Centromedian thalamic responsive neurostimulation for Lennox-Gastaut epilepsy and autism

Abstract

The RNS System is not approved in patients under 18, although a critical need for novel treatment modalities in this vulnerable population persist. We present two pediatric patients with drug-resistant epilepsy secondary to Lennox-Gastaut Syndrome (LGS) and autism spectrum disorder (ASD) treated with the RNS System. Both patients have experienced 75-99% clinical seizure reductions in >1 year of follow-up. We illustrate that children with diffuse onset, multifocal epilepsy, including frontal and thalamic circuits thought to exist in the generation of LGS seizures, can be treated with responsive neurostimulation safely and effectively, targeting thalamic networks, and avoiding palliative disconnections and resections.

Figure 1

(A) MRI T1‐sagittal view demonstrating mild callosal dysgenesis but no focal abnormality; (B) Scalp EEG showing LGS pattern of underlying paroxysmal fast activity (red rectangle) and slow spike and wave (green rectangle); (C) AP X‐ray of the skull displaying relative mirror image stereotactic EEG electrode placement, with investigation of frontal, temporal, and insular networks; (D) sEEG showing generalized seizure pattern (black‐left hemisphere; blue‐right hemisphere).

Figure 2

(A) Merged MPRAGE‐CT neuronavigation targeting right CMT; (B) Merged MPRAGE‐CT neuronavigation targeting left CMT; (C) AP X‐ray of RNS in situ with frontal and centromedian thalamic depth electrodes; (D) Lateral X‐ray of RNS in situ, same patient; (E) Seizure detection on thalamic leads before stimulation is activated; (F) Ictal pattern detected, stimulated and stopped from development in thalamic leads. LCM, left centromedian, RCM, right centromedian. L,R CM1‐L,R CM2 = deeper electrodes; L,R CM3‐L,R CM4 = more superficial electrodes.