Developmental trajectories of spoken language comprehension and functional communication in children with cerebral palsy: A prospective cohort study

Aim: To investigate spoken language comprehension (SLC), single-word comprehension (SWC), functional communication development, and their determinants, in children with cerebral palsy.Method: This was a prospective cohort study in the Netherlands spanning 2 years 6 months. The main outcomes were SLC and SWC, assessed by the Computer-Based instrument for Low motor Language Testing (C-BiLLT) and the Peabody Picture Vocabulary Test-III-NL (PPVT-III-NL) respectively; and functional communication, measured by a subscale of the Focus on the Outcomes of Communication Under Six-34 (FOCUS-34). Linear mixed models were used to determine developmental trajectories, which were compared with norm and reference data. Potential determinants, for example intellectual functions, speech production, functional communication level (classified with the Communication Function Classification System, CFCS), and functional mobility, were added to assess their effects.Results: Children with cerebral palsy (n = 188; mean age 59 months, range 17-110) were monitored for 2 years 6 months. Developmental trajectories for SLC (C-BiLLT) and SWC (PPVT-III-NL) were nonlinear; those for functional communication (FOCUS-34) were linear. Compared with norm and reference groups, significantly delayed SLC, SWC, and functional communication development were found. Determinants for SLC and SWC were intellectual functions and functional communication level (CFCS); and for functional communication development (FOCUS-34), speech production and arm-hand functioning.Interpretation: Children with cerebral palsy showed delayed SLC, SWC, and functional communication development compared with norm and reference groups. Remarkably, functional mobility was not associated with the development of SLC, SWC, or functional communication.