title: Behavioural and cognitive effects during vagus nerve stimulation in children with intractable epilepsy - a randomized controlled trial.
abstract: OBJECTIVE
  In addition to effects on seizure frequency in intractable epilepsy, multiple studies report benefits of vagus nerve stimulation (VNS) on behavioural outcomes and quality of life. The present study aims to investigate the effects of VNS on cognition, mood in general, depression, epilepsy-related restrictions and psychosocial adjustment in children with intractable epilepsy, as well as the relation between these effects and seizure reduction.
  
  
  METHODS
  We conducted a randomized, active-controlled, double-blinded, add-on study in 41 children (age 4-18) with medically refractory epilepsy. We performed cognitive and behavioural testing at baseline (12 weeks), at the end of the blinded phase (20 weeks) in children receiving either high-output or low-output (active control) stimulation, and at the end of the open label phase (19 weeks) with all children receiving high-output stimulation. Seizure frequency was recorded using seizure diaries.
  
  
  RESULTS
  VNS did not have a negative effect on cognition nor on psychosocial adjustment. At the end of the follow-up phase we noted an improvement of mood in general and the depression subscale for the entire group, unrelated to a reduction of seizure frequency. At the end of the blinded phase a ≥50% reduction of seizure frequency occurred in 16% of the high-stimulation group and 21% of the low-stimulation group. At the end of the open-label follow-up phase, 26% of the children experienced a seizure frequency reduction of 50% or more (responders).
  
  
  CONCLUSIONS
  VNS has additional beneficial effects in children with intractable epilepsy. As opposed to anti-epileptic drugs, there are no negative effects on cognition. Moreover, we observed an improvement of mood in general and depressed feelings in particular, irrespective of a reduction in seizure frequency. These beneficial effects should be taken into account when deciding whether to initiate or continue VNS treatment in these children.
authors.affiliation: Department of Neurology, Maastricht University Medical Center, PO Box 5800, 6202 AZ Maastricht, The Netherlands. s.klinkenberg@mumc.nl
authors.forename: Sylvia
authors.initials: S
authors.lastname: Klinkenberg
authors.forename: Charlotte N C J
authors.initials: CN
authors.lastname: van den Bosch
authors.forename: H J Marian
authors.initials: HJ
authors.lastname: Majoie
authors.forename: Marlien W
authors.initials: MW
authors.lastname: Aalbers
authors.forename: Loes
authors.initials: L
authors.lastname: Leenen
authors.forename: Jos
authors.initials: J
authors.lastname: Hendriksen
authors.forename: Erwin M J
authors.initials: EM
authors.lastname: Cornips
authors.forename: Kim
authors.initials: K
authors.lastname: Rijkers
authors.forename: Johan S H
authors.initials: JS
authors.lastname: Vles
authors.forename: Albert P
authors.initials: AP
authors.lastname: Aldenkamp
mesh_terms: D000293:Adolescent; D000339:Affect; D002648:Child; D002675:Child, Preschool; D003071:Cognition; D004311:Double-Blind Method; D004827:Epilepsy / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D055536:Vagus Nerve Stimulation