Constraint-induced movement therapy (CIMT) is the most efficacious treatment for children with hemiparesis from a perinatal arterial stroke but instead, weekly low-dose OT and/or PT is typical. The aims of this study are to compare 2 high doses of treatment to usual care in helping infants improve skills on the hemiplegic hand/arm and to improve bimanual activities. In addition, the association with gross motor, language and cognition will be explored.