Thalamic and limbic involvement in the mechanism of action of vagus nerve stimulation, a SPECT study

Vonck, Kristl; De Herdt, Veerle; Bosman, Tommy; Dedeurwaerdere, Stefanie; Van Laere, Koen; Boon, Paul

doi:10.1016/J.SEIZURE.2008.05.001

Title

Thalamic and limbic involvement in the mechanism of action of vagus nerve stimulation, a SPECT study

Author

Vonck, Kristl

De Herdt, Veerle

Bosman, Tommy

Dedeurwaerdere, Stefanie

Van Laere, Koen

Boon, Paul

Abstract

Purpose: To unravel the mechanism of action of neurostimulation as a treatment for seizures, functional neuroimaging toots allow minimally invasive research in humans. We performed single-photon emission computed tomography (SPECT) in patients with epilepsy, treated with vagus nerve stimulation (VNS). Changes in regional cerebral blood flow (rCBF) at the time of initial stimulation as well as after chronic treatment were correlated with tong-term clinical efficacy. Methods: In this pilot study, 27 patients (14 female and 13 mate) who were treated with VNS at Ghent University Hospital for refractory epilepsy underwent a (99m)Tc-ECD (ethyl cystein dimer) SPECT activation study at the time the first stimulation train was administered. 12 patients underwent an additional (99m)Tc-ECD SPECT activation study 6 months later. Image acquisition was performed on a high-resolution triple-headed gamma camera. Significant rCBF changes were correlated with prospectively assessed clinical efficacy data. Results: Significant rCBF changes were found in the thalamus, the hippocampus and the parahippocampal gyrus. Acute limbic hyper-perfusion and chronic thalamic hypo-perfusion correlate with positive clinical efficacy. Conclusions: Acute and chronic electrical stimulation of the vagus nerve induces rCBF changes that can be measured by SPECT on a group-basis. The thalamus and the limbic system are thought to play a key role in the mechanism of action of VNS. (C) 2008 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Language

English

Source (journal)

Seizure: European journal of epilepsy. - London

Publication

London : 2008

ISSN

1059-1311

DOI

10.1016/J.SEIZURE.2008.05.001

Volume/pages

17 :8 (2008) , p. 699-706