Brain‐responsive neurostimulation in patients with medically intractable mesial temporal lobe epilepsy

Abstract

SUMMARYObjective: Evaluate the seizure-reduction response and safety of mesial temporal lobe (MTL) brain-responsive stimulation in adults with medically intractable partial-onset seizures of mesial temporal lobe origin. Methods: Subjects with mesial temporal lobe epilepsy (MTLE) were identified from prospective clinical trials of a brain-responsive neurostimulator (RNS System, NeuroPace). The seizure reduction over years 2-6 postimplantation was calculated by assessing the seizure frequency compared to a preimplantation baseline. Safety was assessed based on reported adverse events. Results: There were 111 subjects with MTLE; 72% of subjects had bilateral MTL onsets and 28% had unilateral onsets. Subjects had one to four leads placed; only two leads could be connected to the device. Seventy-six subjects had depth leads only, 29 had both depth and strip leads, and 6 had only strip leads. The mean follow-up was 6.1 AE (standard deviation) 2.2 years. The median percent seizure reduction was 70% (last observation carried forward). Twenty-nine percent of subjects experienced at least one seizure-free period of 6 months or longer, and 15% experienced at least one seizure-free period of 1 year or longer. There was no difference in seizure reduction in subjects with and without mesial temporal sclerosis (MTS), bilateral MTL onsets, prior resection, prior intracranial monitoring, and prior vagus nerve stimulation. In addition, seizure reduction was not dependent on the location of depth leads relative to the hippocampus. The most frequent serious device-related adverse event was soft tissue implant-site infection (overall rate, including events categorized as device-related, uncertain, or not device-related: 0.03 per implant year, which is not greater than with other neurostimulation devices). Significance: Brain-responsive stimulation represents a safe and effective treatment option for patients with medically intractable epilepsy, including patients with unilateral or bilateral MTLE who are not candidates for temporal lobectomy or who have failed a prior MTL resection.

Ultra‐long‐term subcutaneous home monitoring of epilepsy—490 days of EEG from nine patients

“…Several other seizure-detection devices have appeared within the last decade, some employing EEG 2,10,17,21,22 and some employing other technologies, such as EMG/accelerometry, 23,24 heart rate variability, 25 electrodermal activity, or a combination of these. Several other seizure-detection devices have appeared within the last decade, some employing EEG 2,10,17,21,22 and some employing other technologies, such as EMG/accelerometry, 23,24 heart rate variability, 25 electrodermal activity, or a combination of these.…”

Clinically indicated electrical stimulation strategies to treat patients with medically refractory epilepsy

“…Of interest, follow‐up studies reported that patients with focal epilepsy responded differently depending on seizure focus (Table ). TLE patients treated with RNS had a median seizure reduction of 70%, and the responder rate was 66% . In patients with neocortical epilepsy, the median reduction was 55%, and the responder rate was 77% …”

“…RNS efficacy was reported at 1 and 2 years postimplantation . Specific efficacy in mTLE was reported in year 6, and seizure freedom rate was based on the previous 6 months . Year 6 efficacy in neocortical epilepsy was based on the previous 3 months .…”

“…Adverse side effects associated with RNS included implant site infections (11.7%), resulting in 9 explants and 7 (6.3%) device lead replacements, and a 2.7% risk of intracranial hemorrhage . Patient‐reported adverse events related to depression and memory impairment in the RNS trial were 1.8% and 6.3%, respectively …”

Curative and palliative MRI-guided laser ablation for drug-resistant epilepsy

“…These devices provide therapy by disrupting epileptogenic networks. They can reduce seizure frequency by 68%–76%, if stimulation continues for 5 years or more 9. In addition, disconnective surgeries (eg, corpus callosotomy and multiple subpial transections) are considered palliative, as epileptogenic foci are not removed.…”