Brain morphometry and IQ measurements in preterm children

Abstract

Although IQ is thought to remain relatively stable in the normal population, a decline in IQ has been noted in children born preterm. It is not clear, however, to what extent the inclusion of children with clear neurological damage has influenced these findings. We examined IQ scores obtained in childhood and then again in adolescence from a group of children born at 30 weeks gestation or less who had been classified as neurologically normal at 7.5-8 years. They showed a significant decline in mean IQ scores over time. MRI scans obtained from a subset of children at adolescence were read as normal in approximately 50% of cases and, in the others, there were no consistent relationships between radiological abnormalities and IQ results. Such children can, however, have relatively subtle brain abnormalities that are not seen on conventional MRI, and we hypothesized that these would be related to declines in IQ. Voxel-based morphometry (VBM) analyses of the MRI scans revealed that absolute IQ scores were related to areas in both the parietal and temporal lobes. The analyses also showed that frontal and temporal lobe regions were associated with the decline in VIQ, while occipital and temporal lobe regions (including the hippocampi) were associated with the decline in PIQ. Hippocampal volume measurements were consistent with the VBM findings. We concluded that preterm children are at risk of declining IQ over time even if they have not suffered obvious neurological damage and that the decline is associated with specific neural regions. Whether this is true of children born at >30 weeks gestation and what other factors predispose to this decline have yet to be determined.

Thalamic changes in a preterm sample with periventricular leukomalacia: correlation with white-matter integrity and cognitive outcome at school age

“…Previous quantitative MRI studies in preterm children found that regional GM changes in regions such as sensorimotor, middle temporal, and postcentral gyri correlated with Articles PVL thalamic changes and correlations FIQ (19,20). It has also been reported that frontal and temporal volume decreases correlate with verbal intelligence quotient decline in preterm children, whereas decreases in temporal and occipital cortical regions are associated with a decline in the performance intelligence quotient (25). In a study of normal brain development during childhood, both cortical and subcortical GM volumes correlated with FIQ, although cortical GM shows the strongest correlations (26).…”

Neuroprotective effects of microRNA-210 against oxygen-glucose deprivation through inhibition of apoptosis in PC12 cells

“…Moderate to severe HIE occurs at a rate of 1-2 per 1,000 full-term live births, with a total HIE incidence of 3-5 per 1,000 (2-4); in developing countries, the incidence of HIE is up to 10-fold higher (5). Almost 50% of term-born infants suffering from severe HIE die within weeks of birth, while up to 25% of the survivors exhibit long-term complications (6), including reductions in cerebellar (7), cortical and hippocampal volumes (8). These reductions are associated in turn with cognitive and behavioral deficits, deficits in the verbal and language domains (9,10), a reduced IQ (11), cerebral palsy and mental retardation (12).…”

Brain Volume Reductions within Multiple Cognitive Systems in Male Preterm Children at Age Twelve

“…8 Several VBM studies of preterm birth have been conducted. [9][10][11][12] However, we used VBM analyses as part of a unique, multimodal study of neurodevelopment in preterm children that included semi-automated volumetric and manual region of interest measurements on the basis of specific gyral boundaries to confirm our VBM findings.…”