Focal Cortex Stimulation With a Novel Implantable Device and Antiseizure Outcomes in 2 Prospective Multicenter Single-Arm Trials

JAMA Neurol. 2023 Jun 1;80(6):588-596. doi: 10.1001/jamaneurol.2023.0066.


Importance: For the large population of people with drug-refractory epilepsy, alternative treatment approaches are needed. Clinical trial outcomes of a novel stimulation device, which is newly available in Europe for the treatment of patients with a predominant seizure focus, are reported for the first time.

Objective: To perform a pooled analysis of the results of 2 prospective, multicenter, single-arm trials, A Pilot Study to Assess the Feasibility of Neurostimulation With the EASEE System to Treat Medically Refractory Focal Epilepsy (EASEE II) and A Pilot Study to Assess the Feasibility of Patient-Controlled Neurostimulation With the EASEE System to Treat Medically Refractory Focal Epilepsy (PIMIDES I), assessing the safety and efficacy of epicranial focal cortex stimulation (FCS) with a novel implantable device (EASEE [Precisis]) as adjunctive treatment for adult patients with drug-refractory focal epilepsy.

Design, setting, and participants: This study was a pooled analysis of 2 nonrandomized uncontrolled trials, EASEE II and PIMIDES I, which began on January 15, 2019, and January 14, 2020, respectively, and ended on July 28, 2021. EASEE II and PIMIDES I were the first in-human, prospective, single-arm trials with an 8-month evaluation period. Patients were recruited at 7 European epilepsy centers. Consecutive participants with drug-refractory focal epilepsy were enrolled. Study data were analyzed from September 29, 2021, to February 2, 2022.

Interventions: After a 1-month prospective baseline period, patients were implanted with the neurostimulation device. After a 1-month postimplantation recovery period, unblinded FCS was activated using both high-frequency and direct current (DC)-like components performed via electrode arrays placed epicranially above the individual epileptic focus region.

Main outcomes and measures: Efficacy was prospectively assessed by the responder rate in the sixth month of stimulation compared with baseline; safety and additional end points were assessed after device implantation and during the stimulation period.

Results: Of the 34 adult patients enrolled at 6 German and 1 Belgian investigational site, 33 (mean [SD] age, 34.6 [13.5] years; 18 male patients [54.5%]) received the neurostimulation device implant. A total of 32 patients underwent combined high-frequency direct current-like stimulation at least until the 8-month postimplant follow-up visit. After 6 months of stimulation, 17 of 32 patients (53.1%) were responders to treatment with at least a 50% reduction in seizure frequency compared with baseline, corresponding to a significant median seizure reduction by 52% (95% CI, 0.37%-0.76%; P < .001). No device- or procedure-related serious adverse events were reported (0; 95% CI, 0%-10.58%). There were no significant alterations in cognition, mood, or overall quality of life.

Conclusions and relevance: Results of this pooled analysis of 2 nonrandomized uncontrolled trials suggest that FCS with a novel neurostimulation device was associated with an effective reduction in seizure frequency in patients with drug-refractory focal epilepsy and may offer a promising treatment option for patients with a predominant epileptic focus.

Trial registration: German Clinical Trials Register: DRKS00015918 and DRKS00017833, respectively, and jointly under PROSPERO: CRD42021266440.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anticonvulsants / therapeutic use
  • Drug Resistant Epilepsy* / therapy
  • Epilepsies, Partial* / therapy
  • Epilepsy* / drug therapy
  • Humans
  • Male
  • Pilot Projects
  • Prospective Studies
  • Quality of Life
  • Seizures / drug therapy
  • Treatment Outcome


  • Anticonvulsants