Reading skill in adult survivors of childhood brain tumor: A theory-based neurocognitive model.

Abstract

Objective: This study investigated the relationship between word reading and white matter (WM) integrity within a neuroanatomical-based reading system comparing adult survivors of childhood brain tumors and controls. It was predicted that the association between WM integrity and word reading would be mediated by processing speed, and this indirect effect would be moderated by group. Method: Thirty-seven adult survivors of childhood brain tumor and typically developing adults participated (age M = 24.19 ± 4.51 years, 62% female). DTI Tractography identified the WM tract for 3 of the reading system connections: inferior fronto-occipital fasciculus (IFOF), arcuate fasciculus (AF), and parietotemporal-occipitotemporal connection (PT-OT). Results: Fractional anisotropy values (FA) of the PT-OT tract were significantly correlated with word reading in survivors and controls (r = .45, .58, respectively; p < .05) and IFOF values were associated with reading in survivors only (r = .59, p < .01). Further, the moderated mediated model was significant for PT-OT and IFOF, such that the indirect effect of processing speed was only present for survivors (CI: PT-OT: 2.90, 28.41, IFOF: 2.92, 40.17). Conclusion: Results suggest the tracts emerging from the occipitotemporal area are a critical component of the reading system in adults. The finding that processing speed was the mechanism by which WM was associated with reading in survivors is in alignment with the developmental cascade model. Current findings bolster the existing theory-based models of reading using innovative diffusion tensor imaging and moderated mediation statistical neurodevelopmental model, establishing the role of processing speed and specific WM pathway integrity in word reading skill.

White Matter Integrity Dissociates Verbal Memory and Auditory Attention Span in Emerging Adults with Congenital Heart Disease

“…Along with findings within the CHD literature, research across a wide range of other clinical populations has suggested relationships between lower WMI in specific brain regions and poorer functioning on cognitive measures (Ellmore, Li, Xue, Wong, & Frye, 2013; Genova, DeLuca, Chiaravalloti, & Wylie, 2013; Nestor et al, 2004; Smith, King, Jayakar, & Morris, 2014). Given these findings, it is possible that reduced microstructural connectivity resulting from early disruption could be related to cognitive performance in emerging adults with CHD.…”

Disruption of White Matter Integrity in Adult Survivors of Childhood Brain Tumors: Correlates with Long-Term Intellectual Outcomes

“…The 4-subtest Wechsler Abbreviated Scale of Intelligence (WASI; Wechsler, 1999) was administered to obtain estimates of intellectual abilities. WASI has been employed in many research studies of child and adult neurological populations including adults survivors of childhood brain tumor [ 12 , 19 ]. Verbal IQ (VIQ) was based on Vocabulary and Similarities subtests.…”

“…Rarely do studies examine brain tumor survivors treated with radiation versus no radiation treatment [ 8 ] and relative to non-clinic referred healthy controls. The reports on cognitive correlations with FA are also limited [ 11 , 12 ]. Furthermore, existing studies on the relationship between FA and intellectual performance (IQ) are inconsistent in pediatric brain tumor patients [ 6 , 13 ].…”

White matter network topology relates to cognitive flexibility and cumulative neurological risk in adult survivors of pediatric brain tumors

“…Neuroimaging studies in survivors of pediatric brain tumor have found reduced white matter integrity in specific tracts ( Aukema et al, 2009 ; King et al, 2015b ; Mabbott et al, 2006 ; Palmer et al, 2012 ; Riggs et al, 2014 ; Rueckriegel et al, 2010 ; Smith et al, 2014 ) and that the integrity of these tracts is associated with performance on neurocognitive measures of processing speed, motor speed, full scale IQ, fine motor function, working memory, memory, and executive functioning ( Aukema et al, 2009 ; Brinkman et al, 2012 ; Law et al, 2011 ; Palmer et al, 2012 ; Riggs et al, 2014 ; Rueckriegel et al, 2015 ). These studies suggest that structural changes to white matter may represent the neurobiological underpinnings of outcomes.…”