Variability of motor imagery in children with cerebral palsy examined using the Hand Laterality Test

To examine motor imagery performance in children with cerebral palsy (CP) compared to typically developing children and develop a composite motor imagery score to differentiate between the two groups.

In this cross-sectional case-control study, 37 participants (17 with CP, 20 typically developing, aged 10-20 years; 22 females) completed the Hand Laterality Task (HLT), judging hand laterality at several rotation angles. Mixed-effects models were used to compare HLT outcomes (reaction time and accuracy) across groups. A composite score was developed to differentiate children with CP from typically developing children. Model performance was evaluated using internal validation with 100 random 70/30 train-test partitions, with classification metrics (mean area under the curve [AUC], accuracy, sensitivity, specificity, precision, F1 score) averaged across iterations.

Children with CP exhibited lower accuracy (p = 0.002) and higher reaction time variability (p < 0.001) than typically developing children, with no significant reaction time differences (p = 0.46). Among multiple models evaluated, the composite score combining accuracy and reaction time variability achieved the best performance compared to models using single parameters. Across 100 random train-test splits, the model demonstrated a mean (SD) of: AUC = 0.89 (0.09), accuracy = 81% (11%), sensitivity = 81% (19%), and specificity = 84% (18%).

The composite score differentiated motor imagery performance in children with CP from that of typically developing children. The findings provide initial evidence for reaction time variability as a distinguishing feature, warranting further research to develop targeted rehabilitation strategies. The findings may also promote clinical use of the HLT for motor imagery.