Seizure activity causing loss of cardiac output after a Fontan operation

MRI patterns of hypoxic-ischemic brain injury in preterm and full term infants - classical and less common MR findings

Hypoxic-ischemic brain injury occurring in antenatal, perinatal or early postnatal period constitutes an important diagnostic problem in both term and prematurely born neonates. Over the past several years magnetic resonance imaging (MRI) has become relatively easily accessible in Poland. On the basis of the central nervous system MRI, the experienced radiologist are able to determine the location of the hypoxic-ischemic lesions, their extent and evolution. Therefore he can help clinicians to answer the question whether the brain damage of the newborn is responsible for its clinical condition and he can contribute to determining the prognosis of the infant's future development. The aim of this study is to present the current knowledge of different types of hypoxic-ischemic brain lesions based on our personal experience and MR images from the archives of the Department of Diagnostic Imaging at the Institute of Mother and Child.

Assessment of developmental coordination disorder in children born with extremely low birth weights

There is no tool that is considered the "gold" standard for identifying children with developmental coordination disorder (DCD) and various techniques have been reported in the research literature. The aim of this study was to examine the prevalence of DCD in a cohort of extremely low birth weight (ELBW; birth weight ≤ 1,000g) children at age 5 years using various methods including standardized motor assessment measures, an established clinic protocol, and a parent report. We also examined the association between selected neonatal risk factors and severity of the motor impairment. Four methods were used to assess motor functioning: (1) the Movement Assessment Battery for Children (Movement ABC); (2) a motor assessment battery, which included the Movement ABC, the Beery-Buktenica Developmental Test of Visual Motor Integration, and the Developmental Test of Visual Perception-2; (3) a Perinatal Follow-up Clinic protocol, which included the Geometric Design and the Mazes subtests of the Wechsler Preschool and Primary Scale of Intelligence-Revised, the Fine and Gross Motor subscales of the Child Development Inventory, and a pediatric neuromotor exam; and (4) a parent completed questionnaire (i.e., Developmental Coordination Disorder Questionnaire (DCDQ)). The prevalence of motor impairment in ELBW children was 64% on the Movement ABC, 67% on the motor assessment battery, 66% on the Perinatal Follow-up Clinic protocol, and 26% on the DCDQ. Sensitivity ranged from 36% to 100% and specificity from 65% to 92% using the Movement ABC as the reference standard. Neonatal risk factors associated with increased severity of motor impairment were bronchopulmonary dysplasia, postnatal steroids, and increasing gestational age. Children with birth weights ≤ 1,000 g are at considerable risk for motor impairment; therefore, developmental evaluations should include an assessment of motor functions. A standardized motor assessment test such as the Movement ABC appears to be the most effective and efficient means of identifying motor impairment in this high-risk population.

Maternal anaphylaxis and fetal brain damage after intrapartum chemoprophylaxis

We report a case of maternal anaphylaxis following intrapartum chemoprophylaxis. The term fetus developed severe brain damage as a consequence of intrapartum asphyxia. The lesions resulted from maternal hypotension following anaphylaxis. We discuss the feto-maternal risks and the controversial treatment of such a condition. The increasing number of penicillin-treated parturients will result in further cases of maternal anaphylaxis than previously found.

Magnetic resonance imaging and T2 relaxometry of cerebral white matter and hippocampus in children born preterm

The objective of this study was to determine whether intelligence and minor motor impairments in children who are born preterm without major disability are associated with cerebral white matter (CWM) and hippocampal abnormalities on magnetic resonance imaging (MRI). A total of 103 preterm children were studied at age 7 y with detailed magnetic resonance brain scans, including a T2-mapping sequence from which T2 relaxation times of the CWM and hippocampal formations were calculated. All of the children had no major motor disability, attended normal school, and had undergone assessment of IQ and a test for minor motor impairment (MMI). Twenty children had visible lesions on MRI, which were associated with lower IQ and more frequent MMI. Mean (SD) IQ was 90 (14.1). Twenty-five children were shown to have MMI (Movement ABC at below the fifth centile). This group was shown to have significantly longer T2 relaxation times for CWM (mean difference 2.1 ms right, 3.1 ms left) but not the hippocampus than the children without MMI. These differences persisted when only children without visible lesions on scans were considered (mean difference 1.5 ms bilaterally). There was no significant correlation between IQ and T2 relaxation times. Children who are born preterm without subsequent major neurodisability may, in addition to visible lesions on MRI scans, have a diffuse abnormality of CWM, manifest as an increase in T2 relaxation time. This abnormality shows a close correlation with minor motor impairment but not with full-scale IQ.

Syncope--an unusual presentation of ventricle dysfunction in a patient with Fontan circulation

We report a case of recurrent syncope in association with moderate ventricular dysfunction and mild AV-valve regurgitation in an 18-year-old girl, 4 years after she underwent total cavopulmonary connection surgery. Cardiac catheterization revealed a transpulmonary gradient of 1-2 mmHg. During exercise, a dramatic fall in blood pressure and blood oxygenation was observed, paralleled by an increase in heart rate and central venous pressure. Although a slight increase in pulmonary vascular resistance could not be excluded, the reaction was interpreted in terms of an extremely low transpulmonary gradient in association with ventricular dysfunction. Five months after heart transplantation, the patient has been completely free from syncope. Fontan circulation usually involves a delicate haemodynamic situation which may necessitate haemodynamic re-evaluations, including dynamic measurements of the central venous pressure during exercise. Also a moderate ventricular dysfunction may result in compromised pulmonary circulation which in turn may lead to syncope during exercise as a result of insufficient systemic circulation.

Developmental coordination disorder in extremely low birth weight children at nine years

Developmental coordination disorder (DCD) is defined as an impairment in the development of motor coordination that interferes with academic achievement or activities of daily living (DSM-IV). DCD has been reported to affect 5% to 9% of children in the normal population. This study describes the prevalence of DCD in a cohort of extremely low birth weight children (ELBW, < or = l800 g) at 8.9 years of age, from which were excluded children with major impairments. Seventy-three children were included in the study group, along with 18 term-born, socially matched controls. Of the 73 ELBW children, 37 (51%) were classified as having DCD. ELBW children with DCD also had significantly lower Performance IQ (PIQ) scores and were more likely (43%) to have a learning difficulty in arithmetic than ELBW children who did not have DCD. This study found that DCD is a common problem in school-aged ELBW children.

Cardiac MR imaging in congenital heart disease

Magnetic resonance imaging is a unique and insightful tool for the assessment of structure and function in congenital heart disease. For anatomic assessment, the large field of view, lack of limitation by patient size, and ability to create three-dimensional surface displays from routine imaging acquisitions offer several advantages over other modalities. The ability of magnetic resonance imaging to assess the volume and mass of bizarre ventricular shapes accurately and myocardial tissue and blood tagging as well as phase encoded velocity mapping has enhanced research in pediatric cardiology. Newer techniques, such as oxygen-sensitive magnetic resonance imaging and echo-planar magnetic resonance imaging, promise even further advances in research and in clinical applications.

The nature of flow in the systemic venous pathway measured by magnetic resonance blood tagging in patients having the Fontan operation

OBJECTIVES

Our objectives were twofold: (1) to determine cardiac and respiratory dependency of systemic venous pathway flow of patients having the Fontan operation with a total cavopulmonary connection and (2) to describe the velocity profile. Systemic venous pathway flow is hypothesized to be mostly respiratory dependent, to be laminar, and to have a smooth velocity profile.

METHODS

Twenty-two patients having the Fontan operation (aged 8.6 +/- 4.7 years) underwent magnetic resonance blood tagging (bolus tagging). Systemic venous pathway spin-echo images parallel to the blood flow were used as a localizer. A saturation pulse labeled the blood, and a cine image was acquired at the inferior and superior venae cavae and midportion of the baffle in the systemic venous pathway, triggered to the electrocardiogram and gated to both end-expiration and end-inspiration. Repetition time was 50 msec.

RESULTS

Flow in the systemic venous pathway was laminar throughout its course and was found to be phasic to both cardiac and respiratory cycles. Approximately 70% of flow was cardiac dependent, and the rest was respiratory. Highest flow occurred near end-systole and early diastole and in inspiration. Lowest flow occurred in diastasis. Velocity was highest and flow least "pluglike" in the mid-baffle area during cardiac or respiratory imaging (45 +/- 17 and 32 +/- 11 cm/sec, respectively).

CONCLUSION

A substantial amount of pulmonary blood flow in patients who have undergone a total cavopulmonary connection type of Fontan operation has a cardiac component. Furthermore, we confirm that this flow is laminar but nonuniform across the systemic venous pathway. Highest flows occurred near end-systole and early diastole, as well as in inspiration, and the lowest flow occurred in diastasis. This information may help in designing the systemic venous pathway and optimizing medical management.