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

Study Overview
=================
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

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

Conditions
-----------------
Schizophrenia, Cognitive Impairment

Intervention / Treatment
-----------------
* Device: transcranial direct current stimulation


Participation Criteria
=================
Eligibility Criteria
-----------------
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.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active tDCS group<br>The experimental arm receives real (or active) electrical stimulation for 20 minutes | Device: transcranial direct current stimulation<br>* 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).<br>* Other names: tES;|
| Sham Comparator: sham tDCS group<br>The sham arm receives sham (or no real) intervention in which stimulation lasts for 30 seconds and ends afterward. | Device: transcranial direct current stimulation<br>* 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).<br>* Other names: 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 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Schizophrenia, cognitive impairment, Transcranial direct current stimulation, fMRI