Paulina Karcz

Brain Maturation—Differences in Biochemical Composition of Fetal and Child's Brain

ABSTRACT Introduction: The aim of this study was to evaluate differences in 1H MRS spectra of the brain of fetuses and children from 6 to 11 years of age. Material and methods: 21 healthy fetuses in the third trimester and 22 children were examined using the proton nuclear magnetic resonance. The relative metabolite concentrations to the sum of all metabolites were calculated. Results: In the 1H MRS spectra of the brain from fetuses and children, there are the same characteristic peaks: N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and myo-inositol (mI). NAA/Σ, NAA/Cr, and Cr/Σ concentrations are significantly higher and Cho/Σ, Cho/Cr, mI/Σ, and mI/Cr are significantly lower in children than in the fetuses. Conclusions: It was found that the brain metabolism changes from fetal life to childhood. The results of this study may provide a valuable basis for further research on brain maturation and “healthy aging.”

Relationship between Proton Magnetic Resonance Spectroscopy of Frontoinsular Gray Matter and Neurodevelopmental Outcomes in Very Low Birth Weight Children at the Age of 4

Very low birth weight is associated with long term neurodevelopmental complications. Macroscopic brain abnormalities in prematurity survivors have been investigated in several studies. However, there is limited data regarding local cerebral metabolic status and neurodevelopmental outcomes. The purpose of this study was to characterize the relationship between proton magnetic resonance spectra in basal ganglia, frontal white matter and frontoinsular gray matter, neurodevelopmental outcomes assessed with the Leiter scale and the Developmental Test of Visual Perception and selected socioeconomic variables in a cohort of very low birth weight children at the age of four. Children were divided in three groups based on the severity of neurodevelopmental impairment. There were no differences in spectroscopy in basal ganglia and frontal white matter between the groups. Lower concentrations of N-acetylaspartate (NAA), choline (Cho) and myoinositol (mI) were observed in the frontoinsular cortex of the left hemisphere in children with neurodevelopmental impairment compared to children with normal neurodevelopmental outcomes. Higher parental education, daycare attendance and breastfeeding after birth were associated with more favorable neurodevelopmental prognosis, whereas rural residence was more prevalent in children with moderate and severe impairment. Our study demonstrates the role of long term neurometabolic disruption in the left frontoinsular cortex and selected socioeconomic variables in determination of neurodevelopmental prognosis in prematurity survivors.

Differences in Metabolite Concentrations Between the Hemispheres of the Brain in Healthy Children A Proton Magnetic Resonance Spectroscopy Study (1HMRS)

The aim of this 1HMRS study was to identify hemispheric asymmetries in metabolismus in healthy children. The study group consisted of children of both sexes aged 6 to 15. Concentrations of 6 metabolites occurring in the brain were determined for 6 locations: hippocampus, frontal lobe, and basal ganglia in the left and right hemispheres. There were no hemispheric differences in the metabolites’ concentrations in the brain in children when the variable of sex was disregarded. Only in the group of boys and in the group of girls did the findings show few discrepancies. In none of these groups, relative concentrations to creatine concentration were found to be significantly different between hemispheres. In clinical practice, concentrations of specific metabolites are most frequently determined relative to the concentration of creatine. Consequently, the analysis of standard 1HMRS examinations in children does not need to take into account interhemispheric differences.

Relationship between Stereoscopic Vision, Visual Perception, and Microstructure Changes of Corpus Callosum and Occipital White Matter in the 4-Year-Old Very Low Birth Weight Children

Aim. To assess the relationship between stereoscopic vision, visual perception, and microstructure of the corpus callosum (CC) and occipital white matter, 61 children born with a mean birth weight of 1024 g (SD 270 g) were subjected to detailed ophthalmologic evaluation, Developmental Test of Visual Perception (DTVP-3), and diffusion tensor imaging (DTI) at the age of 4. Results. Abnormal stereoscopic vision was detected in 16 children. Children with abnormal stereoscopic vision had smaller CC (CC length: 53 ± 6 mm versus 61 ± 4 mm; p < 0.01; estimated CC area: 314 ± 106 mm2 versus 446 ± 79 mm2; p < 0.01) and lower fractional anisotropy (FA) values in CC (FA value of rostrum/genu: 0.7 ± 0.09 versus 0.79 ± 0.07; p < 0.01; FA value of CC body: 0.74 ± 0.13 versus 0.82 ± 0.09; p = 0.03). We found a significant correlation between DTVP-3 scores, CC size, and FA values in rostrum and body. This correlation was unrelated to retinopathy of prematurity. Conclusions. Visual perceptive dysfunction in ex-preterm children without major sequelae of prematurity depends on more subtle changes in the brain microstructure, including CC. Role of interhemispheric connections in visual perception might be more complex than previously anticipated.

Sex differences in brain metabolite concentrations in healthy children – proton magnetic resonance spectroscopy study ( 1 HMRS)

Purpose The aim of this 1HMRS study was to define sex-related differences in metabolic spectrum between healthy children. Forty-nine girls and boys aged 6-15 years were examined. Material and methods Volume of interest was located in seven brain regions: frontal lobes, basal ganglia, hippocampi, and cerebellum. Results Statistical analysis of the results showed significantly higher (p < 0.05) myo-inositol concentrations relative to the total concentrations in the boys than the girls, as well as higher absolute N-acetyl aspartate concentrations in the left frontal lobes in girls. No other significant differences were shown, except for trends in differences. Conclusions In clinical practice the diagnostic process first of all focuses on assessing concentrations of metabolites to relative cerebellum concentration. Thus, the findings of the present study allow the conclusion that when analysing the results of 1HMRS studies in children it is not necessary to take into account the child’s gender.

Evaluation of changes in biochemical composition of fetal brain between 18th and 40th gestational week in proton magnetic resonance spectroscopy

Abstract Introduction: The aim of this study is to determine the right 1H MRS spectra of the brain in fetuses of different age, and then to define what metabolic changes occur between 18th and 40th weeks of pregnancy. Methods: 1H MRS studies of 32 fetuses aged 18–40 gestational weeks were performed, in which the MRI excluded central nervous system malformations. The studied group included 11 fetuses aged 18–25 weeks (the second half of the second trimester), 14 fetuses aged 26–33 weeks (the first half of the third trimester), and seven fetuses aged 34–40 weeks (the second half of the third trimester). The relative ratios of metabolites concentrations to the sum of all metabolites were calculated. Results: Increase in the concentrations of N-acetylaspartate (NAA), Cr, Cho, and myo-inositol (mI) with gestational age is statistically significant. Only increase in Glx is statistically insignificant. In the analyzed period of pregnancy also, an insignificant increase of NAA/Σ and Cr/Σ ratios and a decrease of mI/Σ, Cho/Σ and Glx/Σ ratios were noticed. Conclusions: Changes in the 1H MRS spectrum are visible with increasing age of the fetus. All studied substances in fetal brain change their concentrations during pregnancy, which may be associated with the synaptic and dendritic development as well as myelination. Knowledge about the chemical changes in the fetal brain can provide valuable information in studies of the mechanisms of pregnancy and fetal development, define steps of brain metabolic development and explain reasons of pathologies.

Microstructure changes of occipital white matter are responsible for visual problems in the 3–4-year-old very low birth weight children

Purpose: The main aim of the study was to evaluate which factors affect the long-time visual function in preterm children, whether it is prematurity or retinopathy of prematurity or perhaps disturbances in the visual pathway. Materials and Methods: Fifty-eight children with mean birth weight 1016 g (range 520–1500 g) were evaluated at mean age 48 months (range 42–54 months). All children underwent magnetic resonance imaging (MRI) studies, visual evoked potentials (VEPs), and the Developmental Test of Visual Perception (DTVP). The MRI evaluation included diffusion tensor imaging and fractional anisotropy (FA), and colored orientation maps were calculated for each subject. Based on the results of the VEP evaluation, children were divided into two groups: A-abnormal results of VEP (n = 16) and B-normal VEP results (comparison group, n = 42). Results: FA values of inferior left and right occipital white matter (OWM) were lower in the group of children with abnormal VEP compared to the comparison group (0.34 ± 0.06 vs. 0.38 ± 0.06; P = 0.047; 0.31 ± 0.04 vs. 0.36 ± 0.06; P = 0.007, respectively). Furthermore, there were correlations between the latency (r = −0.35; P = 0.01) and amplitude (r = 0.31; P = 0.02) and FA in OWM. Children with abnormal VEP had lower DTVP scores as compared with children with normal VEP results (88 ± 18 vs. 95 ± 16 points, P = 0.048). Finally, a multivariate logistic regression revealed that FA of the inferior OWM was the only independent risk factor for the abnormal VEP (P = 0.04). Conclusion: Visual perception, VEPs, and white matter microstructural abnormalities in very low birth weight children at the age of 3–4 are significantly correlated.

PO-0415 Corpus Callosum Size As A Predictor Of Visual Problems Among 4-year-old Very Low Birth Weight Children

Background Correlation between corpus callosum (CC) size and motor performance in prematurely born children has been described. It is speculated that the organisation of CC can be associated with visual acuity in preterm children. Aim To assess the relation between CC size and vision impairment, results of Frostig test of visual perception and Visual evoked potentials (VEP) in a group of VLBW children. Methods 40 children born with a mean birthweight of 1023g (SD 230g) were evaluated at the mean age of 4 years (range 3.7–4.3). The children were examined for clinical signs of vision impairment and were subjected to Frostig test. VEP was recorded after checkerboard pattern and flash stimulation. Morphological brain changes and CC size were evaluated using standard MRI sequences. The MRI evaluators were not informed about the results of visual examinations. Results Impaired visual acuity was detected in 9/12 cases with abnormal CC (75%) and in 10% of children with normal CC (p < 0.01). There was a significant correlation between the CC size and Frostig test results (abnormal CC group vs. normal CC group: 91 vs. 80.7 points; p = 0.03 adjusted for history of ROP). Absence of stereoscopic vision was more frequent in the group of abnormal CC (7/12 vs. 2/20; p = 0.03). The frequency of abnormal VEP was similar in the both groups. Conclusion A strong correlation between vision impairment and CC size was observed. This suggests that CC plays important function in integration of visual perception. Study supported by National Science Centre, Poland: grant number: 2011/03/B/NZ5/05678.