Cerebral asymmetry in 14 year olds born very preterm.

The normal pattern of cerebral asymmetry may be altered in neurodevelopmental disorders such as autism and schizophrenia. Babies born very preterm have an increased risk of brain damage, and brain abnormalities which persist into adolescence. This study aimed to ascertain whether preterm birth affects the development of fronto-occipital asymmetry. Structural MRI (magnetic resonance imaging) scans from 14 year old individuals born very preterm (n = 61; mean age 14 years 11 months; 29 male) and age-matched full-term controls (n = 49; mean age 14 years 11 months; 31 male) underwent morphometric analysis, using well-validated stereological methods. Measurements of right and left prefrontal, premotor, sensorimotor and occipitoparietal regional volumes were made and asymmetry indices calculated. These factors underwent a reductive factor analysis. There were no significant between-group differences in fronto-occipital asymmetry between the preterm adolescents and their full-term counterparts. It seems unlikely, therefore, that preterm birth per se deviates the development of normal fronto-occipital asymmetry. Neonatal periventricular haemorrhage with ventricular dilatation revealed by ultrasound may be associated with reversal of asymmetry in the sensorimotor area.