Article Text
Abstract
Objective To assess eye movements in patients with post-concussion syndrome (PCS) and use diffusion tensor imaging (DTI) to determine relationship between eye movements and white matter integrity.
Design cross-sectional study.
Intervention Attention and executive function were tested using Visual Attention Scanning Technology (VAST) [EL-MAR Inc., Toronto, Ontario, Canada]. In a matching task, the normalised number of transitions (NNT) to a master image before making the first selection was used as a surrogate of working memory. During this task, subjects view a set of slides, each slide includes a master image and six variants, and they have to select a variant that is similar to the master (only one variant is an exact replica of the master).
Outcome measures We related performance on VAST to white matter integrity using Tract-Based Spatial Statistics of DTI metrics such as fractional anisotropy (FA) for whole brain analyses as well as seed-based probabilistic tractography analysis of the superior longitudinal fasciculus (SLF), Cingulum tract, and Uncinate fasciculus (UF).
Main results 60 participants (mean age 34.3 years, SD 13.8) had a mean of 4 concussions. There were negative correlations between whole brain FA and NNT (r=−0.501, p<0.001). In addition, when we performed probabilistic tractography analyses, we found a negative correlation between the FA of right SLF and NNT (r=−0.332, p=0.009).
Conclusions Impaired performance on eye tracking measures of attention and executive function may reflect alterations in white matter tracts.
Competing interests None.
Moshe Eizenman is a director in EL-MAR Inc.