Epilepsiechirurgisches Outcome mit und ohne Medikamentenreduktion

The present study was based on a retrospective analysis of medical records of 292 patients who underwent resection from 1998 to 2015 at University Medical Center Gießen/Marburg and participated in follow-up examinations 6 months, 1 year, 2 years and 5 years after epilepsy surgery. Engel Class Ia and seizure freedom for at least one year after surgery were considered as outcome parameters. In total 42,5% of patients had an Engel Class Ia outcome after epilepsy surgery. A drug resistant epilepsy, regional spikes, number of preoperative antiepileptic drugs and years until withdrawal of antiepileptic drugs showed a significant effect on Engel Class Ia outcome. A trend was identified for mean of preoperative seizure frequency per month, febrile seizures and region of seizure onset. A higher number (67,8% of patients) remained seizure free for at least one year after resection. Gender, mean of monthly seizure frequency, concordance of presurgical evaluations, number of preoperative antiepileptic drugs and time to discon-tinuation of drug treatment showed a significant relation to one-year seizure freedom of patients. After surgery 62,7% of patients tried to reduce antiepileptic drugs, with 58,5% of them remaining seizure free after drug reduction. Recurrence of seizures depended significantly on years to drug withdrawal and presence of febrile seizures. A negative trend was detected especially for multiregional spikes in preoperative EEG. Of the 23,6% patients who completely discontinued drugs, 76,8% remained seizure free and had a successful reduction attempt. The study identified febrile seizures as a favorable prognostic indicator for postwithdrawal seizure freedom. The side of the epileptic zone showed a trend. The present study is able to predict the likelihood of a specific outcome for patients with or without reduction of antiepileptic drugs, allowing epilepsy centers to individually evaluate the potential for success of epilepsy surgery prior to operation. Logistic regression was performed using Engel Class Ia, one year postsurgical seizure-freedom and success of antiepileptic drug reduction or withdrawal as potential outcomes. The logistic regression model forecasts a lower probability to become Engel Class Ia for patients with multiregional spikes and a high number of preoperative drugs. The likelihood to remain seizure free for at least one year after surgery is lower for patients with a higher number of drugs used prior to surgery, inconsistent results in EEG and MRT and a higher mean of monthly preoperative seizures. To predict the likelihood for a successful drug reduction the time to discontinue drug use and febrile seizures were significant prognostic factors. The probability increased with a longer time until discontinuation and decreased for patients with febrile seizures. Despite the monocentric procedure the study reaches a large sample size and a heterogeneous patient population fostering valid results with high clinical relevance.