Brain-behavior relationships in young traumatic brain injury patients: DTI metrics are highly correlated with postural control.

Traumatic brain injury (TBI) is a major cause of impairment and functional disability in children and adolescents, including deterioration in fine as well as gross motor skills. The aim of this study was to assess deficits in sensory organization and postural ability in a young group of TBI patients versus controls by using quantitative force-platform recordings, and to test whether balance deficits are related to variation in structural properties of the motor and sensory white matter pathways. Twelve patients with TBI and 14 controls (aged 8-20 years) performed the Sensory Organisation Test (SOT) protocol of the EquiTest (Neurocom). All participants were scanned using Diffusion Tensor Imaging (DTI) along with standard anatomical scans. Quantitative comparisons of DTI parameters (fractional anisotropy, axial and radial diffusivity) between TBI patients and controls were performed. Correlations between DTI parameters and SOT balance scores were determined. Findings revealed that the TBI group scored generally lower than the control group on the SOT, indicative of deficits in postural control. In the TBI group, reductions in fractional anisotropy were noted in the cerebellum, posterior thalamic radiation, and corticospinal tract. Degree of white matter deterioration was highly correlated with balance deficits. This study supports the view that DTI is a valuable tool for assessing the integrity of white matter structures and for selectively predicting functional motor deficits in TBI patients. (c) 2009 Wiley-Liss, Inc.