Cognitive Impairment, Schizophrenia
Conditions
Keywords
Schizophrenia, cognitive impairment, Transcranial direct current stimulation, fMRI
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
Interventions
DEVICEtranscranial 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).
Sponsors
University of British Columbia
Ruhr University of Bochum
Leibniz Research Centre for Working Environment and Human Factors
University of Tehran
The National Brain Mapping Laboratory (NBML)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
Iran
Outcome results
None listed