WM-related activations (N2> N0) in ADHD and Control children.

<p>Brain areas in which BOLD response is higher in the N2 than in the N0 condition in ADHD (top) and Control (bottom) groups. Coordinates x y z (mm) in MNI standard stereotactic space. T = t-statistic value. H = Right or Left hemisphere. K = cluster extent. CJ (conjunction analysis): areas commonly activated in ADHD and Control groups. All results significant at the voxel level p<0.001 uncorrected, except * after correction for multiple comparisons in the whole brain volume (p^corr <.05).</p

Higher WM-related activation in Control than ADHD children.

<p>Brain areas in which BOLD response is higher in the N2 than in the N0 condition, and more so in Control than ADHD children. Coordinates x y z (mm) in MNI standard stereotactic space. T = t-statistic value. H = Right or Left hemisphere. K = cluster extent. All results significant at the voxel level p<0.001 uncorrected, except * after correction in the whole brain volume (p^corr <0.05) or ** after correction in a small ROI volume (p^svccorr <.05) and cluster extent = 20 voxels. Regions of interests (ROI) taken from [a] Kobel et al. 2005, [b] Vance et al. 2007 and [c] Silk et al. 2005.</p

Percent BOLD signal changes from baseline levels in N2 and N0 conditions in Control and ADHD children.

<p>OC: occipital cortex; IPC: inferior parietal cortex; VD: ventral dentate (cerebellum); CN: caudate nucleus; Crus I (cerebellum). Activated areas are displayed at p^unc <0.001, superimposed on the ICBM standardized anatomical template.</p

Working memory-related common and specific neural activity patterns in ADHD.

<p>Left column: WM-related activation (N2> N0) in ADHD children. Middle column: WM-related activation (N2> N0) in Control children. Right column: higher WM activation (N2> N0) in Control than in ADHD children (interaction effect). All effects are displayed at p^unc <0.001, superimposed on the ICBM standardized anatomical template.</p

Positron emission tomography for the early postsurgical evaluation of pediatric brain tumors.

OBJECT: The object was to study the value of postoperative positron emission tomography (PET) to assess the extension of brain tumor resection. METHODS: Twenty children operated on for total resection of a glial tumor (18 low-grade, 2 anaplastic) presented a signal on postoperative magnetic resonance (MR) images raising the question of a possible tumor residue. PET was performed early ((18)F-Fluoro-deoxyglucose in 1, (11)C-methionine in 16, both in 3) to further characterize the nature of the abnormal MR signal in order to consider second-look surgery. An increased tracer uptake found in 14 children led to reoperation on 11 of them, confirming the tumor histologically. No (11)C-methionine uptake led to a conservative attitude in 6 children in whom MR imaging follow-up showed no tumor progression. CONCLUSIONS: The early postoperative PET, especially with (11)C-methionine, appears to be a valid basis for complementary therapeutic decisions, especially second-look surgery, in glial tumors for which a radical resection is a key factor for prognosis.Comparative StudyJournal Articleinfo:eu-repo/semantics/publishe

Working memory-related functional brain patterns in never medicated children with ADHD.

Attention Deficit/Hyperactivity Disorder (ADHD) is a pervasive neurodevelopmental disorder characterized by 3 clusters of age-inappropriate cardinal symptoms: inattention, hyperactivity and impulsivity. These clinical/behavioural symptoms are assumed to result from disturbances within brain systems supporting executive functions including working memory (WM), which refers to the ability to transiently store and flexibly manipulate task-relevant information. Ongoing or past medications, co-morbidity and differences in task performance are potential, independent confounds in assessing the integrity of cerebral patterns in ADHD. In the present study, we recorded WM-related cerebral activity during a memory updating N-back task using functional Magnetic Resonance Imaging (fMRI) in control children and never medicated, prepubescent children with ADHD but without comorbid symptoms. Despite similar updating performance than controls, children with ADHD exhibited decreased, below baseline WM-related activation levels in a widespread cortico-subcortical network encompassing bilateral occipital and inferior parietal areas, caudate nucleus, cerebellum and functionally connected brainstem nuclei. Distinctive functional connectivity patterns were also found in the ADHD in these regions, with a tighter coupling in the updating than in the control condition with a distributed WM-related cerebral network. Especially, cerebellum showed tighter coupling with activity in an area compatible with the brainstem red nucleus. These results in children with clinical core symptoms of ADHD but without comorbid affections and never treated with medication yield evidence for a core functional neuroanatomical network subtending WM-related processes in ADHD, which may participate to the pathophysiology and expression of clinical symptoms.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe