Activity performance curves of individuals with cerebral palsy

OBJECTIVES: Describe development curves of motor and daily activity performance in individuals with cerebral palsy (CP).
METHODS: Participants with CP aged 1 to 20 years at baseline (n = 421) and Gross Motor Functioning Classification System (GMFCS) levels I to V (27% of participants with intellectual disability [ID]) were longitudinally assessed up to a 13-year follow-up period. Motor and daily activity performance were assessed using the relevant subdomains of the Vineland Adaptive Behavior Scales survey. Nonlinear mixed effects analyses were used, estimating the limit (average maximal performance level) and the age by which individuals reached 90% of the limit (age90).
RESULTS: Limits of motor performance decreased with each lower functional level. Age90 for motor performance was reached at ∼6 to 8 years of age in children with GMFCS levels I to III, and at younger ages in those with lower functional levels. Limits of daily activity performance did not differ between individuals without ID with GMFCS levels I to III. The age90s of daily activities were reached between 11 and 14 (personal), 26 and 32 (domestic), and 22 and 26 years of age (community). Individuals with ID reached lower daily activity performance limits earlier.
CONCLUSIONS: Individuals with CP continue to develop motor performance after gross motor capacity limits are reached. For those without ID, daily activities continue to develop into their 20s. Individuals who are severely affected functionally have the least favorable development of motor performance, and those with ID have the least favorable development of daily activity performance.