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

Phase 1

Active, not recruiting

• Conditions: Schizophrenia; Cognitive Impairment
• Interventions: Device: transcranial direct current stimulation

• Registration Number: NCT05200962
• Lead Sponsor: The National Brain Mapping Laboratory (NBML)

Brief Summary

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.

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 Timeline

• Study First Submitted: 2021-12-22
• Study First Submitted QC: 2022-01-07
• Study First Posted: 2022-01-21
• Study Start: 2022-02-01
• Status Verified: 2023-11
• Last Update Submitted: 2023-11-09
• Last Update Posted: 2023-11-13
• Primary Completion: 2024-05-30
• Study Completion: 2024-08-01

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 30

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Active tDCS group	transcranial direct current stimulation	The experimental arm receives real (or active) electrical stimulation for 20 minutes
sham tDCS group	transcranial direct current stimulation	The sham arm receives sham (or no real) intervention in which stimulation lasts for 30 seconds and ends afterward.

Primary Outcome Measures

Name	Time	Method
Working memory behavioral performance	up to 24 hours after the intervention	A computerized version of 3- back letter task, optimized for administration in a functional MRI environment will be employed during the experiment
Modifications to blood-oxygen-level-dependent (BOLD) signal	up to 1 hour	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.

Trial Locations

Locations (1)

The National Brain Mapping Laboratory (NBML); 🇮🇷 Tehran, Iran, Islamic Republic of