771 research outputs found

    Altered Cerebellar Biochemical Profiles in Infants Born Prematurely

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    This study aims to compare the cerebellar biochemical profiles in preterm (PT) infants evaluated at term equivalent age (TEA) and healthy full-term newborns using proton magnetic resonance spectroscopy (1H-MRS). We explore the associations between altered cerebellar metabolite profiles and brain injury topography, severity of injury, and prematurity-related clinical complications. We prospectively collected high quality 1H-MRS in 59 premature infants born ≀32 weeks and 61 healthy full term controls. 1H-MRS data were processed using LCModel software to calculate absolute metabolite concentration for N-acetyl-aspartate (NAA), choline (Cho) and creatine (Cr). PT infants had significantly lower cerebellar NAA (p \u3c 0.025) and higher Cho (p \u3c 0.001) at TEA when compared to healthy controls. Creatine was not different between the two groups. The presence of cerebellar injury was consistently associated with reduced concentrations for NAA, Cho, and Cr. Postnatal infection was negatively associated with NAA and Cr (p \u3c 005), while cerebral cortical brain injury severity was inversely associated with both Cho and Cr (p \u3c 0.01). We report for the first time that premature birth is associated with altered cerebellar metabolite profiles when compared to term born controls. Infection, cerebellar injury and supratentorial injury are important risk factors for impaired preterm cerebellar biochemistry

    Regional microstructural organization of the cerebral cortex is affected by preterm birth.

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    Objectives: To compare regional cerebral cortical microstructural organization between preterm infants at term-equivalent age (TEA) and healthy full-term newborns, and to examine the impact of clinical risk factors on cerebral cortical micro-organization in the preterm cohort. Study design: We prospectively enrolled very preterm infants (gestational age (GA) at birth\u3c32 \u3eweeks; birthweight\u3c1500 \u3eg) and healthy full-term controls. Using non-invasive 3T diffusion tensor imaging (DTI) metrics, we quantified regional micro-organization in ten cerebral cortical areas: medial/dorsolateral prefrontal cortex, anterior/posterior cingulate cortex, insula, posterior parietal cortex, motor/somatosensory/auditory/visual cortex. ANCOVA analyses were performed controlling for sex and postmenstrual age at MRI. Results: We studied 91 preterm infants at TEA and 69 full-term controls. Preterm infants demonstrated significantly higher diffusivity in the prefrontal, parietal, motor, somatosensory, and visual cortices suggesting delayed maturation of these cortical areas. Additionally, postnatal hydrocortisone treatment was related to accelerated microstructural organization in the prefrontal and somatosensory cortices. Conclusions: Preterm birth alters regional microstructural organization of the cerebral cortex in both neurocognitive brain regions and areas with primary sensory/motor functions. We also report for the first time a potential protective effect of postnatal hydrocortisone administration on cerebral cortical development in preterm infants

    Cerebral pressure passivity in newborns with encephalopathy undergoing therapeutic hypothermia

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    We extended our recent modification of the power spectral estimation approach to quantify spectral coherence. We tested both the standard and the modified approaches on simulated data, which showed that the modified approach was highly specific and sensitive to the coupling introduced in the simulation while the standard approach lacked these features. We also applied the modified and standard approaches to quantify the pressure passivity in 4 infants receiving therapeutic hypothermia. This was done by measuring the coupling between continuous cerebral hemoglobin differences and mean arterial blood pressure. Our results showed that the modified approach identified a lower pressure passivity index (PPI, percent time the coherence was above a predefined threshold) than the standard approach (P = 0.0027)

    Neonatal neurobehavioral abnormalities and MRI brain injury in encephalopathic newborns treated with hypothermia

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    Background Neonatal Encephalopathy (NE) is a prominent cause of infant mortality and neurodevelopmental disability. Hypothermia is an effective neuroprotective therapy for newborns with encephalopathy. Post-hypothermia functional–anatomical correlation between neonatal neurobehavioral abnormalities and brain injury findings on MRI in encephalopathic newborns has not been previously described. Aim To evaluate the relationship between neonatal neurobehavioral abnormalities and brain injury on magnetic resonance imaging (MRI) in encephalopathic newborns treated with therapeutic hypothermia. Study design Neonates with hypoxic ischemic encephalopathy (HIE) referred for therapeutic hypothermia were prospectively enrolled in this observational study. Neurobehavioral functioning was assessed with the NICU network neurobehavioral scale (NNNS) performed at target age 14 days. Brain injury was assessed by MRI at target age 7–10 days. NNNS scores were compared between infants with and without severe MRI injury. Subjects & outcome measures Sixty-eight term newborns (62% males) with moderate to severe encephalopathy underwent MRI at median 8 days (range 5–16) and NNNS at median 12 days of life (range 5–20). Fifteen (22%) had severe injury on MRI. Results Overall Total Motor Abnormality Score and individual summary scores for Non-optimal Reflexes and Asymmetry were higher, while Total NNNS Z-score across cognitive/behavioral domains was lower (reflecting poorer performance) in infants with severe MRI injury compared to those without (p \u3c 0.05). Conclusions Neonatal neurobehavioral abnormalities identified by the NNNS are associated with MRI brain injury in encephalopathic newborns post-hypothermia. The NNNS can provide an early functional assessment of structural brain injury in newborns, which may guide rehabilitative therapies in infants after perinatal brain injury

    Thiamine pyrophosphokinase deficiency causes a Leigh disease like phenotype in a sibling pair: Identification through whole exome sequencing and management strategies

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    We present a sibling pair with Leigh-like disease, progressive hypotonia, regression, and chronic encephalopathy. Whole exome sequencing in the younger sibling demonstrated a homozygous thiamine pyrophosphokinase (TPK) mutation. Initiation of high dose thiamine, niacin, biotin, α-lipoic acid and ketogenic diet in this child demonstrated improvement in neurologic function and re-attainment of previously lost milestones. The diagnosis of TPK deficiency was difficult due to inconsistent biochemical and diagnostic parameters, rapidity of clinical demise and would not have been made in a timely manner without the use of whole exome sequencing. Molecular diagnosis allowed for attempt at dietary modification with cofactor supplementation which resulted in an improved clinical cours

    Mild hypoxic-ischemic encephalopathy (HIE): Timing and pattern of MRI brain injury

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    BACKGROUND: Mild hypoxic-ischemic encephalopathy (HIE) is increasingly recognized as a risk factor for neonatal brain injury. We examined the timing and pattern of brain injury in mild HIE. METHODS: This retrospective cohort study includes infants with mild HIE treated at 9 hospitals. Neonatal brain MRIs were scored by 2 reviewers using a validated classification system, with discrepancies resolved by consensus. Severity and timing of MRI brain injury (i.e., acute, subacute, chronic) was scored on the subset of MRIs that were performed at or before 8 days of age. RESULTS: Of 142 infants with mild HIE, 87 (61%) had injury on MRI at median age 5 (IQR 4-6) days. Watershed (23%), deep gray (20%) and punctate white matter (18%) injury were most common. Among the 125 (88%) infants who received a brain MRI at ≀8 days, mild (44%) injury was more common than moderate (11%) or severe (4%) injury. Subacute (37%) lesions were more commonly observed than acute (32%) or chronic lesions (1%). CONCLUSION: Subacute brain injury is common in newborn infants with mild HIE. Novel neuroprotective treatments for mild HIE will ideally target both subacute and acute injury mechanisms. IMPACT: Almost two-thirds of infants with mild HIE have evidence of brain injury on MRI obtained in the early neonatal period. Subacute brain injury was seen in 37% of infants with mild HIE. Neuroprotective treatments for mild HIE will ideally target both acute and subacute injury mechanisms

    Parental Factors Associated With the Decision to Participate in a Neonatal Clinical Trial

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    Importance: It remains poorly understood how parents decide whether to enroll a child in a neonatal clinical trial. This is particularly true for parents from racial or ethnic minority populations. Understanding factors associated with enrollment decisions may improve recruitment processes for families, increase enrollment rates, and decrease disparities in research participation. Objective: To assess differences in parental factors between parents who enrolled their infant and those who declined enrollment for a neonatal randomized clinical trial. Design, setting, and participants: This survey study conducted from July 2017 to October 2019 in 12 US level 3 and 4 neonatal intensive care units included parents of infants who enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial or who were eligible but declined enrollment. Data were analyzed October 2019 through July 2020. Exposure: Parental choice of enrollment in neonatal clinical trial. Main outcomes and measures: Percentages and odds ratios (ORs) of parent participation as categorized by demographic characteristics, self-assessment of child's medical condition, study comprehension, and trust in medical researchers. Survey questions were based on the hypothesis that parents who enrolled their infant in HEAL differ from those who declined enrollment across 4 categories: (1) infant characteristics and parental demographic characteristics, (2) perception of infant's illness, (3) study comprehension, and (4) trust in clinicians and researchers. Results: Of a total 387 eligible parents, 269 (69.5%) completed the survey and were included in analysis. This included 183 of 242 (75.6%) of HEAL-enrolled and 86 of 145 (59.3%) of HEAL-declined parents. Parents who enrolled their infant had lower rates of Medicaid participation (74 [41.1%] vs 47 [55.3%]; P = .04) and higher rates of annual income greater than $55 000 (94 [52.8%] vs 30 [37.5%]; P = .03) compared with those who declined. Black parents had lower enrollment rates compared with White parents (OR, 0.35; 95% CI, 0.17-0.73). Parents who reported their infant's medical condition as more serious had higher enrollment rates (OR, 5.7; 95% CI, 2.0-16.3). Parents who enrolled their infant reported higher trust in medical researchers compared with parents who declined (mean [SD] difference, 5.3 [0.3-10.3]). There was no association between study comprehension and enrollment. Conclusions and relevance: In this study, the following factors were associated with neonatal clinical trial enrollment: demographic characteristics (ie, race/ethnicity, Medicaid status, and reported income), perception of illness, and trust in medical researchers. Future work to confirm these findings and explore the reasons behind them may lead to strategies for better engaging underrepresented groups in neonatal clinical research to reduce enrollment disparities

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe
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