Navigated transcranial magnetic stimulation was used to localize cortical representations of hand and leg muscles from 11 patients (7 female, 4 male; 14–19 yrs). The type and timing of the lesion differed between patients. Both hemispheres were stimulated and motor-evoked potentials were recorded from APB and TA muscles.
In seven patients lateralization of the paretic leg motor representation was similar with the paretic hand representation: two patients had contralateral, three patients ipsilateral and two patients bilateral hand and leg representations. In four patients lateralization of the paretic leg motor representation differed from the paretic hand representation: one patient had bilateral hand and contralateral leg representation, two patients had bilateral hand and ipsilateral leg representation, and one patient had contralateral hand and bilateral leg representation.
Lateralization of the paretic hand and leg motor representations may differ. Lateralization differences between patients and between extremities is most probably affected by the type and timing of the brain lesion.
When determining the lateralization of motor control in children with hemiplegic CP, both hand and leg muscle representations should be localized.