Clinical Scorecard: Effectiveness of a Radiofrequency Thermocoagulation Approach Targeting the Propagation Network in MRI-Negative Post-Encephalitic Insular Epilepsy: A Case Study

At a Glance

Key Highlights

• SEEG identified seizure onset in Heschl’s gyrus and spread to anterior insula and perirolandic area despite negative MRI and PET findings.
• Epileptogenicity index localized high epileptogenicity to left insular cortex and temporal operculum.
• Radiofrequency thermocoagulation (RFTC) targeting the propagation network (PN) via subinsular claustrum and white matter tracts achieved favorable seizure control without resecting eloquent cortex.

Guideline-Based Recommendations

Diagnosis

• Use SEEG to localize epileptogenic and propagation networks in MRI-negative post-encephalitic epilepsy.
• Employ epileptogenicity index mapping and cortical stimulation to delineate functional and epileptogenic areas.

Management

• Consider RFTC to disconnect propagation networks when resection or ablation of epileptogenic cortex is not feasible or functionally risky.
• Plan RFTC trajectories using diffusion tensor imaging tractography to target white matter tracts while avoiding critical structures.
• Perform RFTC under local anesthesia with intraoperative neurological monitoring.

Monitoring & Follow-up

• Monitor for neurological symptoms during RFTC to avoid damage to eloquent cortex and critical pathways.
• Use video-electroencephalography (VEEG) post-procedure to assess seizure frequency and characteristics.

Risks

• Potential injury to pyramidal tract and perforating arteries if RFTC is not precisely targeted.
• Functional deficits if epileptogenic or propagation networks overlap with eloquent cortex.

Patient & Prescribing Data

Young adult female with drug-resistant focal to bilateral tonic–clonic seizures post-encephalitis and MRI-negative findings

RFTC targeting propagation network can be an effective alternative to resection or ablation in eloquent areas, achieving seizure control with preserved neurological function.

Clinical Best Practices

• Integrate multimodal imaging including SEEG, epileptogenicity mapping, and diffusion tensor imaging for precise network localization.
• Avoid resection of language-dominant or eloquent cortex when possible; consider disconnection strategies.
• Use intraoperative stimulation and monitoring to guide safe lesion placement during RFTC.
• Obtain informed consent and adhere to ethical guidelines in experimental or novel surgical interventions.

References

• Epileptogenicity index and network evaluation in epilepsy surgery
• Cortical stimulation mapping in epilepsy surgery