Associations Between Body Weight, Hippocampal Volume, and Tissue Signal Intensity in 12- to 18-Year-Olds.

OBJECTIVE: The hippocampus is a key structure in feeding behaviors and weight regulation. Obesity may lead to disruptions in hippocampal structure. In animals, obesity-related factors (e.g., high-fat/sugar foods) are associated with hippocampal insult (e.g., alterations in the blood brain barrier). In humans, individuals with obesity, relative to healthy weight, have smaller hippocampal volumes. Few studies have examined the association between body weight and the hippocampus during adolescence, a critical brain development period. This study examined hippocampal volume and tissue signal intensity in adolescents across the weight spectrum. METHODS: Structural magnetic resonance imaging and anthropomorphic data were available for 102 12- to 18-year-old adolescents (53% female; 15.07 [SD 1.84] years; standardized BMI [BMIz] scores using the Centers for Disease Control and Prevention growth charts: 0.54 [SD 1.17]) from the Pediatric Imaging, Neurocognition, and Genetics database. Linear regression models controlling for age, sex, genetic ancestry, scanner, and household income examined the relationship between BMIz, hippocampal volume, and T2-weighted hippocampal signal intensity. RESULTS: BMIz was negatively associated with T2-weighted hippocampal signal intensity in the left (t = -3.05; P = 0.003; r = -0.21) and right (t = -2.50; P = 0.01; r = -0.36) hippocampi. BMIz was not significantly associated with hippocampal volume. CONCLUSIONS: BMIz is associated with hippocampal tissue characteristics during adolescence, which could impact later brain development.

Defining and identifying predictors of rapid response to pediatric obesity treatment.

Early weight loss (rapid response [RR]) is associated with better outcomes in adults. Less is known about RR in children enrolled in weight-loss treatment. The aim of the current study was to establish an RR weight-loss threshold following 4 weeks of pediatric obesity treatment and identify characteristics associated with achieving RR. One hundred thirty-seven children aged 8 to 12 with overweight/obesity and parents participated in 6 months of family-based or parent-based treatment. Receiver operating characteristic curves evaluated how weight loss at week 4 related to decreases of 5% at posttreatment and 10% at 6- and 18-month follow-ups of standardized body mass index (BMIz), percentage distance of a child's BMI from the median BMI for sex and age, and percentage above the 95th percentile. Weight loss of 2.4% to 3.4% at week 4 predicted 5% change at posttreatment (AUC's = .68-.75; P's ≤ .002) and 10% change at 6-month follow-up (AUC's = .63-.70; P's ≤ .02). No model was significant at 18-month follow-up. Amount of parent weight (lbs) change at week 4 was associated with child achieving RR. Males and Non-Hispanic Whites were more likely to achieve RR. This threshold could be used to mark early significant progress and guide clinical evaluations of treatment response to paediatric obesity treatment.

Dose-dependent association of accelerometer-measured physical activity and sedentary time with brain perfusion in aging.

INTRODUCTION: Age-related decreases in cerebral blood flow (CBF) may lead to cognitive decline, while physical activity (PA) can maintain CBF and cognition in aging. The intensity of PA needed to affect CBF in aging, and the independent effects of sedentary time on CBF are currently unknown. Moreover, research conducted in free-living environments with objective measures of PA (e.g., accelerometry) is lacking. METHODS: This cross-sectional study used accelerometry to objectively measure sedentary time, all light PA [AllLightPA], moderate-to-vigorous PA [MVPA], and total activity counts [TAC] in 52 cognitively healthy older adults. Robust linear regressions investigated the association of CBF (using arterial spin labeling magnetic resonance imaging) in frontal and medial temporal regions, with each PA intensity and sedentary time. RESULTS: Greater sedentary time was significantly associated with lower CBF in lateral and medial frontal regions after adjusting for MVPA, while higher AllLightPA (adjusted for MVPA), MVPA (adjusted for AllLightPA), and TAC were associated with greater CBF in lateral and medial frontal regions. DISCUSSION: Lighter activities, as well as MVPA, are beneficial to CBF in brain regions typically affected by the aging process and malleable to exercise interventions (i.e., the frontal lobes), whereas sedentary time is an independent risk factor for neurovascular dysregulation in normal aging.

Comparison of Two Models of Family-Based Treatment for Childhood Obesity: A Pilot Study.

BACKGROUND: Family-based weight loss treatment (FBT) for childhood obesity, the current "gold standard," is typically provided in weekly groups for 6 months. Although this program is considered effective, it poses limitations to treatment engagement, due to time commitment and lack of widespread availability. A guided self-help version of FBT (gshFBT; eleven 20-minute sessions and one 1-hour over 5 months) was developed to circumvent such limitations. The current study examined the comparative efficacy of a 5-month FBT and gshFBT program. METHODS: Participants included 50 parent-child dyads enrolled in FBT between 2011 and 2013 and 50 parent-child dyads enrolled in gshFBT between 2009 and 2010. Data were collected at baseline, posttreatment, and 6-month follow-up. Noninferiority analyses were conducted to assess comparative efficacy of changes in parent and child weight status, child nutrition, child physical activity, and drop-out. RESULTS: Results indicated that gshFBT was noninferior to FBT in changes in child BMI z-score, overweight parent BMI, child nutritional intake, child vigorous physical activity, and drop-out. Results did not support noninferiority for changes in moderate to vigorous physical activity. CONCLUSIONS: gshFBT is less intensive, more flexible, and may be similarly effective to FBT and could reach a greater proportion of the pediatric overweight population. Further research, including a randomized clinical trial, is needed to confirm these results.

Relationships between Eye Movements during Sentence Reading Comprehension, Word Spelling and Reading, and DTI and fmri Connectivity In Students with and without Dysgraphia or Dyslexia.

While eye movements were recorded and brains scanned, 29 children with and without specific learning disabilities (SLDs) decided if sentences they read (half with only correctly spelled words and half with homonym foils) were meaningful. Significant main effects were found for diagnostic groups (non-SLD control, dysgraphia control, and dyslexia) in total fixation (dwell) time, total number of fixations, and total regressions in during saccades; the dyslexia group had longer and more fixations and made more regressions in during saccades than either control group. The dyslexia group also differed from both control groups in (a) fractional anisotropy in left optic radiation and (b) silent word reading fluency on a task in which surrounding letters can be distracting, consistent with Rayner's selective attention dyslexia model. Different profiles for non-SLD control, dysgraphia, and dyslexia groups were identified in correlations between total fixation time, total number of fixations, regressions in during saccades, magnitude of gray matter connectivity during the fMRI sentence reading comprehension from left occipital temporal cortex seed with right BA44 and from left inferior frontal gyrus with right inferior frontoccipital fasciculus, and normed word-specific spelling and silent word reading fluency measures. The dysgraphia group was more likely than the non-SLD control or dyslexia groups to show negative correlations between eye movement outcomes and sentences containing incorrect homonym foils. Findings are discussed in reference to a systems approach in future sentence reading comprehension research that integrates eye movement, brain, and literacy measures.

ERPs While Judging Meaningfulness of Sentences With and Without Homonym or Morpheme Spelling Foils: Comparing 4th to 9th Graders With and Without Spelling Disabilities.

Thirteen students with and twelve students without spelling disabilities judged whether sentences (1/3 all correct spellings, 1/3 with homonym foil, 1/3 with morpheme foil) were meaningful while event-related potentials (ERPs) were measured with EGI Geodesic EEG System 300 (128-channel hydro-cell nets). For N400, Rapid Automatic Switching (RAS) correlated with comprehending sentences with homonym foils in control group but with morpheme foils in SLD group. For P600, dictated spelling correlated with comprehending sentences with morpheme foils in the control group but solving anagrams with homonym foils in the SLD group. Educational significance and neuropsychological significance of these contrasting results are discussed.

Using Make for Reproducible and Parallel Neuroimaging Workflow and Quality-Assurance.

The contribution of this paper is to describe how we can program neuroimaging workflow using Make, a software development tool designed for describing how to build executables from source files. A makefile (or a file of instructions for Make) consists of a set of rules that create or update target files if they have not been modified since their dependencies were last modified. These rules are processed to create a directed acyclic dependency graph that allows multiple entry points from which to execute the workflow. We show that using Make we can achieve many of the features of more sophisticated neuroimaging pipeline systems, including reproducibility, parallelization, fault tolerance, and quality assurance reports. We suggest that Make permits a large step toward these features with only a modest increase in programming demands over shell scripts. This approach reduces the technical skill and time required to write, debug, and maintain neuroimaging workflows in a dynamic environment, where pipelines are often modified to accommodate new best practices or to study the effect of alternative preprocessing steps, and where the underlying packages change frequently. This paper has a comprehensive accompanying manual with lab practicals and examples (see Supplemental Materials) and all data, scripts, and makefiles necessary to run the practicals and examples are available in the "makepipelines" project at NITRC.

Effects of Anxiety on Caloric Intake and Satiety-Related Brain Activation in Women and Men.

OBJECTIVE: To test the relationship of anxiety to caloric intake and food cue perception in women and men. METHODS: Fifty-five twins (26 complete, 3 incomplete pairs; 51% women) underwent 2 functional magnetic resonance imaging (fMRI) scans (before and after a standardized meal) and then ate at an ad libitum buffet to objectively assess food intake. State and trait anxiety were assessed using the State-Trait Anxiety Inventory. During the fMRI scans, participants viewed blocks of fattening and nonfattening food images, and nonfood objects. RESULTS: In women, higher trait anxiety was associated with a higher body mass index (BMI) (r = 0.40, p = .010). Trait anxiety was positively associated with kilocalories consumed at the buffet (r = 0.53, p = .005) and percent kilocalories consumed from fat (r = 0.30, p = .006), adjusted for BMI. In within-pair models, which control for shared familial and genetic factors, higher trait anxiety remained associated with kilocalories consumed at the buffet (p = .66, p = .014), but not with BMI. In men, higher state anxiety was related to macronutrient choices, but not to total caloric intake or BMI. FMRI results revealed that women with high trait anxiety did not suppress activation by fattening food cues across brain regions associated with satiety perception after eating a standardized meal (low anxiety, mean difference = -15.4, p < .001; high anxiety, mean difference = -1.53, p = .82, adjusted for BMI). CONCLUSIONS: In women, trait anxiety may promote excess caloric consumption through altered perception of high-calorie environmental food cues, placing women with genetic predispositions toward weight gain at risk of obesity. TRIAL REGISTRATION: Clinicaltrials.govidentifier:NCT02483663.