Functional connectivity of limbic system and prefrontal cortex years after pre‐eclampsia: 7‐Tesla functional magnetic resonance imaging study

Abstract

Objective Pre‐eclampsia is a vascular complication of pregnancy, associated with a long‐term risk of cerebrovascular and mental disorders. We explored whether formerly pre‐eclamptic women exhibit differences in functional brain organization, especially in regions that may explain the commonly reported emotional symptoms and cognitive complaints even years after the pregnancy. Methods Formerly pre‐eclamptic women and control women with a history of normotensive pregnancy underwent structural and functional 7‐Tesla magnetic resonance imaging scans. Using graph theoretical analysis, the efficiency and clustering coefficient of the functional brain network were investigated. The study included local analysis focusing on particular brain structures, such as the limbic system and the prefrontal cortex, and global analysis of the whole cerebrum. Univariable and multivariable linear regression was used to investigate the relationship between brain network‐related graph measures and the group (formerly pre‐eclamptic or control). Results A total of 17 control parous women and 55 women with a history of pre‐eclampsia were recruited. The time intervals between the index pregnancy and recruitment were 8.0 and 5.6 years for the two groups, respectively. Compared with control women, formerly pre‐eclamptic women had higher local efficiency in the prefrontal cortex (P = 0.048) and anterior cingulate cortex (P = 0.03) but lower local efficiency and local clustering coefficient in the amygdala (P = 0.004 and P = 0.02, respectively) and parahippocampal cortex (P = 0.007 and P = 0.008, respectively). No differences were found in the global functional brain organization. Conclusions Compared to controls with a history of normotensive pregnancy, formerly pre‐eclamptic women displayed a different local functional brain organization. These differences in functional connectivity, especially in the limbic regions and the prefrontal cortex, are in line with the psychological and cognitive complaints reported commonly by women with a history of pre‐eclampsia. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Cerebral volume is unaffected after pre‐eclampsia

“…Perhaps, volumetric changes after pre‐eclampsia occur later and, therefore, long‐term follow‐up of mental disorders and brain volumes is needed. Alternatively, cognitive and emotional difficulties in the first decades after pre‐eclampsia are of functional nature 23 , which often precede structural changes and, therefore, are independent of cerebral volumes.…”

“…Volume was obtained for the following brain structures: whole brain, gray and white matter of the whole brain, four brain lobes, ventricular CSF spaces (i.e. lateral, third and fourth ventricles and cavum septi pellucidi), pericortical CSF space and, in more detail, cortical regions related to cognition and emotion that have been investigated previously in relation to brain function, including prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex, amygdala, hippocampus, entorhinal cortex and parahippocampal cortex [21][22][23] .…”