Neurodevelopmental outcomes at 18 months of children diagnosed with CHD compared to children born very preterm.

OBJECTIVE: To compare neurodevelopmental outcomes and parent behaviour ratings of children born term with CHD to children born very preterm. METHODS: A clinical research sample of 181 children (CHD [n = 81]; very preterm [≤32 weeks; n = 100]) was assessed at 18 months. RESULTS: Children with CHD and born very preterm did not differ on Bayley-III cognitive, language, or motor composite scores, or on expressive or receptive language, or on fine motor scaled scores. Children with CHD had lower ross motor scaled scores compared to children born very preterm (p = 0.047). More children with CHD had impaired scores (<70 SS) on language composite (17%), expressive language (16%), and gross motor (14%) indices compared to children born very preterm (6%; 7%; 3%; ps < 0.05). No group differences were found on behaviours rated by parents on the Child Behaviour Checklist (1.5-5 years) or the proportion of children with scores above the clinical cutoff. English as a first language was associated with higher cognitive (p = 0.004) and language composite scores (p < 0.001). Lower median household income and English as a second language were associated with higher total behaviour problems (ps < 0.05). CONCLUSIONS: Children with CHD were more likely to display language and motor impairment compared to children born very preterm at 18 months. Outcomes were associated with language spoken in the home and household income.

Antenatal diagnosis, neonatal brain volumes, and neurodevelopment in transposition of the great arteries.

AIM: To examine whether antenatal diagnosis modifies relationships between neonatal brain volumes and 18-month neurodevelopmental outcomes in children with transposition of the great arteries (TGA). METHOD: In a retrospective cohort of 139 children with TGA (77 antenatally diagnosed), we obtained total brain volumes (TBVs) on pre- (n = 102) and postoperative (n = 112) magnetic resonance imaging. Eighteen-month neurodevelopmental outcomes were assessed using the Bayley Scales of Infant and Toddler Development, Third Edition. Generalized estimating equations with interaction terms were used to determine whether antenatal diagnosis modified associations between TBVs and neurodevelopmental outcomes accounting for postmenstrual age at scan, brain injury, and ventricular septal defect. RESULTS: Infants with postnatal diagnosis had more preoperative hypotension (35% vs 14%, p = 0.004). The interactions between antenatal diagnosis and TBVs were significantly related to cognitive (p = 0.003) outcomes. Specifically, smaller TBVs were associated with lower cognitive scores in infants diagnosed postnatally; this association was attenuated in those diagnosed antenatally. INTERPRETATION: Antenatal diagnosis modifies associations between neonatal brain volume and 18-month cognitive outcome in infants with TGA. These findings suggest that antenatal diagnosis may be neuroprotective, possibly through improved preoperative clinical status. These data highlight the need to improve antenatal diagnosis rates. WHAT THIS PAPER ADDS: Antenatal diagnosis of transposition of the great arteries modified relationships between neonatal brain volume and neurodevelopment. Smaller brain volumes related to poorer cognitive scores with postnatal diagnosis only. There was more preoperative hypotension in the postnatal diagnosis group.

Major Surgery, Brain Injury, and Neurodevelopmental Outcomes in Very Preterm Infants.

OBJECTIVES: We determined whether (1) major surgery is associated with an increased risk for brain injury and adverse neurodevelopment and (2) brain injury modifies associations between major surgery and neurodevelopment in very preterm infants. METHODS: Prospectively enrolled infants across 3 tertiary neonatal intensive care units underwent early-life and/or term-equivalent age MRI to detect moderate-severe brain injury. Eighteen-month neurodevelopmental outcomes were assessed with Bayley Scales of Infant and Toddler Development, third edition. Multivariable logistic and linear regressions were used to determine associations of major surgery with brain injury and neurodevelopment, adjusting for clinical confounders. RESULTS: There were 294 infants in this study. Major surgery was associated with brain injury (odds ratio 2.54, 95% CI 1.12-5.75, p = 0.03) and poorer motor outcomes (ß = -7.92, 95% CI -12.21 to -3.64, p < 0.001), adjusting for clinical confounders. Brain injury x major surgery interaction significantly predicted motor scores (p = 0.04): Lowest motor scores were in infants who required major surgery and had brain injury. DISCUSSION: There is an increased risk for brain injury and adverse motor outcomes in very preterm infants who require major surgery, which may be a marker of clinical illness severity. Routine brain MRI to detect brain injury and close neurodevelopmental surveillance should be considered in this subgroup of infants.

Early-life exposure to analgesia and 18-month neurodevelopmental outcomes in very preterm infants.

BACKGROUND: We assessed variability of analgesic use across three tertiary neonatal intensive care units (NICUs) accounting for early-life pain, quantified as number of invasive procedures. We also determined whether analgesia exposure modifies associations between early-life pain and neurodevelopment. METHODS: Multicenter prospective study of 276 very preterm infants (born <24-32 weeks' gestational age [GA]). Detailed data of number of invasive procedures and duration of analgesia exposure were collected in initial weeks after birth. Eighteen-month neurodevelopmental assessments were completed in 215 children with Bayley Scales for Infant Development-Third edition. RESULTS: Multivariable linear regressions revealed significant differences in morphine use across sites, for a given exposure to early-life pain (interaction p < 0.001). Associations between early-life pain and motor scores differed by duration of morphine exposure (interaction p = 0.01); greater early-life pain was associated with poorer motor scores in infants with no or long (>7 days) exposure, but not short exposure (≤7 days). CONCLUSIONS: Striking cross-site differences in morphine exposure in very preterm infants are observed even when accounting for early-life pain. Negative associations between greater early-life pain and adverse motor outcomes were attenuated in infants with short morphine exposure. These findings emphasize the need for further studies of optimal analgesic approaches in preterm infants. IMPACT: In very preterm neonates, both early-life exposure to pain and analgesia are associated with adverse neurodevelopment and altered brain maturation, with no clear guidelines for neonatal pain management in this population. We found significant cross-site variability in morphine use across three tertiary neonatal intensive care units in Canada. Morphine use modified associations between early-life pain and motor outcomes. In infants with no or long durations of morphine exposure, greater early-life pain was associated with lower motor scores, this relationship was attenuated in those with short morphine exposure. Further trials of optimal treatment approaches with morphine in preterm infants are warranted.

Association of Pediatric Buccal Epigenetic Age Acceleration With Adverse Neonatal Brain Growth and Neurodevelopmental Outcomes Among Children Born Very Preterm With a Neonatal Infection.

Importance: Very preterm neonates (24-32 weeks' gestation) remain at a higher risk of morbidity and neurodevelopmental adversity throughout their lifespan. Because the extent of prematurity alone does not fully explain the risk of adverse neonatal brain growth or neurodevelopmental outcomes, there is a need for neonatal biomarkers to help estimate these risks in this population. Objectives: To characterize the pediatric buccal epigenetic (PedBE) clock-a recently developed tool to measure biological aging-among very preterm neonates and to assess its association with the extent of prematurity, neonatal comorbidities, neonatal brain growth, and neurodevelopmental outcomes at 18 months of age. Design, Setting, and Participants: This prospective cohort study was conducted in 2 neonatal intensive care units of 2 hospitals in Toronto, Ontario, Canada. A total of 35 very preterm neonates (24-32 weeks' gestation) were recruited in 2017 and 2018, and neuroimaging was performed and buccal swab samples were acquired at 2 time points: the first in early life (median postmenstrual age, 32.9 weeks [IQR, 32.0-35.0 weeks]) and the second at term-equivalent age (TEA) at a median postmenstrual age of 43.0 weeks (IQR, 41.0-46.0 weeks). Follow-ups for neurodevelopmental assessments were completed in 2019 and 2020. All neonates in this cohort had at least 1 infection because they were originally enrolled to assess the association of neonatal infection with neurodevelopment. Neonates with congenital malformations, genetic syndromes, or congenital TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes and other agents) infection were excluded. Exposures: The extent of prematurity was measured by gestational age at birth and PedBE age difference. PedBE age was computed using DNA methylation obtained from 94 age-informative CpG (cytosine-phosphate-guanosine) sites. PedBE age difference (weeks) was calculated by subtracting PedBE age at each time point from the corresponding postmenstrual age. Main Outcomes and Measures: Total cerebral volumes and cerebral growth during the neonatal intensive care unit period were obtained from magnetic resonance imaging scans at 2 time points: approximately the first 2 weeks of life and at TEA. Bayley Scales of Infant and Toddler Development, Third Edition, were used to assess neurodevelopmental outcomes at 18 months. Results: Among 35 very preterm neonates (21 boys [60.0%]; median gestational age, 27.0 weeks [IQR, 25.9-29.9 weeks]; 23 [65.7%] born extremely preterm [<28 weeks' gestation]), extremely preterm neonates had an accelerated PedBE age compared with neonates born at a later gestational age (ß = 9.0; 95% CI, 2.7-15.3; P = .01). An accelerated PedBE age was also associated with smaller cerebral volumes (ß = -5356.8; 95% CI, -6899.3 to -2961.7; P = .01) and slower cerebral growth (ß = -2651.5; 95% CI, -5301.2 to -1164.1; P = .04); these associations remained significant after adjusting for clinical neonatal factors. These findings were significant at TEA but not earlier in life. Similarly, an accelerated PedBE age at TEA was associated with lower cognitive (ß = -0.4; 95% CI, -0.8 to -0.03; P = .04) and language (ß = -0.6; 95% CI, -1.1 to -0.06; P = .02) scores at 18 months. Conclusions and Relevance: This cohort study of very preterm neonates suggests that biological aging may be associated with impaired brain growth and neurodevelopmental outcomes. The associations between epigenetic aging and adverse neonatal brain health warrant further attention.

Prevalence, Risk Factors, and Impact of Preoperative Seizures in Neonates With Congenital Heart Disease.

PURPOSE: The purpose of this study was to assess the prevalence, risk factors, and impact of electrographic seizures in neonates with complex congenital heart disease before cardiac surgery. METHODS: A cohort of 31 neonates with congenital heart disease monitored preoperatively with continuous video-EEG (cEEG) was first reviewed for electrographic seizure burden and EEG background abnormalities. Second, cEEG findings were correlated with brain MRI and 18-month outcomes. RESULTS: Continuous video-EEG was recorded preoperatively for a median duration of 20.5 hours (range, 2.5-93.5 hours). The five neonates (16%; 95% confidence interval, 5.5% to 34%) with seizures detected on cEEG in the preoperative period had a diagnosis of transposition of the great arteries or similar physiology, detected in four of five postnatally. None of the 157 recorded electrographic seizures had a clinical correlate. The median time to first seizure was 65 minutes (range, 6-300 minutes) after cEEG hookup. The median maximum hourly seizure burden was 12.4 minutes (range, 7-23 minutes). Before the first electrographic seizure, a prolonged interburst interval (>10 seconds) was not associated with seizures (coefficient 1.2; 95% confidence interval, -1.1 to 3.6). MRI brain lesions were three times more common in neonates with seizures. Sharp wave transients on cEEG were associated with delayed opercular development. CONCLUSIONS: In this cohort, preoperative electrographic seizures were common, were all subclinical, and were associated with MRI brain injury and postnatal diagnosis of transposition of the great arteries. The findings motivate further study of the mechanisms of preoperative brain injury, particularly among neonates with a postnatal diagnosis of transposition of the great arteries.

Decreased Brain Volumes and Infants With Congenital Heart Disease Undergoing Venoarterial Extracorporeal Membrane Oxygenation.

OBJECTIVES: The aims of this study were to: i) determine the spectrum of brain injury and ii) compare brain volumes between pre- and postoperative brain MRI in the infants receiving extracorporeal membrane oxygenation compared with those who did not require extracorporeal membrane oxygenation. DESIGN: Cohort study of infants with D-transposition of the great arteries or single ventricle physiology. Brain volume (cm) was measured using a segmentation of a volumetric T1-weighted gradient echo sequence. Brain imaging findings (intraventricular hemorrhage, white matter injuries, and stroke) were analyzed with respect to known clinical risk factors for brain injury and adverse neurodevelopmental outcomes. Clinical factors were collected by retrospective chart review. The association between brain volume and extracorporeal membrane oxygenation was evaluated using generalized estimating equations to account for repeated measures. SETTING: Prospective and single-centered study. PATIENTS: One hundred nine infants (median gestational age, 39.1 wk) with D-transposition of the great arteries (n = 77) or single ventricle physiology (n = 32) were studied pre- and postoperatively with MRI as per clinical protocol. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 28 infants (26%) receiving extracorporeal membrane oxygenation, 19 (68%) were supported with extracorporeal membrane oxygenation once, and nine (32%) were supported 2-4 times. On postoperative MRI, new white matter injury was found in only five (17%) of the extracorporeal membrane oxygenation infants versus 40 (49%) in the non-extracorporeal membrane oxygenation group (p = 0.073). The rate of stroke (9% vs 10%), intraventricular hemorrhage (24% vs 29%), and hypoxic ischemia (3% vs 14%) did not differ between the non-extracorporeal membrane oxygenation and extracorporeal membrane oxygenation groups (all p > 0.5). Accounting for D-transposition of the great arteries or single ventricle physiology diagnosis, infants requiring extracorporeal membrane oxygenation had slower brain volume with single (ß = -1.67) or multiple extracorporeal membrane oxygenation runs ([ß = -6.54]; overall interaction p = 0.012). CONCLUSIONS: Patients with d-transposition of the great arteries or single ventricle physiology undergoing extracorporeal membrane oxygenation at our center have a similar incidence of brain injury but more significant impairment of perioperative brain volumes than those not requiring extracorporeal membrane oxygenation.

Brain Injury in Infants with Critical Congenital Heart Disease: Insights from Two Clinical Cohorts with Different Practice Approaches.

OBJECTIVES: To determine prevalence and risk factors for brain injury in infants with critical congenital heart disease (CHD) from 2 sites with different practice approaches who were scanned clinically. STUDY DESIGN: Prospective, longitudinal cohort study (2016-2017) performed at Hospital for Sick Children Toronto (HSC) and Wilhelmina Children's Hospital Utrecht (WKZ), including 124 infants with cardiac surgery ≤60 days (HSC = 77; WKZ = 47). Magnetic resonance imaging was performed per clinical protocol, preoperatively (n = 100) and postoperatively (n = 120). Images were reviewed for multifocal (watershed, white matter injury) and focal ischemic injury (stroke, single white matter lesion). RESULTS: The prevalence of ischemic injury was 69% at HSC and 60% at WKZ (P = .20). Preoperative multifocal injury was associated with low cardiac output syndrome (OR, 4.6), which was equally present at HSC and WKZ (20% vs 28%; P = .38). Compared with WKZ, HSC had a higher prevalence of balloon-atrioseptostomy in transposition of the great arteries (83% vs 53%; P = .01) and more frequent preoperative focal injury (27% vs 6%; P = .06). Postoperatively, 30% of new multifocal injury could be attributed to postoperative low cardiac output syndrome, which was equally present at HSC and WKZ (38% vs 28%; P = .33). Postoperative focal injury was associated with intraoperative selective cerebral perfusion in CHD with arch obstruction at both sites (OR, 2.7). Compared with HSC, WKZ had more arch obstructions (62% vs 35%; P < .01) and a higher prevalence of new focal injury (36% vs 16%; P = .01). CONCLUSIONS: Brain injury is common in clinical cohorts of infants with critical CHD and related to practice approaches. This study confirms that the high prevalence of brain injury in critical CHD is a clinical concern and does not simply reflect the inclusion criteria of published research studies.

Associations Between Age at Arterial Switch Operation, Brain Growth, and Development in Infants With Transposition of the Great Arteries.

BACKGROUND: Brain injury, impaired brain growth, and long-term neurodevelopmental problems are common in children with transposition of the great arteries. We sought to identify clinical risk factors for brain injury and poor brain growth in infants with transposition of the great arteries undergoing the arterial switch operation, and to examine their relationship with neurodevelopmental outcome. METHODS: The brains of 45 infants with transposition of the great arteries undergoing surgical repair were imaged pre- and postoperatively using magnetic resonance imaging. Brain weight z scores were calculated based on brain volume and autopsy reference data. Brain injury scores were determined as previously described. Neurodevelopment was assessed at 18 months using the Bayley-III scores of infant development. The relationships between clinical variables, brain injury, perioperative brain growth, and 18-month Bayley-III scores were analyzed. RESULTS: On preoperative imaging, moderate or severe white matter injury was present in 10 of 45 patients, whereas stroke was seen in 4 of 45. A similar prevalence of injury was seen on postoperative imaging, and we were unable to identify any clinical risk factors for brain injury. Brain weight z scores decreased perioperatively in 35 of 45 patients. The presence of a ventricular septal defect ( P=0.009) and older age at surgery ( P=0.007) were associated with impaired perioperative brain growth. When patients were divided into those undergoing surgery during the first 2 weeks of life (32/45) versus those being repaired later (13/45), infants repaired later had significantly worse perioperative brain growth (late repair postoperative brain weight z = -1.0±0.90 versus early repair z = -0.33±0.64; P=0.008). Bayley-III testing scores fell within the normal range for all patients, although age at repair ( P=0.03) and days of open chest ( P=0.03) were associated with a lower composite language score, and length of stay was associated with a lower composite cognitive score ( P=0.02). CONCLUSIONS: Surgery beyond 2 weeks of age is associated with impaired brain growth and slower language development in infants with transposition of the great arteries cared for at our center. Although the mechanisms underlying this association are still unclear, extended periods of cyanosis and pulmonary overcirculation may adversely impact brain growth and subsequent neurodevelopment.

Anticoagulation therapy and the risk of perioperative brain injury in neonates with congenital heart disease.

OBJECTIVE: There is considerable variability in anticoagulation use in neonates with transposition of the great arteries (TGA) and single ventricle physiology (SVP) for secondary stroke prevention and primary cardiovascular indications. Leveraging cross-center differences in anticoagulation use, we compared the risk of new postoperative brain injury in neonates with TGA and SVP treated with anticoagulation relative to untreated neonates. METHODS: Two-center observational cohort study of 118 term-born neonates with TGA (n = 83) and SVP (n = 35), undergoing cardiopulmonary bypass surgery and pre- and postoperative brain magnetic resonance imaging. Anticoagulation and antiplatelet therapy details were obtained. Magnetic resonance images were scored for stroke, white matter injury, and hemorrhage. New postoperative injury was compared between neonates with and without anticoagulation for the 2-center cohort, and subsequently stratified by cardiac lesion type and anticoagulation indication. RESULTS: Thirty-six out of 118 neonates (29%) received anticoagulation: 11 (30%) for preoperative stroke, 20 (56%) for preoperative peripheral/intracardiac thrombus, and 5 (14%) for Blalock-Taussig shunt. Five out of 36 neonates (14%) treated with anticoagulation also received antiplatelet therapy. Although no differences were identified for the 2-center cohort or for neonates with TGA separately, significantly more new postoperative parenchymal brain injury (P = .04), particularly stroke, was found in SVP neonates with compared to without anticoagulation (31% vs 5%). In neonates who experienced preoperative stroke, new subdural hemorrhage (36% vs 0%) was more frequent in neonates treated with anticoagulation therapy compared with those without anticoagulation therapy. CONCLUSIONS: In our cohort of neonates with TGA and SVP, anticoagulation for preoperative stroke, preoperative thrombus, and/or Blalock-Taussig shunt did not have the anticipated benefit of preventing new perioperative brain injury. These findings indicate the critical need for rigorous randomized trials on the safety and effectiveness of anticoagulation therapy in this population.

Early Procedural Pain Is Associated with Regionally-Specific Alterations in Thalamic Development in Preterm Neonates.

Very preterm human neonates are exposed to numerous invasive procedures as part of life-saving care. Evidence suggests that repetitive neonatal procedural pain precedes long-term alterations in brain development. However, to date the link between pain and brain development has limited temporal and anatomic specificity. We hypothesized that early exposure to painful stimuli during a period of rapid brain development, before pain modulatory systems reach maturity, will predict pronounced changes in thalamic development, and thereby cognitive and motor function. In a prospective cohort study, 155 very preterm neonates (82 males, 73 females) born 24-32 weeks' gestation underwent two MRIs at median postmenstrual ages 32 and 40 weeks that included structural, metabolic, and diffusion imaging. Detailed day-by-day clinical data were collected. Cognitive and motor abilities were assessed at 3 years, corrected age. The association of early (skin breaks, birth-Scan 1) and late pain (skin breaks, Scans 1-2) with thalamic volumes and N-acetylaspartate (NAA)/choline (Cho), and fractional anisotropy of white-matter pathways was assessed. Early pain was associated with slower thalamic macrostructural growth, most pronounced in extremely premature neonates. Deformation-based morphometry analyses confirmed early pain-related volume losses were localized to somatosensory regions. In extremely preterm neonates early pain was associated with decreased thalamic NAA/Cho and microstructural alterations in thalamocortical pathways. Thalamic growth was in turn related to cognitive and motor outcomes. We observed regionally-specific alterations in the lateral thalamus and thalamocortical pathways in extremely preterm neonates exposed to more procedural pain. Findings suggest a sensitive period leading to lasting alterations in somatosensory-system development.SIGNIFICANCE STATEMENT Early exposure to repetitive procedural pain in very preterm neonates may disrupt the development of regions involved in somatosensory processing, leading to poor functional outcomes. We demonstrate that early pain is associated with thalamic volume loss in the territory of the somatosensory thalamus and is accompanied by disruptions thalamic metabolic growth and thalamocortical pathway maturation, particularly in extremely preterm neonates. Thalamic growth was associated with cognitive and motor outcome at 3 years corrected age. Findings provide evidence for a developmentally sensitive period whereby subcortical structures in young neonates may be most vulnerable to procedural pain. Furthermore, results suggest that the thalamus may play a key role underlying the association between neonatal pain and poor neurodevelopmental outcomes in these high-risk neonates.

Monomeric red fluorescent protein as a reporter for macromolecular localization in Streptomyces coelicolor.

The enhanced green fluorescent protein (eGFP) is widely used to investigate cell type specific gene expression and protein localization in the filamentous streptomycetes. To broaden the scope of cell biological investigation in these organisms, we have adapted shuttle vectors for the construction of gene fusions to the monomeric red fluorescent protein (mRFP1) and have tested them in Streptomyces coelicolor. Using fusions of mRFP1 to the cell division proteins DivIVA and FtsZ, we show that mRFP1 is comparable to eGFP for cell biological research in this organism and suggest that this paves the way for the future use of two-color imaging and FRET.