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919 results on '"Rombouts, Serge"'

6. Clusterwise Independent Component Analysis (C-ICA):An R package for clustering subjects based on ICA patterns underlying three-way (brain) data

Author

Durieux, Jeffrey, Rombouts, Serge A. R. B., Koini, Marisa, Claramunt Gonzalez, Juan, Wilderjans, Tom F., Durieux, Jeffrey, Rombouts, Serge A. R. B., Koini, Marisa, Claramunt Gonzalez, Juan, and Wilderjans, Tom F.

Abstract

In many areas of science, like neuroscience, genomics and text mining, several important and challenging research questions imply the study of (subject) heterogeneity present in three-way data. In clinical neuroscience, for example, disclosing differences or heterogeneity between subjects in resting state networks (RSNs) underlying multi-subject fMRI data (i.e., time by voxel by subject three-way data) may advance the subtyping of psychiatric and mental diseases. Recently, the Clusterwise Independent Component Analysis (C-ICA) method was proposed that enables the disclosure of heterogeneity between subjects in RSNs that is present in multi-subject rs-fMRI data [1]. Up to now, however, no publicly available software exists that allows to fit C-ICA to empirical data at hand. The goal of this paper, therefore, is to present the CICA R package, which contains the necessary functions to estimate the C-ICA parameters and to interpret and visualize the analysis output. Further, the package also includes functions to select suitable initial values for the C-ICA model parameters and to determine the optimal number of clusters and components for a given empirical data set (i.e., model selection). The use of the main functions of the package is discussed and demonstrated with simulated data. Herewith, the necessary analytical choices that have to be made by the user (e.g., starting values) are explained and showed step by step. The rich functionality of the package is further illustrated by applying C-ICA to empirical rs-fMRI data from a group of Alzheimer patients and elderly control subjects and to multi-country stock market data. Finally, extensions regarding the C-ICA algorithm and procedures for model selection that could be implemented in future releases of the package are discussed.

Published
2024

10. Neurovascular coupling in early stage dementia – A case-control study.

Author

van Dijk, Suzanne E, Drenth, Nadieh, Hafkemeijer, Anne, Labadie, Gerda, Witjes-Ané, Marie-Noëlle W, Blauw, Gerard J, Rombouts, Serge ARB, van der Grond, Jeroen, and van Rooden, Sanneke

Abstract

Cerebral amyloid angiopathy (CAA) is frequently found post mortem in Alzheimer's dementia, but often undetected during life especially since in vivo hallmarks of CAA and its vascular damage become overt relatively late in the disease process. Decreased neurovascular coupling to visual stimulation has been put forward as an early MRI marker for CAA disease severity. The current study investigates the role of neurovascular coupling in AD related dementia and its early stages. We included 25 subjective cognitive impairment, 33 mild cognitive impairment and 17 dementia patients and 44 controls. All participants underwent magnetic resonance imaging of the brain and neuropsychological assessment. Univariate general linear modeling analyses were used to assess neurovascular coupling between patient groups and controls. Moreover, linear regression analyses was used to assess the associations between neurovascular coupling and cognition. Our data show that BOLD amplitude is lower in dementia (mean 0.8 ± 0.2, p = 0.001) and MCI patients (mean 0.9 ± 0.3, p = 0.004) compared with controls (mean 1.1 ± 0.2). A low BOLD amplitude was associated with low scores in multiple cognitive domains. We conclude that cerebrovascular dysfunction, most likely due CAA, is an important comorbidity in early stages of dementia and has an independent effect on cognition. [ABSTRACT FROM AUTHOR]

Published
2024
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14. Structural and functional brain connectivity in presymptomatic familial frontotemporal dementia

Author

Dopper, Elise GP, Rombouts, Serge ARB, Jiskoot, Lize C, Heijer, Tom den, de Graaf, J Roos A, de Koning, Inge, Hammerschlag, Anke R, Seelaar, Harro, Seeley, William W, Veer, Ilya M, van Buchem, Mark A, Rizzu, Patrizia, and van Swieten, John C

Subjects
Alzheimer's Disease, Aging, Dementia, Neurodegenerative, Rare Diseases, Biomedical Imaging, Prevention, Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD), Acquired Cognitive Impairment, Brain Disorders, Neurosciences, Frontotemporal Dementia (FTD), Clinical Research, Neurological, Adult, Aged, Brain Chemistry, Case-Control Studies, Female, Frontal Lobe, Frontotemporal Dementia, Genetic Predisposition to Disease, Humans, Male, Middle Aged, Mutation, Nerve Net, Risk, Structure-Activity Relationship, Clinical Sciences, Cognitive Sciences, Neurology & Neurosurgery
Abstract

ObjectiveWe aimed to investigate whether cognitive deficits and structural and functional connectivity changes can be detected before symptom onset in a large cohort of carriers of microtubule-associated protein tau and progranulin mutations.MethodsIn this case-control study, 75 healthy individuals (aged 20-70 years) with 50% risk for frontotemporal dementia (FTD) underwent DNA screening, neuropsychological assessment, and structural and functional MRI. We used voxel-based morphometry and tract-based spatial statistics for voxelwise analyses of gray matter volume and diffusion tensor imaging measures. Using resting-state fMRI scans, we assessed whole-brain functional connectivity to frontoinsula, anterior midcingulate cortex (aMCC), and posterior cingulate cortex.ResultsAlthough carriers (n = 37) and noncarriers (n = 38) had similar neuropsychological performance, worse performance on Stroop III, Ekman faces, and Happé cartoons correlated with higher age in carriers, but not controls. Reduced fractional anisotropy and increased radial diffusivity throughout frontotemporal white matter tracts were found in carriers and correlated with higher age. Reductions in functional aMCC connectivity were found in carriers compared with controls, and connectivity between frontoinsula and aMCC seeds and several brain regions significantly decreased with higher age in carriers but not controls. We found no significant differences or age correlations in posterior cingulate cortex connectivity. No differences in regional gray matter volume were found.ConclusionsThis study convincingly demonstrates that alterations in structural and functional connectivity develop before the first symptoms of FTD arise. These findings suggest that diffusion tensor imaging and resting-state fMRI may have the potential to become sensitive biomarkers for early FTD in future clinical trials.

Published
2013

36. Presymptomatic cognitive and neuroanatomical changes in genetic frontotemporal dementia in the Genetic Frontotemporal dementia Initiative (GENFI) study: a cross-sectional analysis

Author

Rohrer, Jonathan D, Nicholas, Jennifer M, Cash, David M, van Swieten, John, Dopper, Elise, Jiskoot, Lize, van Minkelen, Rick, Rombouts, Serge A, Cardoso, M Jorge, Clegg, Shona, Espak, Miklos, Mead, Simon, Thomas, David L, De Vita, Enrico, Masellis, Mario, Black, Sandra E, Freedman, Morris, Keren, Ron, MacIntosh, Bradley J, Rogaeva, Ekaterina, Tang-Wai, David, Tartaglia, Maria Carmela, Laforce, Robert, Jr, Tagliavini, Fabrizio, Tiraboschi, Pietro, Redaelli, Veronica, Prioni, Sara, Grisoli, Marina, Borroni, Barbara, Padovani, Alessandro, Galimberti, Daniela, Scarpini, Elio, Arighi, Andrea, Fumagalli, Giorgio, Rowe, James B, Coyle-Gilchrist, Ian, Graff, Caroline, Fallström, Marie, Jelic, Vesna, Ståhlbom, Anne Kinhult, Andersson, Christin, Thonberg, Håkan, Lilius, Lena, Frisoni, Giovanni B, Binetti, Giuliano, Pievani, Michela, Bocchetta, Martina, Benussi, Luisa, Ghidoni, Roberta, Finger, Elizabeth, Sorbi, Sandro, Nacmias, Benedetta, Lombardi, Gemma, Polito, Cristina, Warren, Jason D, Ourselin, Sebastien, Fox, Nick C, and Rossor, Martin N

Published
2015
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46. Developmental Differences in Prefrontal Activation during Working Memory Maintenance and Manipulation for Different Memory Loads

Author

Jolles, Dietsje D., Kleibeuker, Sietske W., and Rombouts, Serge A. R. B.

Abstract

The ability to keep information active in working memory is one of the cornerstones of cognitive development. Prior studies have demonstrated that regions which are important for working memory performance in adults, such as dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), and superior parietal cortex, become increasingly engaged across school-aged development. The primary goal of the present functional MRI study was to investigate the involvement of these regions in the development of working memory manipulation relative to maintenance functions under different loads. We measured activation in DLPFC, VLPFC, and superior parietal cortex during the delay period of a verbal working memory task in 11-13-year-old children and young adults. We found evidence for age-related behavioral improvements in working memory and functional changes within DLPFC and VLPFC activation patterns. Although activation profiles of DLPFC and VLPFC were similar, group differences were most pronounced for right DLPFC. Consistent with prior studies, right DLPFC showed an interaction between age and condition (i.e. manipulation versus maintenance), specifically at the lower loads. This interaction was characterized by increased activation for manipulation relative to maintenance trials in adults compared to children. In contrast, we did not observe a significant age-dependent load sensitivity. These results suggest that age-related differences in the right DLPFC are specific to working memory manipulation and are not related to task difficulty and/or differences in short-term memory capacity.

Published
2011
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47. Longitudinal Brain Atrophy Rates in Presymptomatic Carriers of Genetic Frontotemporal Dementia

Author

Poos, Jackie M., primary, Grandpierre, Leonie D. M., additional, van der Ende, Emma L., additional, Panman, Jessica L., additional, Papma, Janne M., additional, Seelaar, Harro, additional, van den Berg, Esther, additional, van 't Klooster, Ronald, additional, Bron, Esther, additional, Steketee, Rebecca, additional, Vernooij, Meike W., additional, Pijnenburg, Yolande A. L., additional, Rombouts, Serge A. R. B., additional, van Swieten, John, additional, and Jiskoot, Lize C., additional

Published
2022
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