Handwriting skills of children with tic disorders.

Introduction: Although circumstantial evidence suggests children with tic disorders (TD) experience challenges in handwriting which may be attributed to their tics, few studies have systematically investigated handwriting performance among children with TD. This study examined the relationship between handwriting deficits and TD using a causal comparative research design.

Methods: Thirty-four children with TD completed the Test of Handwriting Skills-Revised (THS-R). The overall percentile ranks of the THS-R were analysed to determine if children with TD have lower scores compared to the test's normative values. Writing speed, letter reversals, touching letters and case errors were also evaluated.

Results: Data revealed the median percentile rank of the THS-R for the participants was significantly lower than the median percentile score of the THS-R for the normative sample. Close to 80% (n = 27) of writing samples were scored below 50th percentile. More than one-third (35.3%, n = 12) of the writing samples were scored greater than one standard deviation below the normative mean on the THS-R. Of the four ancillary scores, 82.4% (n = 28) of the participants' writing samples scored below 50th percentile (in the categories of watch or test further) on case errors and 67.6% (n = 23) scored below 50th percentile on writing speed.

Conclusion: Findings suggested that children with TD took longer to complete the writing task, and committed more case substitution errors than the normative sample of the THS-R and were likely to exhibit handwriting deficits.