Fractional anisotropy alterations in individuals born preterm: a diffusion tensor imaging meta‐analysis

Abstract

ALEActivation likelihood estimate DTI Diffusion tensor imaging SMD Standardized mean difference AIM This meta-analysis explored cerebral microstructural changes in individuals born preterm using fractional anisotropy from diffusion tensor imaging.METHOD We used the activation likelihood estimate (ALE) method for the meta-analysis to locate anatomical regions with white matter abnormalities in a group of individuals born preterm and in term-born comparison participants. A statistical analysis of fractional anisotropy was conducted to quantitatively explore the extent of fractional anisotropy changes in the three subregions of the corpus callosum in the preterm group.RESULTS ALE analysis identified 11 regions of decreased fractional anisotropy and four regions of increased fractional anisotropy. Analysis of the corpus callosum revealed the largest decrease in fractional anisotropy in the splenium (standardized mean difference [SMD]=À0.75, 95% confidence interval [CI] À0.93 to À0.57), followed by the body (SMD=À0.73, 95% CI À1.13 to À0.32) and the genu (SMD=À0.65, 95% CI À0.97 to À0.33). INTERPRETATION Significant changes in fractional anisotropy in individuals born pretermreflect white matter abnormalities from childhood to young adulthood, and the mechanism of fractional anisotropy alterations in preterm infants may vary during different stages of white matter development. Furthermore, the variability of fractional anisotropy between studies can primarily be attributed to the age of the individuals at scanning and to the field strength of magnetic resonance scanners.Preterm birth is frequently accompanied by a variety of disabilities, such as cerebral palsy, intellectual disability, deafness, or blindness. The incidence of preterm birth has increased significantly in the past decades, but is associated with higher survival rates 1 and a lower incidence of major disabilities than in the past.2 However, there is strong evidence that preterm survivors without brain malformations, congenital infection, or metabolic disease and with normal outcomes or mild abnormalities on structural brain magnetic resonance imaging (MRI) may experience more problems of motor, cognitive, language, and behavioural functioning throughout childhood and young adulthood. [3][4][5][6] These sequelae have been attributed to perinatal brain injuries, 7,8 which frequently involve white matter, 9 during normal brain maturation. 10 Nevertheless, the location, severity, and mechanism of white matter injuries on neurodevelopment and their impact on future function have not been conclusively determined.11 Additional neuroimaging evidence is necessary to explain the mechanism of white matter injuries and to predict the future influence of these impairments in individuals who are born preterm.Diffusion tensor imaging (DTI), a novel MRI technique, can quantify the fibre orientation and integrity of white matter pathways within neural networks. This technique is superior to conventional MRI methods for the detection of white matter abnormalities becaus...

Correlations between diffusion tensor imaging and levels of consciousness in patients with traumatic brain injury: a systematic review and meta-analysis

“…Previous DTI-related meta-analyses used a visualised method named activation likelihood estimate (ALE) to locate regions with white matter abnormalities 35, 36 . Another meta-analysis pooled FA values to investigate the most vulnerable region 17 .…”

Whole-Brain DTI Assessment of White Matter Damage in Children with Bilateral Cerebral Palsy: Evidence of Involvement beyond the Primary Target of the Anoxic Insult

“…5,32,33 We found a severe involvement of optic tracts, optic radiations, and posterior corona radiata that could affect the integrity of the afferent sensory visual tracts with much more evidence than previously described. 32,34 Although our recruitment criteria excluded children with major visual problems, visual perceptual difficulties characterize the cognitive profile in children with PVL 35 36 Also the different methodology used in cognitive assessment (developmental quotient versus IQ) may have played a role. This study has limitations.…”

Social brain circuitry and social cognition in infants born preterm

“…Eikenes et al (2011) also found reduced FA in the corpus callosum of 49 VLBW (birth weight < 1500 g) PT-born 12-year olds, when compared to 59 term-born controls [134]. A recent meta-analysis [135] incorporated 232 original studies, for a total of 513 PT-born children, adolescents, and young adults and 309 healthy controls. The analysis used an activation likelihood estimate (ALE) procedure to identify regions of abnormal FA in the corpus callosum.…”

“…As Li [135] notes, this may be due at least in part to differences in methodology, including the population of interest, the time at which images are collected, and the manner in which brains are segmented into regions or networks. What is clear is that even uninjured PT-born infants show differences in brain connectivity, both structurally and functionally (as described below).…”