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Abstract
Brief neuropsychological testing batteries and sophisticated balance assessment techniques have been identified as sensitive indicators for the identification of concussion. Typically, these tests are conducted independent of each other, yet sport participation demands the simultaneous performance of cognitive and motor tasks. The purpose of this study was to identify the viability of combining a common cognitive task with a simple balance task into a dual task testing paradigm for concussion assessment. Preseason, baseline data on 456 athletes were obtained. Participants counted backwards by 7s for 30 seconds from randomized starting points between 95 and 105. A rate of seconds to complete a correct subtraction was computed. A timed tandem walk (heel to toe) forward and backward on a standard 2"H X 4"W X 8'L board was performed. After performing the cognitive and motor tasks independent of each other (solo), participants performed the tasks concurrently. Performance of each task independently, always preceded the dual task with the independent tasks counterbalanced. Three trials of all tasks were performed. Paired sample t-tests comparing mean solo scores to mean dual scores revealed that serial 7s rate did not significantly differ (p = .892) from the independent performance of the task (S7s) to the dual performance of the task (D7s). However, beam walk time increased 43% (p < .001) from the independent performance of the task (SBW) to the dual performance of the task (DBW). This suggests athletes compromised performance on the balance task to preserve cognitive performance. Subsequently, 23 athletes from the original sample suffered a concussion and were retested at days 1, 5, and 10 post-injury. An additional 17 athletes volunteered to complete testing as matched controls. Significant group differences were not identified on any of the four dependent variables, however, significant main effects for test day were noted. Planned comparisons suggest that injured athletes perform significantly worse 24 hours after the injury than baseline (SBW) and day 5 (D7s and DBW). It was concluded that cognitive task used in the Multi-Task Head Injury Assessment Test creates interference on the balance task and collectively reflects impaired neurological function immediately post-injury.