1. Intranetwork and internetwork connectivity in patients with Alzheimer disease and the association with cerebrospinal fluid biomarker levels
- Author
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Brunno Machado de Campos, Thamires Naela Cardoso Magalhães, Camila Vieira Ligo Teixeira, Marcio Luiz Figueredo Balthazar, Ana Flávia Mac Knight Carletti-Cassani, Orestes Vicente Forlenza, Raphael F. Casseb, Jéssica Elias Vicentini, Marina Weiler, and Leda Leme Talib
- Subjects
Male ,0301 basic medicine ,Oncology ,medicine.medical_specialty ,Cross-sectional study ,Rest ,Neuropsychological Tests ,Brain mapping ,03 medical and health sciences ,0302 clinical medicine ,Cerebrospinal fluid ,Alzheimer Disease ,Internal medicine ,Neural Pathways ,mental disorders ,medicine ,Humans ,Cognitive Dysfunction ,Pharmacology (medical) ,Pathological ,Biological Psychiatry ,Default mode network ,Aged ,Brain Mapping ,medicine.diagnostic_test ,business.industry ,Brain ,Magnetic resonance imaging ,medicine.disease ,Magnetic Resonance Imaging ,Pathophysiology ,Psychiatry and Mental health ,Cross-Sectional Studies ,030104 developmental biology ,Female ,Alzheimer's disease ,business ,Biomarkers ,030217 neurology & neurosurgery ,Research Paper - Abstract
Background: In the last decade, many studies have reported abnormal connectivity within the default mode network (DMN) in patients with Alzheimer disease. Few studies, however, have investigated other networks and their association with pathophysiological proteins obtained from cerebrospinal fluid (CSF). Methods: We performed 3 T imaging in patients with mild Alzheimer disease, patients with amnestic mild cognitive impairment (aMCI) and healthy controls, and we collected CSF samples from the patients with aMCI and mild Alzheimer disease. We analyzed 57 regions from 8 networks. Additionally, we performed correlation tests to investigate possible associations between the networks’ functional connectivity and the protein levels obtained from the CSF of patients with aMCI and Alzheimer disease. Results: Our sample included 41 patients with Alzheimer disease, 35 with aMCI and 48 controls. We found that the main connectivity abnormalities in those with Alzheimer disease occurred between the DMN and task-positive networks: these patients presented not only a decreased anticorrelation between some regions, but also an inversion of the correlation signal (positive correlation instead of anti-correlation). Those with aMCI did not present statistically different connectivity from patients with Alzheimer disease or controls. Abnormal levels of CSF proteins were associated with functional disconnectivity between several regions in both the aMCI and mild Alzheimer disease groups, extending well beyond the DMN or temporal areas. Limitations: The presented data are cross-sectional in nature, and our findings are dependent on the choice of seed regions used. Conclusion: We found that the main functional connectivity abnormalities occur between the DMN and task-positive networks and that the pathological levels of CSF biomarkers correlate with functional connectivity disruption in patients with Alzheimer disease.
- Published
- 2017