Acute and Long Term Effects of VNS on Memory in Patients With Refractory Epilepsy

Refractory Epilepsy Clinical Trial

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05031208
• Other study ID #: EC/2016/0786
• Status: Completed
• Phase: N/A
• Start date: November 22, 2018
• Est. completion date: August 28, 2020

Study information

• Verified date: May 2023
• Source: University Hospital, Ghent
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 16
• Est. completion date: August 28, 2020
• Est. primary completion date: August 28, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Refractory epilepsy

• Treated with vagus nerve stimulation

• IQ >= 70 and able to perform the memory task

Exclusion Criteria:

• IQ < 70

Related Conditions & MeSH terms

• Drug Resistant Epilepsy
• Epilepsy
• Refractory Epilepsy

Intervention

Diagnostic Test:
• Memory task
Word recognition task

Locations

Country	Name	City	State
Belgium	University Hospital	Ghent

Sponsors (1)

Lead Sponsor	Collaborator
University Hospital, Ghent

Country where clinical trial is conducted

Belgium, 

References & Publications (4)

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. — View 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. — View 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. — View Citation

Steenbergen L, Sellaro R, Stock AK, Verkuil B, Beste C, Colzato LS. 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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Immediate recall score at session 1	Free recall score for correctly recalled words (min score 0,max score 21, higher score indicates better performance), calculated as a percentage	At baseline
Primary	Immediate recall score at session 2	Free recall score for correctly recalled words (min score 0, max score 21, higher score indicates better performance)), calculated as a percentage	After 6 weeks of VNS treatment
Primary	Delayed recognition scores at session 1	Hitscore for correctly recognized target words (min score 0,max score 63, higher score indicates better performance), score for not recognized target words= misses (min score 0,max score 63, higher score indicates worse performance),correct rejection score of non-target related words (min score 0,max score 63, higher score indicates better performance), score for incorrect recognition of non-target related words= false alarms (min score 0,max score 63, higher score indicates worse performance), discrimination index= hit score -false alarm score (min score 0,max score 63, higher score indicates better performance). All scores are calculated as a percentage.	At baseline
Primary	Delayed recognition scores at session 2	Hitscore for correctly recognized target words (min score 0,max score 48, higher score indicates better performance), score for not recognized target words= misses (min score 0,max score 48, higher score indicates worse performance),correct rejection score of non-target related words (min score 0,max score 48, higher score indicates better performance), score for incorrect recognition of non-target related words= false alarms (min score 0,max score 48, higher score indicates worse performance), discrimination index= hit score -false alarm score (min score 0,max score 48, higher score indicates better performance). All scores are calculated as a percentage.	After 6 weeks of VNS treatment
Secondary	Attention score at session 1	Score of correct responses on 6 open question (min score 0, max score 6, higher score indicates better performance), calculated as a percentage	At baseline
Secondary	Attention score at session 2	Score of correct responses on 6 open question (min score 0, max score 6, higher score indicates better performance), calculated as a percentage	After 6 weeks of VNS treatment