Search results for "white matter"
showing 10 items of 164 documents
Increased structural white and grey matter network connectivity compensates for functional decline in early multiple sclerosis
2016
Background: The pathology of multiple sclerosis (MS) consists of demyelination and neuronal injury, which occur early in the disease; yet, remission phases indicate repair. Whether and how the central nervous system (CNS) maintains homeostasis to counteract clinical impairment is not known. Objective: We analyse the structural connectivity of white matter (WM) and grey matter (GM) networks to understand the absence of clinical decline as the disease progresses. Methods: A total of 138 relapsing–remitting MS patients (classified into six groups by disease duration) and 32 healthy controls were investigated using 3-Tesla magnetic resonance imaging (MRI). Networks were analysed using graph the…
Association of 5′ end neuregulin-1 ( NRG1 ) gene variation with subcortical medial frontal microstructure in humans
2007
Animal data suggest that the gene neuregulin-1 (NRG1) is involved in neuronal myelination. A haplotype (deCODE) in the 5' end region of the gene was described to double the risk for schizophrenia in an Icelandic population (Stefansson, H., Sigurdsson, E., Steinthorsdottir, V., Bjornsdottir, S., Sigmundsson, T., Ghosh, S., Brynjolfsson, J., Gunnarsdottir, S., Ivarsson, O., Chou, T.T., Hjaltason, O., Birgisdottir, B., Jonsson, H., Gudnadottir, V.G., Gudmundsdottir, E., Bjornsson, A., Ingvarsson, B., Ingason, A., Sigfusson, S., Hardardottir, H., Harvey, R.P., Lai, D., Zhou, M., Brunner, D., Mutel, V., Gonzalo, A., Lemke, G., Sainz, J., Johannesson, G., Andresson, T., Gudbjartsson, D., Manolesc…
Physical Activity Predicts Population-Level Age-Related Differences in Frontal White Matter
2020
Physical activity has positive effects on brain health and cognitive function throughout the life span. Thus far, few studies have examined the effects of physical activity on white matter microstructure and psychomotor speed within the same, population-based sample (critical if conclusions are to extend to the wider population). Here, using diffusion tensor imaging and a simple reaction time task within a relatively large population-derived sample (N = 399; 18–87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), we demonstrate that physical activity mediates the effect of age on white matter integrity, measured with fractional anisotropy. Higher self-reported daily ph…
The effect of age on cognitive performance of frontal patients
2015
Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanc…
Towards a unified analysis of cerebellum maturation and aging across the entire lifespan: A MRI analysis
2021
[EN] Previous literature about the structural characterization of the human cerebellum is related to the context of a specific pathology or focused in a restricted age range. In fact, studies about the cerebellum maturation across the lifespan are scarce and most of them considered the cerebellum as a whole without investigating each lobule. This lack of study can be explained by the lack of both accurate segmentation methods and data availability. Fortunately, during the last years, several cerebellum segmenta- tion methods have been developed and many databases comprising subjects of dif- ferent ages have been made publically available. This fact opens an opportunity window to obtain a mo…
Physical Activity Predicts Population-Level Age-Related Differences in Frontal White Matter
2018
Physical activity has positive effects on brain health and cognitive function throughout the life span. Thus far, few studies have examined the effects of physical activity on white matter microstructure and psychomotor speed within the same, population-based sample (critical if conclusions are to extend to the wider population). Here, using diffusion tensor imaging and a simple reaction time task within a relatively large population-derived sample (N = 399; 18–87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), we demonstrate that physical activity mediates the effect of age on white matter integrity, measured with fractional anisotropy. Higher self-reported daily ph…
Shape analysis of the cingulum, uncinate and arcuate fasciculi in patients with bipolar disorder
2016
Background: Abnormal maturation of brain connectivity is supposed to underlie the dysfunctional emotion regulation in patients with bipolar disorder (BD). To test this hypothesis, white matter integrity is usually investigated using measures of water diffusivity provided by MRI. Here we consider a more intuitive aspect of the morphometry of the white matter tracts: the shape of the fibre bundles, which is associated with neurodevelopment. We analyzed the shape of 3 tracts involved in BD: the cingulum (CG), uncinate fasciculus (UF) and arcuate fasciculus (AF). Methods: We analyzed diffusion MRI data in patients with BD and healthy controls. The fibre bundles were reconstructed using Q-ball–b…
The grey matter correlates of impaired decision-making in multiple sclerosis.
2014
Objective: People with multiple sclerosis (MS) have difficulties with decision-making but it is unclear if this is due to changes in impulsivity, risk taking, deliberation or risk adjustment, and how this relates to brain pathology. \ud \ud Methods: We assessed these aspects of decision-making in 105 people with MS and 43 healthy controls. We used a novel diffusion MRI method, diffusion orientational complexity (DOC), as an index of grey matter pathology in regions associated with decision-making and also measured grey matter tissue volumes and white matter lesion volumes. \ud \ud Results: People with MS showed less adjustment to risk and slower decision-making than controls. Moreover, impa…
Alzheimer's disease: amyloid plaques in the cerebellum
1989
Two specific silver-staining methods demonstrating either extracellular amyloid and/or precursors of amyloid or intraneuronal neurofibrillary changes were used to examine cerebellar pathology in cases of presenile and senile dementia of the Alzheimer type, cases of Down's syndrome, and non-demented controls. The sensitivity of the techniques permitted visualization of large numbers of amyloid deposits in the cerebellar cortex of demented individuals. Similarly large numbers of amyloid deposits were not found in the cerebella of non-demented individuals. Neurofibrillary changes were absent. The majority of amyloid plaques occurred in the molecular layer. Quite a number of these displayed lar…
Evidence for early, non-lesional cerebellar damage in patients with multiple sclerosis: DTI measures correlate with disability, atrophy, and disease …
2015
Background: Common symptoms of multiple sclerosis (MS) such as gait ataxia, poor coordination of the hands, and intention tremor are usually the result of dysfunctionality in the cerebellum. Magnetic resonance imaging (MRI) has frequently failed to detect cerebellar damage in the form of inflammatory lesions in patients presenting with symptoms of cerebellar dysfunction. Objective: To detect microstructural cerebellar tissue alterations in early MS patients with a “normal appearing” cerebellum using diffusion tensor imaging (DTI). Methods: A total of 68 patients with relapsing–remitting MS (RRMS) and without cerebellar lesions and 26 age-matched healthy controls were admitted to high-resolu…