To Örebro University

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.