Effect of Blue Light on Vagus Nerve Stimulation in Patients With Refractory Epilepsy (BLUELIGHTVNS)

September 3, 2025 updated by: Cliniques universitaires Saint-Luc- Université Catholique de Louvain
Vagus nerve stimulation (VNS) is an adjunctive treatment for refractory epilepsy. Although widely used, there is still a substantial number of patients with insufficient response. Light, and particularly blue light, can stimulate alertness, attention and cognition through modulation of anatomical targets which are common to the vagal afferent network. This project aims at understanding how exposure to blue enriched light may influence VNS effects in patients with refractory epilepsy by exploring the modulation of a series of biomarkers of VNS action. This could possibly lead to new therapeutic strategies to increase efficacy of VNS.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

34

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 Contact

Study Locations

  • Belgium
      • Woluwe-Saint-Lambert, Belgium, 1200
        • Recruiting
        • Cliniques Universitaires Saint Luc
        • Contact:
        • Sub-Investigator:
          • Inci Cakiroglu, Phd student

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

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

Patients:

VNS implanted since at least 3 months age >18-60 years; IQ >55 on Wechsler scale (normal status or mild cognitive impairment)

healthy participants aged between 18 and 35 years without any medical history (neurological / psychiatric disease)

Exclusion criteria:

Patients:

other medical implanted devices than VNS, ocular diseases

Helthy participants:

medical implanted devices, cerebral trauma, ocular disease

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: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patients with refractory epilepsy
Patients will not receive any drugs, but will participate to experiments involving electroencephalograpy, pupillometry and light administration.
Other: electroencephalography, electrocardiogram, pupillometry, evoked potentials, light administration
Recording of the electrical activity of the brain, of the heart. Pupil size will be analyzed. The effect of blue light administration will be assessed on those parameters.
Experimental: Healthy subjects
Subjects will not receive any drugs, but will participate to experiments involving electroencephalograpy, pupillometry and light administration.
Other: transcutaneous vagus nerve stimulation, electroencephalography, pupillometry, electrocardiogram, light administration
Transcutaneous vagus nerve stimulation will be performed in helathy subjects, as well as the recording of the electrical activity of the brain, and of the heart. Pupil size will be analyzed. The effect of blue light administration will be assessed on those parameters.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Effect of blue light on VNS biomarkers
Time Frame: 4 years
Blue light increases VNS induced electroencephalogram desynchronisation in implanted patients
4 years
Effect of blue light on VNS biomarkers
Time Frame: 4 years
Blue light increases P300 amplitude in VNS implanted patients
4 years
Effect of blue light on VNS biomarkers
Time Frame: 4 years
Blue light increases VNS (or tVNS) induced pupil dilation (in patients & healthy subjects).
4 years

Collaborators and Investigators

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

Sponsor

Cliniques universitaires Saint-Luc- Université Catholique de Louvain

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)

July 1, 2023

Primary Completion (Actual)

July 1, 2023

Study Completion (Estimated)

April 1, 2026

Study Registration Dates

First Submitted

April 18, 2023

First Submitted That Met QC Criteria

March 4, 2024

First Posted (Actual)

March 12, 2024

Study Record Updates

Last Update Posted (Estimated)

September 10, 2025

Last Update Submitted That Met QC Criteria

September 3, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • BLUELIGHT-VNS

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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