Decision-making in temporal lobe epilepsy surgery: The contribution of basic non-invasive tests

PURPOSE We studied the extent to which the widely used diagnostic tests contribute to the decision whether or not to perform temporal lobe epilepsy (TLE) surgery in The Netherlands. METHODS This nation-wide, retrospective study included 201 consecutive patients referred for TLE surgery screening. The individual and combined contribution of nine index tests to the consensus decision to perform surgery was investigated. The contribution of each test was quantified using multivariable logistic regression and ROC curves. RESULTS Surgery was performed in 119 patients (59%). Patient history and routine EEG findings were hardly contributory to decision-making, whereas a convergence of MRI with long-term interictal and ictal EEG findings correctly identified the candidates considered eligible for surgery (25% of total). Videotaped seizure semiology contributed less to the results. The area under the ROC curve of the combination of basic tests was 0.75. Ineligibility was never accurately predicted with any test combination. CONCLUSIONS In the Dutch presurgical work-up, when MRI and long-term EEG findings were concordant, a decision for TLE surgery could be reached without further ancillary tests. Videotaped seizure semiology contributed less than expected to the final clinical decision. In our study, basic test findings alone were insufficient to exclude patients from surgery.