Electrical Brain Stimulation for Cognitive Impairment in Schizophrenia: a tDCS-fMRI Study

Investigating the Mechanism of Action of Electrical Brain Stimulation for Cognitive Impairment in Schizophrenia: a tDCS-fMRI Study

The purpose of this study is to investigate the mechanism of action of transcranial electrical brain stimulation over the dorsolateral prefrontal cortex for cognitive impairment in schizophrenia. To do so the effect of a 3-mA stimulation protocol on neurocognitive functions will be investigated using behavioral performance and fMRI.

Study Overview

• Status: Active, not recruiting
• Conditions: Schizophrenia; Cognitive Impairment
• Intervention / Treatment: Device: transcranial direct current stimulation

Detailed Description

Thirty schizophrenic patients will be recruited after meeting the inclusion criteria and will be randomly assigned to active and sham stimulation groups. A single session of concurrent prefrontal tDCS/fMRI will be conducted. Participants will undergo baseline task performance before the intervention. One week later, they will undergo the tDCS intervention (active or sham) next to the scanner during which they perform the working memory task varying in cognitive load. They will perform the task 24 h later again. They will be then transferred to MRI scanner right after stimulation

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Phase 1

Contacts and Locations

Study Locations

• Iran, Islamic Republic of
  • Tehran, Iran, Islamic Republic of
    • The National Brain Mapping Laboratory (NBML)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• men or women (18-50 yrs old) with a DSM 5 SCZ diagnosis,
• If female, negative urine pregnancy test
• significant cognitive impairment (1 SD below the norm on the working memory/executive functioning task performance)
• feasibility for tDCS interventions according to safety guidelines
• stable medication regime especially the classical neuroleptics and all CNS-activating medications, if taken, 4-6 weeks before the experiment
• fluency in the native language
• right-handed
• ability to provide informed consent.

Exclusion Criteria:

• pregnancy
• alcohol or substance dependence
• history of seizure
• history of neurological disorder
• history of head injury
• Presence of ferromagnetic objects in the body that are contraindicated for MRI of the head (pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments) or fear of enclosed spaces). Eligibility will be determined by the "MRI Safety Screening Questionnaire" and verified, if necessary, by a radiology consultant.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active tDCS group; The experimental arm receives real (or active) electrical stimulation for 20 minutes	Device: transcranial direct current stimulation; In tDCS, direct electrical currents are generated by an electrical stimulator and are noninvasively delivered to the scalp through a pair of saline-soaked sponge electrodes (7×5 cm).; Other Names: tDCS; tES
Sham Comparator: sham tDCS group; The sham arm receives sham (or no real) intervention in which stimulation lasts for 30 seconds and ends afterward.	Device: transcranial direct current stimulation; In tDCS, direct electrical currents are generated by an electrical stimulator and are noninvasively delivered to the scalp through a pair of saline-soaked sponge electrodes (7×5 cm).; Other Names: tDCS; tES

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Working memory behavioral performance	A computerized version of 3- back letter task, optimized for administration in a functional MRI environment will be employed during the experiment	up to 24 hours after the intervention
Modifications to blood-oxygen-level-dependent (BOLD) signal	Changes to blood-oxygen-level-dependent (BOLD) signal (arbitrary units) of brain areas that are implicated in cognitive impairment and pathophysiology of schizophrenia during the working memory task, as measured by fMRI following the intervention between the active and sham groups.	up to 1 hour

Collaborators and Investigators

• Sponsor: The National Brain Mapping Laboratory (NBML)
• Collaborators: University of British Columbia; Ruhr University of Bochum; University of Tehran; Leibniz Research Centre for Working Environment and Human Factors

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2022
• Primary Completion (Estimated): May 30, 2024
• Study Completion (Estimated): August 1, 2024

Study Registration Dates

• First Submitted: December 22, 2021
• First Submitted That Met QC Criteria: January 7, 2022
• First Posted (Actual): January 21, 2022

Study Record Updates

• Last Update Posted (Estimated): November 13, 2023
• Last Update Submitted That Met QC Criteria: November 9, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Schizophrenia; fMRI; Transcranial direct current stimulation; cognitive impairment
• Additional Relevant MeSH Terms: Mental Disorders; Neurocognitive Disorders; Schizophrenia Spectrum and Other Psychotic Disorders; Cognition Disorders; Schizophrenia; Cognitive Dysfunction
• Other Study ID Numbers: 2021_01_GF16

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