To determine ictal onset localization with stereo-EEG (SEEG) in patients with history of viral brain infection (HVBI) and to demonstrate that HVBI is a biomarker of unfavorable prognosis regarding seizure freedom after resective epilepsy surgery.

Resective epilepsy surgery could be highly effective in patients with focal drug-resistant epilepsy, however up to 50% of patients experience seizure relapse. We investigate SEEG ictal onset localization and resective epilepsy surgery outcomes in patients with HVBI.

We included patients with HVBI who underwent SEEG evaluation at our center and had at least 6-month follow-up after their last epilepsy surgery (including SEEG).

Twelve patients were identified. Average age at SEEG was 33(18-45) years. Average age at time of viral brain infection (VBI) was 15(2-36) years. The onset of intractable focal epilepsy was at time of VBI in 10 patients, and in two patients – 9 and 24 years after VBI. Three patients failed previous resective surgery before SEEG at our center. All patients had two or more seizure foci localized with SEEG: three – bilateral mesial temporal, one – bilateral mesial and neocortical temporal, two – bilateral neocortical temporal, one – bilateral mesial and neocortical temporal, and extratemporal, two – unilateral mesial and neocortical temporal, one – unilateral mesial temporal and extratemporal, two – broad or multifocal unilateral extratemporal. Three patients with unilateral ictal onsets (one – within anterior temporal lobectomy limit) underwent resection or laser ablation of seizure onset zones, all continue having seizures (follow-up 17(6-40) months).

Our study demonstrates that HVBI in epilepsy surgery candidates could indicate multifocal ictal onset and a low chance for seizure freedom after resection or laser ablation of the seizure onset zone(s). Studies on a larger patient cohort are needed to clarify the prognostic value of HVBI in selection of epilepsy surgery candidates.