Abstracts

Rationale: Patients with congenital hemiparesis and extensive vascular destructive lesions often present refractory seizures. Because some degree of function is usually preserved, there is always the possibility of worsening motor function with resective surgery. Objective: To describe structural and functional MRI (fMRI), cortical electrical stimulation findings and the motor outcome in patients with congenital hemiparesis and extensive vascular destructive lesions undergoing focal resective surgery. Methods: Six patients were evaluated and operated at the PCE/HSL/PUCRS in the last 2 years, with refractory seizures and vascular congenital hemiparesis. All walked independently, moved the paretic arm and had some degree of motor preservation of the paretic hand. All had structural and functional MRI of motor functions probing the affected and the unaffected extremities. Four underwent trans-op electrical cortical stimulation. Resection involved the perilesional cortex in 4 patients. The other 2 had temporal lobectomies. Motor function was digitally filmed before and after surgery. Results: Regarding BOLD-activation of the primary motor cortex, movement (even if slight) of the paretic hand/foot activated exclusively the affected (contralateral) hemisphere in 4 of the 6 patients, and in the other 2 there was concomitant activation of the ipsilateral primary motor cortex. Movement of the paretic foot always activated the contralateral (affected) hemisphere. In the 2 patients undergoing temporal resection and two with perilesional (pré-motor) resection, there was unequivocal functional improvement of the paretic arm / hand, leg / foot and ambulation. In the other 2 patients, undergoing perilesional resections, motor function was unchanged. In no patient motor function worsened. Conclusions: Patents with refractory seizures, congenital hemiparesis and vascular destructive lesions vary in the recruitment of distributed motor networks to use paretic limbs. Resection of perilesional cortex did not lead to motor worsening. Furthermore, perilesional premotor resection and ipsilateral resection of temporal structures may improve motor function, through yet unknown mechanisms.