Impaired neuroanatomic development in infants with congenital heart disease

Early brain magnetic resonance imaging findings and neurodevelopmental outcome in children with congenital heart disease: A systematic review

AIM

To investigate the association between early brain magnetic resonance imaging (MRI) findings and neurodevelopmental outcome (NDO) in children with congenital heart disease (CHD).

METHOD

A search for studies was conducted in Embase, Medline, Web of Science, Cochrane Central, PsycINFO, and Google Scholar. Observational and interventional studies were included, in which patients with CHD underwent surgery before 2 months of age, a brain MRI scan in the first year of life, and neurodevelopmental assessment beyond the age of 1 year.

RESULTS

Eighteen studies were included. Thirteen found an association between either quantitative or qualitative brain metrics and NDO: 5 out of 7 studies showed decreased brain volume was significantly associated with worse NDO, as did 7 out of 10 studies on brain injury. Scanning protocols and neurodevelopmental tests varied strongly.

INTERPRETATION

Reduced brain volume and brain injury in patients with CHD can be associated with impaired NDO, yet standardized scanning protocols and neurodevelopmental assessment are needed to further unravel trajectories of impaired brain development and its effects on outcome.

Increased Cerebello-Prefrontal Connectivity Predicts Poor Executive Function in Congenital Heart Disease

BACKGROUND

Children and adolescents with congenital heart disease (CHD) are at risk for cognitive impairments, such as executive function deficits and motor delays, which can impact their academic and adaptive functioning as well as their quality of life. We investigated whether alterations in connectivity between the prefrontal and cerebellar brain structures exist between CHD and control cohorts and if these alterations could predict cognitive or motor impairment among youths with CHD.

METHODS

53 participants with CHD and 73 healthy control participants completed multi-modal magnetic resonance imaging (MRI) of the brain, including high-resolution diffusion tensor imaging at 3T. We measured connectivity from masked regions of interest in the cerebellum to the frontal cortex using a probabilistic tractography method. Participants also completed neuropsychological tests of cognitive and motor skills using the NIH Toolbox.

RESULTS

In the CHD group, fractional anisotropy (FA) was increased in the cognitive loop connectivity pathways, including from the right cerebellum to the left thalamus (p = 0.0002) and from the left thalamus to the left medial frontal gyrus (MFG) (p = 0.0048) compared with the healthy control group. In contrast, there were no differences between CHD and controls in motor loop connectivity pathways. An increase in FA from the right thalamus to the MFG tract in the cognitive loop (posterior subdivision) predicted (p = 0.03) lower scores on the NIHTB tests, including those of executive functioning. A transient increase in connectivity of the cognitive loop in the adolescent group was observed relative to the child and adult groups.

CONCLUSIONS

Our results suggest that selective alteration of cerebellum-cerebral connectivity circuitry within the cognitive loops predicts cognitive dysfunction in CHD youth. Our study suggests a critical period of cerebellar circuitry plasticity in the adolescent period in CHD subjects that drives neurocognitive function. Further replication and validation in other pediatric CHD cohorts is warranted for future work.

Perioperative Course and Socioeconomic Status Predict Long-Term Neurodevelopment Better Than Perioperative Conventional Neuroimaging in Children with Congenital Heart Disease

OBJECTIVE

The objective of the study was to compare the use of neonatal conventional brain magnetic resonance imaging (MRI) with that of clinical factors and socioeconomic status (SES) to predict long-term neurodevelopment in children with severe congenital heart disease (CHD).

STUDY DESIGN

In this prospective cohort study, perioperative MRIs were acquired in 57 term-born infants with CHD undergoing cardiopulmonary bypass surgery during their first year of life. Total brain volume (TBV) was measured using an automated method. Brain injury severity (BIS) was assessed by an established scoring system. The neurodevelopmental outcome was assessed at 6 years using standardized test batteries. A multiple linear regression model was used for cognitive and motor outcomes with postoperative TBV, perioperative BIS, CHD complexity, length of hospital stay, and SES as covariates.

RESULTS

CHD diagnoses included univentricular heart defect (n = 15), transposition of the great arteries (n = 33), and acyanotic CHD (n = 9). Perioperative moderate-to-severe brain injury was detected in 15 (26%) patients. The total IQ was similar to test norms (P = .11), whereas the total motor score (P < .001) was lower. Neither postoperative TBV nor perioperative BIS predicted the total IQ, but SES (P < .001) and longer hospital stay (P = .004) did. No factor predicted the motor outcome.

CONCLUSION

Although the predictive value of neonatal conventional MRIs for long-term neurodevelopment is low, duration of hospital stay and SES better predict the outcome in this CHD sample. These findings should be considered in initiating early therapeutic support.

Fontan Circulation Associated Organ Abnormalities Beyond the Heart, Lungs, Liver, and Gut: A Systematic Review

Introduction

Patients with a Fontan circulation are at risk for sequelae of Fontan physiology during follow-up. Fontan physiology affects all organ systems and an overview of end-organ damage is needed.

Methods

We performed a systematic review of abnormalities in multiple organ systems for patients with a longstanding Fontan circulation. We searched online databases for articles describing abnormalities in multiple organ systems. Cardio-pulmonary abnormalities, protein losing enteropathy, and Fontan associated liver disease have already extensively been described and were excluded from this systematic review.

Results

Our search returned 5,704 unique articles. After screening, we found 111 articles relating to multiple organ systems. We found abnormalities in, among others, the nervous system, pituitary, kidneys, and musculoskeletal system. Pituitary edema—relating to the unique pituitary vasculature- may affect the thyroid axis. Renal dysfunction is common. Creatinine based renal function estimates may be inappropriate due to myopenia. Both lean muscle mass and bone mineral density are decreased. These abnormalities in multiple organ systems may be related to Fontan physiology, cyanosis, iatrogenic factors, or lifestyle.

Conclusions

Health care providers should be vigilant for hypothyroidism, visual or hearing deficits, and sleep disordered breathing in Fontan patients. We recommend including cystatin C for assessment of renal function. This review may aid health care providers and guide future research.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021232461, PROSPERO, identifier: CRD42021232461.

MRI studies of brain size and growth in individuals with congenital heart disease

Congenital heart disease (CHD) is the most frequent congenital abnormality. Most infants born with CHD now survive. However, survivors of CHD are at increased risk of neurodevelopmental impairment, which may be due to impaired brain development in the fetal and neonatal period. Magnetic resonance imaging (MRI) provides objective measures of brain volume and growth. Here, we review MRI studies assessing brain volume and growth in individuals with CHD from the fetus to adolescence. Smaller brain volumes compared to healthy controls are evident from around 30 weeks gestation in fetuses with CHD and are accompanied by increased extracerebral cerebrospinal fluid. This impaired brain growth persists after birth and throughout childhood to adolescence. Risk factors for impaired brain growth include reduced cerebral oxygen delivery in utero, longer time to surgery and increased hospital stay. There is increasing evidence that smaller total and regional brain volumes in this group are associated with adverse neurodevelopmental outcome. However, to date, few studies have assessed the association between early measures of cerebral volume and neurodevelopmental outcome in later childhood. Large prospective multicentre studies are required to better characterise the relationship between brain volume and growth, clinical risk factors and subsequent cognitive, motor, and behavioural impairments in this at-risk population.

Clinical features of very-low-birthweight infants with congenital heart disease

BACKGROUND

Few studies have investigated the developmental prognosis of very-low-birthweight (VLBW) infants with congenital heart diseases (CHDs). This study aimed to determine the mortality and morbidity, including the developmental prognosis, of VLBW infants with CHD.

METHODS

This single-center, retrospective cohort study included VLBW infants admitted to the neonatal intensive care unit from January 2006 to December 2011. Perinatal records were reviewed for CHD diagnosis, treatment details, comorbidities, mortality, and long-term neurodevelopmental outcomes. The characteristics and neurological developmental quotients at around the age of 3 years were compared among the following three groups of VLBW infants with CHDs: biventricular circulation without intervention (without surgery), biventricular circulation with intervention (catheter intervention or one-stage surgery), and single-ventricular circulation (Fontan-type multiple-stage surgery).

RESULTS

Among a total of 449 VLBW infants admitted during this period, 45 (10.0%) infants had CHDs, including 25 infants with congenital abnormalities (chromosomal abnormalities and/or multiple anomalies). All 13 infants who died before discharge had congenital abnormalities. The incidence rates of comorbidities were not higher in VLBW infants with CHDs than in those without CHDs. The developmental quotients of the no-surgery, catheter intervention or one-stage surgery, and Fontan-type multiple-stage surgery groups were 87.2 ± 10.9, 91.3 ± 4.7, and 63.7 ± 8.6, respectively.

CONCLUSIONS

The neurological development at around the age of 3 years in VLBW infants with biventricular circulation was in the borderline-to-normal range; however, that in infants with single-ventricular circulation was poor. Further studies are needed to comprehend the neurological development of VLBW infants with CHDs better.

Early school-age cognitive performance post-pediatric heart transplantation

BACKGROUND

As survival in pediatric heart transplantation (HTx) has improved due to medical advances, the analysis of long-term outcomes impacting quality of life such as cognition and development becomes increasingly important. Neuropsychological assessments provide a comprehensive understanding of individual needs, allowing for the development of tailored recommendations and interventions.

METHODS

Routine neuropsychological assessment was completed between 5 and 7 years of age in this cohort of pediatric HTx recipients at our center (Jan 2014-Oct 2018), including tests of general intellect (WPPSI-IV, WISC-V), academics (WIAT-II/III), perceptual-motor abilities (Beery VMI), and memory (CMS). Relevant medical variables were collected.

RESULTS

Among 25 children, the median age at testing was 6.7 (IQR:5.8-7.4) years, with a median time since HTx of 5.2 (IQR:4.8-6.8) years. Medical diagnoses included congenital heart disease (CHD; 56%) and cardiomyopathy (44%). Cognitive functioning across the intellectual, academic, and perceptual-motor domains fell within the low-average range, while memory abilities fell within the average range. DSM-5 clinical diagnoses were provided for 14 (56%) children: Intellectual Disability-Mild (20%), Learning Disability (20%), Language Disorder (8%), and Attention-Deficit/Hyperactivity Disorder (12%). The presence of neurological issues and/or CHD predicted poorer performance on various neuropsychological domains.

CONCLUSIONS

Over 50% of this cohort of pediatric heart transplant recipients seen for routine post-HTx neuropsychological assessment received a clinical psychological diagnosis, notably higher than rates in the general population. This population requires monitoring to ensure that high risk children are identified and successfully supported in school and their community.

Toddler Neurodevelopmental Outcomes Are Associated With School-Age IQ in Children With Single Ventricle Physiology

To examine whether neurodevelopment at preschool age predicts IQ levels and needs for special education services in school-age children with single ventricle (SV) physiology. Thirty-five patients with SV physiology were assessed using the Bayley Scale of Infant and Toddler Development (BSID) II or III at 3 years and the Wechsler Intelligence Scale for Children-Fourth Edition (WISC) at 8 years. Whether the children were receiving special education services was also determined. Factors associated with the mental developmental index (MDI) of the BSID, the full-scale IQ (FSIQ) of the WISC, and special education services were also analyzed. The MDI and FSIQ of children with SV physiology were significantly lower than the values in healthy children (P < 0.01). The MDI at 3 years was moderately correlated with FSIQ at 8 years (P < 0.01, R² = 0.41). Ten patients (28.6%) received special education services in their school. Children with MDI <85 were more likely than those with MDI ≥85 to require special education services at school age (53% and 10%, respectively, P < 0.01). Weight at birth and stage II were correlated with the MDI, extracorporeal circulation time at stage II was correlated with FSIQ, and age at Fontan operation was correlated with FSIQ and special education services. The toddler neurodevelopment index may predict not only IQ levels but also the need for special education services in school-age children. Children with low neurodevelopmental scores need to be followed closely for a long time.

Postoperative brain volumes are associated with one-year neurodevelopmental outcome in children with severe congenital heart disease

Children with congenital heart disease (CHD) remain at risk for neurodevelopmental impairment despite improved perioperative care. Our prospective cohort study aimed to determine the relationship between perioperative brain volumes and neurodevelopmental outcome in neonates with severe CHD. Pre- and postoperative cerebral MRI was acquired in term born neonates with CHD undergoing neonatal cardiopulmonary bypass surgery. Brain volumes were measured using an atlas prior-based automated method. One-year neurodevelopmental outcome was assessed with the Bayley-III. CHD infants (n = 77) had lower pre- and postoperative total and regional brain volumes compared to controls (n = 44, all p < 0.01). CHD infants had poorer cognitive and motor outcome (p ≤ 0.0001) and a trend towards lower language composite score compared to controls (p = 0.06). Larger total and selected regional postoperative brain volumes were found to be associated with better cognitive and language outcomes (all p < 0.04) at one year. This association was independent of length of intensive care unit stay for total, cortical, temporal, frontal and cerebellar volumes. Therefore, reduced cerebral volume in CHD neonates undergoing bypass surgery may serve as a biomarker for impaired outcome.

Brain Development of Children With Single Ventricle Physiology or Transposition of the Great Arteries: A Longitudinal Observation Study

To define the correlation between neuroanatomic and developmental outcomes of children with single ventricle (SV) or transposition of the great arteries (TGA), a prospective longitudinal study was performed in preschool and school-age children. Twenty-seven children with congenital heart disease (9, TGA; 18, SV) were included. Participants underwent 3-dimensional magnetic resonance imaging (MRI) and neurodevelopmental assessment at around 3 years (preschool age) and at 9 years (school age), and 48 healthy controls underwent MRI, and their data were used to derive best-fit models for normal brain volumes for comparisons with congenital heart disease patients. Total brain volume (TBV) and regional brain volumes remained significantly smaller in SV children than in TGA children at both time points, though the growth slope of TBV was not significantly different between the SV and TGA groups. Although the psychomotor developmental index at preschool was significantly lower in SV patients, the full-scale IQ at school age was not significantly lower in SV patients. There was a strong correlation between full-scale IQ and TBV (r = 0.49, P = 0.005). Despite the current best practices, persistently lower TBV was seen in SV patients until 9 years of age. For both the SV and TGA groups, TBV at 3 years was a strong predictor of TBV at 9 years. Since there was a correlation between TBV and IQ at 9 years, identification of factors that affect brain growth until 3 years will be imperative to improve patients' cognitive function at school age.

Structural brain abnormalities in adolescents and young adults with congenital heart defect: a systematic review

AIM

The primary objective of this systematic review is to define and quantify brain structural abnormalities present in adolescents and young adults with complex congenital heart defect (CHD). We also aim to evaluate the extent to which these structural abnormalities are associated with functional outcomes.

METHOD

A search of studies examining brain structure by magnetic resonance imaging in adolescents and young adults with complex CHD was performed in Embase, MEDLINE, and Web of Science. A meta-analysis was conducted to determine the odds of brain abnormalities in young people with CHD. Results not included in the meta-analysis were collated using descriptive statistics.

RESULTS

Two hundred and fifty-four studies were identified through the literature search. Among these, 14 original studies were included in the review. The odds of brain abnormalities in young people with CHD were 7.9 times higher (p<0.001) than in typically developing comparison individuals. Focal and multifocal lesions were the most common types of abnormality (odds ratio 22.5 [p<0.001]). Preliminary evidence from volumetric, cortical, and microstructural integrity measurements suggests that brain abnormalities are associated with poorer neurocognitive outcomes.

INTERPRETATION

This review provides strong evidence that adolescents and young adults with CHD are at increased risk of presenting with structural brain abnormalities and highlights the contribution of advanced quantitative magnetic resonance imaging techniques to identify the subtle but frequent brain alterations in this population. However, more studies are needed to clarify how these abnormalities relate to function.

WHAT THIS PAPER ADDS

There is a high prevalence of brain abnormalities in young people with congenital heart defect (CHD). Brain volumes, cortical measurements, and white matter microstructure are altered in young people with CHD. Brain abnormalities are associated with poorer function in young people with CHD.

Alterations in cerebral ventricle size in children with congenital heart disease

PURPOSE

Children with tetralogy of Fallot (TOF) and superior cavopulmonary anastomoses (SCPA) can have chronically elevated central venous pressure (CVP), which has been postulated to put patients at risk for cerebral ventriculomegaly. We aimed to examine cerebral ventricle size in children with these congenital heart lesions before and after surgery to determine how changes in CVP affect ventricle size.

METHODS

We reviewed the records of patients who underwent SCPA or TOF repair between 2006 and 2015. Patients with pre- or post-operative cranial imaging were included. Frontal-occipital (FO) horn ratios were calculated as measures of cerebral ventricle volume. Reported normal mean FO ratio is 0.37 ± 0.03. Patient characteristics including occipito-fronto circumference (OFC) and available CVP measurements were recorded. CVP, FO ratios, and OFC percentiles were compared using paired and unpaired t tests and Wilcoxon matched pairs signed-rank test as appropriate.

RESULTS

We reviewed 44 patients who underwent SCPA and 31 patients who underwent TOF repair who had cranial imaging studies available. In the 22 patients who underwent SCPA and had pre- and post-operative imaging, mean FO ratios significantly increased from 0.37 ± 0.03 to 0.40 ± 0.04 (P < 0.001). In contrast, in the seven patients with TOF with pre- and post-operative imaging, FO ratio was elevated at baseline and remains so after surgical repair, 0.43 ± 0.08 to 0.42 ± 0.08 (P = 0.65). Similar patterns were noted with OFC percentiles, which were significantly increased as compared to baseline after SCPA (P < 0.001) but were not significantly changed after TOF repair (P = 0.58). Finally, when available, preoperative and postoperative CVP measurements of all patients were examined, CVP increased in patients who underwent SCPA, from 6.5 ± 2 mmHg preoperatively to 9.1 ± 2.3 mmHg postoperatively (P < 0.001), while CVP remained statistically unchanged in patients who underwent TOF repair, 12.9 ± 3.3 mmHg preoperatively to 14.4 ± 3.1 mmHg postoperatively (P = 0.2).

CONCLUSION

Cerebral ventriculomegaly was observed in patients with SCPA and TOF, and the observed changes in FO ratio and OFC may be related, at least in part, to CVP.

Prenatal to postnatal trajectory of brain growth in complex congenital heart disease

Altered brain development is a common feature of the neurological sequelae of complex congenital heart disease (CHD). These alterations include abnormalities in brain size and growth that begin prenatally and persist postnatally. However, the longitudinal trajectory of changes in brain volume from the prenatal to postnatal environment have not been investigated. We aimed to evaluate the trajectory of brain growth in a cohort of patients with complex CHD (n = 16) and healthy controls (n = 15) to test the hypothesis that patients with complex CHD would have smaller total brain volume (TBV) prenatally, which would become increasingly prominent by three months of age. Participants underwent fetal magnetic resonance imaging (MRI) at a mean of 32 weeks gestation, a preoperative/neonatal MRI shortly after birth, a postoperative MRI (CHD only), and a 3-month MRI to evaluate the trajectory of brain growth. Three-dimensional volumetric analysis was applied to the MRI data to measure TBV, as well as tissue-specific volumes of the cortical gray matter (CGM), white matter (WM), subcortical (deep nuclear) gray matter (SCGM), cerebellum, and cerebrospinal fluid (CSF). A random coefficients model was used to investigate longitudinal changes in TBV and demonstrated an altered trajectory of brain growth in the CHD population. The estimated slope for TBV from fetal to 3-month MRI was 11.5 cm³ per week for CHD infants compared to 16.7 cm³ per week for controls (p = 0.0002). Brain growth followed a similar trajectory for the CGM (p < 0.0001), SCGM (p = 0.002), and cerebellum (p = 0.005). There was no difference in growth of the WM (p = 0.30) or CSF (p = 0.085). Brain injury was associated with reduced TBV at 3-month MRI (p = 0.02). After removing infants with brain injury from the model, an altered trajectory of brain growth persisted in CHD infants (p = 0.006). These findings extend the existing literature by demonstrating longitudinal impairments in brain development in the CHD population and emphasize the global nature of disrupted brain growth from the prenatal environment through early infancy.

Structural network topology correlates of microstructural brain dysmaturation in term infants with congenital heart disease

Neonates with complex congenital heart disease (CHD) demonstrate microstructural brain dysmaturation, but the relationship with structural network topology is unknown. We performed diffusion tensor imaging (DTI) in term neonates with CHD preoperatively (N = 61) and postoperatively (N = 50) compared with healthy term controls (N = 91). We used network topology (graph) analyses incorporating different weighted and unweighted approaches and subject-specific white matter segmentation to investigate structural topology differences, as well as a voxel-based analysis (VBA) to confirm the presence of microstructural dysmaturation. We demonstrate cost-dependent network inefficiencies in neonatal CHD in the pre- and postoperative period compared with controls, related to microstructural differences. Controlling for cost, we show the presence of increased small-worldness (hierarchical fiber organization) in CHD infants preoperatively, that persists in the postoperative period compared with controls, suggesting the early presence of brain reorganization. Taken together, topological microstructural dysmaturation in CHD infants is accompanied by hierarchical fiber organization during a protracted critical period of early brain development. Our methodology also provides a pipeline for quantitation of network topology changes in neonates and infants with microstructural brain dysmaturation at risk for perinatal brain injury.

Graph theory analysis of cortical thickness networks in adolescents with d-transposition of the great arteries

Objective

Adolescents with d-transposition of the great arteries (d-TGA) who had the arterial switch operation in infancy have been found to have structural brain differences compared to healthy controls. We used cortical thickness measurements obtained from structural brain MRI to determine group differences in global brain organization using a graph theoretical approach.

Methods

Ninety-two d-TGA subjects and 49 controls were scanned using one of two identical 1.5-Tesla MRI systems. Mean cortical thickness was obtained from 34 regions per hemisphere using Freesurfer. A linear model was used for each brain region to adjust for subject age, sex, and scanning location. Structural connectivity for each group was inferred based on the presence of high inter-regional correlations of the linear model residuals, and binary connectivity matrices were created by thresholding over a range of correlation values for each group. Graph theory analysis was performed using packages in R. Permutation tests were performed to determine significance of between-group differences in global network measures.

Results

Within-group connectivity patterns were qualitatively different between groups. At lower network densities, controls had significantly more long-range connections. The location and number of hub regions differed between groups: controls had a greater number of hubs at most network densities. The control network had a significant rightward asymmetry compared to the d-TGA group at all network densities.

Conclusions

Using graph theory analysis of cortical thickness correlations, we found differences in brain structural network organization among d-TGA adolescents compared to controls. These may be related to the white matter and gray matter differences previously found in this cohort, and in turn may be related to the cognitive deficits this cohort presents.

Reduction of brain volumes after neonatal cardiopulmonary bypass surgery in single-ventricle congenital heart disease before Fontan completion

BackgroundLittle is known about the relationship between brain volumes and neurodevelopmental outcome at 2 years of age in children with single-ventricle congenital heart disease (CHD). We hypothesized that reduced brain volumes may be associated with adverse neurodevelopmental outcome.MethodsVolumetric segmentation of cerebral magnetic resonance imaging (MRI) scans was carried out in 44 patients without genetic comorbidities and in 8 controls. Neurodevelopmental outcome was assessed with the Bayley-III scales.ResultsGray matter (GM), deep GM, white matter (WM), and cerebrospinal fluid (CSF) volumes were 611±59, 43±4.5, 277±30, and 16.4 ml, respectively (interquartile range (IQR) 13.1, 23.3 ml). Children undergoing neonatal cardiopulmonary bypass surgery showed smaller deep GM (P=0.005) and WM (P=0.021) volumes. Brain volumes were smaller in patients compared with controls (GM: P=0.017, deep GM: P=0.012, and WM: P=0.015), whereas CSF volumes were greater (P=0.014). Of all intracranial volumes, only CSF volume was associated with neurodevelopmental outcome, accounting for 21% (P=0.011) of variability in the cognitive composite score when combined with common risk factors in a multivariable analysis.ConclusionIncreased CSF volume represents a significant risk factor for neurodevelopmental impairment in children with single-ventricle CHD. Later assessments are warranted to determine the prognostic role of intracranial volumes for long-term outcome.

Regional brain gray matter changes in adolescents with single ventricle heart disease

Adolescents with single ventricle heart disease (SVHD) show autonomic, mood, and cognitive deficits, indicating aberrations in brain areas that regulate these functions. However, the gray matter integrity in autonomic, mood, and cognitive control sites is unclear. We examined regional brain gray matter changes, using high-resolution T1-weighted images (3.0-T magnetic resonance scanner) with voxel based morphometry procedures, as well as mood and cognitive functions in SVHD (n=18; age, 15.7±1.1years; male, 10) and controls (n=31; age, 16.0±1.1years; male, 17). High-resolution T1-weighted images were realigned, gray matter tissue type partitioned, normalized to a common space, smoothed, and compared between groups (analysis of covariance; covariates, age and gender). The mood and cognitive scores were compared between groups using independent samples t-tests. SVHD subjects showed significantly altered mood and cognitive functions over controls. Significantly reduced gray matter emerged in multiple brain areas, including the thalamus, caudate nuclei, putamen, insula, prefrontal, post-central and precentral gyrus, occipital gyrus, para-hippocampal gyrus, temporal gyrus, and cerebellar sites in SVHD over controls. SVHD subjects show compromised gray matter integrity in autonomic, mood and cognitive control sites. The findings indicate that frequent deficits found in SVHD subjects have a brain structural basis in the condition.

Decreased oxygen saturation levels in neonates with transposition of great arteries: Impact on appearance of cerebral veins in susceptibility-weighted imaging

Purpose of this study was to investigate a potential correlation between the pattern of cerebral veins (CV) on susceptibility-weighted imaging (SWI) and blood oxygen saturation, as well as preoperative brain injury, in neonates with transposition of the great arteries (TGA). Eleven neonates with TGA underwent MRI preoperatively, including SWI, T1- and T2-weighted scans. Images were retrospectively evaluated and appearance of CV was graded from 0 (normal appearance) to 3 (severe prominent appearance). White matter injuries (WMI) and strokes were analysed. Results were correlated with preductal arterial oxygen saturation. As findings one subject showed a normal CV appearance (grade 0) whereas 10 showed pathological prominent CV (grades 1–3); median 2. Mean oxygen saturation ranged between 67.5% and 89.0% (median 81.0%). CV grade and mean oxygen saturation correlated significantly (p = 0.011). WMI were absent in 5 cases, mild in 4, and moderate in 2 cases. We conclude, that SWI has the potential to be used to estimate the current hypoxic burden on brain tissue in TGA newborns by assessing the prominence of the CV.

Structural cerebral abnormalities and neurodevelopmental status in single ventricle congenital heart disease before Fontan procedure

Objectives

Neonates with single ventricle congenital heart disease are at risk for structural cerebral abnormalities. Little is known about the further evolution of cerebral abnormalities until Fontan procedure.

Methods

Between August 2012 and July 2015, we conducted a prospective cross-sectional two centre study using cerebral magnetic resonance imaging (MRI) and neuro-developmental outcome assessed by the Bayley-III. Forty-seven children (31 male) were evaluated at a mean age of 25.9 ± 3.4 months with hypoplastic left heart syndrome (25) or other single ventricle (22).

Results

Cerebral MRI was abnormal in 17 patients (36.2%) including liquor space enlargements (10), small grey (9) and minimal white (5) matter injuries. Eight of 17 individuals had combined lesions. Median (range) cognitive composite score (CCS) (100, 65-120) and motor composite score (MCS) (97, 55-124) were comparable to the reference data, while language composite score (LCS) (97, 68-124) was significantly lower ( P  = 0.040). Liquor space enlargement was associated with poorer performance on all Bayley-III subscores (CCS: P  = 0.02; LCS: P  = 0.002; MCS: P  = 0.013). The number of re-operations [odds ratio (OR) 2.2, 95% confidence interval (CI) 1.1-4.3] ( P  = 0.03) and re-interventions (OR 2.1, 95% CI 1.1-3.8) ( P  = 0.03) was associated with a higher rate of overall MRI abnormalities.

Conclusions

Cerebral MRI abnormalities occur in more than one third of children with single ventricle, while the neuro-developmental status is less severely affected before Fontan procedure. Liquor space enlargement is the predominant MRI finding associated with poorer neuro-developmental status, warranting further studies to determine aetiology and further evolution until school-age.

White Matter Volume Predicts Language Development in Congenital Heart Disease

OBJECTIVE

To determine whether brain volume is reduced at 1 year of age and whether these volumes are associated with neurodevelopment in biventricular congenital heart disease (CHD) repaired in infancy.

STUDY DESIGN

Infants with biventricular CHD (n = 48) underwent brain magnetic resonance imaging (MRI) and neurodevelopmental testing with the Bayley Scales of Infant Development-II and the MacArthur-Bates Communicative Development Inventories at 1 year of age. A multitemplate based probabilistic segmentation algorithm was applied to volumetric MRI data. We compared volumes with those of 13 healthy control infants of comparable ages. In the group with CHD, we measured Spearman correlations between neurodevelopmental outcomes and the residuals from linear regression of the volumes on corrected chronological age at MRI and sex.

RESULTS

Compared with controls, infants with CHD had reductions of 54 mL in total brain (P = .009), 40 mL in cerebral white matter (P <.001), and 1.2 mL in brainstem (P = .003) volumes. Within the group with CHD, brain volumes were not correlated with Bayley Scales of Infant Development-II scores but did correlate positively with MacArthur-Bates Communicative Development Inventory language development.

CONCLUSIONS

Infants with biventricular CHD show total brain volume reductions at 1 year of age, driven by differences in cerebral white matter. White matter volume correlates with language development, but not broader developmental indices. These findings suggest that abnormalities in white matter development detected months after corrective heart surgery may contribute to language impairment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00006183.

Altered Gray Matter in Adolescents with d-Transposition of the Great Arteries

OBJECTIVE

To investigate the structural brain characteristics of adolescent patients with d-transposition of the great arteries (d-TGA), repaired with the arterial switch operation in early infancy, using quantitative volumetric magnetic resonance imaging.

STUDY DESIGN

Ninety-two patients with d-TGA from the Boston Circulatory Arrest Study (76% male; median age at scan 16.1 years) and 49 control subjects (41% male; median age at scan 15.7 years) were scanned using a 1.5-Tesla magnetic resonance imaging system. Subcortical and cortical gyral volumes and cortical gyral thicknesses were measured using surface-based morphometry. Group differences were assessed with linear regression.

RESULTS

Compared with controls, patients with d-TGA demonstrated significantly reduced subcortical volumes bilaterally in the striatum and pallidum. Cortical regions that showed significant volume and thickness differences between groups were distributed throughout parietal, medial frontoparietal, cingulate, and temporal gyri. Among adolescents with d-TGA, volumes and thicknesses correlated with several perioperative variables, including age at surgery, cooling duration, total support time, and days in the cardiac intensive care unit.

CONCLUSIONS

Adolescents with d-TGA repaired early in life exhibit widespread differences from control adolescents in gray matter volumes and thicknesses, particularly in parietal, midline, and subcortical brain regions, corresponding to white matter regions already known to demonstrate altered microstructure. These findings complement observations made in white matter in this group and suggest that the adolescent d-TGA cognitive profile derives from altered brain development involving both white and gray matter.

Pre-Adult MRI of Brain Cancer and Neurological Injury: Multivariate Analyses

Brain cancer and neurological injuries, such as stroke, are life-threatening conditions for which further research is needed to overcome the many challenges associated with providing optimal patient care. Multivariate analysis (MVA) is a class of pattern recognition technique involving the processing of data that contains multiple measurements per sample. MVA can be used to address a wide variety of neuroimaging challenges, including identifying variables associated with patient outcomes; understanding an injury's etiology, development, and progression; creating diagnostic tests; assisting in treatment monitoring; and more. Compared to adults, imaging of the developing brain has attracted less attention from MVA researchers, however, remarkable MVA growth has occurred in recent years. This paper presents the results of a systematic review of the literature focusing on MVA technologies applied to brain injury and cancer in neurological fetal, neonatal, and pediatric magnetic resonance imaging (MRI). With a wide variety of MRI modalities providing physiologically meaningful biomarkers and new biomarker measurements constantly under development, MVA techniques hold enormous potential toward combining available measurements toward improving basic research and the creation of technologies that contribute to improving patient care.

Neurodevelopmental delay with critical congenital heart disease is mainly from prenatal injury not infant cardiac surgery: current evidence based on a meta-analysis of functional magnetic resonance imaging

OBJECTIVE

No consensus has been reached regarding whether brain injury related to congenital heart disease (CHD) is caused by infant cardiac surgery and/or prenatal injury resulting from the CHD. We performed this meta-analysis to identify the likely cause of neurodevelopmental delay in CHD patients.

METHODS

We carried out a literature search without language restriction in December 2013, retrieving records from PubMed, EMBASE, the Cochrane Library and the World Health Organization trials center, to identify studies applying functional magnetic resonance imaging (fMRI) evaluation of brain function before surgery and, in some cases, after surgery (both immediate term and short term postoperatively). The preoperative and postoperative fMRI results were extracted, and meta-analysis was performed using Revman 5.1.1 and STATA 11.0, according to the guidelines from the Cochrane review and MOOSE groups.

RESULTS

The electronic search yielded 937 citations. Full text was retrieved for 15 articles and eight articles (nine studies) were eligible for inclusion: six studies (n = 312 cases) with fMRI analysis before surgery and three (n = 36 cases) with complete perioperative fMRI analysis. The overall average diffusivity of CHD cases was significantly higher than that of controls, with a summarized standard (std) mean difference of 1.39 (95% CI, 0.70-2.08), and the fractional anisotropy was lower in CHD cases, with a summarized mean difference of -1.43 (95% CI, -1.95 to -0.91). N-acetylaspartate (NAA)/choline (Cho) for the whole brain was significantly lower in CHD cases compared with healthy ones, while lactate/Cho was significantly higher in CHD cases. Immediate term postoperatively, significant changes in NAA/creatine and NAA/Cho, relative to preoperative values, were found. However, the difference did not persist at the short-term follow-up.

CONCLUSION

This meta-analysis suggests that the delay in neurological development in newborns with CHD is due mainly to prenatal injury, and cardiac surgery might lead to mild brain injuries postoperatively, but fMRI shows recovery within a short period.

Abnormal development of thalamic microstructure in premature neonates with congenital heart disease

Preterm birth is associated with alteration in corticothalamic development, which underlies poor neurodevelopmental outcomes. Our hypothesis was that preterm neonates with CHD would demonstrate abnormal thalamic microstructure when compared to critically ill neonates without CHD. A secondary aim was to identify any association between thalamic microstructural abnormalities and perioperative clinical variables. We compared thalamic DTI measurements in 21 preterm neonates with CHD to two cohorts of neonates without CHD: 28 term and 27 preterm neonates, identified from the same neonatal intensive care unit. Comparison was made with three other selected white matter regions using ROI manual-based measurements. Correlation was made with post-conceptional age and perioperative clinical variables. In preterm neonates with CHD, there were age-related differences in thalamic diffusivity (axial and radial) compared to the preterm and term non-CHD group, in contrast to no differences in anisotropy. Contrary to our hypothesis, abnormal thalamic and optic radiation microstructure was most strongly associated with an elevated first arterial blood gas pO2 and elevated preoperative arterial blood gas pH (p < 0.05). Age-related thalamic microstructural abnormalities were observed in preterm neonates with CHD. Perinatal hyperoxemia and increased perioperative serum pH were associated with abnormal thalamic microstructure in preterm neonates with CHD. This study emphasizes the vulnerability of thalamocortical development in the preterm neonate with CHD.

MRI for neurodevelopmental prognostication in the high-risk term infant

MRI performed in the neonatal period has become a tool widely used by clinicians and researchers to evaluate the developing brain. MRI can provide detailed anatomical resolution, enabling identification of brain injuries due to various perinatal insults. This review will focus on the link between neonatal MRI findings and later neurodevelopmental outcomes in high-risk term infants. In particular, the role of conventional and advanced MR imaging in prognosticating outcomes in neonates with hypoxic-ischemic encephalopathy, ischemic perinatal stroke, need for extracorporeal membrane oxygenation life support, congenital heart disease, and other neonatal neurological conditions will be discussed.

Executive Function in Children and Adolescents with Critical Cyanotic Congenital Heart Disease

Children and adolescents with critical cyanotic congenital heart disease (CHD) are at risk for deficits in aspects of executive function (EF). The primary aim of this investigation was to compare EF outcomes in three groups of children/adolescents with severe CHD and controls (ages 10-19 years). Participants included 463 children/adolescents with CHD [dextro-transposition of the great arteries (TGA), n=139; tetralogy of Fallot (TOF), n=68; and, single-ventricle anatomy requiring Fontan procedure (SVF), n=145] and 111 controls, who underwent laboratory and informant-based evaluation of EF skills. Rates of EF impairment on D-KEFS measures were nearly twice as high for CHD groups (75-81%) than controls (43%). Distinct EF profiles were documented between CHD groups on D-KEFS tasks. Deficits in flexibility/problem-solving and verbally mediated EF skills were documented in all three CHD groups; visuo-spatially mediated EF abilities were impaired in TOF and SVF groups, but preserved in TGA. Parent, teacher, and self-report ratings on the BRIEF highlighted unique patterns of metacognitive and self-regulatory concerns across informants. CHD poses a serious threat to EF development. Greater severity of CHD is associated with worse EF outcomes. With increased understanding of the cognitive and self-regulatory vulnerabilities experienced by children and adolescents with CHD, it may be possible to identify risks early and provide individualized supports to promote optimal neurodevelopment.

D-transposition of the great arteries: the current era of the arterial switch operation

This paper aims to update clinicians on "hot topics" in the management of patients with D-loop transposition of the great arteries (D-TGA) in the current surgical era. The arterial switch operation (ASO) has replaced atrial switch procedures for D-TGA, and 90% of patients now reach adulthood. The Adult Congenital and Pediatric Cardiology Council of the American College of Cardiology assembled a team of experts to summarize current knowledge on genetics, pre-natal diagnosis, surgical timing, balloon atrial septostomy, prostaglandin E1 therapy, intraoperative techniques, imaging, coronary obstruction, arrhythmias, sudden death, neoaortic regurgitation and dilation, neurodevelopmental (ND) issues, and lifelong care of D-TGA patients. In simple D-TGA: 1) familial recurrence risk is low; 2) children diagnosed pre-natally have improved cognitive skills compared with those diagnosed post-natally; 3) echocardiography helps to identify risk factors; 4) routine use of BAS and prostaglandin E1 may not be indicated in all cases; 5) early ASO improves outcomes and reduces costs with a low mortality; 6) single or intramural coronary arteries remain risk factors; 7) post-ASO arrhythmias and cardiac dysfunction should raise suspicion of coronary insufficiency; 8) coronary insufficiency and arrhythmias are rare but are associated with sudden death; 9) early- and late-onset ND abnormalities are common; 10) aortic regurgitation and aortic root dilation are well tolerated; and 11) the aging ASO patient may benefit from "exercise-prescription" rather than restriction. Significant strides have been made in understanding risk factors for cardiac, ND, and other important clinical outcomes after ASO.

Brain volume and neurobehavior in newborns with complex congenital heart defects

OBJECTIVE

To investigate the relationship between tissue-specific alterations in brain volume and neurobehavioral status in newborns with complex congenital heart defects preoperatively.

STUDY DESIGN

Three-dimensional volumetric magnetic resonance imaging was used to calculate tissue-specific brain volumes and a standardized neurobehavioral assessment was performed to assess neurobehavioral status in 35 full-term newborns admitted to the hospital before cardiopulmonary bypass surgery. Multiple linear regression models were performed to evaluate relationships between neurobehavioral status and brain volumes.

RESULTS

Reduced subcortical gray matter (SCGM) volume and increased cerebrospinal fluid (CSF) volume were associated with poor behavioral state regulation (SCGM, P = .04; CSF, P = .007) and poor visual orienting (CSF, P = .003). In cyanotic newborns, reduced SCGM was associated with higher overall abnormal scores on the assessment (P = .001) and poor behavioral state regulation (P = .04), and increased CSF volume was associated with poor behavioral state regulation (P = .02), and poor visual orienting (P = .02). Conversely, acyanotic newborns showed associations between reduced cerebellar volume and poor behavioral state regulation (P = .03).

CONCLUSION

Abnormal neurobehavior is associated with impaired volumetric brain growth before open heart surgery in infants with complex congenital heart defects. This study highlights a need for routine preoperative screening and early intervention to improve neurodevelopmental outcomes.

Brain volumetric, regional cortical thickness and radiographic findings in adults with cyanotic congenital heart disease

Background

Chronic cyanosis in adults with congenital heart disease (CHD) may cause structural brain changes that could contribute to impaired neurological functioning. The extent of these changes has not been adequately characterized.

Hypothesis

We hypothesized that adults with cyanotic CHD would have widespread changes including abnormal brain volumetric measures, decreased cortical thickness and an increased burden of small and large vessel ischemic changes.

Methods

Ten adults with chronic cyanosis from CHD (40 ± 4 years) and mean oxygen saturations of 82 ± 2% were investigated using quantitative MRI. Hematological and biochemical parameters were also assessed. All subjects were free from major physical or intellectual impairment. Brain volumetric results were compared with randomly selected age- and sex-matched controls from our database of normal subjects.

Results

Five of 10 cyanotic subjects had cortical lacunar infarcts. The white matter (WM) hyperintensity burden was also abnormally high (Scheltens Scale was 8 ± 2). Quantitative MRI revealed evidence of extensive generalized WM and gray matter (GM) volumetric loss; global GM volume was reduced in cyanosed subjects (630 ± 16 vs. 696 ± 14 mL in controls, p = 0.01) as was global WM volume (471 ± 10 vs. 564 ± 18 mL, p = 0.003). Ventricular cerebrospinal fluid volume was increased (35 ± 10 vs. 26 ± 5 mL, p = 0.002). There were widespread regions of local cortical thickness reduction observed across the brain. These changes included bilateral thickness reductions in the frontal lobe including the dorsolateral prefrontal cortex and precentral gyrus, the posterior parietal lobe and the middle temporal gyrus. Sub-cortical volume changes were observed in the caudate, putamen and in the thalamus (p ≤ 0.005 for all regions). Cortical GM volume negatively correlated with brain natriuretic peptide (R = − 0.89, p = 0.009), high sensitivity C-reactive protein (R = − 0.964, p < 0.0001) and asymmetric dimethylarginine (R = − 0.75, p = 0.026) but not with oxygen saturations, packed cell volume or viscosity.

Conclusions

We present the first comprehensive analysis of brain structure in adults with chronic neurocyanosis due to congenital heart disease. We demonstrate clear evidence for marked macro- and microvascular injury. Cyanotic patients show global evidence for reduced brain volume as well as specific foci of cortical thickness reduction. The GM volume loss correlated with hsCRP, BNP and ADMA suggesting that inflammation, neurohormonal activation and endothelial dysfunction may have important roles in its pathogenesis.

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A high burden of cerebral small and large vessel ischemic injury.

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Extensive white and gray matter (GM) volumetric loss.

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Regions of bilateral local cortical thickness reduction within the frontal, parietal and temporal lobes.

Abnormal cerebral microstructure in premature neonates with congenital heart disease

BACKGROUND AND PURPOSE

Abnormal cerebral microstructure has been documented in term neonates with congenital heart disease, portending risk for injury and poor neurodevelopmental outcome. Our hypothesis was that preterm neonates with congenital heart disease would demonstrate diffuse cerebral microstructural abnormalities when compared with critically ill neonates without congenital heart disease. A secondary aim was to identify any association between microstructural abnormalities, white matter injury (eg, punctate white matter lesions), and other clinical variables, including heart lesions.

MATERIALS AND METHODS

With the use of tract-based spatial statistics, an unbiased, voxelwise method for analyzing diffusion tensor imaging data, we compared 21 preterm neonates with congenital heart disease with 2 cohorts of neonates without congenital heart disease: 28 term and 27 preterm neonates, identified from the same neonatal intensive care unit.

RESULTS

Compared with term neonates without congenital heart disease, preterm neonates with congenital heart disease had microstructural abnormalities in widespread regions of the central white matter. However, 42% of the preterm neonates with congenital heart disease had punctate white matter lesions. When neonates with punctate white matter lesions were excluded, microstructural abnormalities remained only in the splenium. Preterm neonates with congenital heart disease had similar microstructure to preterm neonates without congenital heart disease.

CONCLUSIONS

Diffuse microstructural abnormalities were observed in preterm neonates with congenital heart disease, strongly associated with punctate white matter lesions. Independently, regional vulnerability of the splenium, a structure associated with visual spatial function, was observed in all preterm neonates with congenital heart disease.

Risk factors for adverse neurocognitive outcomes in school-aged patients after the Fontan operation

OBJECTIVES

As the surgical results for Fontan candidates improve, much attention has been given to the long-term cognitive outcomes. This study aimed to assess the neurocognitive outcomes after Fontan completion, and to determine the factors associated with an extremely low intelligence quotient (IQ <70).

METHODS

A total of 70 local eligible school-aged patients were enrolled in the study (hypoplastic left heart syndrome, 17; right atrial isomerism, 15 and others, 38). Fontan operations were performed at a median age of 1.8 (range, 0.5-8.9) years (primary Fontan, 4 of 70 [6%]). The Wechsler Intelligence Test was taken at a median age of 9 (range, 5.1-14.4) years for the purpose of neurocognitive evaluation. Patients' data were collected from medical records, and a retrospective analysis of potential predictors for an IQ <70 was performed.

RESULTS

The median full-scale IQ (FSIQ) for the entire cohort was 85 (range, 43-118). Of the lower order composites, the perceptual reasoning index and the working memory index were significantly lower in low-FSIQ patients (P < 0.05). Overall, 15 of 70 (21%) of the cohort had an IQ <70. Univariate analysis identified three significant risk factors for FSIQ <70 (15 of 70, 21%): body weight <2.5 kg at initial palliative surgery (P < 0.05), low 5-min Apgar score <4 (P < 0.05) and inter-stage events requiring cardiopulmonary resuscitation (CPR) (P < 0.05). No other patient-specific factors (e.g. cardiac morphology) or modifiable surgical factors (e.g. the use of hypothermic cardiac arrest) were associated with FSIQ <70.

CONCLUSIONS

Low body weight (<2.5 kg) at initial operation, low 5-min Apgar score (<4) and inter-stage CPR were significant risk factors for impaired neurocognitive outcomes. An evolving strategy for preventing inter-stage CPR may improve cognitive outcomes.

Adolescents with D-transposition of the great arteries repaired in early infancy demonstrate reduced white matter microstructure associated with clinical risk factors

OBJECTIVE

Our objective was to use diffusion tensor imaging (DTI) to compare white matter microstructure in adolescents with D-transposition of the great arteries (D-TGA) who underwent the arterial switch operation in early infancy with typically developing control adolescents. We also examined correlates between patient demographic and medical risk factors and white matter as assessed by regional fractional anisotropy (FA) values.

METHODS

We used with magnetic resonance imaging (MRI) to study 49 adolescents with D-TGA and 29 control adolescents. MRI data, including whole brain DTI and conventional anatomic MRI, were acquired from each subject. Each subject's data were analyzed using random effects analysis to evaluate regional white matter differences in FA between D-TGA and control adolescents.

RESULTS

While multifocal punctate MRI hypointensities on T1-weighted (T1W) imaging suggestive of mineralization were found, other evidence of gross white matter injury was absent. Eighteen discrete regions of significantly reduced FA in D-TGA adolescents compared with controls were observed in deep white matter of cerebral hemispheres, cerebellum, and midbrain. Among D-TGA adolescents, lower FA correlated with younger gestational age, shorter duration of intraoperative cooling, higher intraoperative minimum tympanic temperature, longer intensive care unit stay after repair, and greater total number of open cardiac operations.

CONCLUSIONS

Despite scant white matter injury evident on conventional brain MRI, adolescents with D-TGA repaired in infancy demonstrate significant white matter FA reduction that may relate to their reported neurocognitive deficits. Among adolescents with D-TGA, FA values are associated with patient and perioperative factors, some of which are modifiable.

Motor development of infants with univentricular heart at the ages of 16 and 52 weeks

PURPOSE

To compare the motor development of patients with hypoplastic left heart syndrome (HLHS) and other types of univentricular heart (UVH) with peers who are healthy at the ages of 16 and 52 weeks.

METHODS

Motor development was assessed with the Alberta Infant Motor Scale (AIMS).

RESULTS

Both the 23 patients with HLHS and the 13 patients with UVH had lower total AIMS scores in both observations than the controls. At the age of 52 weeks, patients with HLHS had significantly lower scores in all 4 AIMS subscales, whereas patients with UVH had lower scores only in the prone and standing subscales.

CONCLUSION

Motor development of patients with HLHS or UVH is delayed during the first year of life, especially in the prone and standing subscales.

Neurodevelopmental burden at age 5 years in patients with univentricular heart

BACKGROUND

Despite increasing survival, patients with hypoplastic left heart syndrome (HLHS) and other forms of functionally univentricular heart defects (UVHs) remain at increased risk of long-term neurodevelopmental deficits.

METHODS

A nationwide sample of 23 patients with HLHS, 13 with UVH, and 40 controls were followed prospectively until the age of 5 years, when neurologic, neuropsychological, and motor examinations and brain MRI were performed.

RESULTS

The median full-scale IQ was significantly lower in patients with HLHS (97, P < .001) and patients with UVH (112, P = .024) compared with controls (121). Major neurodevelopmental impairment was found in 26% of the patients with HLHS and 23% of those with UVH, and minor neurologic dysfunction was found in 43% and 46%, respectively. MRI revealed abnormalities, mostly ischemic changes of different degrees, in 82% of the patients with HLHS and in 56% of those with UVH. Prominent changes were significantly associated with neurodevelopmental findings and parental reports of adaptive behavior. In linear regression, significant risk factors for a worse outcome were a history of clinical seizures in connection with the primary operation, a lower diameter of the neonatal ascending aorta, and several pre-, peri-, and postoperative factors related to the primary and bidirectional Glenn operations.

CONCLUSIONS

Although median cognitive performance was within the normal range, neurodevelopmental and brain MRI abnormalities were found in the majority of the patients with UVH, and especially in those with HLHS, at preschool age. Both a narrowed ascending aorta and operation-related factors contributed to these findings.

Congenital heart disease affects cerebral size but not brain growth

Infants with congenital heart disease (CHD) have delayed brain maturation and alterations in brain volume. Brain metrics is a simple measurement technique that can be used to evaluate brain growth. This study used brain metrics to test the hypothesis that alterations in brain size persist at 3 months of age and that infants with CHD have slower rates of brain growth than control infants. Fifty-seven infants with CHD underwent serial brain magnetic resonance imaging (MRI). To evaluate brain growth across the first 3 months of life, brain metrics were undertaken using 19 tissue and fluid spaces shown on MRIs performed before surgery and again at 3 months of age. Before surgery, infants with CHD have smaller frontal, parietal, cerebellar, and brain stem measures (p < 0.001). At 3 months of age, alterations persisted in all measures except the cerebellum. There was no difference between control and CHD infants in brain growth. However, the cerebellum trended toward greater growth in infants with CHD. Somatic growth was the primary factor that related to brain growth. Presence of focal white matter lesions before and after surgery did not relate to alterations in brain size or growth. Although infants with CHD have persistent alterations in brain size at 3 months of age, rates of brain growth are similar to that of healthy term infants. Somatic growth was the primary predictor of brain growth, emphasizing the importance of optimal weight gain in this population.

Delayed cortical development in fetuses with complex congenital heart disease

Neurologic impairment is a major complication of complex congenital heart disease (CHD). A growing body of evidence suggests that neurologic dysfunction may be present in a significant proportion of this high-risk population in the early newborn period prior to surgical interventions. We recently provided the first evidence that brain growth impairment in fetuses with complex CHD has its origins in utero. Here, we extend these observations by characterizing global and regional brain development in fetuses with hypoplastic left heart syndrome (HLHS), one of the most severe forms of CHD. Using advanced magnetic resonance imaging techniques, we compared in vivo brain growth in 18 fetuses with HLHS and 30 control fetuses from 25.4-37.0 weeks of gestation. Our findings demonstrate a progressive third trimester fall-off in cortical gray and white matter volumes (P < 0.001), and subcortical gray matter (P < 0.05) in fetuses with HLHS. Significant delays in cortical gyrification were also evident in HLHS fetuses (P < 0.001). In the HLHS fetus, local cortical folding delays were detected as early as 25 weeks in the frontal, parietal, calcarine, temporal, and collateral regions and appear to precede volumetric brain growth disturbances, which may be an early marker of elevated risk for third trimester brain growth failure.

Hypoplastic left heart syndrome in context

Hypoplastic left heart syndrome is a rare condition requiring major cardiac surgery during the neonatal period to sustain life, with subsequent procedures culminating in completion of the Fontan circulation - the common pathway for all 'single ventricle' conditions. Algorithms for care of these children are now well defined with predictable medium-term outcomes with the majority achieving a Fontan circulation. Hypoplastic left heart syndrome is one of a group of conditions that require complex surgery as a neonate and require a similar perioperative approach. Antenatal diagnosis is common in this patient subgroup, and there is a significant body of work that can be drawn on to inform parental choice.

Regional alterations in cerebral growth exist preoperatively in infants with congenital heart disease

OBJECTIVES

Magnetic resonance imaging has been used to define the neurologic abnormalities in infants with congenital heart disease (CHD), including preoperative injury and delayed brain maturation. The present study used qualitative scoring, cerebral biometry, and diffusion imaging to characterize the preoperative brain abnormalities in infants with CHD, including the identification of regions of greater vulnerability.

METHODS

A total of 67 infants with CHD had preoperative magnetic resonance imaging scans available for analysis of brain injury using qualitative scoring and brain development using qualitative scoring, metrics, and diffusion imaging.

RESULTS

Qualitative abnormalities were common, with 42% of infants having preoperative focal white matter lesions. Infants with CHD had smaller brain measures in the frontal lobe, parietal lobe, cerebellum, and brainstem (P < .001), with the frontal lobe and brainstem displaying the greatest alterations (P < .001). A smaller brain size in the frontal and parietal lobes correlated with delayed white matter microstructure reflected by diffusion imaging.

CONCLUSIONS

Infants with CHD commonly display brain injury and delayed brain development. Regional alterations in brain size are present, with the frontal lobe and brainstem demonstrating the greatest alterations. This might reflect a combination of developmental vulnerability and regional differences in cerebral circulation.

Should what we know about neurobehavioral development, complex congenital heart disease, and brain maturation affect the timing of corrective cardiac surgery?

Despite remarkable improvements in perioperative care, adverse neurobehavioral outcomes following neonatal and infant cardiac surgery are commonplace and are associated with substantial morbidity. It is becoming increasingly clear that complex congenital heart disease is associated with both abnormalities in neuroanatomic development and a delay in fetal brain maturation. Substantial cerebral ischemic/hypoxic injury has been detected in neonates with complex congenital heart disease both prior to and following corrective cardiac surgery. The brain of the neonate with complex congenital heart disease appears to be uniquely vulnerable to the types of ischemic/hypoxic injury associated with perioperative care. It remains to be determined whether delaying surgical correction to allow for brain maturation will be associated with improvements in neurobehavioral outcomes.

Abnormal brain structure and function in newborns with complex congenital heart defects before open heart surgery: a review of the evidence

Newborns with complex congenital heart defects are at high risk for developing neurological abnormalities. It is important to understand the timing, progression, and extent of these abnormalities to better elucidate their potential impact on neurodevelopment, and their implications for early screening and intervention. This review synthesizes the recent literature describing neurological and neurobehavioral abnormalities observed in fetuses and newborns before cardiac surgery. A considerable proportion of newborns with complex congenital heart defects exhibit neurobehavioral and electrophysiological abnormalities preoperatively. Likewise, conventional neuroimaging studies reported that a high percentage of this population experienced brain injury. Advanced neuroimaging modalities indicated that fetuses showed delayed third trimester brain growth, and newborns showed impaired white matter maturation, reduced N-acetylaspartate, and increased lactate. These findings suggest a fetal or early postnatal onset of impaired brain growth and development. Consequently, reliable methods for early screening and subsequent developmental intervention must be implemented.

Neurodevelopment in 1-year-old Japanese infants after congenital heart surgery

BACKGROUND

The purpose of this study was to determine the prevalence of persistent neurodevelopmental sequelae in 1-year-old infants after open heart surgery for congenital heart disease, using the Bayley Scales of Infant Development second edition (BSID-II). A secondary objective was to confirm the applicability and usefulness of the BSID-II in Japanese infants.

METHODS

Thirty-nine infants who underwent repair of a ventricular septal defect before 6 months of age and 108 normal Japanese infants at 1 year of age were assessed using the BSID-II.

RESULTS

In normal infants, scores on the Mental Development Index and the Psychomotor Development Index components of the BSID-II ranged from borderline retardation to very superior following a normal distribution similar to those obtained for US controls. No problems were encountered, either in translation or in following the instructions when the BSID-II was used to evaluate the 1-year-old Japanese infants. On the other hand, the mean scores on the Mental Development Index and the Psychomotor Development Index were significantly lower in Japanese patients than in normal Japanese infants, particularly for gross motor development (P < 0.001). Linear regression analysis showed that a longer intensive care unit stay was associated with impaired cognitive development at 1 year of age (P= 0.03).

CONCLUSIONS

Neurodevelopmental functions in 1-year-old infants with congenital heart disease were lower than those in normal infants, especially for gross motor function using the BSID-II. One risk factor that correlated with neurodevelopmental sequelae was the length of intensive care unit stay.