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Structural and functional neuroimaging techniques have recently been used to investigate the mechanisms of sexual attraction to children, a hallmark of pedophilic disorder, and have reported many contradictory or non-replicated findings. Here, our purpose was to identify through functional magnetic resonance imaging the brain responses of 25 male outpatients with pedophilic disorder to visual stimuli depicting children (VSc) and to compare them with 24 male healthy controls matched on sexual orientation (to female or male adults), age, and handedness. No region was differentially activated across the two groups in response to VSc. However, as shown by a random-effects statistical analysis (cluster-level pFWE-corrected < 0.05), in patients with pedophilia, but not in controls, the presentation of VSc induced a bilateral activation in the lateral occipital and temporal cortices, in particular in the right inferior temporal gyrus, as well as an activation in the declive of the cerebellar vermis. In addition, in patients the level of bilateral activation in the above-mentioned regions was positively correlated with ratings of perceived sexual arousal elicited by VSc. These results implicate these regions as possible candidate areas mediating sexual arousal in patients with pedophilic disorder. [ABSTRACT FROM AUTHOR]

Introduction: Extrapyramidal deficits are poorly characterised in amyotrophic lateral sclerosis (ALS) despite their contribution to functional disability, increased fall risk and their quality-of-life implications. Given the concomitant pyramidal and cerebellar degeneration in ALS, the clinical assessment of extrapyramidal features is particularly challenging.Objective: The comprehensive characterisation of postural instability in ALS using standardised clinical assessments, gait analyses and computational neuroimaging tools in a prospective study design.Methods: Parameters of gait initiation in the anticipatory postural adjustment phase (APA) and execution phase (EP) were evaluated in ALS patients with and without postural instability and healthy controls. Clinical and gait analysis parameters were interpreted in the context of brain imaging findings.Results: ALS patients with postural instability exhibit impaired gait initiation with an altered APA phase, poor dynamic postural control and significantly decreased braking index. Consistent with their clinical profile, “unsteady” ALS patients have reduced caudate and brain stem volumes compared to “steady” ALS patients.Interpretation: Our findings highlight that the ALS functional rating scale (ALSFRS-r) does not account for extrapyramidal deficits, which are major contributors to gait impairment in a subset of ALS patients. Basal ganglia degeneration in ALS does not only contribute to cognitive and behavioural deficits, but also adds to the heterogeneity of motor disability. [ABSTRACT FROM AUTHOR]

This paper provides an overview of CATI, a platform dedicated to multicenter neuroimaging. Initiated by the French Alzheimer's plan (2008-2012), CATI is a research project called on to provide service to other projects like an industrial partner. Its core mission is to support the neuroimaging of large populations, providing concrete solutions to the increasing complexity involved in such projects by bringing together a service infrastructure, the know-how of its expert academic teams and a large-scale, harmonized network of imaging facilities. CATI aims to make data sharing across studies easier and promotes sharing as much as possible. In the last 4 years, CATI has assisted the clinical community by taking charge of 35 projects so far and has emerged as a recognized actor at the national and international levels. [ABSTRACT FROM AUTHOR]

The presence of a postconcussion syndrome (PCS) induces substantial socio-professional troubles in mild traumatic brain injury (mTBI) patients. Although the exact origin of these disorders is not known, they may be the consequence of diffuse axonal injury (DAI) impacting structural integrity. In the present study, we compared structural integrity at the subacute and late stages after mTBI and in case of PCS, using diffusion-weighted imaging (DWI). Fifty-three mTBI patients were investigated and compared with 40 healthy controls. All patients underwent a DWI examination at the subacute (8-21 days) and late (6 months) phases after injury. MTBI patients with PCS were detected at the subacute phase using the ICD-10 classification. Groupwise differences in structural integrity were investigated using Tract-Based Spatial Statistics (TBSS). A loss of structural integrity was found in mTBI patients at the subacute phase but partially resolved over time. Moreover, we observed that mTBI patients with PCS had greater and wider structural impairment than patients without PCS. These damages persisted over time for PCS patients, while mTBI patients without PCS partly recovered. In conclusion, our results strengthen the relationship between structural integrity and PCS. [ABSTRACT FROM AUTHOR]

When characterizing regional cerebral gray matter differences in structural magnetic resonance images (sMRI) by voxel-based morphometry (VBM), one faces a known drawback of VBM, namely that histogram unequalization in the intensity images introduces false-positive results. To overcome this limitation, we propose to improve VBM by a new approach (called eVBM for enhanced VBM) that takes the histogram distribution of the sMRI into account by adding a histogram equalization step within the VBM procedure. Combining this technique with two most widely used VBM software packages (FSL and SPM), we studied GM variability in a group of 62 patients with Alzheimer’s disease compared to 73 age-matched elderly controls. The results show that eVBM can reduce the number of false-positive differences in gray matter concentration. Because it takes advantage of the properties of VBM while improving sMRI histogram distribution at the same time, the proposed method is a powerful approach for analyzing gray matter differences in sMRI and may be of value in the investigation of sMRI gray and white matter abnormalities in a variety of brain diseases. [ABSTRACT FROM AUTHOR]

We present and evaluate a new automated method based on support vector machine (SVM) classification of whole-brain anatomical magnetic resonance imaging to discriminate between patients with Alzheimer’s disease (AD) and elderly control subjects. We studied 16 patients with AD [mean age ± standard deviation (SD) = 74.1 ± 5.2 years, mini-mental score examination (MMSE) = 23.1 ± 2.9] and 22 elderly controls (72.3 ± 5.0 years, MMSE = 28.5 ± 1.3). Three-dimensional T1-weighted MR images of each subject were automatically parcellated into regions of interest (ROIs). Based upon the characteristics of gray matter extracted from each ROI, we used an SVM algorithm to classify the subjects and statistical procedures based on bootstrap resampling to ensure the robustness of the results. We obtained 94.5% mean correct classification for AD and control subjects (mean specificity, 96.6%; mean sensitivity, 91.5%). Our method has the potential in distinguishing patients with AD from elderly controls and therefore may help in the early diagnosis of AD. [ABSTRACT FROM AUTHOR]