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

Abstract

INTRODUCTION:Thalamic abnormalities have been well documented in preterms with periventricular leukomalacia (PVL), although their contribution to long-term cognitive dysfunctions has not been thoroughly investigated. RESULTS: significant differences between groups were observed for global thalamic volume. Neuropsychological assessments showed that preterms with PVL scored within the normal range, although significantly below controls in the full intelligence quotient and the specific cognitive domains of processing speed and working memory. correlations of several thalamic regions with Working Memory Index and FIQ were found in the PVL group. Moreover, thalamic atrophy correlated with white-matter (WM) damage indexes (fractional anisotropy and radial diffusivity) assessed by diffusion tensor imaging. DISCUSSION: The findings suggest that thalamic damage is a common correlate of WM microstructural alterations and might be involved in the cognitive deficits seen in premature infants with PVL at school age. METHODS:We analyzed the impact of PVL-associated thalamic injury on cognitive status at school age and its correlation with WM integrity as measured by magnetic resonance imaging techniques. Thalamic volume and shape of 21 preterm children with PVL were compared with those of 11 preterm children of similar gestational age and birth weight with no evidence of focal WM abnormality.

Structural connectivity relates to perinatal factors and functional impairment at 7 years in children born very preterm

“…Many of these regions connected interhemispherically, implicating the corpus callosum as a contributing WM pathway, but thalamocortical and other major tracts may also have been involved. In agreement with our results, both the corpus callosum (Caldu et al, 2006) and thalamus (Zubiaurre-Elorza et al, 2012) have previously been associated with IQ or cognition in preterm populations, as have a range of other WM tracts (Feldman et al, 2012), and the hippocampus (Isaacs et al, 2004). Similar to the current study, structural connectivity within the cortico-basal ganglia-thalamo-cortical circuit, as well as short cortico-cortical connections, has been associated with higher order cognitive and social skills in extremely preterm children (Fischi-Gomez et al, 2014).…”

New MR Imaging Assessment Tool to Define Brain Abnormalities in Very Preterm Infants at Term

“…Appropriate growth of the thalamus could be impaired by a primary insult, such as ischemia or hemorrhage, or by the secondary effects of degeneration or deafferentation caused by WM and/or cortical GM injury. 31 Thus, deep GM volume may, in effect, integrate the consequences of injury to WM and cortical GM, thereby more fully defining the impact of overall abnormalities 32, 33 and reflecting the global nature of disturbances in brain development.…”

The GABRB1 gene is associated with thalamus volume and modulates the association between thalamus volume and intelligence

“…Subjects with intellectual disabilities (IQ b 70) also showed smaller left thalamus than did normal controls (Mannerkoski et al, 2009). In addition, reduced thalamus volume was found to be correlated with various poor intellectual performance in patients with alcohol-dependence, schizophrenia, complex partial seizures, sickle cell anemia, tuberous sclerosis complex, and periventricular leukomalacia (Chanraud et al, 2007;Coscia et al, 2009;Lin et al, 2013;Mackin et al, 2014;Ridler et al, 2007;Zubiaurre-Elorza et al, 2012).…”