title: Regional brain perfusion changes during standard and microburst vagus nerve stimulation in dogs.
abstract: OBJECTIVE
  Vagus nerve stimulation (VNS) is an effective adjunctive treatment for refractory epilepsy in humans, but its mechanism of action (MOA) and optimal stimulation parameters are still unknown. Functional neuroimaging studies could provide better insight into the brain structures involved in the activity of VNS, but have not yet been described in dogs. The aim of this study was to investigate the effect of acute VNS on the regional cerebral blood flow (rCBF) in dogs using micro-SPECT (μ-SPECT). Additionally, a novel stimulation paradigm (microburst VNS) was used and compared with standard VNS.
  
  
  METHODS
  A VNS Therapy System was implanted in ten Beagle dogs. μ-SPECT was performed after sham, standard and microburst VNS in a randomized, cross-over study. Nineteen volumes of interest (VOIs) were semi-quantitatively analysed and perfusion indices (PIs) were calculated. Furthermore, a rostro-caudal gradient (R-C), an asymmetry index (AI) and a cortical-subcortical index (Co-SCo) were determined. The SPECT results after standard and microburst VNS were compared pairwise with sham stimulation.
  
  
  RESULTS
  Acute standard VNS did not cause significant rCBF alterations. Acute microburst VNS caused a significant hypoperfusion in the left frontal lobe (P=0.023) and in the right parietal lobe (P=0.035). Both stimulation paradigms did not cause changes in R-C, AI nor Co-SCo.
  
  
  CONCLUSIONS
  Microburst VNS is more potent than standard VNS to modulate the rCBF in the dog. Our results promote further research towards the antiepileptic effect of microburst VNS in dogs and humans.
authors.affiliation: Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Valentine.Martle@UGent.be.
authors.forename: Valentine
authors.initials: V
authors.lastname: Martlé
authors.affiliation: Department of Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Kathelijne.Peremans@UGent.be.
authors.forename: Kathelijne
authors.initials: K
authors.lastname: Peremans
authors.affiliation: Laboratory for Clinical and Experimental Neurophysiology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Electronic address: Robrecht.Raedt@UGent.be.
authors.forename: Robrecht
authors.initials: R
authors.lastname: Raedt
authors.affiliation: Department of Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: simonvermeire@hotmail.com.
authors.forename: Simon
authors.initials: S
authors.lastname: Vermeire
authors.affiliation: Laboratory for Clinical and Experimental Neurophysiology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Electronic address: Kristl.Vonck@UGent.be.
authors.forename: Kristl
authors.initials: K
authors.lastname: Vonck
authors.affiliation: Laboratory for Clinical and Experimental Neurophysiology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Electronic address: Paul.Boon@UGent.be.
authors.forename: Paul
authors.initials: P
authors.lastname: Boon
authors.affiliation: Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Luc.Vanham@UGent.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Van Ham
authors.affiliation: Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Mulenda.Tshamala@UGent.be.
authors.forename: Mulenda
authors.initials: M
authors.lastname: Tshamala
authors.affiliation: Department of Neurosurgery, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Electronic address: Jacques.Caemaert@UGent.be.
authors.forename: Jacques
authors.initials: J
authors.lastname: Caemaert
authors.affiliation: Department of Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; Department of Nuclear Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium. Electronic address: andre.dobbeleir@skynet.be.
authors.forename: André
authors.initials: A
authors.lastname: Dobbeleir
authors.affiliation: Department of Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Luc.Duchateau@UGent.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Duchateau
authors.affiliation: Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: timwaelbers@me.com.
authors.forename: Tim
authors.initials: T
authors.lastname: Waelbers
authors.affiliation: Department of Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Ingrid.Gielen@UGent.be.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Gielen
authors.affiliation: Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium. Electronic address: Sofie.Bhatti@UGent.be.
authors.forename: Sofie
authors.initials: S
authors.lastname: Bhatti
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D018592:Cross-Over Studies; D004285:Dogs; D059907:Functional Neuroimaging; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D055536:Vagus Nerve Stimulation / Q000379:methods*
keywords: Dog; Microburst; Regional brain perfusion; Vagus nerve stimulation; μ-SPECT