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

May 2, 2023 updated by: University Hospital, Ghent

Research on the Acute and Long Term Effects on Memory and the Mechanism of Action of Vagus Nerve Stimulation in Patients With Refractory Epilepsy

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

16

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Belgium
      • Ghent, Belgium, 9000
        • University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

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

Exclusion Criteria:

  • IQ < 70

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Vagus nerve stimulation
Invasive vagus nerve stimulation
Diagnostic test: Memory task
Word recognition task
Experimental: Transcutaneous vagus nerve stimulation
Cymba concha stimulation
Diagnostic test: Memory task
Word recognition task
Sham Comparator: Sham vagus nerve stimulation
No vagus nerve stimulation
Diagnostic test: Memory task
Word recognition task

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Immediate recall score at session 1
Time Frame: At baseline
Free recall score for correctly recalled words (min score 0,max score 21, higher score indicates better performance), calculated as a percentage
At baseline
Immediate recall score at session 2
Time Frame: After 6 weeks of VNS treatment
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
Delayed recognition scores at session 1
Time Frame: At baseline
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
Delayed recognition scores at session 2
Time Frame: After 6 weeks of VNS treatment
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 Outcome Measures

Outcome Measure
Measure Description
Time Frame
Attention score at session 1
Time Frame: At baseline
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
Attention score at session 2
Time Frame: After 6 weeks of VNS treatment
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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital, Ghent

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 22, 2018

Primary Completion (Actual)

August 28, 2020

Study Completion (Actual)

August 28, 2020

Study Registration Dates

First Submitted

August 19, 2021

First Submitted That Met QC Criteria

August 26, 2021

First Posted (Actual)

September 1, 2021

Study Record Updates

Last Update Posted (Estimate)

May 4, 2023

Last Update Submitted That Met QC Criteria

May 2, 2023

Last Verified

May 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • EC/2016/0786

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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