UCSF

Posterior quadrant epilepsy surgery, involving the occipital lobe, parietal lobe, or the posterior border of the temporal lobe, accounts for a small percentage of focal resections for medically refractory epilepsy. Prior studies investigating seizure control from posterior quadrant epilepsy surgery are limited. In this study, a retrospective database of patients undergoing surgery for left sided posterior cortex epilepsy at a single large level 4 epilepsy center was analyzed between August 2008 to April 2021 in order to characterize seizure control outcomes. Nine patients presented with epileptogenic foci in the left posterior cortex with a malformation of cortical development deemed as the etiology of seizures for all but one patient. Absolute seizure freedom (Engel I) was achieved in 4 of 9 patients, with the remaining 5 patients achieving an improvement in the frequency of seizures (Engel II/III). Complete resection of the anatomic and physiologic abnormalities was performed in 3 of 4 patients with Engel 1 outcomes and 1 of 5 patients with Class II/III outcomes. Five patients developed new right sided visual field defects, all of which were expected based on the sub-lobar, occipital localization and were viewed as acceptable by the patients and did not interfere with activities of daily living. Overall, our study demonstrates the potential for surgical resection to yield excellent seizure-control outcomes with anticipated, tolerable neurological deficits. This information is important for patients with disabling seizures who may not benefit sufficiently from palliative procedures.