Responsive Neurostimulation in Patients with a History of Viral Brain Infections—A Single-Center Experience

Drug-resistant epilepsy (DRE) secondary to viral brain infections (VBI) may have multiple seizure foci, making it not amenable to surgical resection but could respond to responsive neurostimulation (RNS). We aimed to evaluate characteristics of DRE patients with a VBI history who did or did not respond to RNS therapy; 9 patients met criteria. Four out of 9 patients were responders to RNS therapy with ≥50% of seizure-frequency reduction at an average 39-month follow-up. Five patients were non-responders, an average 47-month follow-up. Two responders had a prior destructive surgery. Four non-responders had a prior neurosurgery including 1 focal resection, 2 vagus nerve stimulation, and 1 prior RNS. Patients in the responder group had shorter DRE duration prior to RNS placement than in the non-responder group (average 11.0 years versus 14.4 years). Three responders and four non-responders had a history of focal to bilateral tonic-clonic seizures (FBTC) pre-RNS. Post-RNS, all responders and 2 non-responders stopped experiencing FBTC. Our study demonstrates that RNS therapy could be effective in patients with DRE secondary to VBI, even if the patients failed previous surgical intervention(s). Patients in both responder and non-responder groups had reduction of convulsive seizures. These findings should be considered preliminary observations due to a small sample-size.