Background: Cortical, thalamic and hippocampal gray matter atrophy in relapsing-remitting MS (RRMS) is associated cognitive deficits. However, the role of interconnecting white matter pathways including the fornix, cingulum, and uncinate fasciculus (UF) is less well studied.
Objective: To assess MS damage to a hippocampal-thalamic-prefrontal network and the relative contributions of its components to specific cognitive domains.
Methods: We calculated diffusion tensor fractional anisotropy (FA) in the fornix, cingulum and UF as well as thalamic and hippocampal volumes in 27 RRMS patients and 20 healthy controls. A neuropsychological battery was administered and 4 core tests known to be sensitive to MS changes were used to assess cognitive impairment. To determine the relationships between structure and cognition, all tests were grouped into 4 domains: attention/executive function, processing speed, verbal memory, and spatial memory. Univariate correlations with structural measures and depressive symptoms identified potential contributors to cognitive performance and subsequent linear regression determined their relative effects on performance in each domain. For significant predictors, we also explored the effects of laterality and axial versus radial diffusivity.
Results: RRMS patients had worse performance on the Symbol Digit Modalities Test, but no significant impairment in the 4 cognitive domains. RRMS had reduced mean FA of all 3 pathways and reduced thalamic and hippocampal volumes compared to controls. In RRMS we found that thalamic volume and BDI predicted attention/executive function, UF FA predicted processing speed, thalamic volume predicted verbal memory, and UF FA and BDI predicted spatial memory.
Conclusions: Hippocampal-thalamic-prefrontal disruption affects cognitive performance in early RRMS with mild to minimal cognitive impairment, confirming both white and gray matter involvement in MS and demonstrating utility in assessing functional networks to monitor cognition.
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http://dx.doi.org/10.1016/j.nicl.2014.12.015 | DOI Listing |
Sleep Adv
December 2024
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Study Objectives: Sleep spindles, defining electroencephalographic oscillations of nonrapid eye movement (NREM) stage 2 sleep (N2), mediate sleep-dependent memory consolidation (SDMC). Spindles are also thought to protect sleep continuity by suppressing thalamocortical sensory relay. Schizophrenia is characterized by spindle deficits and a correlated reduction of SDMC.
View Article and Find Full Text PDFEur J Neurol
January 2025
Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.
Background: Temporal lobe epilepsy (TLE) can lead to structural brain abnormalities, with thalamus atrophy being the most common extratemporal alteration. This study used probabilistic tractography to investigate the structural connectivity between individual thalamic nuclei and the hippocampus in TLE.
Methods: Thirty-six TLE patients who underwent pre-surgical 3 Tesla magnetic resonance imaging (MRI) and 18 healthy controls were enrolled in this study.
Theranostics
January 2025
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, 27599, USA.
Alzheimer's Disease (AD) is the most common form of dementia and one of the leading causes of death. AD is known to be correlated to tortuosity in the microvasculature as well as decreases in blood flow throughout the brain. However, the mechanisms behind these changes and their causal relation to AD are poorly understood.
View Article and Find Full Text PDFNat Neurosci
January 2025
Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
Brain-resident macrophages, microglia, have been proposed to have an active role in synaptic refinement and maturation, influencing plasticity and circuit-level connectivity. Here we show that several neurodevelopmental processes previously attributed to microglia can proceed without them. Using a genetically modified mouse that lacks microglia (Csf1r), we find that intrinsic properties, synapse number and synaptic maturation are largely normal in the hippocampal CA1 region and somatosensory cortex at stages where microglia have been implicated.
View Article and Find Full Text PDFSleep Med
January 2025
Department of Radiology, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University Nanchang, 330006, China; Intelligent Medical Imaging of Jiangxi Key Laboratory, 330006, Nanchang, China; School of Biomedical Engineering, National Graduate College for Engineers, Tsinghua University, 100084, Beijing, China. Electronic address:
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