Spatial working memory performance following acute sport-related concussion

Abstract

Introduction: An important problem in the field of sport-related concussion is the lack of a 'gold-standard' clinical assessment tool. Currently, the diagnosis relies heavily on self-reporting of symptoms and observation of clinical signs by medical professionals. To address this, our group has been motivated to develop objective measures of neurological impairment following concussion. Spatial working memory is an important aspect of cognitive function that might be impaired following concussion. In the present study, we measured spatial working memory using a robotic spatial span task. We first assessed test-retest reliability in 82 healthy athletes who underwent baseline testing across two athletic seasons using intraclass correlation coefficients. We then assessed spatial span performance relative to baseline in 47 athletes acutely following sport-related concussion using a reliable change index with 80% confidence limits to define impairment on an individual basis. Results: We found good test-retest reliability for the mean span (a measure of spatial working memory span length; intraclass correlation coefficient ¼ 0.79), and moderate reliability for the response duration (time taken per spatial target; intraclass correlation coefficient ¼ 0.64) in healthy athletes. However, only 19% of acutely concussed athletes showed evidence of impairment relative to baseline in mean span, and even fewer (9%) showed evidence of impairment in response duration. Analysis of serial position curves revealed primacy and recency effects for this task, but no grouplevel differences between concussed and healthy athletes. Analysis of specific types of errors showed a higher rate of substitution errors in the concussed group at baseline, suggesting possible malingering in a small number of athletes. Conclusion: Overall, few athletes showed evidence of impaired spatial working memory acutely following concussion, suggesting either that spatial working memory is not commonly impaired acutely post-concussion, or that the present task is not sufficiently demanding.

Assessing various sensorimotor and cognitive functions in people with epilepsy is feasible with robotics

“…The Kinarm robotic assessment system (Kinarm, Kingston, ON, Canada) is a tool that quantifies performance on a collection of behavioral tasks that test motor, cognitive, and sensory functions, referred to as Kinarm Standard Tests™ (KSTs). It has been used to characterize deficits in a variety of clinical populations such as stroke ( [14][15][16]), ALS [17], Parkinson's disease [18], TIA [19], and concussion [20]. Furthermore, previous work has highlighted the test-retest reliability of Kinarm assessment results [21].…”

The feasibility of assessing cognitive and motor function in multiple sclerosis patients using robotics

“…Kinarm has been used to assess individuals with diverse neurological conditions, including stroke, 11 – 13 amyotrophic lateral sclerosis, 14 and concussion. 15 Previous work assessing upper-limb function using robotics in people with MS has provided detailed accounts of individual kinematic parameters in some instances, 16 and purely motor skill in others. 17 Here, we investigate a broad range of motor, sensory and cognitive tasks with emphasis on performance across multiple behavioural domains.…”

Assessment of Postural Stability During an Upper Extremity Rapid, Bimanual Motor Task After Sport-Related Concussion

“…Moreover, compared with healthy control athletes, the percentage of athletes identified as impaired was generally higher among athletes who selfreported as symptomatic and were within 10 days of SRC. 6 Nevertheless, the SRC-related impairments were fewer on these tests than we expected to observe in subjectively symptomatic athletes (range ¼ 4%-27% using reliable change indices [RCIs] with an impairment cutoff of .80% confidence limit), 6,7 suggesting that more complex tasks that engage additional neurologic functions may be required to objectively detect impairments after SRC.…”

“…Relative to traditional clinical tools, the potential benefits of applying robotic technology to SRC assessment include high levels of accuracy, precision, and objectivity. 8 In initial work 7,9 with healthy athletes, moderate to good test-retest reliability of several robotic tests (KINARM Standard Tests) designed to evaluate motor, sensory, and cognitive function was demonstrated. Briefly, researchers from our laboratory investigated 6 tests that together were designed to assess elements of upper extremity visuomotor capability, upper extremity proprioceptive capability (ie, position sense), rapid bimanual motor control, attention, rapid motor selection, response inhibition, task-switching, 6,[9][10][11] and spatial working memory performance.…”

“…Briefly, researchers from our laboratory investigated 6 tests that together were designed to assess elements of upper extremity visuomotor capability, upper extremity proprioceptive capability (ie, position sense), rapid bimanual motor control, attention, rapid motor selection, response inhibition, task-switching, 6,[9][10][11] and spatial working memory performance. 7 These tests are efficient (approximately 2 minutes each) and collectively compose a multidimensional neurologic assessment. Moreover, compared with healthy control athletes, the percentage of athletes identified as impaired was generally higher among athletes who selfreported as symptomatic and were within 10 days of SRC.…”