Category: Brain

Association of Child Poverty, Brain Development, and Academic Achievement

pjgrier March 31, 2016 Brain, Hot Topics in Research

Association of Child Poverty, Brain Development, and Academic Achievement

Importance Children living in poverty generally perform poorly in school, with markedly lower standardized test scores and lower educational attainment. The longer children live in poverty, the greater their academic deficits. These patterns persist to adulthood, contributing to lifetime-reduced occupational attainment.
Objective To determine whether atypical patterns of structural brain development mediate the relationship between household poverty and impaired academic performance.
Design, Setting, and Participants Longitudinal cohort study analyzing 823 magnetic resonance imaging scans of 389 typically developing children and adolescents aged 4 to 22 years from the National Institutes of Health Magnetic Resonance Imaging Study of Normal Brain Development with complete sociodemographic and neuroimaging data. Data collection began in November 2001 and ended in August 2007. Participants were screened for a variety of factors suspected to adversely affect brain development, recruited at 6 data collection sites across the United States, assessed at baseline, and followed up at 24-month intervals for a total of 3 periods. Each study center used community-based sampling to reflect regional and overall US demographics of income, race, and ethnicity based on the US Department of Housing and Urban Development definitions of area income. One-quarter of sample households reported the total family income below 200% of the federal poverty level. Repeated observations were available for 301 participants.
Exposure Household poverty measured by family income and adjusted for family size as a percentage of the federal poverty level.
Main Outcomes and Measures Children’s scores on cognitive and academic achievement assessments and brain tissue, including gray matter of the total brain, frontal lobe, temporal lobe, and hippocampus.
Results Poverty is tied to structural differences in several areas of the brain associated with school readiness skills, with the largest influence observed among children from the poorest households. Regional gray matter volumes of children below 1.5 times the federal poverty level were 3 to 4 percentage points below the developmental norm (P < .05). A larger gap of 8 to 10 percentage points was observed for children below the federal poverty level (P < .05). These developmental differences had consequences for children’s academic achievement. On average, children from low-income households scored 4 to 7 points lower on standardized tests (P < .05). As much as 20% of the gap in test scores could be explained by maturational lags in the frontal and temporal lobes.
Conclusions and Relevance The influence of poverty on children’s learning and achievement is mediated by structural brain development. To avoid long-term costs of impaired academic functioning, households below 150% of the federal poverty level should be targeted for additional resources aimed at remediating early childhood environments.
Nicole L. Hair, PhD; Jamie L. Hanson, PhD; Barbara L. Wolfe, PhD; Seth D. Pollak, PhD
JAMA Pediatr. 2015;169(9):822-829. doi:10.1001/jamapediatrics.2015.1475.

Zebrafish Reel in Phenotypic Suppressors of Autism

pjgrier March 2, 2016 Brain, Hot Topics in Research

Zebrafish Reel in Phenotypic Suppressors of Autism
Chemical genetics can help decipher novel pathways underlying neurodevelopmental psychiatric impairments. Hoffman et al. (2016) utilized behavioral profiling of psychoactive compounds in zebrafish and identified estrogens as suppressors of a phenotype resulting from loss of an autism risk gene.

Neuron, Volume 89, Issue 4, 17 February 2016, Pages 673–675

Paradoxical Motor Recovery From a First Stroke After Induction of a Second Stroke: Reopening a Postischemic Sensitive Period

pjgrier February 8, 2016 Brain, Cardiology, Hot Topics in Research

Paradoxical Motor Recovery From a First Stroke After Induction of a Second Stroke: Reopening a Postischemic Sensitive Period
Abstract Background and objective. Prior studies have suggested that after stroke there is a time-limited period of increased responsiveness to training as a result of heightened plasticity—a sensitive period thought to be induced by ischemia itself. Using a mouse model, we have previously shown that most training-associated recovery after a caudal forelimb area (CFA) stroke occurs in the first week and is attributable to reorganization in a medial premotor area (AGm). The existence of a stroke-induced sensitive period leads to the counterintuitive prediction that a second stroke should reopen this window and promote full recovery from the first stroke. To test this prediction, we induced a second stroke in the AGm of mice with incomplete recovery after a first stroke in CFA. Methods. Mice were trained to perform a skilled prehension (reachto-grasp) task to an asymptotic level of performance, after which they underwent photocoagulation-induced stroke in CFA. After a 7-day poststroke delay, the mice were then retrained to asymptote. We then induced a second stroke in the AGm, and after only a 1-day delay, retrained the mice. Results. Recovery of prehension was incomplete when training was started after a 7-day poststroke delay and continued for 19 days. However, a second focal stroke in the AGm led to a dramatic response to 9 days of training, with full recovery to normal levels of performance. Conclusions. New ischemia can reopen a sensitive period of heightened responsiveness to training and mediate full recovery from a previous stroke.

Steven R. Zeiler, MD, PhD , Robert Hubbard , Ellen M. Gibson , Tony Zheng , Kwan Ng, MD, PhD , Richard O’Brien, MD, PhD , and John W. Krakauer, MD

Long-term toxic effects of proton radiotherapy for paediatric medulloblastoma: a phase 2 single-arm study

pjgrier Brain, Hot Topics in Research, Oncology, Pediatrics

Long-term toxic effects of proton radiotherapy for paediatric medulloblastoma: a phase 2 single-arm study

Background

Compared with traditional photon radiotherapy, proton radiotherapy irradiates less normal tissue and might improve health outcomes associated with photon radiotherapy by reducing toxic effects to normal tissue. We did a trial to assess late complications, acute side-effects, and survival associated with proton radiotherapy in children with medulloblastoma.

Methods

In this non-randomised, open-label, single-centre, phase 2 trial, we enrolled patients aged 3–21 years who had medulloblastoma. Patients had craniospinal irradiation of 18–36 Gy radiobiological equivalents (GyRBE) delivered at 1·8 GyRBE per fraction followed by a boost dose. The primary outcome was cumulative incidence of ototoxicity at 3 years, graded with the Pediatric Oncology Group ototoxicity scale (0–4), in the intention-to-treat population. Secondary outcomes were neuroendocrine toxic effects and neurocognitive toxic effects, assessed by intention-to-treat. This study is registered at ClinicalTrials.gov, number NCT00105560.

Findings

We enrolled 59 patients from May 20, 2003, to Dec 10, 2009: 39 with standard-risk disease, six with intermediate-risk disease, and 14 with high-risk disease. 59 patients received chemotherapy. Median follow-up of survivors was 7·0 years (IQR 5·2–8·6). All patients received the intended doses of proton radiotherapy. The median craniospinal irradiation dose was 23·4 GyRBE (IQR 23·4–27·0) and median boost dose was 54·0 GyRBE (IQR 54·0–54·0). Four (9%) of 45 evaluable patients had grade 3–4 ototoxicity according to Pediatric Oncology Group ototoxicity scale in both ears at follow-up, and three (7%) of 45 patients developed grade 3–4 ototoxicity in one ear, although one later reverted to grade 2. The cumulative incidence of grade 3–4 hearing loss at 3 years was 12% (95% CI 4–25). At 5 years, it was 16% (95% CI 6–29). Pediatric Oncology Group hearing ototoxicity score at a follow-up of 5·0 years (IQR 2·9–6·4) was the same as at baseline or improved by 1 point in 34 (35%) of 98 ears, worsened by 1 point in 21 (21%), worsened by 2 points in 35 (36%), worsened by 3 points in six (6%), and worsened by 4 points in two (2%). Full Scale Intelligence Quotient decreased by 1·5 points (95% CI 0·9–2·1) per year after median follow-up up of 5·2 years (IQR 2·6–6·4), driven by decrements in processing speed and verbal comprehension index. Perceptual reasoning index and working memory did not change significantly. Cumulative incidence of any neuroendocrine deficit at 5 years was 55% (95% CI 41–67), with growth hormone deficit being most common. We recorded no cardiac, pulmonary, or gastrointestinal late toxic effects. 3-year progression-free survival was 83% (95% CI 71–90) for all patients. In post-hoc analyses, 5-year progression-free survival was 80% (95% CI 67–88) and 5-year overall survival was 83% (95% CI 70–90).

Interpretation

Proton radiotherapy resulted in acceptable toxicity and had similar survival outcomes to those noted with conventional radiotherapy, suggesting that the use of the treatment may be an alternative to photon-based treatments.

Torunn I Yock, Beow Y Yeap, David H Ebb, Elizabeth Weyman, Bree R Eaton, Nicole A Sherry, Robin M Jones, Shannon M MacDonald, Margaret B Pulsifer, Beverly Lavally, Annah N Abrams, Mary S Huang, Karen J Marcus, Nancy J Tarbell

The Lancet Oncology

Effects of aging on circadian patterns of gene expression in the human prefrontal cortex

pjgrier January 5, 2016 Brain, Dementia, Hot Topics in Research, Memory Impairment, Neurology

Effects of aging on circadian patterns of gene expression in the human prefrontal cortex
With aging, significant changes in circadian rhythms occur, including a shift in phase toward a “morning” chronotype and a loss of rhythmicity in circulating hormones. However, the effects of aging on molecular rhythms in the human brain have remained elusive. Here, we used a previously described time-of-death analysis to identify transcripts throughout the genome that have a significant circadian rhythm in expression in the human prefrontal cortex [Brodmann’s area 11 (BA11) and BA47]. Expression levels were determined by microarray analysis in 146 individuals. Rhythmicity in expression was found in ∼10% of detected transcripts (P < 0.05). Using a metaanalysis across the two brain areas, we identified a core set of 235 genes (q < 0.05) with significant circadian rhythms of expression. These 235 genes showed 92% concordance in the phase of expression between the two areas. In addition to the canonical core circadian genes, a number of other genes were found to exhibit rhythmic expression in the brain. Notably, we identified more than 1,000 genes (1,186 in BA11; 1,591 in BA47) that exhibited age-dependent rhythmicity or alterations in rhythmicity patterns with aging. Interestingly, a set of transcripts gained rhythmicity in older individuals, which may represent a compensatory mechanism due to a loss of canonical clock function. Thus, we confirm that rhythmic gene expression can be reliably measured in human brain and identified for the first time (to our knowledge) significant changes in molecular rhythms with aging that may contribute to altered cognition, sleep, and mood in later life.

Cho-Yi Chen, Proceedings of the National Academy of Sciences 2015 of the USA ; published ahead of print December 22, 2015, doi:10.1073/pnas.1508249112.

Findings from Structural MR Imaging in Military Traumatic Brain Injury

pjgrier Brain, Hot Topics in Research, Neurosurgery, Radiology

Findings from Structural MR Imaging in Military Traumatic Brain Injury

Purpose

To describe the initial neuroradiology findings in a cohort of military service members with primarily chronic mild traumatic brain injury (TBI) from blast by using an integrated magnetic resonance (MR) imaging protocol.

Materials and Methods

This study was approved by the Walter Reed National Military Medical Center institutional review board and is compliant with HIPAA guidelines. All participants were military service members or dependents recruited between August 2009 and August 2014. There were 834 participants with a history of TBI and 42 participants in a control group without TBI (not explicitly age- and sex-matched). MR examinations were performed at 3 T primarily with three-dimensional volume imaging at smaller than 1 mm³ voxels for the structural portion of the examination. The structural portion of this examination, including T1-weighted, T2-weighted, before and after contrast agent administrtion T2 fluid attenuation inversion recovery, and susceptibility-weighted images, was evaluated by neuroradiologists by using a modified version of the neuroradiology TBI common data elements (CDEs). Incident odds ratios (ORs) between the TBI participants and a comparison group without TBI were calculated.

Results

The 834 participants were diagnosed with predominantly chronic (mean, 1381 days; median, 888 days after injury) and mild (92% [768 of 834]) TBI. Of these participants, 84.2% (688 of 817) reported one or more blast-related incident and 63.0% (515 of 817) reported loss of consciousness at the time of injury. The presence of white matter T2-weighted hyperintense areas was the most common pathologic finding, observed in 51.8% (432 of 834; OR, 1.75) of TBI participants. Cerebral microhemorrhages were observed in a small percentage of participants (7.2% [60 of 834]; OR, 6.64) and showed increased incidence with TBI severity (P < .001, moderate and severe vs mild). T2-weighted hyperintense areas and microhemorrhages did not collocate by visual inspection. Pituitary abnormalities were identified in a large proportion (29.0% [242 of 834]; OR, 16.8) of TBI participants.

Conclusion

Blast-related injury and loss of consciousness is common in military TBI. Structural MR imaging demonstrates a high incidence of white matter T2-weighted hyperintense areas and pituitary abnormalities, with a low incidence of microhemorrhage in the chronic phase.

Radiology; 278;1 (Ahead of Print), Gerard Riedy, MD, PhD , Justin S. Senseney, MS , Wei Liu, DSc , John Ollinger, PhD , Elyssa Sham, BA , Pavel Krapiva, MD , Jigar B. Patel, MD , Alice Smith, MD , Ping-Hong Yeh, PhD , John Graner, PhD , Dominic Nathan, PhD , Jesus Caban, PhD , Louis M. French, PsyD , Jamie Harper, MPH , Victoria Eskay, BA , John Morissette , Terrence R. Oakes, PhD. DOI: http://dx.doi.org/10.1148/radiol.2015150438

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Category: Brain