Altered resting functional network topology assessed using graph theory in youth with attention-deficit/hyperactivity disorder

Notwithstanding an extensive literature about attention-deficit/hyperactivity disorder (ADHD) and brain structure and function, the controversy of ADHD resulting from dysfunction or developmental delay remains unclear. Graph analysis studies have reached consensus about the pattern of increased integration and decreased randomness during childhood and early adulthood. Here, we hypothesized that ADHD is a neurodevelopmental disorder resulting from developmental delay and would show a pattern of decreased integration and increased randomness during childhood and early adulthood compared with typically developing children. To test this hypothesis, publicly available resting-state fMRI data from 102 children with ADHD and 143 typically developing controls (TDC) were compared using graph theoretical analysis. Functional connectivity was estimated using Pearson correlation analysis, and network topology was characterized using small-world (SW) and minimum spanning tree (MST) properties. The mean strength of global connectivity was significantly weaker in those with ADHD and was related to ADHD diagnosis scores. Significant group differences were observed for SW(clustering coefficient, path length, global and local efficiency) and MST (leaf number, kappa and hierarchy) topology. In addition, except for global efficiency, all of these parameters showed significant correlations with ADHD-related disability. The topology of SW and MST showed less integration and more randomness, which confirmed that ADHD is a disorder associated with developmental delay. Moreover, the topology of resting-state functional networks in children with ADHD that show abnormalities was associated with the degree of disability, which can be considered neurological hallmarks of neurodevelopmental disorders and may facilitate the evaluation and monitoring of clinical status in individuals with ADHD.

Disrupted Resting Frontal-Parietal Attention Network Topology Is Associated With a Clinical Measure in Children With Attention-Deficit/Hyperactivity Disorder

Purpose: Although alterations in resting-state functional connectivity between brain regions have been reported in children with attention-deficit/hyperactivity disorder (ADHD), the spatial organization of these changes remains largely unknown. Here, we studied frontal-parietal attention network topology in children with ADHD, and related topology to a clinical measure of disease progression. Methods: Resting-state fMRI scans were obtained from New York University Child Study Center, including 119 children with ADHD (male n = 89; female n = 30) and 69 typically developing controls (male n = 33; female n = 36). We characterized frontal-parietal functional networks using standard graph analysis (clustering coefficient and shortest path length) and the construction of a minimum spanning tree, a novel approach that allows a unique and unbiased characterization of brain networks. Results: Clustering coefficient and path length in the frontal-parietal attention network were similar in children with ADHD and typically developing controls; however, diameter was greater and leaf number, tree hierarchy, and kappa were lower in children with ADHD, and were significantly correlated with ADHD symptom score. There were significant alterations in nodal eccentricity in children with ADHD, involving prefrontal and occipital cortex regions, which are compatible with the results of previous ADHD studies. Conclusions: Our results indicate the tendency to deviate from a more centralized organization (star-like topology) towards a more decentralized organization (line-like topology) in the frontal-parietal attention network of children with ADHD. This represents a more random network that is associated with impaired global efficiency and network decentralization. These changes appear to reflect clinically relevant phenomena and hold promise as markers of disease progression.

Low-dose methotrexate with leucovorin (folinic acid) in the management of rheumatoid arthritis. Results of a multicenter randomized, double-blind, placebo-controlled trial

OBJECTIVE

To determine whether the side effects of methotrexate can be decreased by the concurrent use of leucovorin, without affecting the efficacy of the methotrexate.

METHODS

We conducted a multicenter randomized, double-blind, placebo-controlled trial of leucovorin administration, 2.5-5.0 mg orally, to be given 24 hours after the single, weekly, oral dose of methotrexate. Every 3 weeks for 52 weeks, patients were evaluated for rheumatic disease activity and side effects. Dosage adjustments for both methotrexate and leucovorin were made as needed, according to a defined protocol. The primary outcome evaluated was the frequency of study withdrawals because of side effects and/or inefficacy. Secondary outcomes evaluated included the frequency of side effects and the relative efficacy of methotrexate in the leucovorin and placebo treatment groups.

RESULTS

Ninety-two evaluable patients were analyzed (44 took leucovorin and 48 placebo). Twenty-two patients withdrew early because of side effects unresponsive to our protocol, and 1 because of inefficacy; 17 had been taking placebo and 6 had been taking leucovorin (35% versus 14%, P < 0.02). The number of visits during which side effects were reported was reduced by almost 50% in the leucovorin treatment group (P < 0.001). There were significant reductions in the frequencies of all common side effects. At 52 weeks, disease activity was similar in both patient groups.

CONCLUSION

The methotrexate-leucovorin protocol used significantly reduces common side effects of methotrexate therapy without significantly altering efficacy.

Mitral subannular left ventricular aneurysm. A case presenting with ventricular tachycardia

A young African immigrant presented with ventricular tachycardia in association with two mitral subannular left ventricular aneurysms. Although an unusual finding, the recognition of such aneurysms is important as prophylactic measures may prevent complications. Furthermore, they are a surgically treatable cause of heart failure and arrhythmias.