The vestibulo-ocular reflex during active head motion in children and adolescents.

BACKGROUND: Little information is available on the performance and maturity of the vestibulo-ocular reflex (VOR) in children and adolescents during active head motion as encountered during normal locomotion. We investigated the active VOR performance in children and adolescents to determine its norm and variation with age.

METHODS: We recorded the angular active VOR using an infrared eye tracker and a magnetic head tracker in 38 children, aged 8-19 years. Participants made sinusoidal head-on-body rotations in yaw (left-right) and pitch (up-down) at frequencies of about 0.5 and 2 Hz in the dark.

RESULTS: Mean VOR gains, the ratios of eye to head velocities, were close to unity and were significantly higher at 2 Hz than at 0.5 Hz. VOR gains did not vary with age.

CONCLUSION: The angular VOR during active head motion is functionally mature in children 8 years or older at 0.5 and 2 Hz head rotations.