Balance Markers and Saccadic Eye-Movement Measures in Adolescents With Postconcussion Syndrome.

CONTEXT: Deficits in both balance and oculomotor function, including impairments in saccadic eye movements, are observed in approximately 30% of patients postconcussion. Whereas balance and saccadic eye movements are routinely assessed separately, growing evidence suggests that they should be assessed concurrently.

OBJECTIVE: To compare balance measures and saccades between adolescents 1 to 3 months postconcussion and healthy uninjured adolescents.

DESIGN: Case-control study.

SETTING: Concussion clinic and 2 private schools.

PATIENTS OR OTHER PARTICIPANTS: Twenty-five adolescents (10 boys, 15 girls; median [interquartile range (IQR)] age = 14 years [11.5-16 years]) between 1 and 3 months postconcussion (median [IQR] time since injury = 39.5 days [30-56.75 days]) and 33 uninjured adolescents (18 boys, 15 girls; median [IQR] age = 13 years [11.5-14 years]).

MAIN OUTCOME MEASURE(S): The center-of-pressure 95% ellipse area and medial-lateral and anterior-posterior velocity and the number of saccades in the dual-task balance conditions including a high cognitive load (cognitive condition), a low cognitive load and a gaze-shifting component (visual condition), or both a high cognitive load and a gaze-shifting component (combined condition).

RESULTS: Concussion-group participants swayed over larger center-of-pressure ellipse areas in the visual ( P = .02; effect size = 0.73) and combined ( P = .005; effect size = 0.86) conditions but not in the cognitive condition ( P = .07; effect size = 0.50). No group differences were identified for anterior-posterior ( F 1,56 = 2.57, P = .12) or medial-lateral ( F 1,56 = 0.157, P = .69) velocity. Concussion-group participants also did not perform more saccades than the control-group participants ( F 1,56 = 2.04, P = .16).

CONCLUSIONS: Performing dual-task balance conditions for which the secondary task involves a gaze-shifting component or both a gaze-shifting component and a high cognitive load resulted in greater sway amplitude in adolescents with concussion. However, these larger amounts of postural sway were not associated with increased saccadic eye movements.