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Vagus nerve stimulation in refractory epilepsy: SPECT activation study.

Koenraad Van Laere, Kristl Vonck UGent, Paul Boon UGent, B BRANS, T VANDEKERCKHOVE and Rudi Dierckx UGent (2000) JOURNAL OF NUCLEAR MEDICINE. 41(7). p.1145-1154
abstract
Left-sided vagus nerve stimulation (VNS) is an efficacious treatment for patients with refractory epilepsy. The exact mechanism of action remains to be elucidated. This study investigated the acute effects of initial VNS in patients with refractory complex partial epilepsy with or without secondary generalization (complex partial seizures [CPS] +/- SG) by means of a perfusion activation study with SPECT. Methods: Twelve patients (mean age, 32.2 +/- 10.2 y; age range, 12-47 y) with a mean duration of CPS +/- SG of 19.8 +/- 10.0 y (range, 5-33 y) received VNS. All patients were considered unsuitable candidates for resective surgery because of nonlocalizing findings on presurgical evaluation. VNS efficacy was evaluated for patients with at least 4-mo follow-up. VNS-induced regional cerebral blood flow alterations were studied by a Tc-99m-ethyl cysteinate dimer activation study with a single-day split-dose protocol before and immediately after an initial stimulation. Images were acquired on a triple-head camera with fanbeam collimators. After coregistration to a standardized template, both a semiquantitative analysis using predefined volumes of interest and a voxel-by-voxel analysis of the intrasubject activation (statistical parametric mapping) were performed. Results: Seizure-frequency changes ranged from 100% decrease to 0% after VNS. The semiquantitative analysis revealed a consistent decrease of activity in the left thalamus (ratio stimulator on/off = 0.94 +/- 0.04; P = 0.005). These results were concordant with the voxel-by-voxel analysis in which a significant deactivation in the left thalamus was found with spread to the ipsilateral hippocampus. There was no statistically significant correlation between initial VNS-induced thalamic hypoperfusion and seizure reduction at maximum follow-up. Conclusion: Our findings are consistent with the hypothesis that acute VNS reduces seizure onset or propagation through inhibition of the thalamic relay center. Differences with limited (H2O)-O-15 PET data may be associated with temporal effects caused by a stimulation-induced local hemodynamic response and need further investigation. SPECT allows study of cerebral physiopathologic effects of vagus nerve electrostimulation in complex partial epilepsy.
Please use this url to cite or link to this publication:
author
organization
year
type
journalArticle (original)
publication status
published
subject
journal title
JOURNAL OF NUCLEAR MEDICINE
J. Nucl. Med.
volume
41
issue
7
pages
1145-1154 pages
Web of Science type
Article
Web of Science id
000089888700017
ISSN
0161-5505
language
English
UGent publication?
yes
classification
A1
id
172750
handle
http://hdl.handle.net/1854/LU-172750
date created
2004-01-14 13:40:00
date last changed
2009-06-22 09:42:18
@article{172750,
  abstract     = {Left-sided vagus nerve stimulation (VNS) is an efficacious treatment for patients with refractory epilepsy. The exact mechanism of action remains to be elucidated. This study investigated the acute effects of initial VNS in patients with refractory complex partial epilepsy with or without secondary generalization (complex partial seizures [CPS] +/- SG) by means of a perfusion activation study with SPECT. Methods: Twelve patients (mean age, 32.2 +/- 10.2 y; age range, 12-47 y) with a mean duration of CPS +/- SG of 19.8 +/- 10.0 y (range, 5-33 y) received VNS. All patients were considered unsuitable candidates for resective surgery because of nonlocalizing findings on presurgical evaluation. VNS efficacy was evaluated for patients with at least 4-mo follow-up. VNS-induced regional cerebral blood flow alterations were studied by a Tc-99m-ethyl cysteinate dimer activation study with a single-day split-dose protocol before and immediately after an initial stimulation. Images were acquired on a triple-head camera with fanbeam collimators. After coregistration to a standardized template, both a semiquantitative analysis using predefined volumes of interest and a voxel-by-voxel analysis of the intrasubject activation (statistical parametric mapping) were performed. Results: Seizure-frequency changes ranged from 100\% decrease to 0\% after VNS. The semiquantitative analysis revealed a consistent decrease of activity in the left thalamus (ratio stimulator on/off = 0.94 +/- 0.04; P = 0.005). These results were concordant with the voxel-by-voxel analysis in which a significant deactivation in the left thalamus was found with spread to the ipsilateral hippocampus. There was no statistically significant correlation between initial VNS-induced thalamic hypoperfusion and seizure reduction at maximum follow-up. Conclusion: Our findings are consistent with the hypothesis that acute VNS reduces seizure onset or propagation through inhibition of the thalamic relay center. Differences with limited (H2O)-O-15 PET data may be associated with temporal effects caused by a stimulation-induced local hemodynamic response and need further investigation. SPECT allows study of cerebral physiopathologic effects of vagus nerve electrostimulation in complex partial epilepsy.},
  author       = {Van Laere, Koenraad and Vonck, Kristl and Boon, Paul and BRANS, B and VANDEKERCKHOVE, T and Dierckx, Rudi},
  issn         = {0161-5505},
  journal      = {JOURNAL OF NUCLEAR MEDICINE},
  language     = {eng},
  number       = {7},
  pages        = {1145--1154},
  title        = {Vagus nerve stimulation in refractory epilepsy: SPECT activation study.},
  volume       = {41},
  year         = {2000},
}

Chicago
Van Laere, Koenraad, Kristl Vonck, Paul Boon, B BRANS, T VANDEKERCKHOVE, and Rudi Dierckx. 2000. “Vagus Nerve Stimulation in Refractory Epilepsy: SPECT Activation Study.” Journal of Nuclear Medicine 41 (7): 1145–1154.
APA
Van Laere, Koenraad, Vonck, K., Boon, P., BRANS, B., VANDEKERCKHOVE, T., & Dierckx, R. (2000). Vagus nerve stimulation in refractory epilepsy: SPECT activation study. JOURNAL OF NUCLEAR MEDICINE, 41(7), 1145–1154.
Vancouver
1.
Van Laere K, Vonck K, Boon P, BRANS B, VANDEKERCKHOVE T, Dierckx R. Vagus nerve stimulation in refractory epilepsy: SPECT activation study. JOURNAL OF NUCLEAR MEDICINE. 2000;41(7):1145–54.
MLA
Van Laere, Koenraad, Kristl Vonck, Paul Boon, et al. “Vagus Nerve Stimulation in Refractory Epilepsy: SPECT Activation Study.” JOURNAL OF NUCLEAR MEDICINE 41.7 (2000): 1145–1154. Print.