Symptomatic psychosis risk and physiological fluctuation in functional MRI data

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Physiological brain pulsations are crucial for glymphatic brain clearance and interstitial homeostasis.
• Previous research has not fully explored the relationship between psychotic symptomatology and physiological brain variations.

Purpose of the Study:

• To investigate the association between psychotic symptomatology and physiological variations in the human brain using functional magnetic resonance imaging (fMRI).
• To utilize the coefficient of variation of the Blood-Oxygen-Level-Dependent (BOLD) signal (CV_BOLD) as a measure of physiological brain pulsatility.

Main Methods:

• fMRI data analyzed from 277 participants in the Northern Finland Birth Cohort 1986.
• Psychotic symptoms assessed using the Positive Symptoms Scale of the Structured Interview for Prodromal Syndromes (SIPS).
• CV_BOLD analyses controlled for motion, age, sex, and education, and compared with meta-analyses of schizophrenia studies.

Main Results:

• Participants with psychotic-like symptoms exhibited higher global CV_BOLD in cerebrospinal fluid (CSF) and white matter (WM) compared to controls.
• Voxel-wise analysis indicated increased CV_BOLD in periventricular white matter, basal ganglia, cerebellum, and cortical regions.
• Regions with altered physiological fluctuations in psychosis risk showed minimal overlap (<6%) with regions affected in schizophrenia meta-analyses.

Conclusions:

• Psychotic-like symptoms are associated with elevated physiological brain pulsatility (CV_BOLD) across various brain regions.
• These findings provide novel insights into cerebral physiological fluctuations, potentially explaining aspects of brain function not captured by conventional fMRI or VBM studies.