{"title":"Frequency-dependent and temporal variability of low-frequency fluctuations in patients with primary Sjögren's syndrome.","authors":"Chunfeng Hu, Luoyu Wang, Xiuhong Ge, Zhijiang Han, Xiaofang Zhang, Xinyun Du, Yushan Shang, Huijun Cao, Chengcheng Gao, Peiying Wei, Jiao Huang","doi":"10.1136/lupus-2025-001655","DOIUrl":null,"url":null,"abstract":"<p><strong>Objectives: </strong>The central nervous system is a significant extraglandular target in primary Sjögren's syndrome (pSS), often characterised by cognitive deficits. However, the underlying mechanisms remain elusive. This study aims to investigate the alterations in amplitude of low-frequency fluctuations (ALFF) in patients with pSS and to explore whether it exhibits frequency dependence and temporal variability, attempting to explore its mechanism.</p><p><strong>Methods: </strong>The study comprised 68 patients with pSS and 69 healthy controls, all of whom underwent resting-state functional MRI and neuropsychological assessments. The ALFF method was used to ascertain whether frequency-dependent alterations occur within the slow-5 (0.01-0.027 Hz) and slow-4 (0.027-0.073 Hz) frequency bands. Additionally, dynamic ALFF (dALFF) analysis was conducted to explore the temporal variability. Ultimately, the correlation between the abnormal brain regions and neuropsychological assessments was elucidated.</p><p><strong>Results: </strong>The right fusiform gyrus of patients with pSS shows abnormalities in ALFF and its two sub-bands, while the left precentral gyrus and right middle frontal gyrus exhibited abnormal increase limited to the slow-5 frequency band. dALFF showed an abnormal activity in the left supplementary motor area in patients with pSS. Additionally, the differential brain regions identified by the slow-5 frequency band of ALFF correlated with certain neuropsychological scales.</p><p><strong>Conclusions: </strong>This research indicates that ALFF metrics offer enhanced insights into the alterations of regional brain function in patients with pSS, which exhibits both frequency-dependent and temporal variability characteristics, complementing traditional metrics and enhancing our comprehension of brain function in pSS and suggests that ALFF may emerge as a novel instrument for exploring the underlying neural mechanisms in patients with pSS.</p>","PeriodicalId":18126,"journal":{"name":"Lupus Science & Medicine","volume":"12 2","pages":""},"PeriodicalIF":3.5000,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12443196/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Lupus Science & Medicine","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1136/lupus-2025-001655","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RHEUMATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives: The central nervous system is a significant extraglandular target in primary Sjögren's syndrome (pSS), often characterised by cognitive deficits. However, the underlying mechanisms remain elusive. This study aims to investigate the alterations in amplitude of low-frequency fluctuations (ALFF) in patients with pSS and to explore whether it exhibits frequency dependence and temporal variability, attempting to explore its mechanism.
Methods: The study comprised 68 patients with pSS and 69 healthy controls, all of whom underwent resting-state functional MRI and neuropsychological assessments. The ALFF method was used to ascertain whether frequency-dependent alterations occur within the slow-5 (0.01-0.027 Hz) and slow-4 (0.027-0.073 Hz) frequency bands. Additionally, dynamic ALFF (dALFF) analysis was conducted to explore the temporal variability. Ultimately, the correlation between the abnormal brain regions and neuropsychological assessments was elucidated.
Results: The right fusiform gyrus of patients with pSS shows abnormalities in ALFF and its two sub-bands, while the left precentral gyrus and right middle frontal gyrus exhibited abnormal increase limited to the slow-5 frequency band. dALFF showed an abnormal activity in the left supplementary motor area in patients with pSS. Additionally, the differential brain regions identified by the slow-5 frequency band of ALFF correlated with certain neuropsychological scales.
Conclusions: This research indicates that ALFF metrics offer enhanced insights into the alterations of regional brain function in patients with pSS, which exhibits both frequency-dependent and temporal variability characteristics, complementing traditional metrics and enhancing our comprehension of brain function in pSS and suggests that ALFF may emerge as a novel instrument for exploring the underlying neural mechanisms in patients with pSS.
期刊介绍:
Lupus Science & Medicine is a global, peer reviewed, open access online journal that provides a central point for publication of basic, clinical, translational, and epidemiological studies of all aspects of lupus and related diseases. It is the first lupus-specific open access journal in the world and was developed in response to the need for a barrier-free forum for publication of groundbreaking studies in lupus. The journal publishes research on lupus from fields including, but not limited to: rheumatology, dermatology, nephrology, immunology, pediatrics, cardiology, hepatology, pulmonology, obstetrics and gynecology, and psychiatry.