Abstract
Objectives Our recently published ESTEL study of deep brain stimulation (DBS) for Lennox-Gastaut syndrome (LGS) showed a median 50% reduction in diary-recorded seizures. Here, we examined whether EEG features predict response to DBS treatment.
Methods We measured generalised paroxysmal fast activity (GPFA) and electrographic seizures in 17 young adults with LGS (mean age ±1SD=24.9±6.6) and determined their associations with diary-recorded seizure frequency over the course of our ESTEL randomised clinical trial of DBS lasting 12 months (comprising a 3-month pre-implantation baseline and 9 months of post-implantation follow-up).
Results Changes in GPFA duration and frequency, quantified over 2-hours of sleep EEG, were associated with changes in the daily rate of diary-recorded seizures over the prior 3 months (p<0.001, η²p = 0.31–0.55). We did not find a relationship between electrographic seizures in the 24-hour EEG and diary recorded seizures over subsequent months. Following ≥3-months of active DBS, both GPFA and diary-recorded seizures reduced from baseline (38.7% and 31.4%, respectively). During baseline, median seizures per day on seizure diaries were 2.6 (IQR:1.4–5), compared with 284 (IQR:120.5–360) electrographic seizures per day, confirming that diaries capture only a fraction of seizure burden.
Conclusions Changes in GPFA within an individual may allow estimation of diary-recorded treatment response in participants undergoing DBS. When seeking to optimise treatment in patients with LGS, monitoring changes in the burden of GPFA may allow more rapid adjustment of treatment parameters, than relying on feedback from seizure diaries.
