Nine-year prospective efficacy and safety of brain-responsive neurostimulation for focal epilepsy

Neurology. 2020 Sep 1;95(9):e1244-e1256. doi: 10.1212/WNL.0000000000010154. Epub 2020 Jul 20.


Objective: To prospectively evaluate safety and efficacy of brain-responsive neurostimulation in adults with medically intractable focal onset seizures (FOS) over 9 years.

Methods: Adults treated with brain-responsive neurostimulation in 2-year feasibility or randomized controlled trials were enrolled in a long-term prospective open label trial (LTT) to assess safety, efficacy, and quality of life (QOL) over an additional 7 years. Safety was assessed as adverse events (AEs), efficacy as median percent change in seizure frequency and responder rate, and QOL with the Quality of Life in Epilepsy (QOLIE-89) inventory.

Results: Of 256 patients treated in the initial trials, 230 participated in the LTT. At 9 years, the median percent reduction in seizure frequency was 75% (p < 0.0001, Wilcoxon signed rank), responder rate was 73%, and 35% had a ≥90% reduction in seizure frequency. We found that 18.4% (47 of 256) experienced ≥1 year of seizure freedom, with 62% (29 of 47) seizure-free at the last follow-up and an average seizure-free period of 3.2 years (range 1.04-9.6 years). Overall QOL and epilepsy-targeted and cognitive domains of QOLIE-89 remained significantly improved (p < 0.05). There were no serious AEs related to stimulation, and the sudden unexplained death in epilepsy (SUDEP) rate was significantly lower than predefined comparators (p < 0.05, 1-tailed χ2).

Conclusions: Adjunctive brain-responsive neurostimulation provides significant and sustained reductions in the frequency of FOS with improved QOL. Stimulation was well tolerated; implantation-related AEs were typical of other neurostimulation devices; and SUDEP rates were low.

Clinicaltrialsgov identifier: NCT00572195.

Classification of evidence: This study provides Class IV evidence that brain-responsive neurostimulation significantly reduces focal seizures with acceptable safety over 9 years.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Depressive Disorder / epidemiology
  • Drug Resistant Epilepsy / physiopathology
  • Drug Resistant Epilepsy / psychology
  • Drug Resistant Epilepsy / therapy*
  • Electric Stimulation Therapy / methods*
  • Epilepsies, Partial / physiopathology
  • Epilepsies, Partial / psychology
  • Epilepsies, Partial / therapy*
  • Female
  • Follow-Up Studies
  • Humans
  • Implantable Neurostimulators*
  • Intracranial Hemorrhages / epidemiology
  • Male
  • Memory Disorders / epidemiology
  • Middle Aged
  • Prospective Studies
  • Prosthesis-Related Infections / epidemiology
  • Quality of Life*
  • Randomized Controlled Trials as Topic
  • Status Epilepticus / epidemiology
  • Sudden Unexpected Death in Epilepsy / epidemiology
  • Suicide / statistics & numerical data
  • Treatment Outcome
  • Young Adult

Associated data