Hippocampal subfield involvement in patients with transient global amnesia.

Background And Purpose: Transient global amnesia (TGA) is a rare neurological disorder causing a transient disturbance of episodic long-term memory. Its etiology remains yet to be identified; the only consistently reported findings in patients with TGA are small hyperintense lesions in the hippocampus on diffusion-weighted magnetic resonance imaging (DWI). The aim of this study was to define whether these lesions are subfield specific, as suggested previously.

Association of iron rim lesions with brain and cervical cord volume in relapsing multiple sclerosis.

Objectives: In multiple sclerosis (MS), iron rim lesions (IRLs) are indicators of chronic low-grade inflammation and ongoing tissue destruction. The aim of this study was to assess the relationship of IRLs with clinical measures and magnetic resonance imaging (MRI) markers, in particular brain and cervical cord volume.

Methods: Clinical and MRI parameters from 102 relapsing MS patients (no relapses for at least 6 months, no contrast-enhancing lesions) were included; follow-up data obtained after 12 months was available in 49 patients.

MRI topography of lesions related to internuclear ophthalmoplegia in patients with multiple sclerosis or ischemic stroke.

Background And Purpose: Internuclear ophthalmoplegia is a dysfunction of conjugate eye movements, caused by lesions affecting the medial longitudinal fasciculus (MLF). Multiple sclerosis (MS) and ischemic stroke represent the most common pathophysiologies. While magnetic resonance imaging (MRI) allows for localizing lesions affecting the MLF, comprehensive comparative studies exploring potential different spatial characteristics of lesions affecting the MLF are missing until now.

Diffusely appearing white matter in multiple sclerosis: Insights from sodium (Na) MRI.

Background: In multiple sclerosis (MS), magnetic resonance imaging (MRI) frequently shows ill-defined areas with intermediate signal intensity between the normal appearing white matter (NAWM) and focal T2-hyperintense lesions, termed "diffusely appearing white matter" (DAWM). Even though several advanced MRI techniques have shown the potential to detect and quantify subtle commonly not visible microscopic tissue changes, to date only a few advanced MRI studies investigated DAWM changes in a quantitative manner. The aim of this study was to detect and quantify tissue abnormalities in the DAWM in comparison to focal lesions and the NAWM in MS patients by sodium (Na) MRI.

Resting-state connectivity alterations during transient global amnesia.

While the pathophysiology of transient global amnesia (TGA) is not understood, due to the specific nature of the clinical deficits, transient dysfunction in the medial temporal lobe, especially in the hippocampus, is assumed; however, concomitant disturbances in other brain regions and in executive function have been postulated. In this study, a cohort of 16 patients was prospectively recruited from the emergency department for resting-state functional MRI (fMRI) during the acute stage of TGA, as confirmed by a standardized neuropsychological assessment. Twenty age- and sex-matched controls, as well as twenty patients with a history of TGA, were recruited for comparison.

Temporal evolution of acute multiple sclerosis lesions on serial sodium (Na) MRI.

Background: Several studies have reported the characteristics of acute multiple sclerosis (MS) lesions on diffusion-weighted magnetic resonance imaging (DWI MRI). Current publications reported a transient reduction of the apparent diffusion coefficient (ADC) delineating an early phase of lesion evolution, before increased diffusion occurs in parallel to blood-brain-barrier (BBB) breakdown. Sodium MRI might provide another perspective on lesion development, but clinical applications have been limited to high field MR systems.

Arterial Spin Labeling Cerebral Perfusion Magnetic Resonance Imaging in Migraine Aura: An Observational Study.

Background: Changes in cerebral perfusion during migraine with aura (MA) have been assessed mainly using dynamic susceptibility contrast (DSC) magnetic resonance perfusion imaging. A contrast agent-free method to assess these changes would be desirable. We assessed changes in cerebral perfusion during MA using arterial spin labeling (ASL) perfusion magnetic resonance imaging.

Heterogeneity of acute multiple sclerosis lesions on sodium (23Na) MRI.

Background: Advanced magnetic resonance imaging (MRI) techniques provide a window into pathological processes in multiple sclerosis (MS). Nevertheless, to date only few studies have performed sodium MRI in MS.

Objectives: We analysed total sodium concentration (TSC) in hyperacute, acute and chronic lesions in MS with (23)Na MRI.

Clinical and MRI patterns of pericallosal artery infarctions: the significance of supplementary motor area lesions.

Cerebral infarctions in the anterior cerebral artery (ACA) territory account for only up to 3-5% of strokes. Subject to the affected ACA branches, different clinical patterns can be defined. We report a case series of patients with isolated infarctions of the pericallosal (PC) artery territory.

Loss of callosal fibre integrity in healthy elderly with age-related white matter changes.

Age-related white matter changes (ARWMC) appear to correspond to a continuum from normal functioning to clinically overt neurological syndromes. Disturbance of the structural integrity of cerebral fibre tracts-the so-called cerebral network-by ARWMC might be one explanation for this development. From 3 T magnetic resonance imaging (MRI) data of 34 healthy elderly subjects (60-82 years) we calculated the lesion volume of ARWMC and the area of the corpus callosum (CC).

Deviations from the diffusion tensor model as revealed by contour plot visualization using high angular resolution diffusion-weighted imaging (HARDI).

The standard diffusion tensor model is limited in its ability to provide detailed information about multidirectional fiber architecture in human white matter. Additional directional acquisition of diffusivity properties with high angular resolution diffusion-weighted imaging (HARDI) acquisition schemes may deliver more information on areas with fiber crossings than standard DTI. However, representation of the additional information and the rating and visualization of fiber complexity is challenging.