Prolonged cognitive-motor impairments in children and adolescents with a history of concussion

Abstract

Aim: We investigated whether children and adolescents with concussion history show cognitive-motor integration (CMI) deficits.

Method: Asymptomatic children and adolescents with concussion history (n = 50; mean 12.84 years) and no history (n = 49; mean: 11.63 years) slid a cursor to targets using their finger on a dual-touch-screen laptop; target location and motor action were not aligned in the CMI task.

Results: Children and adolescents with concussion history showed prolonged CMI deficits, in that their performance did not match that of no history controls until nearly 2 years postevent.

Conclusion: These CMI deficits may be due to disruptions in fronto-parietal networks, contributing to an increased vulnerability to further injury. Current return-to-play assessments that do not test CMI may not fully capture functional abilities postconcussion.

Keywords: cognitive–motor integration; performance; youth.

Figure 1.. Experimental setup and sample participant data.

(A) Schematic drawing of the both experimental conditions V and HR. Visual stimuli were presented on the vertical monitor for all conditions. Green circle, light gray eye and hand symbols denote the starting position for each trial (home target). Dark grey eye and hand symbols denote the instructed eye and hand movements for each task. Red circles denote the peripheral (reach) target, presented randomly in one of four locations (left, up, right and down). The dark crosshair denotes the cursor feedback provided during each condition. (B) Typical full hand path data of one participant with no history of concussion and one participant with concussion history, performing the V and HR condition. Note the poorer hand path in condition HR compared with V for both subjects, and the poorer hand path of the participant with concussion history compared with the participant with no history of concussion in condition HR. HR: Horizontal reversal; V: Vertical.

Figure 2.. Behavioral performance as a function of task complexity and concussion history.

Movement timing values of (A) mean reaction time and (B) mean movement time, for both groups (concussion history, no history) across both conditions (V, HR). Movement execution values of (C) mean ballistic pathlength, (D) mean full pathlength, (E) mean AE (constant error) and (F) mean absolute on-axis values for both groups (concussion history, no history) across both conditions (V, HR). *p < 0.05, **p < 0.01. ***p < 0.001. Error bars represent standard error of the mean. AE: Constant absolute error, end point accuracy; HR: Horizontal rotated; V: Vertical.

Figure 3.. Movement timing and movement execution as a function of dissociation from direct interaction (i.e., horizontal rotated values–vertical values).

(A) Mean movement time values for the nonstandard mapping condition (HR) subtracted from the standard mapping condition (V) for both groups (concussion history, no history). (B) Mean ballistic pathlength absolute values for the nonstandard mapping condition (HR) subtracted from the standard mapping condition (V) for both groups (concussion history, no history). (C) Mean full pathlength absolute values for the nonstandard mapping condition (HR) subtracted from the standard mapping condition (V) for both groups (concussion history, no history). HR: Horizontal rotated; V: Vertical.

Figure 4.. Correlation of performance score and concussion history time (i.e., the time point of the last concussion) for participants with concussion history.

The graph shows the relationship between (A) MT values for the nonstandard mapping condition (HR) subtracted from the standard mapping condition (V) and the time since the last concussion for participants with concussion history, plotted as linear function. The graph also shows the mean MT values for the nonstandard mapping condition (HR) subtracted from the standard mapping condition (V) of control participants with no history of concussion (i.e., the baseline performance of healthy age-matched participants) plotted as grey solid line along the x axis, and baseline SEM represented by the both grey dashed lines along the x axis. (B & C) show similar information, but for the relationship between TMT (B) and PeakVel (C) of HR and the time since the last concussion for the participants with concussion history. Note that in all significant correlations and graphs, respectively, the regression line of the performance of participants with concussion history crossed the baseline performance of participants with no history of concussion at approximately 24 months. HR: Horizontal rotated; MT: Movement time; SEM: Standard error of the mean; V: Vertical.

Figure 5.. Step-wise discriminant analysis results.

Normal distribution of discriminant scores for participants (A) from the control group with no history of concussion and (B) with concussion history. Scores are a weighted contribution of dependent variables chosen by the analysis to maximize differentiation between groups. Note the difference between participant groups. SD: Standard deviation.