Brain structural and microstructural alterations associated with cerebral palsy and motor impairments in adolescents born extremely preterm and/or extremely low birthweight. (21st July 2015) - Kelly, Claire E
Abstract : Aim: To elucidate neurobiological changes underlying motor impairments in adolescents born extremely preterm (gestation <28wks) and/or with extremely low birthweight (ELBW, <1000g), our aims were the following: (1) to compare corticospinal tract (CST) microstructure and primary motor cortex (M1) volume, area, and thickness between extremely preterm/ELBW adolescents and a comparison group with normal birthweight (>2499g); (2) to compare CST microstructure and M1 volume, area, and thickness between extremely preterm/ELBW adolescents with cerebral palsy (CP), motor impairment without CP, and no motor impairment; and (3) to investigate associations between CST microstructure and M1 measures. Method: This study used diffusion and structural magnetic resonance imaging to examine the CST and M1 in a geographical cohort of 191 extremely preterm/ELBW adolescents (mean age 18y 2.4mo [SD 9.6mo]; 87 males, 104 females) and 141 adolescents in the comparison group (mean age 18y 1.2mo [SD 9.6mo]; 59 males, 82 females). Results: Extremely preterm/ELBW adolescents had higher CST axial, radial, and mean diffusivities and lower M1 thickness than the comparison group. Extremely preterm/ELBW adolescents with CP had higher CST diffusivities than non‐motor‐impaired extremely preterm/ELBW adolescents. CST diffusivities correlated with M1 volume and area. Interpretation: Extremely preterm/ELBW adolescents have altered CST microstructure, which is associated with CP. Furthermore, the results elucidate how CST and M1 alterations interrelate to potentially influence motor function in extremely preterm/ELBW adolescents. What this paper adds: Corticospinal tract microstructure is altered in extremely preterm/extremely low birthweight (ELBW) adolescents. Primary motor cortical thickness is reduced in extremely preterm/ELBW adolescents. Extremely preterm/ELBW adolescents with cerebral palsy exhibit altered corticospinal tract microstructure. Corticospinal tract microstructure and primary motor cortical volume are interrelated. This article is commented on by Kumar on pages1090–1091 of this issue.