Meta-analysis of vagus nerve stimulation treatment for epilepsy: correlation between device setting parameters and acute response.
BACKGROUND
Vagus nerve stimulation (VNS) is an adjunctive neurophysiological treatment for those patients who have pharmacoresistant or surgically resistant partial onset epilepsy.


OBJECTIVE
The aim of this study is to determine the effects of high and low stimulation paradigms on a responder rate of ≥50 and ≥75% reduction in seizure frequency and associated adverse effects in adults and children.


METHODS
A literature search was performed using Medline, PubMed, EMBASE, and Cochrane library for studies using vagus nerve stimulation published from January 1980 until July 2014 for medically or surgically resistant partial onset seizures, in children and adults. No restrictions on languages were imposed.


METHODS
Four authors reviewed and selected studies for inclusion and exclusion. The search identified five randomized control trials that fit with our inclusion criteria. The following outcomes were evaluated: 50% or greater reduction in total seizure frequency, 75% or greater reduction in total seizure frequency, and adverse effects.


RESULTS
Four randomized controlled trials were analyzed in this meta-analysis. Results indicate high stimulation is more effective in adult patients who experienced ≥50 and ≥75% reduction in seizure frequency with a significant difference within both high and low stimulation groups. In children, there was no significant difference between the two groups and patients with ≥50 % reduction in seizures. Adverse effects such as hoarseness and dyspnea were more common in the high stimulation group where the remaining side effects were not statistically different among both groups.


CONCLUSIONS
High stimulation is more effective than low stimulation in producing a greater reduction in seizure frequency in patients with medically and surgically resistant epilepsy.
Department of Psychiatry, School of Medicine, University of Arizona, Tucson, AZ, USA.|Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, WI, USA.
S
S
Ghani
Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Fort Wayne, IN, USA.
J
J
Vilensky
Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, WI, USA.
B
B
Turner
Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, WI, USA.|Pediatric Neurosurgery, Children's Hospital, Birmingham, AL, USA.
R S
RS
Tubbs
Department of Anatomical Sciences, School of Medicine, St. George's University, Grenada, WI, USA. mloukas@sgu.edu.
M
M
Loukas
D000328:Adult; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D004827:Epilepsy / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation / Q000379:methods*
Adults; Children; Epilepsy; NCP; VNS; Vagus nerve stimulation