Cerebrovascular pathophysiology in preeclampsia and eclampsia

The brain plays a pivotal role in the preeclampsia syndrome. Recent progress has been made in understanding the causes and consequences of its cerebrovascular complications. Non-invasive techniques such as transcranial Doppler (TCD) and high-resolution magnetic resonance imaging (MRI) have made it possible to study adaptations in the brain to pregnancy and preeclampsia. Animal studies highlight several underlying mechanisms by which pregnancy and experimental preeclampsia influence cerebrovascular structure and function. Some clinical and pathological as well as neuroimaging features of eclampsia are an expression of the posterior reversible encephalopathy syndrome (PRES). Its pathophysiology is a matter of debate and, recently, its reversibility has been questioned. Current emphasis includes failure of the autoregulatory capacity and breakdown of the blood-brain barrier in the presence of endothelial dysfunction. All eclampsia can no longer be conceptualized as a transient and fully reversible event and it may have serious life-long consequences. This concept bears important implications for current pathophysiologic, preventive, and therapeutic concepts of eclampsia.