Impaired Cerebral Autoregulation is Associated with Functional Connectivity in Schizophrenia

Dr. Hsiao-Lun Ku

Department of Psychiatry, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan

Brain and Consciousness Research Center, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan

 

Background

Schizophrenic patients (SCZ) have high risk and mortality of cardio- & cerebral-vascular disease (CVD). Impaired cerebral autoregulation (CA) is the risk factor of CVD and its mortality. Our research has found SCZ have impaired dynamic cerebral blood flow autoregulation (dCA), which might be caused by autonomic dysfunction. Changes of regional cerebral blood flow (CBF), CBF connectivity and functional connectivity (FC) in default mode network (DMN) and cingulate cortex in SCZ have been reported. Activities of  DMN and cingulate cortex were found associated with autonomic regulation. This study aims to investigate if the impaired CA in SCZ is associated with the function of DMN and cingulate cortex.

 

Method

CA and resting-state functional magnetic resonance imaging (resting fMRI) were assessed in SCZ. CA was assessed by analyzing the spontaneous fluctuations of blood pressure (BP) and cerebral blood flow velocity (CBFV) of internal carotid artery measured by Doppler sonography. Correlation coefficient between mean BP and CBFV (Mx) and transfer function analysis were analyzed. The functional connectivity (FC) of DMN and cingulate cortex was analyzed and was correlated with two CA indices: Mx and phase shift between BP and CBFV.

 

Result

The Mx was positively correlated with FCs between right posterior cingulate cortex (PCC) and regions of interest (ROIs) associated with sympathetic regulation including right midcingulate cortex (MCC), left subgenual anterior cingulate cortex (subACC), and ventromedial prefrontal cortex (vmPFC) (false discovery rate [FDR] corrected p<0.05). The phase shift (0.07~0.20Hz) was positively correlated with FCs between Rt PCC and ROIs associated with parasympathetic regulation including left inferior parietal lobule (IPL) & right hippocampal formation (HF) (FDR-corrected p<0.05). PANSS was positively associated with FC between Rt PCC and Lt subACC (uncorrected p<0.05). FC between Rt PCC and vmPFC was higher in SCZ with Mx>0.3(Mann-Whitney U test, p=0.009).

 

Conclusion

To our knowledge, this is the first study assessing the association between CA and FC in SCZ. We found that the impaired CA in SCZ was associated with FC in DMN and cingulate cortex. Further investigation of the underlying mechanism is warranted.