Search results for "White matter"
showing 10 items of 164 documents
Gray matter alteration in dyslexia: converging evidence from volumetric and voxel-by-voxel MRI analyses.
2004
Affecting up to 4-10% of the population, dyslexia is a highly prevalent, childhood onset developmental disorder adversely influencing multiple domains of adaptive functioning throughout the lifespan. The present brain imaging study was conducted in order to investigate the neuroanatomical correlates of developmental dyslexia. The MRI brain scans of 10 males with dyslexia and 14 matched controls were analyzed with (1) a classical volumetric method measuring gray and white matter lobar volumes and (2) a voxel-by-voxel method. The voxel-by-voxel method identifies changes in tissue density and localizes morphologic alterations without limiting the analyses to predefined regions. Subsequent corr…
Broad disruption of brain white matter microstructure and relationship with neuropsychological performance in male patients with severe alcohol depen…
2012
Aims In the last years, refined magnetic resonance diffusion tensor imaging (DTI) methods have become available to study microstructural alterations in the human brain. We investigated to what extent white matter tissue abnormalities are present in male patients after chronic, excessive alcohol consumption and if these alterations are correlated with measures of alcohol consumption and neuropsychological performance. Methods Twenty-four detoxified adult male patients with severe alcohol dependence and 23 healthy male control subjects were included in the study. Neuropsychological tests were assessed for executive function, attention, memory and visuospatial function. DTI was acquired and pr…
Disruption of White Matter Integrity in Bipolar Depression as a Possible Structural Marker of Illness
2011
Background: Diffusion tensor imaging allows the study of integrity of white matter (WM) tracts. Literature suggests that WM integrity could be altered in bipolar disorder. Heterogeneity of brain imaging methods, the studied samples, and drug treatments make localization, nature, and severity of the WM abnormalities unclear. Methods: We applied tract-based spatial statistics of diffusion tensor imaging measures to compare fractional anisotropy (FA), mean, and radial diffusivity of the WM skeleton in a group of 40 consecutively admitted inpatients affected by a major depressive episode without psychotic features with a diagnosis of bipolar disorder type I and 21 unrelated healthy volunteers f…
Dysfunctional decision-making related to white matter alterations in bipolar I disorder.
2015
Abstract Objective This study investigated how frontal white matter (WM) alterations in patients with bipolar I disorder (BD-I) are linked to motivational dysregulation, often reported in the form of risk-taking and impulsivity, and whether structure–function relations in patients might differ from healthy subjects (HC). Method We acquired diffusion data from 24 euthymic BD-I patients and 24 controls, to evaluate WM integrity of selected frontal tracts. Risk-taking was assessed by the Cambridge Gambling Task and impulsivity by self-report with the Barratt-Impulsiveness Scale. Results BD-I patients displayed significantly lower integrity in the right cingulum compared to HC. They also showed…
Impaired anatomical connectivity and related executive functions: differentiating vulnerability and disease marker in bipolar disorder.
2012
Background Bipolar 1 disorder (BD1) has been associated with impaired set shifting, increased risk taking, and impaired integrity of frontolimbic white matter. However, it remains unknown to what extent these findings are related to each other and whether these abnormalities represent risk factors or consequences of the illness. Methods We addressed the first question by comparing 19 patients with BD1 and 19 healthy control subjects (sample 1) with diffusion tensor imaging, the Intra-Extra Dimensional Set Shift Task, and the Cambridge Gambling Task. The second question we approached by applying the same protocol to 22 healthy first-degree relatives of patients with BD1 and 22 persons withou…
Spectroscopic axonal damage of the right locus coeruleus relates to selective attention impairment in early stage relapsing-remitting multiple sclero…
2003
Summary Lower levels of N-acetylaspartate (NAA), a marker of axonal damage, have been found in the normal-appearing white matter (NAWM) of relapsing-remitting multiple sclerosis (RRMS) patients with low physical disability. However, its relation to the clinical status of these patients remains unclear. We explored the association between NAA levels [normalized to creatine (Cr), NAA/Cr] and a cognitive feature that is not measured by the standard scales that address functional disability [e.g. Expanded Disability Scale Score (EDSS)] in early RRMS. Given that a considerable number of RRMS patients present attentional dysfunction early in the disease and assuming a functional-anatomical orient…
Early imaging predicts later cognitive impairment in primary progressive multiple sclerosis
2010
Background: Cognitive impairment in primary progressive multiple sclerosis (PPMS) is common and correlates modestly with contemporary lesion burden and brain volume. Using a cohort/case control methodology, we explore the ability of MRI abnormalities, including those in the normal-appearing brain tissue, to predict future cognitive dysfunction in PPMS. Methods: Thirty-one patients recruited into a longitudinal study within 5 years of onset of PPMS were assessed neuropsychologically on average 5.5 years later along with 31 matched healthy controls. MRI data obtained at entry into the study (lesion metrics, brain volumes, magnetization transfer ratio histogram metrics, and magnetic resonance …
Multiple sclerosis: prevalence of the ‘central vein’ sign in white matter lesions on gadolinium-enhanced susceptibility-weighted images
2021
Aims To evaluate prospectively whether an intravenous gadolinium injection could improve the detection of the central vein sign on susceptibility-weighted imaging sequences obtained with a 1.5 T magnetic resonance scanner in patients with multiple sclerosis compared to unenhanced susceptibility-weighted images. Materials and methods This prospective, institution review board-approved study included 19 patients affected by multiple sclerosis (six men; 13 women; mean age 40.8 years, range 20–74 years). Patients had the relapsing–remitting clinical subtype in 95% of cases, and only one (5%) patient had the primary progressive clinical subtype of multiple sclerosis. T2-weighted images, fluid-at…
Correlation between fatigue and brain atrophy and lesion load in multiple sclerosis patients independent of disability.
2007
Abstract Background Fatigue is a major problem in multiple sclerosis (MS), and its association with MRI features is debated. Objective To study the correlation between fatigue and lesion load, white matter (WM), and grey matter (GM), in MS patients independent of disability. Methods We studied 222 relapsing remitting MS patients with low disability (scores ≤ 2 at the Kurtzke Expanded Disability Status Scale). Lesion load, WM and GM were measured by fully automated, operator-independent, multi-parametric segmentation method. T1 and T2 lesion volume were also measured by a semi-automated method. Fatigue was assessed by the Fatigue Severity Scale (FSS), and patients divided in high-fatigue (FS…
Disturbed structural connectivity is related to inattention and impulsivity in adult attention deficit hyperactivity disorder
2010
Inattention and impulsivity are the most prominent clinical features of attention deficit hyperactivity disorder (ADHD) in adulthood. Structural and functional neuroimaging studies of subjects with ADHD have demonstrated abnormalities in several brain areas, including fronto-striatal and fronto-cerebellar networks. Mostly, these studies were based on volumetric measurements and have been conducted in children. We investigated white matter (WM) integrity and correlation with measures of attention and impulsivity in adult patients with ADHD adopting diffusion tensor imaging (DTI). N = 37 (21 males) never-medicated adult patients with ADHD combined subtype and N = 34 (16 males) healthy control…