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 (F1,56 = 2.57, P = .12) or medial-lateral (F1,56 = 0.157, P = .69) velocity. Concussion-group participants also did not perform more saccades than the control-group participants (F1,56 = 2.04, P = .16).
Conclusions
Performing dual-task balance conditions for which the secondary task involved 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.
Saccadic Eye Movements Attenuate Postural Sway but Less in Sleep-Deprived Young Adults
