Table 2.

General efficacy: seizure reduction and responder rates

		3mo	1yr	2yr	3yr	5yr	Long term (7-15yr)
Therapy	Outcome
VNS
	Responder rate	23-31%9-11	31-49%16,21,112,113	43%112	43-63%16,112	-	68-86%12,19
	Median (or mean)* reduction in seizure freq.	25-28%9-11	26-52%12,13,16,21,112,113	44-58%12,112	44-63%12,16,112	30-60%12,13	52-76%12,13
	6-month seizure-free intervals	-	5%16	-	8%16	-	-
	12-month seizure-free intervals	-	-	-	-	-	7-20%12,13,16-19
	≥50% increase in seizures	4%11	3%21	-	-	-	-
DBS
	Responder rate	-	43%6	54%6	67%6	68%22	74%15
	Median reduction in seizure freq.	40%6	41%6	56%6	-	69%22	75%15
	6-month seizure-free intervals	-	-	-	13%6	16%22	18%15
	12-month seizure-free intervals	-	-	-	7%6	-	-
	≥50% increase in seizures	-	-	-	-	3%22	-
RNS
	Responder rate	29%8	43%8	46%8	58-61%23	50-61%23	73%14
	Median reduction in seizure freq.	38%8	44%23	53%23	60-66%23	48-66%23	75%14
	6-month seizure-free intervals	-	-	-	-	23%23	28%14
	12-month seizure-free intervals	-	-	-	-	13%23	18%14
	≥50% increase in seizures	-	-	-	-	8%23	5%14

3-month data is for the prospective, blinded, and controlled studies, while later timepoints include unblinded/uncontrolled and retrospective studies. All seizure-freedom rates for VNS are from uncontrolled retrospective studies, hence there is a wide range of values reported.

^*Seizure reductions are quoted as medians where available, and means where medians not available.