gms | German Medical Science

Objective: Epilepsy surgery is well established as a method of treatment for patients with refractory temporal lobe epilepsy (TLE). The assessment of postsurgical seizure control is essential, because of the very elective nature of epilepsy surgery and its potentially irreversible effects. The presurgical prediction of seizure outcome remains difficult despite of all achievements of modern presurgical evaluation. The aim of this study was to evaluate the seizure outcome in patients with TLE who underwent resective temporal lobe surgery (rTLS) at our center and to determine features associated with unfavorable postsurgical seizure control.

Methods: Therefore, we conducted the analysis of postsurgical outcome in patients who had undergone rTLS for TLE between 11/2012 and 10/2016 at our institution. Complete datasets for 141 consecutive patients were available. All patients were presurgically assessed in the department of epileptology and were considered to be suitable for surgery. The patients were divided into two groups according to the seizure outcome at 12 months after the surgery (group I: ILAE Class 1; group II: ILAE Class ≥ 2). The clinical characteristics, preoperative MR imaging findings, and surgery modality were analyzed and compared between the two groups.

Results: In group I were 105 patients, and 36 patients in group II. The analysis revealed no significant difference between the two groups (group I vs. group II) with regard to gender (male: 50.5% vs. 61%), mean age in years (y) at seizure onset (17.4y±13 vs. 16.4y±11.3), mean age at time of surgery (37y±15.5 vs. 35y±12.5), and surgery modalities. There were significantly more patients with left-sited surgery in group II vs. group I (67% vs. 45%, p=0.033). Patients in group II had significantly more often temporal lesion without evidence for hippocampus sclerosis (HS) on preoperative MRI (33% vs. 14%, p=0.025). The proportion of patients with preoperative negative MRI for typical epileptogenic lesion was also significantly higher in group II (17% vs. 5%, p=0.03).

Conclusion: rTLS is an effective treatment method in patients with refractory TLE. However, patients with a preoperative negative MRI or with temporal lesion without evidence of HS on MRI, and patients with left-sited surgery might have a higher probability for an unfavorable postsurgical seizure outcome. Therefore, these facts should be carefully taken into account and each of these patients needs an individual approach during the selection process for surgery.