Properties of the prefrontal tracts and cingulum bundle in children with prenatal alcohol exposure

Prenatal alcohol exposure (PAE) significantly impacts brain structure and function, including cognition and behavior. The cingulum bundle and frontal lobe mediate social-, emotional- and cognitive-related functioning that are affected by PAE. However, the neurobehavioural development of the cingulum and intra-frontal tracts has not been examined in people with PAE.

We recruited 29 children and adolescents with PAE and 42 age- and gender-matched unexposed controls. Diffusion magnetic resonance imaging (MRI) data were acquired on a 3 T scanner. The rostral, dorsal and parahippocampal cingulum as well as medio-orbitofrontal, lateral-orbitofrontal, dorsolateral-prefrontal and medial-prefrontal tracts, were delineated and their fractional anisotropy and mean (MD), radial (RD), and axial (AD) diffusivities were calculated using constrained spherical deconvolution and deterministic tractography. We measured behavioural and emotional difficulties using the Behavior Assessment System for Children, 2nd Edition, Parent Rating Scale, and then explored their associations with diffusion metrics that differed between groups.

We found lower MD, RD, and AD in the right parahippocampal cingulum and multiple intra-frontal tracts in youth with PAE compared to controls; however, these differences did not withstand correction for multiple comparisons. While, youth with PAE showed significantly more emotional and behavioural difficulties compared to unexposed controls, these challenges were not associated with differences in diffusion metrics between groups.

PAE may be weakly associated with restricted diffusion in the right parahippocampal cingulum and multiple intra-frontal tracts. However, diffusivity changes related to PAE might not be the primary contributor to emotional and behavioural challenges in children and adolescents with PAE.