Non-right-handedness in children born extremely preterm: Relation to early neuroimaging and long-term neurodevelopment

Abstract

Objective: This study aimed to define the prevalence and predictors of non-right-handedness and its link to long-term neurodevelopmental outcome and early neuroimaging in a cohort of children born extremely preterm (<28 weeks gestation).

Methods: 179 children born extremely preterm admitted to the Neonatal Intensive Care Unit of our tertiary centre from 2006-2013 were included in a prospective longitudinal cohort study. Collected data included perinatal data, demographic characteristics, neurodevelopmental outcome measured by the Bayley Scales of Infant and Toddler Development at 2 years and the Movement Assessment Battery for Children at 5 years, and handedness measured at school age (4-8 years). Magnetic resonance imaging performed at term-equivalent age was used to study overt brain injury. Diffusion tensor imaging scans were analysed using tract-based spatial statistics to assess white matter microstructure in relation to handedness and neurodevelopmental outcome.

Results: The prevalence of non-right-handedness in our cohort was 22.9%, compared to 12% in the general population. Weaker fine motor skills at 2 years and paternal non-right-handedness were significantly associated with non-right-handedness. Both overt brain injury and fractional anisotropy of white matter structures on diffusion tensor images were not related to handedness. Fractional anisotropy measurements showed significant associations with neurodevelopmental outcome.

Conclusions: Our data show that non-right-handedness in children born extremely preterm occurs almost twice as frequently as in the general population. In the studied population, non-right-handedness is associated with weaker fine motor skills and paternal non-right-handedness, but not with overt brain injury or microstructural brain development on early magnetic resonance imaging.

Fig 1. Flowchart of study participants.

Abbreviations: NICU, Neonatal Intensive Care Unit; GA, gestational age; CP, cerebral palsy; MABC-2-NL, Movement Assessment Battery for Children, second edition, Dutch version; DTI, diffusion tensor imaging; MRI, magnetic resonance imaging; TBSS, tract-based spatial statistics.

Fig 2. Tract-based spatial statistics: White matter changes on diffusion tensor imaging in relation to neurodevelopmental outcome.

The results of the tract-based spatial statistics analysis. A. The color indicates the degree of significance of the association of its fractional anisotropy (FA) value with the studied outcome variable, as presented at the top of each series of images. B. Partial regression plots showing the linear relationship between the different outcome measures and the FA value extracted from the significant voxels, corrected for GA at birth and PMA at scan. For each subtest a significant positive correlation between FA and neurodevelopmental outcome is shown. Abbreviations: BSITD-III, Bayley Scales of Infant and Toddler Development, third edition, Dutch version; MABC-2-NL, Movement Assessment Battery for Children, second edition, Dutch version; FA, fractional anisotropy.