Development of hand function during the first year of life in children with unilateral cerebral palsy

Aim: To identify developmental trajectories of hand function in infants aged 3 months to 12 months with unilateral cerebral palsy (CP). Method: Infants at high risk of unilateral CP were recruited from 3 months of age from follow-up programmes and clinics in Sweden, the Netherlands, Italy, and Australia. Measurements on the Hand Assessment for Infants (HAI) were completed until 12 months of age. Group-based trajectory modelling was used to identify subgroups of infants with similar trajectories of development. Multinomial logistic regression determined associations between demographic variables and trajectory membership. Results: Ninety-seven infants (52 males, 45 females; median gestational age 38wks [interquartile range 30–40wks]) were included. Infants were assessed between two and seven times (mean 4, SD 1.2) with a total of 387 observations. A three-group trajectory model identified a ‘low-functioning group’ (n=45: 46%), ‘moderate-functioning group’ (n=30: 31%), and ‘high-functioning group’ (n=22: 23%). Mean posterior probabilities (0.91–0.96) and odds of correct classification (26.3–33.2) indicated good model fit. Type of brain lesion, sex, side of hemiplegia, country, gestational age, and access to intensive intervention were not associated with group membership. Interpretation: Three trajectories of hand function development for infants with unilateral CP were identified and indicate some greater distinctions between groups with increasing age. The HAI is a valuable measure, capturing development of hand function of infants with unilateral CP over time. What this paper adds: Three distinct developmental trajectories of hand function in infants with unilateral cerebral palsy were identified. A low-functioning group made little progress in development of hand function in the first year of life. The degree of impairment on the impaired hand at 6 months of age is highly associated with trajectory membership. Infants with all types of brain lesion were represented across each trajectory group