Neuroanatomical consequences of very preterm birth in middle childhood

Individuals born preterm can demonstrate reductions in brain volume, cortical surface area and thickness. However, the extent of these neuroanatomical deficits and the relation among these measures in middle childhood, a critical developmental period, have not been determined. We assessed differences in brain structure by acquiring high-resolution T₁-weighted scans in 25 children born very preterm (<32 weeks gestational age) without significant post-natal neurological sequelae and 32 age-matched term-born children (7–10 years). Children born very preterm had decreased brain volume, surface area and cortical thickness compared to term-born children. Furthermore, children born preterm did not display the robust relation between total brain volume and basal ganglia and thalamic volume apparent in the term-born children. Cortical thickness analyses revealed that the cortex was thinner for children born preterm than term-born children in the anterior cingulate cortex/supplementary motor area, isthmus of the cingulate gyrus, right superior temporal sulcus, right anterior insula, postcentral gyrus and precuneus. Follow-up analyses revealed that right precuneus thickness was correlated with gestational age. Thus, even without significant postnatal medical sequelae, very preterm-born children showed atypical brain structure and developmental patterns in areas related to higher cognitive function. Disruptions of the typical neurodevelopmental trajectory in the third trimester of pregnancy likely underlie these differences persisting into middle childhood.     

Opportunistic and other infections in HIV-infected children in Latin America compared to a similar cohort in the United States

Opportunistic and other infections have declined since the introduction of highly active antiretroviral therapy (HAART) in developed countries but few studies have addressed the impact of HAART in HIV-infected children from developing countries. This study examines the prevalence and incidence of opportunistic and other infections in Latin America during the HAART era. Vertically HIV-infected children enrolled in a cohort study between 2002 and 2007 were followed for the occurrence of 29 targeted infections. Cross-sectional and longitudinal analyses were performed to calculate the prevalence of infections before enrollment and the incidence rates of opportunistic and other infections after enrollment. Comparisons were made with data from a U.S. cohort (PACTG 219C). Of the 731 vertically HIV-infected children 568 (78%) had at least one opportunistic or other infection prior to enrollment. The most prevalent infections were bacterial pneumonia, oral candidiasis, varicella, tuberculosis, herpes zoster, and Pneumocystis jiroveci pneumonia. After enrollment, the overall incidence was 23.5 per 100 person-years; the most common infections (per 100 person-years) were bacterial pneumonia (7.8), varicella (3.0), dermatophyte infections (2.9), herpes simplex (2.5), and herpes zoster (1.8). All of these incidence rates were higher than those reported in PACTG 219C. The types and relative distribution of infections among HIV-infected children in Latin America in this study are similar to those seen in the United States but the incidence rates are higher. Further research is necessary to determine the reasons for these higher rates.     

A systematic review of tests to predict cerebral palsy in young children

Aim

This systematic review evaluates the accuracy of predictive assessments and investigations used to assist in the diagnosis of cerebral palsy (CP) in preschool‐age children (<5y).

Method

Six databases were searched for studies that included a diagnosis of CP validated after 2 years of age. The validity of the studies meeting the criteria was evaluated using the Standards for Reporting Diagnostic Accuracy criteria. Where possible, results were pooled and a meta‐analysis was undertaken.

Results

Nineteen out of 351 studies met the full inclusion criteria, including studies of general movements assessment (GMA), cranial ultrasound, brain magnetic resonance imaging (MRI), and neurological examination. All studies assessed high‐risk populations including preterm (gestational range 23–41wks) and low‐birthweight infants (range 500–4350g). Summary estimates of sensitivity and specificity of GMA were 98% (95% confidence interval [CI] 74–100%) and 91% (95% CI 83–93%) respectively; of cranial ultrasound 74% (95% CI 63–83%) and 92% (95% CI 81–96%) respectively; and of neurological examination 88% (95% CI 55–97%) and 87% (95% CI 57–97%) respectively. MRI performed at term corrected age (in preterm infants) appeared to be a strong predictor of CP, with sensitivity ranging in individual studies from 86 to 100% and specificity ranging from 89 to 97% There was inadequate evidence for the use of other predictive tools.

Summary

This review found that the assessment with the best evidence and strength for predictive accuracy is the GMA. MRI has a good predictive value when performed at term‐corrected age. Cranial ultrasound is as specific as MRI and has the advantage of being readily available at the bedside. Studies to date have focused on high‐risk infants. The accuracy of these tests in low‐risk infants remains unclear and requires further research.     

Hydrogen Peroxide in Exhaled Breath Condensate (EBC) vs Eosinophil Count in Induced Sputum (IS) in Parenchymal vs Airways Lung Diseases"

We compared exhaled breath condensate (EBC) and induced sputum (IS) for assessing inflammation in pulmonary diseases in patients with obstructive lung disease (n = 20), persistent cough >6 months (n = 20), interstitial lung disease (n = 25) and controls (n = 10). EBC was collected by suspending a Teflon perfluoroalkoxy tube installed in an ice-filled container and connected to a polypropylene test tube. IS was recovered after 20’ inhalation of 3% saline with an ultrasonic nebulizer, and 300 cells were differentially counted in cytospin Giemsa-stained slides. H₂0₂ was measured by a method based on oxidation of phenolsulfonphthalein (phenol red) mediated by horseradish peroxidases and H₂0₂. Pulmonary function tests were performed by conventional methods. H₂0₂ levels in EBC and % eosinophils in IS were significantly different between groups. A positive and significant correlation was found between % eosinophils in IS and the levels of H₂0₂ in EBC for each group and for all patients combined.     

Pulmonary sequestration of cardioplegia administered via the aortic root during aortocoronary bypass surgery

A semi-quantitative method was devised of tracing blood flow through the heart and lungs at the time of cardioplegia delivery and circulatory arrest of the heart during coronary artery bypass graft surgery (CABG). There were no previous studies confirming or disputing an accepted 'observation' by cardiac surgeons that cardioplegia solution does enter the lung parenchyma during cardiopulmonary bypass (CPB). This study was conducted as part of a larger (n = 142) double-blind, randomised, controlled, clinical research study. OBJECTIVE: The objective was initially to establish the efficacy of measures to prevent cardioplegia entering the lungs and, subsequently, to determine whether cardioplegia indeed circulates through the lung parenchyma or merely accumulates and 'pools'. METHOD: A prospective study on 20 consecutive patients (5 per group) admitted for CABG was made. Technetium (Tc-99m), a radioactive isotope, was added to the cold blood cardioplegia solution prior to cardioplegia delivery in order to track flow of cardioplegia solution. An independent nuclear medicine radiographer measured the samples with the use of a 'Curimentor' dose calibrator for presence and quantity of radiation in the samples. Decay was factored into the results. The Tc-99m tracer samples were also analysed using Gamma Acquisition and Analysis on the Genie 2000vdm Well Counter to confirm the presence and quantity of Tc-99m. RESULTS: In the four groups, it was confirmed that the pulmonary artery (PA) vent is 90-100% effective in retrieving any cardioplegia solution not drained by the atriocaval cannulae. CONCLUSIONS: The PA vent is effective in preventing cold blood cardioplegia solution from entering the lungs. Any cardioplegia that does enter the lung parenchyma during CPB circulates through the lungs and can be retrieved by a vent in the left atrium. This method may be useful in other studies that require investigation.