Intra-session test-retest reliability of functional connectivity in infants.

Resting functional MRI studies of the infant brain are increasingly becoming an important tool in developmental neuroscience. Whereas the test-retest reliability of functional connectivity (FC) measures derived from resting fMRI data have been characterized in the adult and child brain, similar assessments have not been conducted in infants. In this study, we examined the intra-session test-retest reliability of FC measures from 119 infant brain MRI scans from four neurodevelopmental studies. We investigated edge-level and subject-level reliability within one MRI session (between and within runs) measured by the Intraclass correlation coefficient (ICC). First, using an atlas-based approach, we examined whole-brain connectivity as well as connectivity within two common resting fMRI networks - the default mode network (DMN) and the sensorimotor network (SMN). Second, we examined the influence of run duration, study site, and scanning manufacturer (e.g., Philips and General Electric) on ICCs. Lastly, we tested spatial similarity using the Jaccard Index from networks derived from independent component analysis (ICA). Consistent with resting fMRI studies from adults, our findings indicated poor edge-level reliability (ICC = 0.14-0.18), but moderate-to-good subject-level intra-session reliability for whole-brain, DMN, and SMN connectivity (ICC = 0.40-0.78). We also found significant effects of run duration, site, and scanning manufacturer on reliability estimates. Some ICA-derived networks showed strong spatial reproducibility (e.g., DMN, SMN, and Visual Network), and were labelled based on their spatial similarity to analogous networks measured in adults. These networks were reproducibly found across different study sites. However, other ICA-networks (e.g. Executive Control Network) did not show strong spatial reproducibility, suggesting that the reliability and/or maturational course of functional connectivity may vary by network. In sum, our findings suggest that developmental scientists may be on safe ground examining the functional organization of some major neural networks (e.g. DMN and SMN), but judicious interpretation of functional connectivity is essential to its ongoing success.

Mental health of children who work on the streets in Brazil after enrollment in a psychosocial program.

PURPOSE: To evaluate the mental health status of children working on the streets in Sao Paulo City, Brazil, two years after their participation in a psychosocial program, and to identify factors associated with their mental health status. METHODS: From a total sample of 126 children working on the streets, 107 (85%) were re-evaluated two years after the initiation of a psychosocial program which aimed to cease their work on the streets. The focus was the presence of mental health problems, defined based on a screening instrument (Strengths and Difficulties Questionnaire). Logistic regression models tested factors related to the probability that a child would not present mental health problems at follow-up. RESULTS: The likelihood of a child presenting mental health problems was higher at baseline compared to the two-year follow-up (67.5 and 56.1%, respectively). Absence of mental health problems two years after a psychosocial intervention was significantly correlated with the following baseline factors: lower level of caregiver's psychiatric symptoms as measured by the SRQ (Self-Report Questionnaire) (AOR = 0.84, p = 0.0065), absence of child physical neglect (AOR = 0.38, p = 0.0705) and parental Protestant religion affiliation, compared to other religions (AOR = 4.06; p = 0.0107). CONCLUSIONS: Different factors are related to the absence of mental health problems of children working on the streets after enrollment in a two-year psychosocial program. Our findings suggest that interventions that aim to improve child mental health should consider the detection of psychiatric symptoms in caregivers, provide treatment when it is needed, and also assess other problems such as neglect in the family setting.

Does pediatric post-traumatic stress disorder alter the brain? Systematic review and meta-analysis of structural and functional magnetic resonance imaging studies.

Several studies have recently demonstrated that the volumes of specific brain regions are reduced in children and adolescents with post-traumatic stress disorder (PTSD) compared with those of healthy controls. Our study investigated the potential association between early traumatic experiences and altered brain regions and functions. We conducted a systematic review of the scientific literature regarding functional magnetic resonance imaging and a meta-analysis of structural magnetic resonance imaging studies that investigated cerebral region volumes in pediatric patients with PTSD. We searched for articles from 2000 to 2014 in the PsycINFO, PubMed, Medline, Lilacs, and ISI (Web of Knowledge) databases. All data regarding the amygdala, hippocampus, corpus callosum, brain, and intracranial volumes that fit the inclusion criteria were extracted and combined in a meta-analysis that assessed differences between groups. The meta-analysis found reduced total corpus callosum areas and reduced total cerebral and intracranial volumes in the patients with PTSD. The total hippocampus (left and right hippocampus) and gray matter volumes of the amygdala and frontal lobe were also reduced, but these differences were not significant. The functional studies revealed differences in brain region activation in response to stimuli in the post-traumatic stress symptoms/PTSD group. Our results confirmed that the pediatric patients with PTSD exhibited structural and functional brain abnormalities and that some of the abnormalities occurred in different brain regions than those observed in adults.