Cortical recruitment patterns in children born prematurely compared with control subjects during a passive listening functional magnetic resonance imaging task

Abstract

Objectives-To use functional magnetic resonance imaging (fMRI) to test the hypothesis that subjects who were born prematurely develop alternative systems for processing language.Study design-Subjects who were born prematurely (n = 14; 600-1250 g birthweight) without neonatal brain injury and 10 matched term control subjects were examined with a fMRI passive listening task of language, the Clinical Evaluation of Language Fundamentals (CELF) and portions of the Comprehensive Test of Phonological Processing (CTOPP). The fMRI task was evaluated for both phonologic and semantic processing.Results-Although there were differences in CELF scores between the subjects born prematurely and control subjects, there were no significant differences in the CTOPP measures in the 2 groups. fMRI studies demonstrated that the groups differentially engaged neural systems known to process language. Children born at term were significantly more likely to activate systems for the semantic processing of language, whereas subjects born prematurely preferentially engaged regions that subserve phonology.Conclusions-At 12 years of age, children born prematurely and children born at term activate neural systems for the auditory processing of language differently. Subjects born prematurely engage different networks for phonologic processing; this strategy is associated with phonologic language scores that are similar to those of control subjects. These biologically based developmental strategies may provide the substrate for the improving language skills noted in children who are born prematurely.Magnetic resonance imaging (MRI) permits the investigation of structural aspects of the developing brain. 1,2 Volumetric, diffusion tensor imaging, and magnetic resonance spectroscopy studies suggest that preterm birth is associated with significant alterations in corticogenesis, and several investigators have suggested that those cortical regions that subserve language are particularly vulnerable to the injury associated with preterm birth. 3,4 In contrast, neural processing has been less well studied in subjects born prematurely, but may offer important insights into the functional aspects of brain development after preterm birth. 5Reprint requests: Laura R. Ment, MD, Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06520; E-mail: laura.ment@yale.edu. Functional MRI (fMRI) is used extensively to study language processing in adults and children with known developmental disorders. 6,7 Preliminary studies of auditory tasks in children who were born prematurely suggest the presence of aberrant systems for language at school age, 5,8 yet recent neuropsychological studies document improvement in testing scores and school performance with time in children who were born prematurely. 9-12 NIH Public AccessWe previously reported in a study of almost 300 children born weighing 600 to 1250 g that the median Peabody Picture Vocabulary Test-Revised (PPVT-R) score, a standard measure for receptive vocabulary, incre...

fMRI: blood oxygen level–dependent activation during a working memory–selective attention task in children born extremely preterm

“…The present study indicates the existence of neuronal markers of selective cognitive impairments at the age of 11 in EPT/ELBW children. The results fit nicely with the few previous fMRI studies of preterm children/adolescents (born <33 wk) looking at response inhibition (22), language (13,16,17,23), visual and auditory tasks (14,24), and verbal fluency (25), which also show reduced activation in preterm as compared with term-born children.…”

“…Recent studies have reported increased activation in areas unique to preterm children as compared with controls, and a suggested interpretation has been that they have developed alternative networks (16,17,22). We did not find evidence of increased activation in alternative networks in our preterm group.…”

“…One of the main strengths of this study is the populationbased study group, which in fMRI studies of preterm children is virtually unique, and the high participation rate. This reduces the risk of effects arising from confounding factors typically found in comparable nonpopulation-based studies with lower sample sizes (16,17,22). The same argument applies to control selection based on time of birth (regardless of socioeconomic status), rather than advertisements (which risks attracting high numbers of well-educated families) or classmates (which will be influenced by geographical factors).…”

“…Functional magnetic resonance imaging (fMRI) has revealed differences in neuronal brain activation between preterm and term children for a range of processes such as memory, language, and auditory measures (15)(16)(17). A common feature of these studies is that preterm children appear to mostly use the same neuronal pathways as term children, but they display significantly reduced magnitudes of activation.…”

Executive functions of children born very preterm—deficit or delay?

“…It is possible that VPT/VLBW children compensate for reduced regional cerebral volume [34] by recruiting supplementary brain regions to achieve the same level of performance as controls. Accordingly, VPT/VLBW children at 12 years of age were observed to activate different functional networks during a language processing task than controls, despite similar task performance [30]. Furthermore, catch-up might depend on environmental factors.…”