Spatial orientation of attention and obstacle avoidance following concussion.

Re-injury to the brain during recovery from an initial concussion leads to increased probability of permanent brain damage or death. Recovery from concussion has been proposed to be ongoing even up to a month post-injury. The goal of the current study was to investigate the relationship between the visuospatial orientation of attention and obstacle avoidance during gait in individuals that have recently suffered a concussion (mTBI) over a month post-injury. MTBI subjects and matched control subjects performed the attentional network test (ANT), designed to isolate several different components of attention. Obstacle crossing during gait with and without a concurrent attention dividing task was also performed. Reaction times from the ANT and obstacle clearance measurements were the main dependent variables. We observed that concussed individuals had statistically more obstacle contacts than controls. The ability to orient attention in space was also statistically deficient immediately after a concussion, and this was correlated with lower obstacle clearances of the leading foot. Similar correlations could also be found between both leading and trailing foot avoidance and spatial orientation of attention in participants with concussion when attention was divided during obstacle crossing, and these relationships gradually weakened as recovery progressed. By contrast, spatial attention and obstacle clearance were not significantly correlated in control subjects. These findings indicate that patients with mTBI who display greater spatial attention deficits cross over the obstacle with a lower clearance than patients with less or without spatial attention deficits, leading to an increased probability of obstacle contact.