Application of RNS in refractory epilepsy: Targeting insula

Area of Science:

• Neuroscience
• Neurosurgery
• Epileptology

Background:

• Responsive neurostimulation (RNS) is an established treatment for refractory focal epilepsy.
• Limited data exists on the efficacy of RNS targeting specific brain regions like the insular lobe.

Purpose of the Study:

• To evaluate the safety and effectiveness of RNS when targeting the insular lobe in adult patients with epilepsy.
• To identify clinical features and diagnostic methods predictive of successful RNS treatment for insular epilepsy.

Main Methods:

• Retrospective review of eight adult patients who underwent RNS implantation with at least one electrode in the insula.
• Analysis of preoperative data, including imaging, scalp EEG, and intraoperative electrocorticography (ECoG).
• Assessment of postoperative seizure frequency reduction and complications over a minimum of six months follow-up.

Main Results:

• Intracranial EEG or intraoperative ECoG confirmed insular origin of seizures in patients with inconclusive scalp EEG or MRI.
• Four out of eight patients achieved a 50-75% reduction in seizure frequency.
• One patient experienced a 75% seizure reduction, and another became nearly seizure-free.
• No direct complications from insular RNS placement or stimulation were reported; two patients had unrelated surgical complications.

Conclusions:

• Insular RNS electrode placement is relatively safe in selected patients.
• RNS may offer significant seizure reduction for carefully selected patients with insular epilepsy.
• Further research is warranted to optimize patient selection and treatment outcomes for insular epilepsy.