Quantitative assessment of mirror movements in children and adolescents with hemiplegic cerebral palsy

Mirror movements in individuals with hemiplegic cerebral palsy (CP) may res ult from a reorganization of the central sensorimotor system. Motor perform ances of both hands were measured to characterize mirror activity (or mirro ring) and hand functions in 22 participants (6 to 18 years) with hemiplegic CP and in 17 control participants. During a unimanual repetitive squeezing task, contractions of the active hand and fingertip forces of the opposite hand were recorded simultaneously. In the control group, slight mirror act ivity (or mirroring) was found that decreased with age. In participants wit h GP, mirror activity was 15 times stronger than in the control group, and was found at all age levels. Mirroring was more prominent in the unaffected hand of the CP group. The amount of mirror activity was not related to the degree of hemiplegia, which was assessed with measures of spasticity, stre ngth, and dexterity. Mirror movements disturbed functional bimanual skills, although to some extent they could be suppressed by voluntary effort.