MRI-based prediction of conversion from clinically isolated syndrome to clinically definite multiple sclerosis using SVM and lesion geometry.

Neuroanatomical pattern classification using support vector machines (SVMs) has shown promising results in classifying Multiple Sclerosis (MS) patients based on individual structural magnetic resonance images (MRI). To determine whether pattern classification using SVMs facilitates predicting conversion to clinically definite multiple sclerosis (CDMS) from clinically isolated syndrome (CIS). We used baseline MRI data from 364 patients with CIS, randomised to interferon beta-1b or placebo.

Urgent challenges in quantification and interpretation of brain grey matter atrophy in individual MS patients using MRI.

Atrophy of the brain grey matter (GM) is an accepted and important feature of multiple sclerosis (MS). However, its accurate measurement is hampered by various technical, pathological and physiological factors. As a consequence, it is challenging to investigate the role of GM atrophy in the disease process as well as the effect of treatments that aim to reduce neurodegeneration.

Hippocampal volume in subjects at clinical high-risk for psychosis: A systematic review and meta-analysis.

Several magnetic resonance imaging studies have reported reductions in hippocampal volume in patients with psychosis. It is unclear whether structural abnormalities predate illness onset. We conducted a detailed, systematic literature search for studies reporting hippocampal volume in subjects with clinical high-risk, compared to healthy controls.

Alterations in the hippocampus and thalamus in individuals at high risk for psychosis.

Reduction in hippocampal volume is a hallmark of schizophrenia and already present in the clinical high-risk state. Nevertheless, other subcortical structures, such as the thalamus, amygdala and pallidum can differentiate schizophrenia patients from controls. We studied the role of hippocampal and subcortical structures in clinical high-risk individuals from two cohorts.

Classifying individuals at high-risk for psychosis based on functional brain activity during working memory processing.

The psychosis high-risk state is accompanied by alterations in functional brain activity during working memory processing. We used binary automatic pattern-classification to discriminate between the at-risk mental state (ARMS), first episode psychosis (FEP) and healthy controls (HCs) based on n-back WM-induced brain activity. Linear support vector machines and leave-one-out-cross-validation were applied to fMRI data of matched ARMS, FEP and HC (19 subjects/group).

Age of second language acquisition in multilinguals has an impact on gray matter volume in language-associated brain areas.

Numerous structural studies have established that experience shapes and reshapes the brain throughout a lifetime. The impact of early development, however, is still a matter of debate. Further clues may come from studying multilinguals who acquired their second language at different ages.

Modulation of motivational salience processing during the early stages of psychosis.

Background: Deficits in motivational salience processing have been related to psychotic symptoms and disturbances in dopaminergic neurotransmission. We aimed at exploring changes in salience processing and brain activity during different stages of psychosis and antipsychotic medication effect.

Methods: We used fMRI during the Salience Attribution Task to investigate hemodynamic differences between 19 healthy controls (HCs), 34 at-risk mental state (ARMS) individuals and 29 individuals with first-episode psychosis (FEP), including a subgroup of 17 FEP without antipsychotic medication (FEP-UM) and 12 FEP with antipsychotic medication (FEP-M).

Subcortical brain segmentation of two dimensional T1-weighted data sets with FMRIB's Integrated Registration and Segmentation Tool (FIRST).

Brain atrophy has been identified as an important contributing factor to the development of disability in multiple sclerosis (MS). In this respect, more and more interest is focussing on the role of deep grey matter (DGM) areas. Novel data analysis pipelines are available for the automatic segmentation of DGM using three-dimensional (3D) MRI data.

Spatial modeling of multiple sclerosis for disease subtype prediction.

Magnetic resonance imaging (MRI) has become an essential tool in the diagnosis and managing of Multiple Sclerosis (MS). Currently, the assessment of MS is based on a combination of clinical scores and subjective rating of lesion images by clinicians. In this work we present an objective 5-way classification of MS disease subtype as well as a comparison between three different approaches.

Association of cognitive impairment and lesion volumes in multiple sclerosis--a MRI study.

Unlabelled: Cognitive impairment (CI) can be demonstrated in 40-65% of multiple sclerosis (MS) patients, sometimes starting from the early stages of the disease. The objective of this study was a community-based investigation of FLAIR-hyperintense lesion volumes (LV) and their association with CI in patients with relapsing remitting (RR) MS. The neurocognitive assessment was conducted with the brief cognitive screening instrument, MUSIC.

ANALYSIS OF MULTIPLE SCLEROSIS LESIONS VIA SPATIALLY VARYING COEFFICIENTS.

Magnetic resonance imaging (MRI) plays a vital role in the scientific investigation and clinical management of multiple sclerosis. Analyses of binary multiple sclerosis lesion maps are typically "mass univariate" and conducted with standard linear models that are ill suited to the binary nature of the data and ignore the spatial dependence between nearby voxels (volume elements). Smoothing the lesion maps does not entirely eliminate the non-Gaussian nature of the data and requires an arbitrary choice of the smoothing parameter.

Altered prefrontal connectivity after acute heroin administration during cognitive control.

Neuroimaging studies have reported reduced activity in a broad network of brain regions during response inhibition in heroin-dependent patients. However, how heroin in an acute dose modulates the neural correlates of response inhibition and the underlying brain connectivity has not yet been investigated. In this double-blind placebo-controlled study, we used functional magnetic resonance imaging to examine whether acute heroin administration changed whole brain activity during response inhibition in 26 heroin-dependent patients.

Abnormal effective connectivity and psychopathological symptoms in the psychosis high-risk state.

Background: Recent evidence has revealed abnormal functional connectivity between the frontal and parietal brain regions during working memory processing in patients with schizophrenia and first-episode psychosis. However, it still remains unclear whether abnormal frontoparietal connectivity during working memory processing is already evident in the psychosis high-risk state and whether the connection strengths are related to psychopathological outcomes.

Methods: Healthy controls and antipsychotic-naive individuals with an at-risk mental state (ARMS) performed an n-back working memory task while undergoing functional magnetic resonance imaging.

Brain atrophy: an in-vivo measure of disease activity in multiple sclerosis.

Multiple sclerosis (MS) has traditionally been considered to be primarily an inflammatory demyelinating disorder. Nowadays it is recognised as both an inflammatory and a neurodegenerative condition. This recognition is reflected in the development of new disease-modifying therapies that may offer the potential to reduce axon damage, either by inhibiting neurodegeneration or by promoting endogenous repair mechanisms.

Global N-acetylaspartate concentration in benign and non-benign multiple sclerosis patients of long disease duration.

Background And Objective: To examine whether clinically benign multiple sclerosis patients (BMS) show similar losses of their global N-acetylaspartate (NAA) neuronal marker relative to more clinically disabled patients of similar disease duration.

Methods: The whole-brain NAA concentration (WBNAA) was acquired with whole-head non-localizing proton MR spectroscopy. Fractional brain parenchymal volume (fBPV), T2 and T1 lesion loads, were obtained from the MRI in: (i) 24 BMS patients: 23.

Effects of cannabis on impulsivity: a systematic review of neuroimaging findings.

We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations.

Progression in disability and regional grey matter atrophy in relapsing-remitting multiple sclerosis.

Background: In multiple sclerosis (MS) regional grey matter (GM) atrophy has been associated with disability progression.

Objective: The aim of this study was to compare regional GM volume changes in relapsing-remitting MS (RRMS) patients with progressive and stable disability, using voxel-based morphometry (VBM).

Methods: We acquired baseline and 1-year follow-up 3-dimensional (3D) T1-weighted magnetic resonance imaging (MRI) data of RRMS patients, using two 1.

Inferior frontal cortex modulation with an acute dose of heroin during cognitive control.

Impairments in inhibitory control and in stimulus-driven attention are hallmarks of drug addiction and are associated with decreased activation in the right inferior frontal gyrus (IFG). Although previous studies indicate that the response inhibition function is impaired in abstinent heroin dependents, and that this is mediated by reduced IFG activity, it remains completely unknown whether and how an acute dose of heroin modulates IFG activity during cognitive control in heroin-dependent patients. This study investigates the acute effects of heroin administration on IFG activity during response inhibition and stimulus-driven attention in heroin-dependent patients.

Contribution of cortical and white matter lesions to cognitive impairment in multiple sclerosis.

Background: Cortical lesions (CLs) have been reported to be a better predictor for cognitive impairment than white matter (WM) lesions in relapsing-remitting multiple sclerosis (RRMS).

Objectives: The objectives of this article are to investigate the contribution of CLs and WM lesions to cognitive impairment in 91 patients with MS and clinically isolated syndrome, and to test potential associations of CLs and WM lesions with fatigue and depression.

Methods: Lesions were scored and segmented on 3D double inversion recovery sequences, according to their location (cortical, WM).

Resting state abnormalities in psychosis compared to acute cannabinoids and opioids challenges: a systematic review of functional imaging studies.

We conducted a systematic review on resting state cerebral blood flow activities found in first-episode psychosis (FEP) and during acute effects of cannabinoids and opioids, mental states that can be profoundly different from normal functioning. The main goal was to identify connections of cerebral blood flow measure and regional brain activity patterns associated with subjective experiences and to find out whether there are similarities between the three mental states. The present study reviewed systematically the current state of research with respect to cannabinoids and opioids on resting state activity patterns as investigated by different neuroimaging techniques.

Biplanar MRI for the assessment of the spinal cord in multiple sclerosis.

Objective: To investigate the entire spinal cord (SC) of multiple sclerosis (MS) patients with biplanar MRI and to relate these MRI findings to clinical functional scores.

Methods: Two hundred and two patients (140 women, 62 men 24-74 years, Expanded Disability Status Scale (EDSS) scores 0-7.5) were investigated clinically and with biplanar MRI.

Spatiotemporal distribution of white matter lesions in relapsing-remitting and secondary progressive multiple sclerosis.

Background: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. MS lesions show a typical distribution pattern and primarily affect the white matter (WM) in the periventricular zone and in the centrum semiovale.

Objective: To track lesion development during disease progression, we compared the spatiotemporal distribution patterns of lesions in relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS).

Multivariate pattern classification of gray matter pathology in multiple sclerosis.

Univariate analyses have identified gray matter (GM) alterations in different groups of MS patients. While these methods detect differences on the basis of the single voxel or cluster, multivariate methods like support vector machines (SVM) identify the complex neuroanatomical patterns of GM differences. Using multivariate linear SVM analysis and leave-one-out cross-validation, we aimed at identifying neuroanatomical GM patterns relevant for individual classification of MS patients.

Different duration of at-risk mental state associated with neurofunctional abnormalities. A multimodal imaging study.

Objectives: Neurofunctional alterations are correlates of vulnerability to psychosis, as well as of the disorder itself. How these abnormalities relate to different probabilities for later transition to psychosis is unclear. We investigated vulnerability- versus disease-related versus resilience biomarkers of psychosis during working memory (WM) processing in individuals with an at-risk mental state (ARMS).