Clinical trial NCT05031208: Acute and Long Term Effects of VNS on Memory in Patients With Refractory Epilepsy
Official title: Research on the Acute and Long Term Effects on Memory and the Mechanism of Action of Vagus Nerve Stimulation in Patients With Refractory Epilepsy
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Refractory Epilepsy
Keywords: Vagus nerve stimulation
Transcutaneous vagus nerve stimulation
Word recognition paradigm
Lead sponsor: University Hospital, Ghent
Sponsor class: OTHER
First posted: 2021-09-01
Enrollment: 16
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Refractory epilepsy patients implanted with a vagus nerve stimulator perform a memory test at baseline in three conditions: invasive vagus nerve stimulation (VNS), transcutaneous vagus nerve stimulation (taVNS) and sham stimulation. After 6 weeks of VNS treatment, the memory test is repeated in two condition: invasive vagus nerve stimulation (VNS) and sham stimulation.

The endpoint of this experiment is assessing the effect of VNS and taVNS on memory performance.

Detailed description: Previous studies underlined the potential of both invasive as transcutaneous auricular vagus nerve stimulation to ameliorate certain cognitive functions.

In this randomized, controlled cross-over within-subjects study, a memory test is conducted in patients with refractory epilepsy who are implanted with a vagus nerve stimulation.

The memory test consists out of a word recognition paradigm based on the study of Clarck et al. published in 1999 in Nature Neuroscience. Testing is performed at baseline (before start of the stimulation) and after 6 weeks of treatment with vagus nerve stimulation.

During the first session, the patients complete the word recognition task during three interventions:

* Invasive vagus nerve stimulation
* Transcutaneous vagus nerve stimulation (cymba concha)
* Sham vagus nerve stimulation (no stimulation)

During the second session, the patients complete the word recognition task during two interventions:

* Invasive vagus nerve stimulation
* Sham vagus nerve stimulation (no stimulation)

The goal is to investigate if invasive vagus nerve stimulation and transcutaneous nerve stimulation can influence (i.e. improve) the performance on the memory task and if this performance is improved after 6 weeks of VNS treatment.

Eligibility criteria: Inclusion Criteria:

* Refractory epilepsy
* Treated with vagus nerve stimulation
* IQ \>= 70 and able to perform the memory task

Exclusion Criteria:

* IQ \< 70

Primary outcomes:
measure: Immediate recall score at session 1
timeFrame: At baseline
measure: Immediate recall score at session 2
timeFrame: After 6 weeks of VNS treatment
measure: Delayed recognition scores at session 1
timeFrame: At baseline
measure: Delayed recognition scores at session 2
timeFrame: After 6 weeks of VNS treatment
Secondary outcomes:
measure: Attention score at session 1
timeFrame: At baseline
measure: Attention score at session 2
timeFrame: After 6 weeks of VNS treatment
Other outcomes:
Locations:
city: Ghent
country: Belgium
facility: University Hospital
Study officials:
References:
citation: Clark KB, Naritoku DK, Smith DC, Browning RA, Jensen RA. Enhanced recognition memory following vagus nerve stimulation in human subjects. Nat Neurosci. 1999 Jan;2(1):94-8. doi: 10.1038/4600.
citation: Jacobs HI, Riphagen JM, Razat CM, Wiese S, Sack AT. Transcutaneous vagus nerve stimulation boosts associative memory in older individuals. Neurobiol Aging. 2015 May;36(5):1860-7. doi: 10.1016/j.neurobiolaging.2015.02.023. Epub 2015 Feb 28.
citation: Colzato LS, Ritter SM, Steenbergen L. Transcutaneous vagus nerve stimulation (tVNS) enhances divergent thinking. Neuropsychologia. 2018 Mar;111:72-76. doi: 10.1016/j.neuropsychologia.2018.01.003. Epub 2018 Jan 8.
citation: Steenbergen L, Sellaro R, Stock AK, Verkuil B, Beste C, Colzato LS. RETRACTED: Transcutaneous vagus nerve stimulation (tVNS) enhances response selection during action cascading processes. Eur Neuropsychopharmacol. 2015 Jun;25(6):773-8. doi: 10.1016/j.euroneuro.2015.03.015. Epub 2015 Mar 30.
citation: Mertens A, Gadeyne S, Lescrauwaet E, Carrette E, Meurs A, De Herdt V, Dewaele F, Raedt R, Miatton M, Boon P, Vonck K. The potential of invasive and non-invasive vagus nerve stimulation to improve verbal memory performance in epilepsy patients. Sci Rep. 2022 Feb 7;12(1):1984. doi: 10.1038/s41598-022-05842-3.