Risperidone Effects on Brain Dynamic Connectivity-A Prospective Resting-State fMRI Study in Schizophrenia.
Kristin K Lottman1, Nina V Kraguljac2, David M White2
1Department of Biomedical Engineering, University of Alabama at Birmingham , Birmingham, AL , USA.
Frontiers in Psychiatry
|February 22, 2017
Summary
Dynamic functional connectivity in schizophrenia reveals altered brain network temporal dynamics. Unmedicated patients spent more time in intermediate states, which risperidone partially normalized, suggesting temporal alterations contribute to schizophrenia
Area of Science:
- Neuroscience
- Psychiatry
- Medical Imaging
Background:
- Resting-state functional connectivity (rsFC) studies in schizophrenia often show inconsistent findings regarding network integration.
- Examining dynamic functional connectivity (dFC) may offer insights into these inconsistencies and the temporal dynamics of brain networks in schizophrenia.
Purpose of the Study:
- To assess dynamic network connectivity in unmedicated schizophrenia patients, during risperidone treatment, and in matched controls.
- To investigate how temporal dynamics of brain networks differ between schizophrenia patients and controls and how they are affected by treatment.
Main Methods:
- Resting-state functional MRI data were acquired from unmedicated patients, patients undergoing 1-week and 6-week risperidone treatment, and controls.
- Dynamic functional connectivity was analyzed using sliding window analysis on independent component (IC) timecourses, with window size optimized via support vector machines.
- Windowed correlation matrices were clustered into three connectivity states (sparse, intermediate, abundant), and dwell times and fraction of time in each state were analyzed.
Main Results:
- Unmedicated patients showed altered static connectivity (increased in 5 pairs, decreased in 2 pairs of ICs) compared to controls.
- Dynamic connectivity revealed increased thalamus-somatomotor network connectivity in one of three states in unmedicated patients.
- Unmedicated patients spent less time in the sparse state and more time in the intermediate state compared to controls; risperidone partially normalized mean dwell times in these states after 6 weeks.
Conclusions:
- Schizophrenia-related static connectivity abnormalities may stem partly from altered brain network temporal dynamics.
- Dynamic functional connectivity analysis provides a complementary approach to understand network dysconnectivity in schizophrenia.
- Findings highlight the importance of considering temporal variations in brain network activity for a comprehensive understanding of schizophrenia.
