Abstracts

Parietal resections are seldom performed for treatment of refractory epilepsy. This paper reports our experience with parietal resection performed either as an isolated procedure or as part of multilobar resective procedures. Forty-four patients were studied. Sixty percent of them had lesions seen on MRI; there were 10 patients with gliotic/anoxic lesions, 6 with cavernoma, 7 with cortical dysplasia, 2 with tumor and 1 with arteriovenous malformation. All patients with normal MRI were submitted to invasive evaluation using subdural grids[acute] electrodes. Fifteen patients were submitted to parietal resection alone; in 22 patients, parietal resection was part of posterior quadrantectomy and in 7 part of other multilobar resections (4 frontal and 3 temporal). Five out of the 15 patients submitted to exclusively parietal resections had total parietal , 6 had superior parietal and 4 inferior parietal lobe removals. In non-dominant hemisphere posterior quadrantectomy, total parietal lobe resection was performed; in dominant hemisphere posterior quadrantectomy, the antero-inferior parietal lobe quadrant was spared. Two out of 7 patients submitted to other multilobar resections had complete, 4 had superior and 1 had inferior parietal resection. Eight patients were submitted to subpial resection of the postcentral gyrus. Fourteen patients were submitted to surgery on the dominant hemisphere. Sixty-nine percent of the patients have been seizure-free after surgery. Transient postoperative dysphasia was present in 6 patients and in one patient it persisted chronically; this patient also presented with other characteristics of Gerstmann syndrome. No aspect of Gerstmann syndrome was observed in patients submitted to resections sparing the inferior parietal lobe. There was no morbidity associated to resection of the postcentral gyrus. Parietal resection are safe and can be performed isolately or as part of multilobar resections. Postcentral gyrus resections are well tolerated as far as the vessels related to the central sulcus are preserved during the procedure. Only somatosensitive partial seizures could be considered localizatory. All patients with normal MRI should be submitted to invasive studies during the preoperative work-up. Patients with mesial parietal lobe foci may present with seizures that resemble those arising from the supplementary motor area or tonic spasms (similar to West[acute]s). (Supported by Sao Paulo Secretary of Health)