Effect of blood pressure on reversible posterior leukoencephalopathy syndrome in pre-eclampsia or eclampsia

Eclampsia in the 21st century

The reported incidence of eclampsia is 1.6 to 10 per 10,000 deliveries in developed countries, whereas it is 50 to 151 per 10,000 deliveries in developing countries. In addition, low-resource countries have substantially higher rates of maternal and perinatal mortalities and morbidities. This disparity in incidence and pregnancy outcomes may be related to universal access to prenatal care, early detection of preeclampsia, timely delivery, and availability of healthcare resources in developed countries compared to developing countries. Because of its infrequency in developed countries, many obstetrical providers and maternity units have minimal to no experience in the acute management of eclampsia and its complications. Therefore, clear protocols for prevention of eclampsia in those with severe preeclampsia and acute treatment of eclamptic seizures at all levels of healthcare are required for better maternal and neonatal outcomes. Eclamptic seizure will occur in 2% of women with preeclampsia with severe features who are not receiving magnesium sulfate and in <0.6% in those receiving magnesium sulfate. The pathogenesis of an eclamptic seizure is not well understood; however, the blood-brain barrier disruption with the passage of fluid, ions, and plasma protein into the brain parenchyma remains the leading theory. New data suggest that blood-brain barrier permeability may increase by circulating factors found in preeclamptic women plasma, such as vascular endothelial growth factor and placental growth factor. The management of an eclamptic seizure will include supportive care to prevent serious maternal injury, magnesium sulfate for prevention of recurrent seizures, and promoting delivery. Although routine imagining following an eclamptic seizure is not recommended, the classic finding is referred to as the posterior reversible encephalopathy syndrome. Most patients with posterior reversible encephalopathy syndrome will show complete resolution of the imaging finding within 1 to 2 weeks, but routine imaging follow-up is unnecessary unless there are findings of intracranial hemorrhage, infraction, or ongoing neurologic deficit. Eclampsia is associated with increased risk of maternal mortality and morbidity, such as placental abruption, disseminated intravascular coagulation, pulmonary edema, aspiration pneumonia, cardiopulmonary arrest, and acute renal failure. Furthermore, a history of eclamptic seizures may be related to long-term cardiovascular risk and cognitive difficulties related to memory and concentration years after the index pregnancy. Finally, limited data suggest that placental growth factor levels in women with preeclampsia are superior to clinical markers in prediction of adverse pregnancy outcomes. This data may be extrapolated to the prediction of eclampsia in future studies. This summary of available evidence provides data and expert opinion on possible pathogenesis of eclampsia, imaging findings, differential diagnosis, and stepwise approach regarding the management of eclampsia before delivery and after delivery as well as current recommendations for the prevention of eclamptic seizures in women with preeclampsia.

MRI characteristics of brain edema in preeclampsia/eclampsia patients with posterior reversible encephalopathy syndrome

BACKGROUND

The neuroimaging manifestations of eclampsia and preeclampsia often overlap, mainly presenting as posterior reversible encephalopathy syndrome (PRES). The purpose of this retrospective study was to compare the extent and nature of brain edema in eclampsia and preeclampsia patients with PRES based on MRI characteristics.

METHODS

One hundred fifty women diagnosed with preeclampsia-eclampsia and undergoing cranial MRI were enrolled; 24 of these were diagnosed as having eclampsia. According to clinicoradiologic diagnosis of PRES, eligible patients were classified as having eclampsia with PRES (group E-PRES) and preeclampsia with PRES (group P-PRES). A scale on T2W FLAIR-SPIR images was established to evaluate the extent of brain edema, and the score of brain edema (SBE) of both groups was compared. In patients of the two groups who also underwent DWI sequence, the presence or absence of hyperintensity on DWI and hypointensity on ADC maps were determined to compare the nature of brain edema. Furthermore, clinical and biochemical data of the two groups were compared.

RESULTS

The incidence of PRES in eclampsia patients was significantly higher than that in preeclampsia patients (87.50% vs. 46.03%, P<0.001). The SBE of all regions and typical regions in group E-PRES patients were significantly higher than those in group P-PRES patients (15.88±8.72 vs. 10.90±10.21, P=0.021; 8.52±3.87 vs. 5.01±4.19, P=0.002; respectively). The presence of hyperintensity on DWI was determined more frequently in group E-PRES patients than group P-PRES patients (71.43% vs. 32.00%, P=0.024). Age, systolic blood pressure, white blood cell count, neutrophil count and percentage of neutrophils were significantly different between the two groups (P<0.05).

CONCLUSIONS

Certain MRI characteristics that reflect the extent and nature of brain edema were different between eclampsia and preeclampsia patients with PRES. Additional prospective studies are still required to explore whether these MRI characteristics of brain edema may further become a potential predictor for eclamptic seizures in preeclampsia patients with PRES.

Serum Neurofilament Light: a Potential Diagnostic and Prognostic Biomarker in Obstetric Posterior Reversible Encephalopathy Syndrome

Obstetric posterior reversible encephalopathy syndrome (PRES), caused by preeclampsia (PE) or eclampsia, is a clinical imaging syndrome and a critical maternal complication, with vasogenic edema in white matter as a typical imaging characteristic. Serum neurofilament light (NFL) is a marker of neuroaxonal injury. Therefore, we performed this study to explore the diagnostic and prognostic role of NFL in obstetric PRES. We used stored serum samples and clinical data obtained from 2148 PE or eclampsia patients from the Guangzhou Medical Centre for Critical Pregnant Women from January 2015 to January 2020. The serum NFL concentration was measured by Simoa assay. Patients without complete data and MRI examinations were excluded. All patients were grouped into the PRES and non-PRES groups based on the PRES diagnostic criteria. In total, 222 patients met the inclusion criteria and were grouped into the PRES (n = 123) and non-PRES (n = 99) groups. The NFL level was significantly higher in the PRES group than in the non-PRES group (p < 0.0001). The discriminatory accuracy of diagnostic panels (headaches + NFL, NFL) in receiver operating characteristic curve analysis (area under the curve) was 0.9338 and 0.7664. Importantly, the NFL level was significantly correlated with edema severity (Spearman's correlation, p < 0.0001), and a poorer pregnancy outcome was observed in the PRES group. In conclusion, an increased NFL level can add predictive value for diagnosing obstetric PRES, and its level is associated with both clinical severity and pregnancy outcome, suggesting that NFL could serve as a diagnostic and prognostic biomarker for obstetric PRES.

Cerebrovascular events during pregnancy and puerperium

Though cerebrovascular complications of pregnancy remain relatively rare, they represent a potentially devastating event that necessitates prompt identification and treatment. Eighteen percent of strokes occurring in young women are linked to pregnancy. They occur mostly in the third trimester or during the post-partum period. Their biggest risk factors are hypertension, preeclampsia/eclampsia and migraine. Cerebrovascular events occurring during this period may involve specific pathophysiological processes that include embolic phenomena or endothelial dysfunction, but can also have common etiologies that are simply favored by the context of pregnancy. Thus, posterior encephalopathy and vasoconstriction cerebral syndrome are relatively frequently involved in cerebrovascular complications of pregnancy. Other very specific causes like amniotic fluid embolism or postpartum cardiomyopathy can also be responsible for such events. The management of stroke during pregnancy must be multidisciplinary and include a neurovascular expertise. Some conditions can lead to a long-life follow-up and modify the management of a future pregnancy.

Anti-glomerular basement membrane disease complicated with posterior reversible encephalopathy syndrome and subcortical cerebral hemorrhage: a case report and review of the literature

A 71-year-old woman was hospitalized for the treatment of fatigue, fever, and cough. On admission, she showed increased serum inflammation markers, severe anemia, pulmonary hemorrhage, and advanced acute kidney injury requiring hemodialysis. Her serum anti-glomerular basement membrane (GBM) antibody titer was found to be extremely high on the 7th hospital day. She was eventually diagnosed with anti-GBM disease. She was treated with a combination of corticosteroid pulse therapy, oral prednisolone and cyclophosphamide, and plasma exchange, but continued to require maintenance hemodialysis for end-stage kidney disease. During her treatment, she suddenly developed headache, blindness, seizure, and consciousness disturbance. She was diagnosed by magnetic resonance imaging with posterior reversible encephalopathy syndrome (PRES) with subcortical cerebral hemorrhage. Both the PRES and cerebral hemorrhage subsided soon after control of her hypertension and reinforcement of immunosuppressive treatment. PRES, particularly when accompanied by cerebral hemorrhage, may cause irreversible and lethal neurological abnormalities, and nephrologists should, therefore, be aware of the potential risk of PRES in patients with anti-GBM disease. We discuss the current case in the light of the previous literature.

Posterior reversible encephalopathy syndrome in preeclampsia and eclampsia: The role of hypomagnesemia

PURPOSE

Posterior reversible encephalopathy syndrome (PRES), defined by its clinical and imaging manifestations, is a critical maternal complication. The specific pathophysiological mechanism of PRES has not been fully elucidated and remains controversial. Recently, several case studies reported that hypomagnesemia is present in the acute phase of PRES regardless of its etiology. Moreover, magnesium sulfate is a conventional treatment for preeclampsia (PE) and eclampsia; therefore, we hypothesized that hypomagnesemia might play an important role in the cascades involved in PRES in PE or eclampsia.

METHOD

We consecutively collected PE and eclampsia patients who were examined via magnetic resonance imaging (MRI) and tested for magnesium levels between January 2013 and January 2017. All patients were grouped into PRES and non-PRES groups based on MRI results. Demographic data, magnesium levels and imaging features were collected retrospectively.

RESULTS

A total of 72 patients met the inclusion criteria; these participants were sorted into PRES (n = 38) and non-PRES (n = 34) groups. Twenty-four patients (63%) in the PRES group and 2 patients (6%) in the non-PRES group presented hypomagnesemia. Moreover, magnesium levels were significantly lower in the PRES group during both the acute phase (p < 0.001) and the post-phase (p = 0.04) than in the non-PRES group. However, there was no correlation between magnesium levels and edema severity during the acute phase.

CONCLUSIONS

These results demonstrate that hypomagnesemia frequently occurs in the acute phase of obstetric PRES and suggest a potential relationship between them. Such a connection would support the application of magnesium sulfate in PE and eclampsia patients to prevent PRES. However, additional randomized trials are needed.