Evaluation of cortical plasticity in children with cerebral palsy undergoing constraint-induced movement therapy based on functional near-infrared spectroscopy

Abstract. Sensorimotorcortexplasticityinducedbyconstraint-inducedmovementtherapy(CIMT)insixchildren(10.2 2.1 years old) with hemiplegic cerebral palsy was assessed by functional near-infrared spectroscopy(fNIRS). The activation laterality index and time-to-peak/duration during a finger-tapping task and the rest-ing-state functional connectivity were quantified before, immediately after, and 6 months after CIMT. ThesefNIRS-based metrics were used to help explain changes in clinical scores of manual performance obtainedconcurrentlywithimagingtimepoints.Fiveage-matchedhealthychildren(9.8 1.3yearsold)werealsoimagedto provide comparative activation metrics for normal controls. Interestingly, the activation time-to-peak/durationfor all sensorimotor centers displayed significant normalization immediately after CIMT that persisted 6 monthslater. In contrast to this improved localized activation response, the laterality index and resting-state connectivitymetrics that depended on communication between sensorimotor centers improved immediately after CIMT, butrelapsed 6 months later. In addition, for the subjects measured in this work, there was either a trade-off betweenimproving unimanual versus bimanual performance when sensorimotor activation patterns normalized afterCIMT, or an improvement occurred in both unimanual and bimanual performance but at the cost of very abnor-mal plastic changes in sensorimotor activity.