Intellectual disability in cerebral palsy: a population-based retrospective study

AimA population-based observational study design was used to describe the epidemiology of intellectual disability in cerebral palsy (CP) in terms of clinical and neuroimaging associations, and to report the impact of intellectual disability on utilization of health services and length of survival. MethodPopulation CP registry data were used to retrospectively assess the frequency of intellectual disability and strength of associations between intellectual disability and mobility, epilepsy, vision, hearing, communication, and neuroimaging patterns (n=1141). Data linkage was undertaken to assess usage of hospital inpatient and emergency department services. Survival analysis was performed in a 30-year birth cohort (n=3248). ResultsIntellectual disability, present in 45% of the cohort, was associated with non-ambulation (47% vs 8%), later walking (mean 2y 7mo vs 1y 9mo), hypotonic (8% vs 1%) or dyskinetic (9% vs 5%) CP, a quadriplegic pattern of motor impairment (42% vs 5%), epilepsy (52% vs 12%), more emergency and multi-day hospital admissions, and reduced 35-year survival (96% vs 71%). Grey matter injuries (13% vs 6%), malformations (18% vs 6%), and miscellaneous neuroimaging patterns (12% vs 4%) were more common in people with intellectual disability. InterpretationIntellectual disability adds substantially to the overall medical complexity in CP and may increase health and mortality disparities.