Efficacy of a radiofrequency thermocoagulation strategy targeting the propagation network in MRI-negative post-encephalitic insular epilepsy: a case report

Insular epilepsy after encephalitis is often drug-resistant and MRI-negative, limiting resection due to eloquent cortex involvement. We describe a case in which radiofrequency thermocoagulation (RFTC) was applied to disconnect the propagation network (PN) identified by stereoelectroencephalography. In a woman with focal to bilateral tonic-clonic seizures, the epileptogenic network (EN) was in the left insula and temporal operculum, and the PN spread to the perirolandic area. PN-targeted RFTC, guided by tractography, preserved the EN. At 18 months, seizures decreased by 95.6% with preserved function. Selective PN disconnection may be an option when EN resection is limited.