Altered Neuronal Activity Patterns of the Prefrontal Cortex in Alzheimer’s Disease After Transcranial Alternating Current Stimulation: A Resting-State fMRI Study

Article type: Research Article

Authors: Wang, Tao^{a; b; c; 1} | Yan, Shaozhen^{a; b; c; 1} | Shan, Yi^{a; b; c} | Xing, Yi^d | Bi, Sheng^{a; b; c} | Chen, Zhigeng^{a; b; c} | Xi, Hanyu^{a; b; c} | Xue, Hanxiao^{a; b; c} | Qi, Zhigang^{a; b; c} | Tang, Yi^{d; *} | Lu, Jie^{a; b; c; *}

Affiliations: [a] Department of Radiology and Nuclear Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China | [b] Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, China | [c] Key Laboratory of Neurodegenerative Diseases, Ministry of Education, Beijing, China | [d] Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China

Correspondence: [*] Correspondence to: Yi Tang, PhD, Department of Neurology and Innovation Center for Neurological Disorders, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Beijing 100053, China. E-mail: tangyi@xwhosp.org and Jie Lu, PhD, Department of Radiology and Nuclear Medicine, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Beijing 100053, China. E-mail: imaginglu@hotmail.com.

Note: [1] These authors contributed equally to this work.

Abstract: Background:Transcranial alternating current stimulation (tACS) could improve cognition in patients with Alzheimer’s disease (AD). However, the effects of tACS on brain activity remain unclear. Objective:The purpose is to investigate the change in regional neuronal activity after tACS in AD patients employing resting-state functional magnetic resonance imaging (rs-fMRI). Methods:A total of 46 patients with mild AD were enrolled. Each patient received 30 one-hour sessions of real or sham tACS for three weeks (clinical trial: NCT03920826). The fractional amplitude of low-frequency fluctuations (fALFF) and the regional homogeneity (ReHo) measured by rs-fMRI were calculated to evaluate the regional brain activity. Results:Compared to baseline, AD patients in the real group exhibited increased fALFF in the left middle frontal gyrus-orbital part and right inferior frontal gyrus-orbital part, as well as increased ReHo in the left precentral gyrus and right middle frontal gyrus at the end of intervention. At the 3-month follow-up, fALFF increased in the left superior parietal lobule and right inferior temporal gyrus, as well as ReHo, in the left middle frontal gyrus and right superior medial frontal gyrus. A higher fALFF in the right lingual gyrus and ReHo in the right parahippocampal gyrus were observed in the response group than in the nonresponse group. Conclusions:The findings demonstrated the beneficial effects of tACS on the neuronal activity of the prefrontal cortex and even more extensive regions and provided a neuroimaging biomarker of treatment response in AD patients.

Keywords: Alzheimer’s disease, functional magnetic resonance imaging, transcranial alternating current stimulation

DOI: 10.3233/JAD-240400

Journal: Journal of Alzheimer's Disease, vol. 101, no. 3, pp. 901-912, 2024