Are psychotic symptoms related to vagus nerve stimulation in epilepsy patients?
Four patients with refractory epilepsy presented with psychotic symptoms following treatment with vagus nerve stimulation (VNS) to control seizures. Besides its anti-epileptic effect VNS has been shown to have an effect on various cognitive and behavioural functions. VNS is known to increase alertness and reduce sedation, which is independent from seizure control. VNS has also been shown to positively affect cognition and to exert strong antidepressant effects. Co-morbidity in epilepsy often comprises psychiatric illnesses. Increased psychiatric symptoms have mainly been described in association with successful outcome following epilepsy surgery as a result of 'forced normalisation'. Different hypotheses on the underlying aetiology of VNS-induced psychotic symptoms other than the previously described 'forced normalisation' are discussed.
De Herdt
Veerle
V
Reference Center for Refractory Epilepsy, Department of Neurology, Ghent University Hospital, Belgium.
Boon
Paul
P
Vonck
Kristl
K
Goossens
Lutgard
L
Nieuwenhuis
Lotte
L
Paemeleire
Koen
K
Meire
Veronique
V
Michielsen
Geert
G
Dewaele
Frank
F
Baert
Edward
E
van Roost
Dirk
D
D000328:Adult; D004599:Electric Stimulation Therapy / Q000009:adverse effects*; D004827:Epilepsy / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000209:etiology*; D014630:Vagus Nerve / Q000502:physiology*