Objective assessment of dyskinesia in children with cerebral palsy.

The clinical classification of children with cerebral palsy is limited by multiple factors. Distinguishing between spasticity and dyskinesia is critical, because the outcome after standard orthopaedic and neurosurgical interventions is less predictable in children with cerebral palsy who have a significant dyskinetic component. This study applied computer-based analysis of gait to assess objectively the presence of significant dyskinesia in children with cerebral palsy. Three-dimensional gait analysis was performed on 18 normal children, 17 children with principally spastic cerebral palsy, and 23 children with significantly dyskinetic cerebral palsy. Children were assigned to the spastic or dyskinetic groups prospectively, based on clinical analysis by an experienced physician and physical therapist. The children with dyskinesia were found to have a significantly wider, and more variable normalized dynamic base of support, a smaller step profile (step length divided by step width), and a greater and more variable maximal lateral acceleration than the spastic and normal groups (mixed model analysis of variance, p = 0.0001). A predictive model of dyskinesia, (developed by logistic regression analysis), using these gait parameters, exhibited excellent sensitivity, correctly classifying 20 (87%) of 23 children as dyskinetic. This study shows that children with dyskinetic cerebral palsy have distinct gait parameters and that objective assessment of dyskinesia in children with cerebral palsy is possible with computer-based analysis of gait.