Abstract Details

Title Novel EEG Microstate Map with Intracranial Generators in Right Superior and Medial Frontal Gyrus Distinguish Patients with Schizophrenia from Controls

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P3 - Poster Session 3 (5:30 PM-6:30 PM)

Poster/Presentation
Number 9-016

Background Spatio-temporal dynamics of the quasi-stable EEG “functional microstates” and their intracranial generators can potentially be a state and trait marker for different cognitive and diseased states. Working memory deficits, a stable aspect of schizophrenia, tested by computer administered VSWM task with simultaneous dense array EEG acquisition to assess large scale brain networks can broaden our understanding of the disease and contribute in improving diagnostic accuracy.

Objective To study qEEG microstates and their cortical sources during changing Visio-Spatial Working Memory (VSWM) load in patients with schizophrenia as compared to healthy subjects.

Design/Methods After taking informed consent, 30 patients diagnosed with schizophrenia (as per DSM-5 criteria) and 30 age-matched controls were administered questionnaires (Edinburgh Handedness Inventory, Hindi MMSE, SAPS, and SANS). Thereafter, 128 channel EEG, ECG, and GSR (Galvanic Skin Resistance) were recorded during eyes closed, eyes open, and VSWM task performance. Following which, EEG preprocessing, down sampling, average referencing and Independent Component Analysis were done. Epoch wise data from each experimental condition was extracted and subjected to microstate analysis. Further, cortical generators of each microstate map were found. Statistical analysis was done to compare temporal microstate parameters (Global explained variance, number of time frames, mean duration, time coverage, and segment count density) and cortical sources of each microstate map in and across the groups.

Results A novel topographical map whose Global Explained Variance, Time Coverage, and Segment Count Density was significantly reduced in patients with schizophrenia associated with hypoactivation at right superior and medial frontal gyrus during pre-encoding phase of VSWM task which could potentially be a trait marker for schizophrenia.

Conclusions Spatio-temporal parameters of EEG microstates could distinguish patients with schizophrenia from controls.

Authors/Disclosures
Madhavi Nayyar, MD, MBBS (All India Institute of Medical Sciences, New Delhi) PRESENTER	Dr. Nayyar has nothing to disclose.
RATNA SHARMA (DEPT OF PHYSIOLOGY)	No disclosure on file
Mamta Sood	No disclosure on file
Suriya Prakash Muthukrishnan (All India Institute of Medical Sciences)	No disclosure on file
Prashant Tayade	No disclosure on file
Simran Kaur	No disclosure on file
Sunaina Soni	No disclosure on file
Abhisek Sahoo	No disclosure on file