Wang Tao, Yan Shaozhen, Shan Yi, Xue Hanxiao, Xing Yi, Bi Sheng, Chen Zhigeng, Xi Hanyu, Qi Zhigang, Tang Yi, Lu Jie
Department of Radiology and Nuclear Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.
Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, China.
Radiology. 2025 Jun;315(3):e241463. doi: 10.1148/radiol.241463.
Background Transcranial alternating current stimulation (tACS) may be effective for improving cognitive function in Alzheimer disease (AD), but its impact on brain functional connectivity (FC) has not been well studied. Purpose To evaluate tACS efficacy in improving cognitive performance and modulating FC between brain regions in individuals with AD using functional MRI. Materials and Methods In this prospective randomized controlled trial (September 2020 to April 2022), participants with mild AD were assigned to active (40 Hz tACS with 15-mA intensity) or sham (no γ frequency or current) tACS groups for 3 weeks (referred to as week 3), with a 3-month follow-up (referred to as month 3). Functional MRI and cognitive testing were performed at baseline, week 3, and month 3. Primary outcomes were changes in Mini-Mental State Examination and Montreal Cognitive Assessment scores from baseline to week 3. Secondary outcomes included FC changes within multiple cortical networks and between cortex and hippocampus from baseline to week 3 and month 3, assessed using Fisher -transformed correlation coefficient (hereafter, score). Results Forty-six participants were randomized into the active group ( = 23; median age, 66 years; IQR, 62-69 years; 16 female participants) or the sham group ( = 23; mean age, 64 years; IQR, 61-69 years; 14 female participants). The active group had higher Mini-Mental State Examination (median score change, 2 [IQR, 1-5] vs 0 [IQR, -1 to 2]; = .001) and Montreal Cognitive Assessment (median score change, 2 [IQR, 0-4] vs 0 [IQR, -1 to 2]; = .03) scores than the sham group at week 3, respectively. Compared with the sham group, the active group had increased FC between left hippocampus and left middle cingulate gyrus ( score difference, 0.29; 95% CI: 0.17, 0.42; false discovery rate [FDR]-adjusted < .001) and between the left hippocampus and the left middle frontal gyrus ( score difference, 0.16; 95% CI: 0.03, 0.29; FDR-adjusted = .04) within the posterior default-mode network ( score difference, 0.40; 95% CI: 0.07, 0.73; FDR-adjusted = .046) and within the visual network ( score difference, 0.45; 95% CI: 0.17, 0.73; FDR-adjusted = .007) from baseline to week 3. Conclusion Cognitive performance in mild AD improved following tACS, with increased FC within cortical networks and between the hippocampus and specific cortical regions. ClinicalTrials.gov Identifier: NCT03920826 © RSNA, 2025 See also the editorial by Shepherd in this issue.
背景 经颅交流电刺激（tACS）可能对改善阿尔茨海默病（AD）的认知功能有效，但其对脑功能连接（FC）的影响尚未得到充分研究。目的 使用功能磁共振成像评估tACS对改善AD患者认知表现及调节脑区之间FC的疗效。材料与方法 在这项前瞻性随机对照试验（2020年9月至2022年4月）中，轻度AD患者被分配到主动治疗组（40Hz、强度15mA的tACS）或假刺激组（无γ频率或电流），为期3周（称为第3周），并进行3个月的随访（称为第3个月）。在基线、第3周和第3个月进行功能磁共振成像和认知测试。主要结局是从基线到第3周简易精神状态检查表和蒙特利尔认知评估得分的变化。次要结局包括从基线到第3周和第3个月多个皮质网络内以及皮质与海马之间FC的变化，使用Fisher变换相关系数（以下简称 得分）进行评估。结果 46名参与者被随机分为主动治疗组（n = 23；中位年龄66岁；四分位数间距，62 - 69岁；16名女性参与者）或假刺激组（n = 23；平均年龄64岁；四分位数间距，61 - 69岁；14名女性参与者）。在第3周时，主动治疗组的简易精神状态检查表（中位得分变化，2[四分位数间距，1 - 5]对0[四分位数间距， - 1至2]；P = .001）和蒙特利尔认知评估（中位得分变化，2[四分位数间距，0 - 4]对0[四分位数间距， - 1至2]；P = .03）得分分别高于假刺激组。与假刺激组相比，主动治疗组在基线到第3周期间，后默认模式网络内（得分差异，0.40；95%置信区间：0.07，0.73；错误发现率[FDR]校正P = .046）以及视觉网络内（得分差异，0.45；95%置信区间：0.17，0.73；FDR校正P = .007），左侧海马与左侧中央扣带回之间（得分差异，0.29；
