The influence of severe preeclampsia on maternal cerebral perfusion

Introduction

The method of transcranial color scan can be used to improve and to simplify cerebral blood flow investigations. Combination of digital wide-range neurosonography and transcranial energetic Doppler scan provides a possibility of effective monitoring of cerebral blood flow. The goal of this study was to analyze cerebral flow disturbances in pregnant patients with preeclampsia.

Methods

Eighty-eight patients with severe preeclampsia, age 17–32 years (mean age 26 ± 4.6 years), and 90 patients with normal pregnancy, third trimester, without significant co-morbid states, age 19–34 years (mean age 25.9 ± 4.2 years), were included in the study. Patients with the following features were excluded from both groups: potentially haemodynamically significant stenosis or occlusion of magistral arteries of the head and basilar region; clinical features of congestive heart failure; arrhythmia. All patients underwent duplex scan of extracranial portions of brachiocephalic arteries with a linear probe and transcranial duplex scan (TCDS) in the area of the middle cerebral artery (MCA). By the transtemporal approach in the MCA M1 segment we determined the peak systolic flow velocity (V_ps), maximal end-diastolic velocity (V_ed), time-adjusted maximal velocity (TAMX), resistance index (RI), pulsative index (PI), and systolic/diastolic ratio (S/D). Significance of mean values differences in groups was estimated using Student t criteria.

Results

All haemodynamic values in preeclamptic patients were decreased in comparison with the same values in healthy pregnant women: PI (mean 0.71 vs 0.84, P < 0.0001); RI (mean 0.49 vs 0.54, P < 0.0001); V_ps (mean 72.8 vs 104.8 cm/s, P < 0.0001); V_ed (mean 34.7 vs 48.7 cm/s, P < 0.0001); TAMX (mean 48.5 vs 67.5 cm/s, P < 0.0001); S/D (mean 1.94 vs 2.05, P < 0.001). These pathophysiological changes of cerebral haemodynamics were consistent with the Dopplerographic pattern of diminished perfusion and are typical for vascular segments, which are located proximally to the zone of abnormally high haemodynamic resistance.

Conclusion

The results of the performed study showed that patients with severe preeclampsia had decreased cerebral perfusion and TCDS is an effective method for estimation of preeclampsia severity.