A new approach to corpus callosum anomalies in idiopathic scoliosis using diffusion tensor magnetic resonance imaging

Idiopathic scoliosis (IS) is a frequent 3D structural deformity of the spine with a multi-factorial aetiology which remains largely unclear. In the last decade, human magnetic resonance imaging (MRI) morphometry studies (e.g. cortical thickness, 2D shape of the corpus callosum) have aimed to investigate the potential contribution of the central nervous system in the etiopathogenesis of IS. Recent developments in diffusion tensor imaging (DTI) allow us to extend the previous work to the study of white matter microstructure. Here, we hypothesized that part of the corpus callosum could show a difference in white matter microstructure in IS patients as compared to healthy controls.

We acquired DTI in 10 girls with IS and in 49 gender-matched controls to quantify the fractional anisotropy (FA) along the corpus callosum.

Despite a very similar pattern of FA along the corpus callosum (maxima in the splenium and the genu and minimum in the isthmus), we found a significantly lower FA in the body in patients with IS as compared to control subjects. This region is known to connect the motor and premotor cortices of the two hemispheres.

This first diffusion magnetic resonance imaging brain study in IS patients, suggests that differences in white matter development, such as synchronization of axonal myelination and pruning could be involved in the etiopathogenesis of IS.