Randomized controlled trial of trigeminal nerve stimulation for drug-resistant epilepsy.
OBJECTIVE
To explore the safety and efficacy of external trigeminal nerve stimulation (eTNS) in patients with drug-resistant epilepsy (DRE) using a double-blind randomized controlled trial design, and to test the suitability of treatment and control parameters in preparation for a phase III multicenter clinical trial.


METHODS
This is a double-blind randomized active-control trial in DRE. Fifty subjects with 2 or more partial onset seizures per month (complex partial or tonic-clonic) entered a 6-week baseline period, and then were evaluated at 6, 12, and 18 weeks during the acute treatment period. Subjects were randomized to treatment (eTNS 120 Hz) or control (eTNS 2 Hz) parameters.


RESULTS
At entry, subjects were highly drug-resistant, averaging 8.7 seizures per month (treatment group) and 4.8 seizures per month (active controls). On average, subjects failed 3.35 antiepileptic drugs prior to enrollment, with an average duration of epilepsy of 21.5 years (treatment group) and 23.7 years (active control group), respectively. eTNS was well-tolerated. Side effects included anxiety (4%), headache (4%), and skin irritation (14%). The responder rate, defined as >50% reduction in seizure frequency, was 30.2% for the treatment group vs 21.1% for the active control group for the 18-week treatment period (not significant, p = 0.31, generalized estimating equation [GEE] model). The treatment group experienced a significant within-group improvement in responder rate over the 18-week treatment period (from 17.8% at 6 weeks to 40.5% at 18 weeks, p = 0.01, GEE). Subjects in the treatment group were more likely to respond than patients randomized to control (odds ratio 1.73, confidence interval 0.59-0.51). eTNS was associated with reductions in seizure frequency as measured by the response ratio (p = 0.04, analysis of variance [ANOVA]), and improvements in mood on the Beck Depression Inventory (p = 0.02, ANOVA).


CONCLUSIONS
This study provides preliminary evidence that eTNS is safe and may be effective in subjects with DRE. Side effects were primarily limited to anxiety, headache, and skin irritation. These results will serve as a basis to inform and power a larger multicenter phase III clinical trial.


METHODS
This phase II study provides Class II evidence that trigeminal nerve stimulation may be safe and effective in reducing seizures in people with DRE.
Departments of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. cmd@mednet.ucla.edu
Christopher M
CM
DeGiorgio
Jason
J
Soss
Ian A
IA
Cook
Daniela
D
Markovic
Jeffrey
J
Gornbein
Diana
D
Murray
Sandra
S
Oviedo
Steven
S
Gordon
Guadalupe
G
Corralle-Leyva
Colin P
CP
Kealey
Christi N
CN
Heck
D000328:Adult; D017326:Clinical Trials, Phase III as Topic; D004311:Double-Blind Method; D004827:Epilepsy / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D004561:Transcutaneous Electric Nerve Stimulation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome; D014276:Trigeminal Nerve / Q000502:physiology* / Q000503:physiopathology; D055815:Young Adult