Effects of a secondary task on postural control in children with Tourette syndrome.

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by involuntary motor and vocal tics. Sub-clinical postural control anomalies have recently been reported in children with TS. The goal of the present study was to determine whether these anomalies interact with attention in postural control. Thirty-two younger (below 10 years) and 21 older (above 10 years) children with TS were compared to 13 younger and 15 older age-matched controls. Postural control was examined during standing with and without a secondary visual attention task. Sway velocity was higher in younger children than older ones and also higher in children with TS than in controls. The secondary task exacerbated the velocity anomalies in younger children with TS. The effects were independent of tic severity, medication, and attention deficit. The results suggest that postural control anomalies in TS are sensitive to attentional requirements.