Nine-year prospective efficacy and safety of brain-responsive neurostimulation for focal epilepsy
Nair DR, Laxer KD, Weber PB, Murro AM, Park YD, Barkley GL, Smith BJ, Gwinn RP, Doherty MJ, Noe KH, Zimmerman RS, Bergey GK, Anderson WS, Heck C, Liu CY, Lee RW, Sadler T, Duckrow RB, Hirsch LJ, Wharen RE, Jr., Tatum W, Srinivasan S, McKhann GM, Agostini MA, Alexopoulos AV, Jobst BC, Roberts DW, Salanova V, Witt TC, Cash SS, Cole AJ, Worrell GA, Lundstrom BN, Edwards JC, Halford JJ, Spencer DC, Ernst L, Skidmore CT, Sperling MR, Miller I, Geller EB, Berg MJ, Fessler AJ, Rutecki P, Goldman AM, Mizrahi EM, Gross RE, Shields DC, Schwartz TH, Labar DR, Fountain NB, Elias WJ, Olejniczak PW, Villemarette-Pittman NR, Eisenschenk S, Roper SN, Boggs JG, Courtney TA, Sun FT, Seale CG, Miller KL, Skarpaas TL, and Morrell MJ. Nine-year prospective efficacy and safety of brain-responsive neurostimulation for focal epilepsy. Neurology 2020.
OBJECTIVE: 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 within 2 year feasibility or randomized controlled trials enrolled into 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 using the quality of life in epilepsy (QOLIE-89) inventory.
RESULTS: 230 of 256 patients treated in the initial trials 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. 18.4% (47/256) experienced ≥1 year of seizure freedom with 62% (29/47) seizure free at last follow-up and an average seizure-free period of 3.2 years (range: 1.04 - 9.6 years). Overall QOL, 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; one-tailed Chi Square).
CONCLUSIONS: Adjunctive brain-responsive neurostimulation provides significant and sustained reductions in the frequency of FOS with improved QOL. Stimulation was well tolerated, implant related AEs were typical of other neurostimulation devices, and SUDEP rates were low.
CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that brain-responsive neurostimulation significantly reduces focal seizures with acceptable safety over 9 years.
ePub ahead of print