Ten-year follow-up study found that motor-free intelligence quotient declined in children with mild-to-moderate cerebral palsy

Aim This 10-year follow-up study examined cognitive change in a cohort of children with cerebral palsy from preschool to adolescence at the group and individual levels. Methods The Wechsler Preschool and Primary Scale of Intelligence was administered to 80 children with cerebral palsy (mean = 4 years 6 months, standard deviation = 7 months) at baseline (Time 1). At 10-year follow-up (Time 2), 28 adolescents (mean = 14 years 6 months, standard deviation = 9 months) returned for assessment with the Wechsler Intelligence Scale for Children. Motor-free intelligence quotient (IQ) scores were calculated and paired-samples t-tests and the Reliable Change Index (RCI) were used to investigate change in IQ over time. Results At the group level, nonverbal IQ scores declined significantly. At the individual level, RCI indicated nine and 11 children showed a clinically significant decline in Full Scale IQ (FSIQ) and nonverbal IQ scores, respectively. Decline in FSIQ was related to a history of seizures whereas decline in nonverbal IQ was associated with higher initial IQ. Conclusion Cognitive abilities in children with cerebral palsy evolve over time and selective deficits may not be observable until a later age, highlighting the importance of repeated cognitive assessment throughout childhood and adolescence.