Pre- Surgical Evaluation Of Stereo EEG Recordings With High Frequency Oscillations
Purpose: High frequency oscillations (HFO 80–500 Hz) are recognized as biomarkers for epileptogenic brain tissue to be resected in epilepsy surgery. While several studies describe group level statistics, assessment in the individual patient still needs further validation. Here we compare automated HFO analysis with routine pre- surgical evaluation.
Method: We analyzed long- term stereo EEG recordings of 9 epilepsy patients. For each patient, we identified at least
30 minutes of NREM sleep. HFO were detected by a fully automated algorithm and EEG contacts with the highest rate
designated the HFO area. We quantified the stability of the HFO area over time and compared it with the seizure onset
Results: Focal SOZ was identified in 8/9 patients. The HFO area was included in the SOZ in 7/8 patients with mesial temporal, temporal and insular SOZ. In the one patient with multifocal seizures, the HFO analysis showed poor stability over time.
Conclusion: HFO could reliably identify focal SOZ in our cohort. Therefore, high stability of the HFO pattern is clinically relevant for epilepsy surgery.