Is outcome of constraint‐induced movement therapy in unilateral cerebral palsy dependent on corticomotor projection pattern and brain lesion characteristics?

Aim The aim of the study was to explore individual variations in outcome of hand function after constraint‐induced movement therapy (CIMT) in relation to the organization of corticomotor projection and brain lesion characteristics in participants with unilateral cerebral palsy (CP). Method Sixteen participants (eight males, eight females; mean age 13y, [SD 2y] range 10–16y) with unilateral CP (nine right‐sided; Manual Ability Classification System [MACS] level I, n=1; level II, n=15) who participated in a 2‐week CIMT day camp (63h) were included in the study. Various aspects of hand function were measured by the Jebsen–Taylor Hand Function Test (JTHFT), the Assisting Hand Assessment (AHA), and the Melbourne Assessment, both before and after the day camp. Transcranial magnetic stimulation was used to explore the corticomotor organization, and brain lesion characteristics were described by visual assessment of conventional structural magnetic resonance images. Results At a group level, the training was associated with significant improvements in JTHFT (p=0.003) and AHA (p=0.046), but not in Melbourne Assessment scores. Improvements were found in all types of corticomotor projection patterns, i.e. contralateral, mixed, and ipsilateral. There was no relationship between functional improvement and brain lesion characteristics. Interpretation Individuals with CP experience improved motor outcomes after CIMT, independent of corticomotor projection pattern and lesion characteristics. What this paper adds Improved motor outcomes after CIMT were found regardless of brain lesion characteristics and corticomotor projection pattern. An ipsilateral projection pattern does not rule out the possibility of improving hand function with intensive CIMT. CIMT affected specific aspects of hand function differently for individual participants. This article is commented on by Staudt and Berweck on pages 202–203 of this issue.