Hand function assessment in the first years of life in unilateral cerebral palsy: Correlation with neuroimaging and cortico-spinal reorganization

Aim The purpose of the present study was to correlate early hand function assessment during the first years of life with neuroimaging findings and the different patterns of cortico-motor reorganization in children with unilateral cerebral palsy (UCP). Methods We conducted a long prospective observational study, in which 17 children with UCP (8 left-sided hemiplegia; Manual Ability Classification System level 1-3) were first assessed at a mean age of 24 months (range 18-28), and followed up by means of the Besta Scale, a new standardized protocol assessing both unimanual and bimanual hand function. They also underwent Melbourne Assessment of Unilateral Upper Limb Function (MUUL) and single-pulse Transcranial Magnetic Stimulation (TMS) at a mean age of 10 years 5 months (range 9 y 1 m-12 y 8 m). Brain MRIs of all the 17 children were independently assessed and scored by two blinded observers, according to a defined protocol. Possible correlations between hand function at first assessment, neuroimaging and TMS data were analyzed. Results Early hand function impairment significantly correlated with the extension of brain damage (ρ = -0.531, p = 0.028), number of involved areas (ρ = -0.608, p = 0.010), presence of radiological signs of cortico-spinal degeneration (ρ = -0.628, p = 0.007), and basal ganglia involvement (ρ = -0.485, p = 0.049). Additionally, higher hand function scores (i.e. better hand function) at first assessment significantly correlated with contralateral cortico-spinal projections, while lower scores significantly correlated with either mixed or ipsilateral cortico-spinal projections to the affected hand (χ²(2) = 11.418, p = 0.003; post-hoc tests: contralateral TMS group versus ipsilateral: Z = -2.943, p = 0.002 and contralateral TMS group versus mixed: Z = -2.775, p = 0.006). Conclusions To our knowledge, this is the first study correlating hand function assessment in the first years of life, and its evolution over time, with neuroimaging and cortico-spinal projection patterns in children with UCP. These findings could contribute to an improved prediction of prognosis and a better delineation of therapeutic interventions in young children with UCP.