Investigation The Effect of Conventional Vs. Individualized tDCS Intensity to Achieve Uniform E-Fields

Investigation The Effect of Conventional Vs. Individualized Transcranial Direct Current Stimulation Intensity to Achieve Uniform E-Fields

Background: Replications of studies employing transcranial direct stimulation (tDCS) shows great variations in physiological and behavioral outcomes. The disparity between studies is based on the expectations of getting the same cortical activity changes consistently once the procedures and current parameters have been repeated. Nevertheless, this assumption was inoperative, due to the individualized variations of numerous parameters such as: age, disease type, symptom severity, head geometry, etc.

Objective: Through this clinical trial we aim to reduce the variability of the physiological and behavioral outcomes of tDCS by individualizing the current intensity and to study the neurophysiological and behavioral outcome differences between participants who receive the customized current intensity in comparison to the others who would receive a fixed dose.

Methods: Based on individual patient's structural MRI images, the Electrical field (E-field) distribution can be modeled and the individualized current dose to stimulate a target region can be determined. A group of thirty persons with multiple sclerosis (PWMS) would be pseudo-randomized into three groups receiving all 3 treatments of individualized tDCS, fixed currents (2 mA), and sham tDCS. Baseline and post-intervention assessment of physiological and behavioral outcome measures will be assessed using respectively, transcranial magnetic stimulation (TMS) recruitment curve and a stop-signal task and GO/No-go test.

Significant statement and clinical relevance: Individualizing the patient's tDCS current intensity will result in a better clinical outcome (i.e. more robust physiological and behavioral effects), as compared to a tDCS application that is based on a fixed current.

Study Overview

• Status: Not yet recruiting
• Conditions: Multiple Sclerosis; Neurophysiologic Abnormality
• Intervention / Treatment: Device: Transcranial direct current stimulation (tDCS)

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hussein Youssef, MSc; Phone Number: +32488332512; Email: youssef.hussein@uhasselt.be

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Right-handed volunteers, assessed by Edinburgh handedness inventory
• Normal or corrected-to-normal vision
• Greater than or equal to 18 years old
• Relapsing-remitting type of MS (RRMS)
• Moderate disability EDSS score ≤ 6.5
• Free of relapsing attack at least a month before recruitment

Exclusion Criteria:

• Subject recently had a seizure or epilepsy
• Subject is a habitual smoker;
• Subject has a history of any major disease that may interfere with the investigations (especially liver and kidney disease, upper limb pathologies, history of significant multiple traumas, or diabetes) or cancer;
• Subject has any history of a major neurological disorder in addition to MS (including previous severe brain trauma and cognitive impairment) or known cerebral structural abnormalities;
• Subject has a diagnosed mental disorder (e.g., depression, bipolar disorder, schizophrenia, psychoses);
• Subject is currently a user (including ''recreational use'') of any illicit drugs or has a history of drug or alcohol abuse;
• Subject has significant abnormalities on T1/T2 MRI scan;
• Subject has a contra-indication for MRI scanning or TMS measurements (see screening forms for MRI and TMS);
• Subject does not understand the study procedure;
• Subject is unwilling or unable to perform all study procedures, or is considered unsuitable in any way by the principal investigator;
• Subject is not able to perform the motor tasks;
• Subject is (potentially) pregnant (in case of doubt, hCG test will be conducted in female participants); subject is breastfeeding at the time of the study;
• Subject chronically uses medication, especially sedatives or sleep medication (contraceptives allowed). Other medication that is only taken as needed will be allowed at the investigator's discretion;
• Using TMS, no (sufficiently stable) MEPs can be evoked at left M1;

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Individualized tDCS; Each participant will be screened according to their brain scan, they will receive individualized dose of tDCS currents.	Device: Transcranial direct current stimulation (tDCS); Transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation which involves the use of low intensity currents propagated via the scalp, is widely implemented as both a fundamental and clinical neuroscientific tool. Over the last decades, tDCS showed significant therapeutic promise, as numerous studies revealed that it can result in improved attention and executive functions in patients with neurological disorders, through modification of neuronal excitability.
Active Comparator: Fixed currents tDCS; All of the participant will receive standardized dose of tDCS currents intensity of 2 mA.	Device: Transcranial direct current stimulation (tDCS); Transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation which involves the use of low intensity currents propagated via the scalp, is widely implemented as both a fundamental and clinical neuroscientific tool. Over the last decades, tDCS showed significant therapeutic promise, as numerous studies revealed that it can result in improved attention and executive functions in patients with neurological disorders, through modification of neuronal excitability.
Sham Comparator: Sham tDCS; The electrodes will applied to the cortical areas, however none of all of the participant will receive the current dose of tDCS.	Device: Transcranial direct current stimulation (tDCS); Transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation which involves the use of low intensity currents propagated via the scalp, is widely implemented as both a fundamental and clinical neuroscientific tool. Over the last decades, tDCS showed significant therapeutic promise, as numerous studies revealed that it can result in improved attention and executive functions in patients with neurological disorders, through modification of neuronal excitability.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Transcranial Magnetic Stimulation (TMS) Assessment	Changes in cortical excitability will be measured by single and paired TMS pulses. The final values will be assessed for improvements.	Baseline assessment before tDCS session (Pre-intervention), and immediately following tDCS session (Post-intervention).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Behavioral Assessment	A cognitive test battery consisting of: 1- Symbol Digit Modality Test (SDMT); the final score is the correct number of substitutions in 90 seconds, and scores range between 0 and 110, where higher scores indicating better outcome, and the lower scores indicating worse outcome.	Baseline assessment before tDCS session (Pre-intervention), and immediately following tDCS session (Post-intervention).

Collaborators and Investigators

• Sponsor: Koen Cuypers
• Collaborators: BOF-BILA
• Investigators: Principal Investigator: Koen Cuypers, PhD, UHasselt

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2024
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): July 31, 2025

Study Registration Dates

• First Submitted: June 2, 2023
• First Submitted That Met QC Criteria: July 24, 2023
• First Posted (Actual): July 27, 2023

Study Record Updates

• Last Update Posted (Actual): July 27, 2023
• Last Update Submitted That Met QC Criteria: July 24, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: Multiple Sclerosis; Brain Stimulation; Non-invasive Brain Stimulation
• Additional Relevant MeSH Terms: Pathologic Processes; Nervous System Diseases; Immune System Diseases; Demyelinating Autoimmune Diseases, CNS; Autoimmune Diseases of the Nervous System; Demyelinating Diseases; Autoimmune Diseases; Multiple Sclerosis; Sclerosis
• Other Study ID Numbers: B1152023000005; BOF23DOCBL02 (Other Grant/Funding Number: Special Research Fund (BOF))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

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