Impact of seizure outcome and extent of neocortical resection on emotional well-being in patients with epilepsy one year after temporal lobe surgery

Background: Seizure frequency and cognitive function are common parameters in assessing epilepsy surgery outcomes. However, psychobehavioral outcomes, such as symptoms of depression and quality of life (QOL), have not found equal attention yet. Objective: To assess the effect of seizure frequency, the extent of resection, and cognitive function on the psychobehavioral outcome of patients after temporal lobe surgery for pharmacoresistant epilepsy. Methods: We retrospectively reviewed all consecutive patients who underwent surgery for intractable temporal lobe epilepsy between 09/2015 and 07/2019. We examined seizure outcome, surgical plan, resection volume, cognitive functions, and psychobehavioral outcome. Results: This study included 77 patients (31 males, 46 females) who underwent temporal lobe surgery. One year after surgery, 53 patients (68.8 %) were completely seizure-free (Engel IA) and 92.2 % of patients showed a worthwhile improvement in seizure frequency (Engel I-III). Resection volume was significantly negatively correlated with QOL (r =- 0.284, p = 0.041). However, after controlling for the effect of seizure outcome, no significant correlation remained. Patients with a worthwhile improvement in seizure frequency showed significantly fewer symptoms of depression (p = 0.024) and a significantly higher QOL (p = 0.012) one year after surgery. The differences in symptoms of depression (p = 0.044) and QOL (p = 0.030) between patients with and without improvements in seizure frequency remained significant after controlling for the effect of resection volume. After procedures sparing the amygdala and hippocampus (neocortical resection), patients presented significantly fewer symptoms of depression (p = 0.044) and significantly better QOL (p p = 0.008) than patients after procedures involving mesial-temporal structures, independent of the resection volume, and after controlling for the side of the procedure (dominant vs. non-dominant). After also controlling for seizure outcome, the difference remained for QOL (p = 0.014) but not for symptoms of depression. Conclusions: A patient's emotional well-being one year after surgery for pharmacoresistant temporal lobe epilepsy strongly depends on their seizure outcome. As an individual factor, the extent of neocortical resection negatively affects postsurgical emotional well-being, but a favorable seizure outcome outweighs this effect, independent of the resection volume. A favorable seizure outcome even outweighs the negative effects of procedures involving mesial-temporal structures on symptoms of depression.