Abnormal cortical development after premature birth shown by altered allometric scaling of brain growth

Autor: N. Saeed, A. David Edwards, Jaroslav Stark, Joanna M. Allsop, Leigh Dyet, Frances M. Cowan, Mary A. Rutherford, Olga Kapellou, Philip Duggan, Elia F. Maalouf, Morenike Ajayi-Obe, James P. Boardman, Serena J. Counsell, N Kennea, Jo Hajnal
Přispěvatelé: Engineering & Physical Science Research Council (EPSRC)
Jazyk: angličtina
Rok vydání: 2006
Předmět:
Male
Pediatrics
Developmental Disabilities
Physiology
INFANTS
CHILDREN
Cohort Studies
Cerebral Cortex
Gestational age
Brain
General Medicine
BORN PRETERM
11 Medical And Health Sciences
Magnetic Resonance Imaging
medicine.anatomical_structure
Neurology
Cerebral cortex
Premature birth
Gestation
Medicine
Female
medicine.symptom
Life Sciences & Biomedicine
Infant
Premature
Research Article
medicine.medical_specialty
Biometry
Central nervous system
Models
Neurological
Gestational Age
Brain damage
EXTREMELY PRETERM BIRTH
Medicine
General & Internal
Sex Factors
General & Internal Medicine
CEREBRAL-CORTEX
medicine
Humans
VISUAL-CORTEX
OPTIMIZATION
Science & Technology
business.industry
DISABILITY
Infant
Newborn
Neonates
medicine.disease
SUBPLATE NEURONS
Confidence interval
Visual cortex
WEIGHT
business
Zdroj: PLoS Medicine, Vol 3, Iss 8, p e265 (2006)
PLoS Medicine
ISSN: 1549-1676
Popis: Background We postulated that during ontogenesis cortical surface area and cerebral volume are related by a scaling law whose exponent gives a quantitative measure of cortical development. We used this approach to investigate the hypothesis that premature termination of the intrauterine environment by preterm birth reduces cortical development in a dose-dependent manner, providing a neural substrate for functional impairment. Methods and Findings We analyzed 274 magnetic resonance images that recorded brain growth from 23 to 48 wk of gestation in 113 extremely preterm infants born at 22 to 29 wk of gestation, 63 of whom underwent neurodevelopmental assessment at a median age of 2 y. Cortical surface area was related to cerebral volume by a scaling law with an exponent of 1.29 (95% confidence interval, 1.25–1.33), which was proportional to later neurodevelopmental impairment. Increasing prematurity and male gender were associated with a lower scaling exponent (p < 0.0001) independent of intrauterine or postnatal somatic growth. Conclusions Human brain growth obeys an allometric scaling relation that is disrupted by preterm birth in a dose-dependent, sexually dimorphic fashion that directly parallels the incidence of neurodevelopmental impairments in preterm infants. This result focuses attention on brain growth and cortical development during the weeks following preterm delivery as a neural substrate for neurodevelopmental impairment after premature delivery.
Measurement of the way that the brain grows after birth in preterm infants, particularly the relation between surface area and cortical volume, may help to predict neurodevelopmental impairment.
Editors' Summary Background. Nowadays, many children who are born prematurely can be expected to survive. However, children who are born very prematurely have a high chance of having brain damage that leads to delayed development compared with children of the same age but who were not born prematurely. This delay continues into school age at least and is worse in boys than in girls. Although some children have large obvious areas of brain damage, shown on brain scans, most do not and the changes that cause the delay must be more subtle. One possibility is that the underlying abnormality may be due to the fact that in these children the surface of the brain grows at too slow a rate compared to the volume of the brain. It is already known that the human brain (and the brain of closely related monkeys) has a very high surface area compared to its volume and that during normal development this surface area grows much faster than the volume. This extra growth appears to be necessary for the brain to make all the connections it needs. Why Was This Study Done? The researchers wanted to look at how the different parts of the brain grew in very premature babies born before 30 weeks (the normal time of gestation is around 40 weeks). In particular, they wanted to see if there were changes in the rates at which the different parts of the brain grew in relation to each other (the study of the change in proportion of various parts of an organism as a consequence of growth is known as Allometrics—hence the title of the paper). They then wanted to see if the rates of brain growth were affected by a variety of factors, including the sex of the baby or how premature he or she was, and whether there was a relationship between the rate of brain growth and later delayed development. What Did the Researchers Do and Find? Using a specially designed magnetic resonance imaging (MRI) machine—a type of scanner that allows very detailed pictures to be taken of the brain—the authors took 274 images that recorded brain growth from 23 to 48 wk of gestation in 113 extremely premature infants born between 22 and 29 weeks of gestation. 63 of these children were then assessed to see how they were developing mentally at around 2 years of age. As expected, the researchers found that the brain surface area grew faster than the brain volume and that the rate of growth was proportional to the chances of having delayed development later—that is, the slower the rate of growth of surface area relative to volume the more likely there was to be delayed development. In addition, the more premature babies, and those that were male, were most likely to have a slower growth of the brain surface compared with the brain volume. What Do These Findings Mean? It seems that human brains grow during development in a particular way, which means that the surface area grows more than the volume. When babies are born prematurely this pattern of growth is disrupted, and the amount of disruption of the growth seems to predict whether there is delayed development 2 years later. The earlier the birth, the greater the disruption is; in addition, boys are affected more than girls. These results will need to be confirmed in more babies, but if they are correct then it may be possible to monitor brain growth after birth in order to predict which children might need development support later on. The research also suggests useful avenues for further work to understand the exact neuroanatomy of disability in these children. Additional Information. Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030265. • MedlinePlus has a page of links to information on premature babies • The March of Dimes is a US charity that funds research on prematurity • Action Medical Research and Wellbeing are UK charities that fund research in this area
Databáze: OpenAIRE
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