ATTENTION AND GAIT PERFORMANCE FOLLOWING A CONCUSSION by ROBERT

Original approval signatures are on file with the Graduate School and the University of Oregon Libraries. Currently the information on attention-balance control interactions following concussion is incomplete and not given particular consideration during clinical examinations of concussion. The purposes of this dissertation were to (1) test different gait paradigms for their sensitivity of identifying concussion symptoms and to (2) test how individual components of attention interact with gait performance. The long-term goal of this study is to establish more functional and succinct protocols for return-to-play decisions. Grade II (AAN guidelines) concussed individuals were recruited to participate in testing at 2, 6, 14, and 28 days post-injury. Gait and components of attention were analyzed during each session through a number of different paradigms. Control subjects were matched by stature, age, and athletic participation. The results indicate that the dynamic balance deficits following a concussion are immediately identified with an attention dividing gait task. Obstacle crossing identified v more conservative adaptations 2 weeks after injury. A task combining the two did not clearly identify concussion deficits. Two components of attention showed promise as interacting with gait to cause balance deficits. The spatial orientation component showed an interaction with obstacle avoidance indicating that the same concussed individuals that had poor spatial orientation of attention also came closer to hitting the obstacle during crossings. An analysis of divided attention showed that concussed individuals performing poorly in one task also performed poorly in the other during a dual-task paradigm, but during anyone particular trial there was a trade-off between task performances, which was not present in control individuals. The findings of this dissertation point to the use of a divided attention task to distinguish concussed individuals from healthy individuals immediately after a possible inj urious event. How several different components of attention interact with gait performance is identified. Finally, if a concussion has occurred, an obstacle crossing task might be suitable for a long-term analysis of full recovery of balance control. Ultimately, it is my hope that the information provided here will lead to functionally relevant and clinically executable tests of concussed individuals before they are placed in harm's way due purely to an incomplete diagnosis of their injuries. V111 ACKNOWLEDGMENTS Love, friendship, encouragement and five years of long work days and managing household duties is what my wife provided while I was left to focus on my studies. For this, I must gratefully acknowledge …