Perinatal hypertensive disorder including pre-eclampsia is a systemic syndrome that occurs in 3–5% of pregnant women. It can result in various degrees of brain damage. A recent study suggested that even gestational hypertension without proteinuria can cause cardiovascular or cognitive impairments later in life. We hypothesized that perinatal hypertension affects the brain functional connectivity (FC) regardless of the clinical manifestation of brain functional impairment. In the present study, we analyzed regional global connectivity (rGC) strength (mean cross-correlation coefficient between a brain region and all other regions) using resting-state functional magnetic resonance imaging to clarify brain FC changes associated with perinatal blood pressure using data from 16 women with a normal pregnancy and 21 pregnant women with pre-eclampsia. The rGC values in the bilateral orbitofrontal gyri were negatively correlated with diastolic blood pressure (dBP), which could not be explained by other pre-eclampsia symptoms. The strength of FC seeding at the left orbitofrontal gyrus was negatively correlated with dBP in the anterior cingulate gyri and right middle frontal gyrus. These results suggest that dBP elevation during pregnancy can affect the brain FC. Since FC is known to be associated with various brain functions and diseases, our findings are important for elucidating the neural correlate of cognitive impairments related to hypertension in pregnancy.

The review was performed to investigate the functional brain alterations in patients with various kinds of chronic pain including fibromyalgia, chronic low back pain, migraine and the other chronic pain conditions. In these patients functional connectivity was different not only in the sensorymotor system but also in the affective and reward system. New technology have allowed us to identify and understand the neural mechanisms contributing to chronic pain, which provides us novel targets for future research and treatment.

Postherpetic neuralgia (PHN) is a chronic pain condition after a cure of herpes zoster. Patients with PHN often suffer from physical pain and psychological distress. We investigated the relationship between functional alternations in the brains of patients with PHN and their clinical manifestations using resting-state fMRI. We acquired resting-state fMRI data from 17 patients with PHN and matched healthy controls. We performed seed-based functional connectivity (FC) analysis and statistical comparisons in FC. We also performed correlation analysis between FC strengths and clinical scores about pain intensity, anxiety, depression and pain catastrophizing. In FC analysis, brain regions in the salience, default mode, sensorimotor and reward network were set as seeds. FC between the medial prefrontal cortex (mPFC) and hippocampus increased in PHN group. In contrast, FC between the hippocampus and primary somatosensory cortex (SI) decreased in PHN group. Furthermore, the SI-hippocampus FC was negatively correlated with pain intensity and the mPFC-hippocampus FC was positively correlated with pain catastrophizing tendency. Our findings indicate that the hippocampus is related to pain perception and catastrophic thinking habits in patients with PHN. Functional alteration of the hippocampus may have a major role in the development and maintenance of chronic pain condition in patients with PHN.

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