Effects of unilateral clefts on brain structure.

OBJECTIVE To evaluate potential abnormalities in brain structure of children and adolescents with unilateral clefts. DESIGN Case-control study. SETTING Tertiary care center. PARTICIPANTS Boys aged 7 to 17 years with right (n=14) and left (n=19) clefts were compared with healthy age-matched boys (n=57). MAIN EXPOSURES Structural brain measures were obtained using magnetic resonance imaging. OUTCOME MEASURE It was explored whether laterality of clefts had a significant effect on brain structure. To this end, volumes of tissue types and various brain regions were evaluated. RESULTS Total white matter was significantly lower in boys with right clefts compared with boys with left clefts and healthy boys. Gross regional analyses demonstrated that reductions in white matter were evident in both the cerebellum and the cerebrum in boys with right clefts. Furthermore, within the cerebrum, white matter volumes were particularly low in the frontal lobes and the occipital lobes. CONCLUSIONS These preliminary results suggest that right clefts may be associated with more abnormalities in brain structure. More generally, laterality of a birth defect may have a significant effect on a developing organism.