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

AIM: 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. METHOD: 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. RESULTS: 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%). INTERPRETATION: 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.