The objective of this study was to examine the relationship between physical activity levels, sleep and tic severity in children with chronic tic disorders. 

Tic disorders are common in children.  Though there is a high rate of resolution of tics in late adolescence, tics can be distressing to children and their families.  Parents often ask if there are lifestyle modifications which improve tics, but little research has been performed in this area. 

We recruited children ages 6 to 17 years with a chronic tic disorder to participate in this study. Children wore the GeneActiv device, a wrist-worn accelerometer that measures physical activity intensity and sleep/wake parameters. Children wore the devices continuously for a period of seven days.  Symptom severity of tics over the same week was measured using the Yale Global Tic Severity Scale (YGTSS).  

50 children completed the study, with an average age of 10.6 years; 80% were male. Mean motor tic severity on the YGTSS during the study period was 12.28 points (SD 4.54); mean vocal tic severity was 8.47 points (SD 5.49). There was a significant negative correlation between the percentage of time spent performing vigorous physical activity and motor tic severity on the YGTSS, with a Pearson correlation coefficient of -0.29 (p<0.05).  Linear regression analysis showed that for every 1% increase in the proportion of daily vigorous activity, there was a decrease in the motor tic severity scale score on the YGTSS of 0.52 points (95% CI 0.03-1.01, p<0.05).  The relationship between vocal tic severity and vigorous activity was not significant. There was no correlation between total sleep time, sleep efficiency and motor or vocal tic severity. 

This study provides preliminary evidence that greater daily vigorous physical activity is associated with lower motor tic severity, suggesting that exercise could be a therapeutic strategy for the management of motor tics in children.