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
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
Moshe Eizenman is a director in EL-MAR Inc.