Brain and Behavior. 2018;8:e00983.
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1 | INTRODUCTION
Patients with refractory epilepsy comprise approximately 30% of all
patients with epilepsy (Kwan & Brodie, 2000). Resective surgery is
the treatment of choice for this patient group with focal epilepsy,
but only 10- 30% of patients are eventually amenable for surgery.
Optimizing the pharmacological treatment can make some of these
patients seizure free (Liimatainen, Raitanen, Ylinen, Peltola, &
Peltola, 2008), but possibilities for major improvement with antiepi-
leptic drug (AED) therapy are limited. Neurostimulation has offered
new treatment options in refractory epilepsy, first with vagus nerve
stimulation (VNS) and later with deep brain stimulation (DBS) of the
anterior nucleus of the thalamus (ANT).
VNS delivers an electrical current to the 10th cranial nerve via
electrode, wrapped around surgically the exposed vagal nerve.
Currently, VNS devices are being implanted in patients with refrac-
tory seizures who cannot have resective surgery or who have had
surgery with poor results. Moreover, many of these patients have
been treated with several antiepileptic drugs before receiving VNS
implants (Ben- Menachem, 2002). The biological mechanisms causing
Similarities between the responses to ANT- DBS and prior VNS
in refractory epilepsy
| Joonas Haapasalo
| Kai Lehtimäki
| Sirpa Rainesalo
| Jukka Peltola
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,
provided the original work is properly cited.
© 2018 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.
Department of Neurosciences and
Rehabilitation, Tampere University Hospital,
Faculty of Medicine, University of Tampere,
Toni Kulju, Department of Neurosciences
and Rehabilitation, Tampere University
Hospital, Tampere, Finland.
Eisai; Medtronic; UCB; Cyberonics
Objectives: Neurostimulation has offered new treatment options in refractory epi-
lepsy, first with vagus nerve stimulation (VNS) and more recently with deep brain
stimulation (DBS). There is a lack of previous detailed data assessing the relationship
between VNS and ANT- DBS. The aim of this study was to investigate the potential
correlation between therapeutic responses to VNS and ANT- DBS.
Materials and Methods: A total of 11 patients with previous VNS therapy underwent
ANT- DBS implantation. Monthly seizure counts starting from baseline before VNS
extending to long- term DBS treatment were analyzed. The reasons for VNS discon-
tinuation were assessed.
Results: Altogether in 10 of 11 patients, the response to VNS seemed to be similar to
the response to DBS therapy. Progressive response to VNS was likely to correlate
with a progressive response to DBS in three of three patients. Partial response to
VNS was associated with a fluctuating response pattern to DBS in two patients. Five
of six nonresponders to VNS were also nonresponders to DBS. One of the VNS non-
responders obtained progressive response to DBS.
Conclusions: This is the first study to evaluate in detail the effect of both VNS and
ANT- DBS in refractory epilepsy patients. There is a putative association between
VNS and DBS responses suggesting the need for further studies.
deep brain stimulation, epilepsy, follow-up, seizure, vagus nerve stimulation