White matter tracts related to memory and emotion in very preterm children.

BACKGROUND: Very preterm (VP) children are at risk of memory and emotional impairments; however, the neural correlates remain incompletely defined. This study investigated the effect of VP birth on white matter tracts traditionally related to episodic memory and emotion. METHODS: The cingulum, fornix, uncinate fasciculus, medial forebrain bundle and anterior thalamic radiation were reconstructed using tractography in 144 VP children and 33 full-term controls at age 7 years. RESULTS: Compared with controls, VP children had higher axial, radial, and mean diffusivities and neurite orientation dispersion, and lower volume and neurite density in the fornix, along with higher neurite orientation dispersion in the medial forebrain bundle. Support vector classification models based on tract measures significantly classified VP children and controls. Higher fractional anisotropy and lower diffusivities in the cingulum, uncinate fasciculus, medial forebrain bundle and anterior thalamic radiation were associated with better episodic memory, independent of key perinatal risk factors. Support vector regression models using tract measures did not predict episodic memory and emotional outcomes. CONCLUSIONS: Altered tract structure is related to adverse episodic memory outcomes in VP children, but further research is required to determine the ability of tract structure to predict outcomes of individual children. IMPACT: We studied white matter fibre tracts thought to be involved in episodic memory and emotion in VP and full-term children using diffusion magnetic resonance imaging and machine learning. VP children have altered fornix and medial forebrain bundle structure compared with full-term children. Altered tract structure can be detected using machine learning, which accurately classified VP and full-term children using tract data. Altered cingulum, uncinate fasciculus, medial forebrain bundle and anterior thalamic radiation structure was associated with poorer episodic memory skills using linear regression. The ability of tract structure to predict episodic memory and emotional outcomes of individual children based on support vector regression was limited.

Desikan-Killiany-Tourville Atlas Compatible Version of M-CRIB Neonatal Parcellated Whole Brain Atlas: The M-CRIB 2.0.

Our recently published M-CRIB atlas comprises 100 neonatal brain regions including 68 compatible with the widely-used Desikan-Killiany adult cortical atlas. A successor to the Desikan-Killiany atlas is the Desikan-Killiany-Tourville atlas, in which some regions with unclear boundaries were removed, and many existing boundaries were revised to conform to clearer landmarks in sulcal fundi. Our first aim here was to modify cortical M-CRIB regions to comply with the Desikan-Killiany-Tourville protocol, in order to offer: (a) compatibility with this adult cortical atlas, (b) greater labeling accuracy due to clearer landmarks, and (c) optimisation of cortical regions for integration with surface-based infant parcellation pipelines. Secondly, we aimed to update subcortical regions in order to offer greater compatibility with subcortical segmentations produced in FreeSurfer. Data utilized were the T2-weighted MRI scans in our M-CRIB atlas, for 10 healthy neonates (post-menstrual age at MRI 40-43 weeks, four female), and corresponding parcellated images. Edits were performed on the parcellated images in volume space using ITK-SNAP. Cortical updates included deletion of frontal and temporal poles and 'Banks STS,' and modification of boundaries of many other regions. Changes to subcortical regions included the addition of 'ventral diencephalon,' and deletion of 'subcortical matter' labels. A detailed updated parcellation protocol was produced. The resulting whole-brain M-CRIB 2.0 atlas comprises 94 regions altogether. This atlas provides comparability with adult Desikan-Killiany-Tourville-labeled cortical data and FreeSurfer-labeed subcortical data, and is more readily adaptable for incorporation into surface-based neonatal parcellation pipelines. As such, it offers the ability to help facilitate a broad range of investigations into brain structure and function both at the neonatal time point and developmentally across the lifespan.

Changes in neonatal regional brain volume associated with preterm birth and perinatal factors.

BACKGROUND: Preterm birth is associated with altered brain development, with younger gestational age (GA) at birth often associated with greater brain volume reduction. Such volume alterations at term equivalent age (TEA) have been found with differing magnitude across different brain regions, although this has mostly been investigated with regards to whole tissue volumes and large-scale subdivisions. In addition to degree of prematurity, many other perinatal factors have been found to influence brain structure and development in infants born preterm. We aimed to clarify the relationships between degree of prematurity and regional brain volumes at TEA, and between perinatal factors and regional brain volumes at TEA, in finer spatial detail. METHODS: 285 preterm and term-born infants (GA at birth 24.6-42.1 weeks; 145 female; 59 born at term) were scanned at TEA. Data on perinatal factors were obtained by chart review, including sex, multiple birth, birthweight standard deviation (SD) score, postnatal growth and social risk. The Melbourne Children's Regional Infant Brain (M-CRIB) atlas was registered to the current sample, then 100 brain regions were labelled for volumetric analyses. Linear regressions with generalised estimating equations and likelihood ratio tests were performed to investigate whether GA at birth or perinatal factors were associated with regional volumes at TEA. RESULTS: Younger GA at birth was associated with smaller volumes at TEA in some regions including bilateral cerebral white matter, middle temporal gyri, amygdalae, pallidum and brainstem. In other regions, younger GA at birth was associated with larger volumes, including in primary visual, motor and somatosensory cortices. Positive associations between perinatal factors and regional volumes at TEA were found in many brain regions for birthweight SD score, and male sex, independent of GA at birth. These associations were seen on both univariable analyses, and multivariable analyses controlling for other perinatal factors. Social risk and multiple birth were generally not associated with regional brain volumes, and postnatal growth was associated with volume in many regions only after adjusting for other perinatal factors. CONCLUSIONS: These results elucidate regional brain volume differences associated with preterm birth and perinatal factors at a more detailed parcellated level than previously reported, and contribute to understanding of the complex array of correlates of preterm birth.

Neurocognitive and Symptom Trajectories of ADHD from Childhood to Early Adolescence.

OBJECTIVE: This longitudinal study investigated changes in neurocognitive functioning from childhood to early adolescence in a sample of children diagnosed with DSM-IV attention-deficit hyperactivity disorder (ADHD). It also compared the neurocognitive trajectories of children who continued to meet the diagnostic criteria for ADHD at follow-up and those in partial remission. METHODS: Children diagnosed with ADHD (N = 55) were tested at baseline (M = 7.7 years, SD = 1.5) and 4 years later (M = 11.7 years, SD = 1.5) on measures of intellectual, academic, and executive functioning. Group and individual analyses were used to examine neurocognitive functioning over this period. RESULTS: Intellectual function was stable over the 4-year interval. Reliable change analyses highlighted variability in academic performance. Approximately half the sample showed a reliable decline in at least 1 academic subject with almost a third showing reliable improvement. Executive functions generally followed a stable or improving course, with significant improvements on measures of information processing, attentional control, cognitive flexibility, and goal setting. There was some evidence of better neurocognitive performance in those with partial symptom remission at follow-up. CONCLUSION: Study findings emphasize the importance of monitoring academic performance in children with ADHD, including examination of change at the individual level. Declines in academic performance were observed, despite stable intellectual and improving executive function. Early cognitive functioning did not predict symptom remission; however, reduced symptoms at follow-up were associated with better executive function.

A new neonatal cortical and subcortical brain atlas: the Melbourne Children's Regional Infant Brain (M-CRIB) atlas.

Investigating neonatal brain structure and function can offer valuable insights into behaviour and cognition in healthy and clinical populations; both at term age, and longitudinally in comparison with later time points. Parcellated brain atlases for adult populations are readily available, however warping infant data to adult template space is not ideal due to morphological and tissue differences between these groups. Several parcellated neonatal atlases have been developed, although there remains strong demand for manually parcellated ground truth data with detailed cortical definition. Additionally, compatibility with existing adult atlases is favourable for use in longitudinal investigations. We aimed to address these needs by replicating the widely-used Desikan-Killiany (2006) adult cortical atlas in neonates. We also aimed to extend brain coverage by complementing this cortical scheme with basal ganglia, thalamus, cerebellum and other subcortical segmentations. Thus, we have manually parcellated these areas volumetrically using high-resolution neonatal T2-weighted MRI scans, and initial automated and manually edited tissue classification, providing 100 regions in all. Linear and nonlinear T2-weighted structural templates were also generated. In this paper we provide manual parcellation protocols, and present the parcellated probability maps and structural templates together as the Melbourne Children's Regional Infant Brain (M-CRIB) atlas.

How Can We Improve Retention of the First-Time Donor? A Systematic Review of the Current Evidence.

Blood products are critical to health systems and donations by voluntary nonremunerated donors are recommended. Worldwide, however, only around 5% of those eligible to donate do so and around half of those never return to donate again. This review focuses on what deters first-time donors, what predicts their retention, and what interventions may promote retention of this group. A comprehensive search of relevant databases identified 9 studies investigating motives and deterrents of first-time donors, 14 studies investigating predictors for first-time donors (13 whole blood [WB] and 2 plasmapheresis), and 15 studies (in 14 published articles) detailing interventions conducted on first-time donors. Drawing on an established blood donation taxonomy, studies were classified by 2 independent raters. Interventions were also classified into traditional, behavioral, or social science interventions. With only 2 eligible studies among first-time plasmapheresis donors, analyses focused on WB donors. First-time WB donors reported benevolent and collectivistic motivations, as well as personal benefits to commence WB donation. Self-reported deterrents have typically not been examined. Intention predicted first-time donor retention with intention determined by attitudes and a sense of (perceived behavioral) control. However, anxiety, adverse events, and deferrals all deterred retention. Traditional interventions, such as reminders and incentives, are widespread yet had only a small effect on return of first-time donors. Although behavioral science interventions such as fluid loading are effective, the strongest effect for the return of first-time donors was found when individual psychological support was provided. The purpose of this analysis was to identify the factors associated with the commencement and continuation of first WB donations. The current review revealed that self-reported motivators are typically not effective, and most successful predictive factors identified have not been translated into interventions. Future work would do well to identify, manage, and meet donors' expectations along with developing more individualized donation experiences. Blood donor research should delineate donor career stages; addressing first-time donor retention will support stable panels for blood collection agencies.

White matter abnormalities and impaired attention abilities in children born very preterm.

While attention impairments are commonly observed in very preterm (<32weeks' gestational age) children, neuroanatomical correlates of these difficulties are unclear. We aimed to determine whether the microstructural organization of key white matter tracts thought to be involved in attention (cingulum bundle, superior longitudinal fasciculi, reticular activating system, and corpus callosum) were altered in very preterm children compared with term-born controls. We also aimed to determine whether alterations in microstructural organization of these tracts were associated with attention functioning in very preterm children. One hundred and forty-nine very preterm children and 36 term-born controls underwent neuroimaging and assessment of their attention abilities at 7years. Constrained spherical deconvolution and probabilistic tractography was used to identify the key white matter tracts. Altered microstructural organization and reduced tract volume within reticular activating system and corpus callosum were found in the very preterm group compared with the control group. Diffusion and volume changes in the cingulum bundle, superior longitudinal fasciculi, reticular activating system, and corpus callosum were related to variations in attention functioning in the very preterm children. These findings emphasize that white matter tract integrity is associated with later attentional abilities in very preterm children.

Neonatal brain pathology predicts adverse attention and processing speed outcomes in very preterm and/or very low birth weight children.

OBJECTIVE: This study aimed to examine attention and processing speed outcomes in very preterm (VPT; < 32 weeks' gestational age) or very low birth weight (VLBW; < 1,500 g) children, and to determine whether brain abnormality measured by neonatal MRI can be used to predict outcome in these domains. METHOD: A cohort of 198 children born < 30 weeks' gestational age and/or < 1,250 g and 70 term controls were examined. Neonatal MRI scans at term equivalent age were quantitatively assessed for white matter, cortical gray matter, deep gray matter, and cerebellar abnormalities. Attention and processing speed were assessed at 7 years using standardized neuropsychological tests. Group differences were tested in attention and processing speed, and the relationships between these cognitive domains and brain abnormalities at birth were investigated. RESULTS: At 7 years of age, the VPT/VLBW group performed significantly poorer than term controls on all attention and processing speed outcomes. Associations between adverse attention and processing speed performances at 7 years and higher neonatal brain abnormality scores were found; in particular, white matter and deep gray matter abnormalities were reasonable predictors of long-term cognitive outcomes. CONCLUSION: Attention and processing speed are significant areas of concern in VPT/VLBW children. This is the first study to show that adverse attention and processing speed outcomes at 7 years are associated with neonatal brain pathology.

Neuropsychological outcomes of stereotactic radiotherapy for cerebral arteriovenous malformations.

To our knowledge, this is the first study to investigate cognitive outcome in patients with large or surgically inaccessible cerebral arteriovenous malformations (AVMs), who were treated with hypo-fractionated stereotactic radiotherapy (HSRT). A sample of 10 patients with AVMs was assessed up to 3.5 years post-HSRT. All patients were treated with HSRT to a total dose of 55 Gy in 11 fractions over a treatment period of 2.5 weeks. Neuropsychological assessments were given prior to radiotherapy and then at three time points following radiotherapy: 6 weeks, 6 months and 2.5-3.5 years post-treatment. The cognitive domains of attention, processing speed, learning, memory, semantic processing, naming, verbal fluency, visuospatial and executive function were assessed. Findings revealed that prior to radiotherapy the patient group was impaired in five of the nine cognitive domains. Post-treatment performances remained stable in the majority of domains; however, there was some fluctuation in semantic processing and memory performances. At 6 weeks post-treatment, a mild decrement was found in semantic processing ability; however, restoration to baseline levels was observed from 6 months onwards. At 2.5-3.5 years post-treatment, improvement was seen in the cohort's ability to remember new information when performances were compared with earlier time points. This study demonstrated improvements in memory several years after HSRT treatment. Further, this form of treatment was not associated with long-term, harmful cognitive side effects for these 10 patients encouraging further study of this treatment method. Further evaluation of the entire cohort is required to assess efficacy in terms of AVM obliteration and other potential side effects.

A systematic review and meta-analysis of antecedents of blood donation behavior and intentions.

This meta-analysis sought to identify the strongest antecedents of blood donation behavior and intentions. It synthesized the results of 24 predictive correlational studies of donation behavior and 37 studies of donation intentions. The antecedents were grouped into six research programs: (1) the Theory of Planned Behavior (TPB) and its extensions, (2) prosocial motivation, (3) affective expectations, (4) donor site experience, (5) past donation behavior, and (6) donor demographics. Antecedent categories were cross-validated by multiple coders, and combined effect sizes were analyzed using a random-effects model. For donation behavior, medium positive associations were found with five of the constructs from the extended TPB: intentions to donate, perceived behavioral control, attitude toward donation, self-efficacy and donor role identity. Other antecedents displaying a positive association with donation behavior included anticipated regret for not donating, number of past donations and donor age. Donor experiences at the collection site in the form of temporary deferral or adverse reactions had a medium negative association with behavior. For donation intentions, strong positive associations were observed for perceived behavioral control, attitude, self-efficacy, role identity and anticipated regret. Medium positive associations were observed for personal moral norm, subjective norm, satisfaction, and service quality. All other potential antecedents had weak or non-significant associations with behavior and intentions. Several of these associations were moderated by between-study differences, including donor experience, the period of data collection in which donation behavior was observed, and the use of a nominal (yes/no return) versus a ratio measure of donation behavior. Collectively, the results underscore the importance of enhancing donors' attitudes towards donation and building their perceived behavioral control and self-efficacy to donate. Further, minimizing the risk of adverse reactions and enacting re-recruitment policies for temporarily deferred donors will help protect future donation behavior. Implications of these findings for blood collection agencies and researchers are discussed.