095). The global efficiency became lower over a network sparsity range between 0.47–0.75 (0.015 < p < 0.063).

Conclusions: Improvement of language function and changes of cortico-cortical interaction between language-related cortical areas were observed after HF-rTMS on the most activated area identified by fNIRS with combined speech therapy in the post-stroke aphasia patients.