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Perelman School of Medicine University of Pennsylvania, Philadelphia, PA, 5/19/2008
University of Washington Pediatric Residency, Seattle, WA, 06/30/2011
Stanford University Developmental-Behavioral Pediatrics Fellowship, Palo Alto, CA, 07/06/2020
Pediatrics, American Board of Pediatrics
View details for DOI 10.1097/DBP.0000000000000793
View details for Web of Science ID 000526690100004
View details for Web of Science ID 000526852800038
To determine whether variability in diffusion MRI (dMRI) white matter tract metrics, obtained in a cohort of preterm infants prior to neonatal hospital discharge, would be associated with language outcomes at age 2years, after consideration of age at scan and number of major neonatal complications.30 children, gestational age 28.9 (2.4) weeks, underwent dMRI at mean post menstrual age 36.4 (1.4) weeks and language assessment with the Bayley Scales of Infant Development-III at mean age 22.2 (1.7) months chronological age. Mean fractional anisotropy (FA) and mean diffusivity (MD) were calculated for 5 white matter tracts. Hierarchical linear regression assessed associations between tract FA, moderating variables, and language outcomes.FA of the left inferior longitudinal fasciculus accounted for 17% (p=0.03) of the variance in composite language and FA of the posterior corpus callosum accounted for 19% (p=0.02) of the variance in composite language, beyond that accounted for by post-menstrual age at scan and neonatal medical complications. The number of neonatal medical complications moderated the relationship between language and posterior corpus callosum FA but did not moderate the association in the other tract.Language at age 2 is associated with white matter metrics in early infancy in preterm children. The different pattern of associations by fiber group may relate to the stage of brain maturation and/or the nature and timing of medical complications related to preterm birth. Future studies should replicate these findings with a larger sample size to assure reliability of the findings.
View details for DOI 10.1016/j.nicl.2020.102446
View details for PubMedID 33035964
View details for DOI 10.1016/j.nicl.2019.101832
View details for Web of Science ID 000485804400037
The impact of childhood Crohn's disease (CD) on volumetric bone mineral density (vBMD), bone structure, and muscle mass have not been established. The objective of this longitudinal study was to assess musculoskeletal outcomes in an incident cohort of children with CD using peripheral quantitative computed tomography (pQCT).Tibia pQCT was performed in 78 CD subjects (ages, 5-18 years) at diagnosis and in 67 over the subsequent year. pQCT outcomes were converted to sex- and race-specific z scores based on reference data in over 650 controls. Multivariable linear regression models identified factors associated with changes in bone outcomes.At diagnosis, CD subjects had significant deficits in trabecular vBMD (z score, -1.32+/-1.32; P< .001), cortical section modulus (a measure of bone geometry and strength) (z score, -0.44+/-1.11; P< .01), and muscle (z score, -0.96+/-1.02; P< .001) compared with controls. Over the first 6 months, trabecular vBMD and muscle z scores improved significantly (both, P< .001); however, section modulus worsened (P= .0001), and all 3 parameters remained low after 1 year. Increases in muscle z scores were associated with less severe declines in cortical section modulus z scores. Improvements in trabecular vBMD z scores were greater in prepubertal subjects. Glucocorticoids were associated with increases in cortical vBMD.Substantial deficits in trabecular vBMD, cortical bone geometry, and muscle were observed at CD diagnosis. Trabecular vBMD improved incompletely; however, cortical deficits progressed despite improvements in muscle. Glucocorticoids were not associated with bone loss. Therapies to improve bone accrual in childhood CD are needed.
View details for DOI 10.1053/j.gastro.2008.09.072
View details for Web of Science ID 000262028500020
View details for PubMedID 19026647
View details for PubMedCentralID PMC2705767
To identify determinants of musculoskeletal deficits (muscle cross-sectional area [mCSA], trabecular volumetric bone mineral density [vBMD], and cortical bone strength [section modulus]) in patients with juvenile idiopathic arthritis (JIA) and to determine if cortical bone strength is appropriately adapted to muscle forces.Peripheral quantitative computed tomography (pQCT) of the tibia was performed in 101 patients with JIA (79% female; 24 with oligoarticular JIA, 40 with polyarticular JIA, 18 with systemic JIA, and 19 with spondylarthritis [SpA]) and 830 healthy control subjects; all were ages 5-22 years. Outcomes of pQCT were expressed as sex- and race-specific Z scores. Multivariable linear regression models assessed mCSA and bone status in JIA patients compared with controls and identified factors associated with musculoskeletal deficits in JIA.The median duration of JIA was 40 months; 29% of the JIA patients had active arthritis, and 28% had received glucocorticoid therapy during the previous year. Compared with the controls, the mCSA and section modulus Z scores were significantly lower in patients with polyarticular JIA and those with SpA. Trabecular vBMD Z scores were significantly lower in patients with polyarticular JIA, those with systemic JIA, and those with SpA. Significant predictors of musculoskeletal deficits included active arthritis in the previous 6 months (mCSA), temporomandibular joint disease (mCSA and section modulus), functional disability (mCSA and vBMD), short stature (vBMD), infliximab exposure (vBMD), and JIA duration (section modulus). The section modulus was significantly reduced relative to mCSA in patients with JIA after adjustment for age and limb length.Marked deficits in vBMD and bone strength occur in JIA in association with severe and longstanding disease. Contrary to the findings of previous studies, bone deficits were greater than expected relative to the mCSA, which illustrates the importance of adjusting for age and bone length.
View details for DOI 10.1002/art.23683
View details for Web of Science ID 000259055400037
View details for PubMedID 18668565
View details for PubMedCentralID PMC2705769
Although children with juvenile idiopathic arthritis (JIA) are at risk for vertebral fractures, recent conventional posterior-anterior (PA) spine dual-energy X-ray absorptiometry studies reported minimal areal bone mineral density (aBMD, g/cm2) deficits. Width-adjusted BMD (WA-BMD, g/cm3) represents the bone mineral content (BMC) from the lateral projection, excluding the dense cortical spinous processes, divided by the estimated vertebral body volume based on paired PA-lateral bone dimensions. Therefore, WA-BMD may be more sensitive to JIA effects on the predominantly trabecular vertebral body. Age- and sex-specific Z-scores for spine aBMD and WA-BMD were generated in 84 JIA subjects compared with healthy controls, aged 5-21 yr. JIA was associated with lower mean WA-BMD Z-scores (-0.78, 95% CI: -1.03, -0.53; p<0.001) and aBMD Z-scores (-0.26, 95% CI: -0.49, -0.02; p<0.05), compared with controls. WA-BMD Z-scores were significantly lower than aBMD Z-scores in JIA (p<0.001). A significant JIA by age interaction (p<0.001) indicated that the magnitude of the difference between WA-BMD and aBMD Z-scores was greater in younger subjects. In conclusion, WA-BMD may be more sensitive to disease effects in children because it selectively measures the trabecular-rich vertebral body and is independent of growth-related changes in BMC of the dense spinous processes.
View details for DOI 10.1016/j.jocd.2007.10.005
View details for Web of Science ID 000256640900012
View details for PubMedID 18164636