Brain Volumes in Adolescents With Very Low Birth Weight: Effects on Brain Structure and Associations With Neuropsychological Outcomes

Abstract

The aims of this study were to examine abnormalities in brain structure in adolescents and young adults with very low birth weight (VLBW, <1,500 g) and associations of these abnormalities with neuropsychological outcomes. The sample of 108 participants from 14 to 19 years of age included 37 participants with <750 g birth weight, 35 with 750-1,499 g birth weight, and 36 normal birth weight (NBW) controls. One or both of the VLBW groups had smaller brain volumes, larger lateral ventricles, and a small surface area of the corpus callosum than the NBW controls. Group differences in white matter (WM) structures, subcortical gray matter (GM), and the cerebellum were found even when controlling for whole brain volume (WBV), and were most pronounced in the <750 g group. WM reductions in the two VLBW groups relative to NBW controls were associated with more pervasive cognitive deficits than were reductions in subcortical GM. Associations of cognitive outcomes with structural abnormalities remained when controlling for WBV or neonatal risks. The results are consistent with previous findings of residual brain abnormalities in adolescents and young adults with VLBW and provide new information on their cognitive correlates.

Reduced Cholinergic Basal Forebrain Integrity Links Neonatal Complications and Adult Cognitive Deficits After Premature Birth

“…Reductions in cerebral WM volume have been described to be the most prevalent form of neuronal damage associated with premature birth (7) and to be a major determinant of IQ in VP/VLBW adolescents (11,29). However, in our sample of VP/VLBW adults, total WM volume was only marginally reduced compared to controls and was not related to intellectual impairments.…”

“…WM alterations have been described to be the most prevalent form of neuronal damage associated with preterm birth (7) and previous imaging studies found reductions in total WM volume to be a major determinant of IQ in VP/VLBW adolescents (11,29). To account for differences in head size, cBF as well as global GM and WM volumes were scaled to the intracranial volume (ICV), calculated as the sum of total segmented volumes of the GM, WM and cerebrospinal fluid partitions.…”

“…Previous research has shown that perinatal brain injury affects primarily the forebrain's white matter, characterized by immature and vulnerable glia cells and a relatively poor vascularization before 32 weeks of gestation (7). With increasing severity of injury, white matter impairments extend to gray matter, particularly affecting subcortical structures such as thalamus or basal ganglia (8)(9)(10)(11)(12). In this regard, the cholinergic basal forebrain (cBF) may be of special interest, since -at least in animal models -proper development of this system of cortically-projecting nuclei has been shown to be highly sensitive to perinatal stressors, such as glucocorticoid exposure (13), hypoxic-ischemic events (14), or neonatal psychosocial stress (15), resulting in structural and functional impairments that persist into adulthood.…”

A crucial role for white matter alterations in interference control problems of very preterm children

“…In this study, we found that altered FA values of fiber tracts connecting the thalamus with the dACC underpin interference control problems of very preterm children. Interestingly, this finding may illustrate a pathway by which the thalamus, as a cortical "relay station, " is associated with cognitive and executive dysfunctioning of very preterm children (19,20). Measures of radial and axial diffusivity may elucidate the origin of differences in FA values between very preterm children and term controls, although interpretation(s) in terms of the underlying pathology might need further validation (21).…”

Cerebral White Matter Injuries Following a Hypoxic/Ischemic Insult During the Perinatal Period: Pathophysiology, Prognostic Factors, and Future Strategy of Treatment Approach. A Minireview

“…This decrease in brain volume was also correlated with a reduction in IQ levels, which suggested that perinatal brain injury associated with VLBW induces permanent deficits in cognitive abilities later on in life. Taylor et al [71] also reported a significant correlation between IQ levels and cerebral white matter volume in VLBW adolescents.…”