Preeclampsia-eclampsia: clinical and neuroradiographic correlates and insights into the pathogenesis of hypertensive encephalopathy

Posterior reversible encephalopathy syndrome in postpartum patients with gestational hypertension: A case report emphasizing early recognition and management

Posterior reversible encephalopathy syndrome (PRES) is a rare neuroradiological condition causing headaches, altered mental status, seizures, visual disturbances, and focal deficits. It is often associated with preeclampsia and eclampsia in pregnancy, but can also occur in patients with other medical conditions, such as hypertension, autoimmune diseases, renal dysfunction etc. This case report highlights the importance of recognizing PRES in postpartum patients with hypertension and the need for prompt diagnosis and management to prevent potential complications. A 30-year-old woman with gestational hypertension underwent scheduled induction of labor. After a successful delivery, she experienced a sudden headache but no other neurological symptoms. Imaging showed bilateral frontoparietal white matter edema, consistent with PRES. She was closely monitored, treated with analgesics, and improved within a week. The case highlights the rarity of PRES in postpartum patients without preeclampsia or eclampsia. It underscores the importance of considering PRES as a possible diagnosis in postpartum patients with hypertension, even in the absence of typical risk factors. Prompt control of blood pressure and careful monitoring are essential to ensure a positive outcome, as PRES can lead to life-threatening complications if not managed appropriately. The study highlights the importance of heightened awareness of PRES in postpartum patients with gestational hypertension. Early detection and timely management can improve prognosis, even in atypical cases. Healthcare professionals should be vigilant in assessing hypertension patients to diagnose and manage PRES, preventing neurological sequelae. Further research is needed to better understand PRES pathophysiology and risk factors in postpartum patients.

Pre-eclampsia and Cardiovascular Disease: From Pregnancy to Postpartum

Hypertensive disorders of pregnancy (HDP) complicate approximately 10% of pregnancies. In addition to multiorgan manifestations related to endothelial dysfunction, HDP confers an increased risk of cardiovascular disease during delivery hospitalisation, such as heart failure, pulmonary oedema, acute MI and cerebrovascular events. However, the cardiovascular legacy of HDP extends beyond birth since these women are significantly more likely to develop cardiovascular risk factors in the immediate postnatal period and major cardiovascular disease in the long term. The main mediator of cardiovascular disease in women with a history of HDP is chronic hypertension, followed by obesity, hypercholesterolaemia and diabetes. Therefore, optimising blood pressure levels from the immediate postpartum period until the first months postnatally could have beneficial effects on the development of hypertension and improve long-term cardiovascular health. Peripartum screening based on maternal demographic, and clinical and echocardiographic data could help clinicians identify women with HDP at highest risk of developing postpartum hypertension who would benefit from targeted primary cardiovascular prevention.

Optic nerve sheath diameter measurements using ultrasonography to diagnose raised intracranial pressure in preeclampsia: an observational study

Objective

To estimate the incidence of raised intracranial pressure (ICP) as evident by enlarged optic nerve sheath diameter (ONSD) by ocular ultrasound among patients with preeclampsia and its relationship to severity of disease.

Material and Methods

Sixty pregnant mothers with preeclampsia were compared to 30 normotensive, uncomplicated pregnant controls. For ONSD measurement, a 7-MHZ linear probe was used and three values from each optic nerve were taken and the mean of six values of both eyes was recorded. All study subjects were followed until seven days after delivery.

Results

Two cut off values (5.8 mm and 4.6 mm) were used to compare ONSD in severe and non-severe preeclampsia with that of healthy pregnant individuals. The incidence of raised ICP among severe preeclampsia above 5.8 mm and 4.6 mm cut-off were 43.3% and 90%, respectively, before delivery. ONSD was significantly elevated among preeclampsia subjects at both cut-off values at pre-delivery (p=0.004 for ONSD >5.8 mm and p<0.001 for ONSD >4.6 mm) compared to controls. There a significant association between presence of neurological manifestations and enlarged ONSD (p<0.001 for ONSD >5.8 mm and p=0.04 for ONSD >4.6 mm) before delivery.

Conclusion

Severe preeclampsia with neurological features was associated with increased ONSD, reflecting raised ICP. Further studies are needed to compare ONSD values with invasive ICP monitoring for better understanding of this relationship.

Blood-brain barrier leakage years after pre-eclampsia: dynamic contrast-enhanced 7-Tesla MRI study

OBJECTIVE

Pre-eclampsia is a hypertensive complication of pregnancy that is associated with an increased risk of long-term cardiovascular and cerebrovascular disorders. Although the underlying mechanism of persistent susceptibility to cerebral complications after pre-eclampsia remains largely unclear, impaired blood-brain barrier (BBB) integrity has been suggested to precede several cerebrovascular diseases. In this study, we aimed to investigate the integrity of the BBB years after pre-eclampsia.

METHODS

This was an observational study of premenopausal formerly pre-eclamptic women and controls with a history of normotensive pregnancy who underwent cerebral magnetic resonance imaging (MRI) at ultra-high field (7 Tesla) to assess the integrity of the BBB. Permeability of the BBB was determined by assessing leakage rate and fractional leakage volume of the contrast agent gadobutrol using dynamic contrast-enhanced MRI. BBB leakage measures were determined for the whole brain and lobar white and gray matter. Multivariable analyses were performed, and odds ratios were calculated to compare women with and those without a history of pre-eclampsia, adjusting for potential confounding effects of age, hypertension status at MRI and Fazekas score.

RESULTS

Twenty-two formerly pre-eclamptic women (mean age, 37.8 ± 5.4 years) and 13 control women with a history of normotensive pregnancy (mean age, 40.8 ± 5.5 years) were included in the study. The time since the index pregnancy was 6.6 ± 3.2 years in the pre-eclamptic group and 9.0 ± 3.7 years in controls. The leakage rate and fractional leakage volume were significantly higher in formerly pre-eclamptic women than in controls in the global white (P = 0.001) and gray (P = 0.02) matter. Regionally, the frontal (P = 0.04) and parietal (P = 0.009) cortical gray matter, and the frontal (P = 0.001), temporal (P &lt; 0.05) and occipital (P = 0.007) white matter showed higher leakage rates in formerly pre-eclamptic women. The odds of a high leakage rate after pre-eclampsia were generally higher in white-matter regions than in gray-matter regions.

CONCLUSION

This observational study demonstrates global impairment of the BBB years after a pre-eclamptic pregnancy, which could be an early marker of long-term cerebrovascular disorders. © 2022 The Authors. Ultrasound in Obstetrics &amp; Gynecology published by John Wiley &amp; Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Role of MRI and CT in the Evaluation of Headache in Pregnancy and the Postpartum Period

Approximately 35% of acute headaches in pregnant women are secondary to an underlying condition. Headaches are also common in the postpartum period where they occur in 30% to 40% of patients. The majority of secondary headaches are due to hypertensive disorders: preeclampsia-eclampsia, posterior reversible encephalopathy syndrome, and acute arterial hypertension. Other causes include reversible cerebral vasoconstriction syndrome and pituitary apoplexy, as well as life-threatening conditions such as cerebral venous thrombosis. In this article, we review general recommendations for imaging the pregnant patients and discuss the imaging findings of common causes of headaches in pregnancy and the postpartum period.

Optic nerve sheath diameter in severe preeclampsia with neurologic features versus controls

Background

Optic nerve sheath diameters (ONSD) have been validated as an accurate screening tool to detect elevated intracranial pressure in hypertensive encephalopathy. The neurologic manifestations of preeclampsia and/or eclampsia mimic those of hypertensive encephalopathy. This study was performed to assess the incidence of elevated optic nerve sheath diameters of patients with severe preeclampsia and neurologic criteria compared to non-preeclamptic patients. The secondary objective was to determine baseline optic nerve sheath diameters in patients with severe preeclampsia without neurologic criteria and preeclampsia without severe features.

Methods

Single site cohort study including 62 pregnant women 18 years or older and 20 weeks or further gestation. Patients with preeclampsia without severe features, preeclampsia with severe features by non-neurologic criteria, preeclampsia with severe features with neurologic criteria, and patients without preeclampsia were enrolled via convenience sampling. One blinded reviewer measured sheath diameters; baseline demographics and pregnancy data were collected by chart review. Statistical analysis was completed with STATA/IC 16. Categorical variables were compared by the χ2 test. Continuous variables were presented as mean ± standard deviation, and discrete variables were presented as medians and compared by Kruskal–Wallis testing. Normality was confirmed by Shapiro–Wilk testing. Linear and logistic regression were used to test the association between the preeclampsia groups and optic nerve sheath diameters. Models were presented as unadjusted and adjusted for BMI, gestation, hypertension, diabetes, parity, and gravidity.

Results

The incidence of optic nerve sheath diameters > 5.8 mm was 43.8% in the severe preeclampsia with neurologic features cohort, and 42.1% in the control cohort, with a relative risk of 1.04. Patients with severe preeclampsia without neurologic features had sheath diameters of 5.75 mm ± 1.09 mm; non-severe preeclampsia patients had sheath diameters of 5.54 mm ± 1.26 mm.

Conclusions

We did not find a significant elevated optic nerve sheath diameter relative risk between severe preeclampsia patients with neurologic features and non-preeclampsia control patients. This is the first study to assess a North American population utilizing ACOG criteria for severe and non-severe preeclampsia, with severe cohorts additionally stratified by neurologic criteria.

How Soluble Fms-Like Tyrosine Kinase 1 Could Contribute to Blood-Brain Barrier Dysfunction in Preeclampsia?

Preeclampsia is a pregnancy-related syndrome that courses with severe cerebrovascular complications if not properly managed. Findings from pre-clinical and clinical studies have proposed that the imbalance between pro- and anti-angiogenic factors exhibited in preeclampsia is a major component of its pathophysiology. In this regard, measurement of circulating levels of soluble tyrosine kinase-1 similar to fms (sFlt-1), a decoy receptor for vascular endothelial growth factor (VEGF), is a moderately reliable biomarker for the diagnosis of preeclampsia. However, few studies have established a mechanistic approach to determine how the high levels of sFlt-1 are responsible for the endothelial dysfunction, and even less is known about its effects at the blood-brain barrier (BBB). Since the expression pattern of VEGF receptors type 1 and 2 in brain endothelial cells differs from the observed in peripheral endothelial cells, and components of the neurovascular unit of the BBB provide paracrine secretion of VEGF, this compartmentalization of VEGF signaling could help to see in a different viewpoint the role of sFlt-1 in the development of endothelial dysfunction. In this article, we provide a hypothesis of how sFlt-1 could eventually be a protective factor for brain endothelial cells of the BBB under preeclampsia.

Sonographic Optic Nerve Sheath Diameter Following Seizure Prophylaxis in Pre-Eclamptic Parturients With Severe Features: A Prospective, Observational Study

OBJECTIVES

Neurological manifestations, including raised intracranial pressures, are a hallmark of worsening pre-eclampsia. Invasive methods for measuring intracranial pressure, though a gold standard, are not always a viable option. Maternal ocular sonography is a promising bedside tool, which serves as a noninvasive, cost-effective means for measuring optic nerve sheath diameter (ONSD), a surrogate marker of raised intracranial pressures. We studied the ultrasonographically measured ONSD in severely pre-eclamptic women, and the effect of magnesium sulfate therapy on its values.

METHODS

Thirty severely pre-eclamptic women at ≥28 weeks gestation were included. We recorded baseline ONSD values, serum magnesium levels, neurological symptoms, vitals, and repeated them at 4 and 12 hours following magnesium sulfate therapy, and then at 24 hours postpartum. An ONSD value >5.8 mm was suggestive of raised intracranial pressure. Primary outcome measure was to evaluate changes in ultrasonographically measured ONSD following seizure prophylaxis with magnesium sulfate.

RESULTS

Women, 73.3%, had baseline ONSD >5.8 mm, with mean diameter being significantly high (6.02 ± 0.77 mm). There was a statistically nonsignificant decline in mean ONSD values at 4 and 12 hours, as well as at 24 hours postpartum. Patients with neurological symptoms declined significantly (from 70 to 10%; p value <.001) following magnesium sulfate therapy.

CONCLUSIONS

Majority of severely pre-eclamptic parturients had high ONSD value suggestive of raised intracranial pressures, which persisted in the postpartum period and was unaffected by magnesium sulfate therapy. Ultrasound can thus serve as a point-of-care, cost-effective, easily available bedside tool for indirectly measuring intracranial pressures in this high-risk population.

Disruption of the Blood-Brain Barrier by Extracellular Vesicles From Preeclampsia Plasma and Hypoxic Placentae: Attenuation by Magnesium Sulfate

[Figure: see text].

Maternal microvascular dysfunction during preeclamptic pregnancy

Preeclampsia is a hypertensive disorder of pregnancy effecting ∼5-8% of pregnancies in the United States, and ∼8 million pregnancies worldwide. Preeclampsia is clinically diagnosed after the 20th week of gestation and is characterized by new onset hypertension accompanied by proteinuria and/or thrombocytopenia, renal insufficiency, impaired liver function, pulmonary edema, or cerebral or visual symptoms. This broad definition emphasizes the heterogeneity of the clinical presentation of preeclampsia, but also underscores the role of the microvascular beds, specifically the renal, cerebral, and hepatic circulations, in the pathophysiology of the disease. While the diagnostic criteria for preeclampsia relies on the development of de novo hypertension and accompanying clinical symptoms after 20-week gestation, it is likely that subclinical dysfunction of the maternal microvascular beds occurs in parallel and may even precede the development of overt cardiovascular symptoms in these women. However, little is known about the physiology of the non-reproductive maternal microvascular beds during preeclampsia, and the mechanism(s) mediating microvascular dysfunction during preeclamptic pregnancy are largely unexplored in humans despite their integral role in the pathophysiology of the disease. Therefore, the purpose of this review is to provide a summary of the existing literature on maternal microvascular dysfunction during preeclamptic pregnancy by reviewing the functional evidence in humans, highlighting potential mechanisms, and providing recommendations for future work in this area.

Effect of magnesium sulphate on the intracranial pressure of preeclampsia patients using ultrasound-guided optic nerve sheath diameter: A pilot study

Background:

Increased intracranial pressure (ICP) is a known complication of pre-eclampsia with severe features. The use of magnesium sulphate (MgSO₄) is the standard treatment and is associated with marked reduction of cerebral perfusion pressure (CPP) and prevention of cerebral damage. Optic nerve sheath diameter (ONSD) ultrasonography is a bedside tool used to reflect changes in the ICP. The aim of this study is to detect the effect of MgSO₄ administration on ICP in severe preeclampsia through measuring changes in the ONDS.

Methods:

Thirty pregnant female patients suffering from severe pre-eclampsia were enrolled in this prospective pilot study. Ultrasound measurement of ONSD was measured before the commencement of MgSO4 and after 1, 6, and 24 h after the administration.

Results:

There was a significant difference in ONSD measurements between that at baseline and post magnesium administration at 1, 6, and 24 h (P-value 0.001). Additionally, a significant difference in measurements between 1 and 6 and 6 and 24 h after magnesium initiation (P-value 0.001).

Conclusions:

Ultrasound ONSD measurement in patients with severe preeclampsia is a non-invasive easy tool to detect increased intracranial pressure and monitor the response to magnesium sulphate infusion.

Cognitive Sequelae of Central-Variant Posterior Reversible Encephalopathy Syndrome (PRES)

Introduction

Although the posterior reversible encephalopathy syndrome (PRES) is often associated with headache and visual changes, central-variant PRES can be difficult to clinically diagnose in a patient with alteration of consciousness. Central-variant PRES has been previously described in the literature affecting subcortical white matter and the brainstem. Case Presentation. We describe a case presenting with hypertension (192/98) and altered level of consciousness requiring intubation. She was ultimately found to have extensive symmetric cortical and subcortical edema, with extensive involvement of bilateral thalami, consistent with central-variant PRES. Her mentation rapidly improved with blood pressure management. Confirmation of the diagnosis of central-variant PRES was made on repeat brain imaging. Our case is unique in demonstrating dramatic central white matter changes and their reversibility on repeat imaging six days later. Finally, persistent cognitive deficits at follow-up four months later are described.

Conclusion

Atypical presentations of PRES, involving alterations in levels of consciousness, can be difficult to clinically diagnose. A thorough differential diagnosis is even more important in cases of PRES with atypical imaging. Recognition of the diagnostic patterns of PRES on brain imaging, with prompt reversal of the causative factors, is crucial for the appropriate care of these patients. The long-term sequelae, which could include cognitive deficits, are poorly studied and understood.

Maternal Stroke: A Call for Action

Maternal mortality rates have been steadily increasing in the United States, and cardiovascular mortality is the leading cause of death among pregnant and postpartum women. Maternal stroke accounts for a significant burden of cardiovascular mortality. Data suggest that rates of maternal stroke have been increasing in recent years. Advancing maternal age at the time of birth and the increasing prevalence of traditional cardiovascular risk factors, and other risk factors, as well, such as hypertensive disorders of pregnancy, migraine, and infections, may contribute to increased rates of maternal stroke. In this article, we provide an overview of the epidemiology of maternal stroke, explore mechanisms that may explain increasing rates of stroke among pregnant women, and identify key knowledge gaps for future investigation in this area.

Correlation between cerebral biomarkers and optic nerve sheath diameter in patients with severe preeclampsia

Objective: To examine the correlation between plasma cerebral biomarkers (S100B and neuron-specific enolase (NSE)) and ultrasonographic optic-nerve-sheath-diameter (ONSD) in preeclampsia. Methods: Thirty preeclampsia patients and 27 controls were included. Mann-Whitney-U test was used for comparison of S100B, NSE, and ONSD in preeclampsia vs. controls. Kendall's tau was used to assess the correlation between biomarkers and ONSD (p < 0.05 significant). Results: ONSD, S100B and NSE were significantly higher in preeclampsia (p < 0.001, p = 0.004, and p < 0.001, respectively). There was significant correlation between NSE levels and ONSD: Kendall's tau = 0.26; p = 0.01. Conclusions: S100B and NSE are elevated in severe preeclampsia. NSE correlates with increased ONSD suggesting cerebral edema.

Posterior reversible encephalopathy syndrome (PRES): presentation, diagnosis and treatment

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder which is characterised by variable symptoms, which include visual disturbances, headache, vomiting, seizures and altered consciousness. The exact pathophysiology of PRES has not been completely explained, but hypertension and endothelial injury seem to be almost always present. Vasoconstriction resulting in vasogenic and cytotoxic edema is suspected to be responsible for the clinical symptoms as well as the neuro-radiological presentation. On imaging studies, Symmetrical white matter abnormalities suggestive of edema are seen in the computer tomography (CT) and magnetic resonance imaging (MRI) scans, commonly but not exclusively in the posterior parieto-occipital regions of the cerebral hemispheres. The management is chiefly concerned with stabilization of the patient, adequate and prompt control of blood pressure, prevention of seizures and timely caesarean section in obstetric cases with pre-eclampsia/eclampsia. In conclusion, persistently elevated blood pressures remain the chief culprit for the clinical symptoms as well as the neurological deficits. Early diagnosis by diffusion weighted MRI scans, and differentiation from other causes of altered sensorium i.e. seizures, meningitis and psychosis, is extremely important to initiate treatment and prevent further complications. Although most cases resolve successfully and carry a favorable prognosis, patients with inadequate therapeutic support or delay in treatment may not project a positive outcome.

Preeclampsia, eclampsia, and posterior reversible encephalopathy syndrome

Preeclampsia is a disorder of pregnancy associated with gestational hypertension and end-organ dysfunction. Patients with eclampsia, by definition, have seizures as part of the clinical syndrome. However, patients with preeclampsia can also have other neurologic symptoms and deficits. Both disorders can be associated with radiographic abnormalities similar to that of posterior reversible encephalopathy syndrome, suggesting a common pathophysiology or unified clinical spectrum of disorders. This chapter reviews the pathophysiology, clinical presentation, diagnostic findings, and prognosis of patients with neurologic complications associated with preeclampsia and eclampsia.

Posterior reversible encephalopathy syndrome (PRES): Is DWI a prognosis factor?

INTRODUCTION

Posterior reversible encephalopathy syndrome is a clinicoradiologic entity with typical MR imaging showing a white matter vasogenic edema predominantly affecting the occipital and parietal lobes of the brain. The aim of this article is evaluated the importance of DWI as a prognosis factor in patients with PRES.

MATERIALS AND METHODS

We reviewed data from 70 patients with PRES (35 with restricted DWI and 35 with no DWI abnormalities), that were admitted to Hospital São Lucas-PUCRS. These two groups were evaluated in age, sex, previous diseases and past medical history, use of medications, the neurologic manifestations, the highest blood pressure during the neurologic presentation and the highest creatinine during the period of observation.

RESULTS

Evaluating 70 patients with PRES with a mean age of 25.4 years old (range from 2 to 74 years old; 55 female and 15 male) we identified 35 cases were brain MRI presents with restricted DWI. Restricted DWI was associated with higher mortality in 90 days (14.2% vs 0.0%; p: 0.027).

CONCLUSIONS

Few articles present new data that will help clinicians in therapeutic decisions or that modify the knowledge of this syndrome. We suggested that restricted DWI is associated with a worst prognosis in PRES.

Hypertensive crisis in children and adolescents

Hypertensive crisis is a relatively rare condition in children. However, if not treated, it might be life-threatening and lead to irreversible damage of vital organs. Clinical presentation of patients with hypertensive crisis can vary from very mild (hypertensive urgency) to severe symptoms (hypertensive emergency) despite similarly high blood pressure (BP). Individualized assessment of patients presenting with high BP with emphasis on the evaluation of end-organ damage rather than on the specific BP number is a key in guiding physician's initial management of a hypertensive crisis. The main aim of the treatment of hypertensive crisis is the prevention or treatment of life-threatening complications of hypertension-induced organ dysfunction, including neurologic, ophthalmologic, renal, and cardiac complications. While the treatment strategy must be directed toward the immediate reduction of BP to reduce the hypertensive damage to these organs, it should not be at a too fast rate to cause hypoperfusion of vital organs by an excessively rapid reduction of BP. Thus, intravenous continuous infusions rather than intravenous boluses of antihypertensive medications should be the preferable mode of initial treatment of children with hypertensive emergency.

Posterior Reversible Encephalopathy Syndrome Secondary to Hypertensive Encephalopathy Brought on by a MAO Inhibitor: A Case Report

An elderly woman was admitted to the Family Medicine inpatient service for altered mental status after being brought to the emergency room by a concerned neighbor, who had come across the patient speaking incoherently. Initial evaluation was notable for elevated blood pressures, but extensive lab testing and head computed tomographic imaging were within normal limits. However, subsequent magnetic resonance imaging showed white matter changes consistent with posterior reversible encephalopathy syndrome (PRES), a neurologic syndrome characterized by headache, altered mental status, loss of vision, and seizures as well as radiographic findings of posterior cerebral white matter edema. Multiple etiologies of PRES have been described and include hypertensive encephalopathy, immunosuppressant medications, and eclampsia. This case describes an episode of PRES secondary to hypertensive encephalopathy brought about by an inappropriate dose of a monoamine oxidase (MAO) inhibitor. The patient had significant improvement in symptoms with removal of the offending agent and control of her blood pressure. While PRES generally has a good prognosis, prompt recognition, and management are important in preventing significant disease morbidity and mortality.

Isolated brainstem involvement in posterior reversible encephalopathy syndrome: a case report and review of the literature

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological syndrome, reversible vasogenic edema predominantly within parieto-occipital regions. However, isolated brainstem involvement in PRES has been rarely reported, little is known about its clinical manifestations, radiological features and outcomes. We reported a case with PRES with only brainstem involvement and performed a systematic review of published cases. Twenty-four cases, together with our case, were included in the analysis. Mean age was 43 years and 63% were males. Hypertension (50%), nephropathy (25%) and chemotherapy (21%) were the major risk factors. All patients except two had acute hypertension and 50% of patients had renal dysfunction at onset. The most common symptoms were altered consciousness (46%) and headache (46%), Seizure was only presented in 21% of patients. All patients except two were treated with antihypertension. Most patients recovered to their neurological baseline. Clinicians should recognize this unique variant finding in PRES. which always affects males with severe hypertension, especially combined with renal dysfunction. Antihypertensive treatment is the most widely used therapy. Outcome is usually well.

Current and emerging pharmacotherapy for emergency management of preeclampsia

INTRODUCTION

Preeclampsia is a disease specific to pregnancy characterised by new onset hypertension with maternal organ dysfunction and/or fetal growth restriction. It remains a major cause of maternal and perinatal morbidity and mortality. For fifty years, antihypertensives have been the mainstay of treating preeclampsia, reducing maternal morbidity and mortality. With increased knowledge of the mechanisms underlying the disease has come opportunities for novel therapies that complement antihypertensives by protecting the maternal vasculature. Areas covered: In this review, the authors consider, in detail, the antihypertensives commonly used today in the emergency care of women with severe preeclampsia. They also review less common anti-hypertensive agents and discuss the role of magnesium sulphate in the management of preeclampsia and the prevention of eclampsia. Finally, they explore novel therapeutics for the acute management of preeclampsia. Expert opinion: The rapid control of maternal hypertension will, and must, remain the mainstay of emergency treatment for women with severe preeclampsia. The role of magnesium sulphate as a primary prevention for eclampsia is context dependant and should not displace a focus on correcting blood pressure safely. The exploration of novel adjuvant therapies will likely allow us to prolong pregnancy longer and improve perinatal outcomes safely for the mother.

Peripheral Anti-Angiogenic Imbalance during Pregnancy Impairs Myogenic Tone and Increases Cerebral Edema in a Rodent Model of HELLP Syndrome

Using an animal model of hemolysis elevated liver enzymes low platelets (HELLP) that has systemic inflammation and neuroinflammation we wanted to determine if blood brain barrier (BBB) permeability, cerebral edema, vascular tone, and occludin expression were altered in pregnant rats. Anti-angiogenic proteins sFlt-1 and sEng (4.7 and 7 µg/kg/day, respectively) were chronically infused into normal pregnant (NP) rats beginning on gestational day 12 via a mini-osmotic pump. On gestational day 19, blood pressure was measured via a carotid catheter and brains were collected. BBB permeability was assessed in select brain regions from rats infused with 0.5 mg/mL Texas Red Dextran and phenylephrine. Occludin, sFlt-1, and sEng were analyzed via western blot or ELISA. Infusion of sFlt-1 and sEng into NP rats increased hemolysis and liver enzymes, and decreased platelets and led to hypertension. HELLP rats had significant impairment in the myogenic response and increased BBB permeability in the posterior cortex and brainstem. Brain water content in the posterior cortex was increased and sEng protein expression in the brainstem was significantly increased in HELLP rats. The results from this study suggest that a peripheral anti-angiogenic imbalance during pregnancy is associated with decreased myogenic tone, vasogenic edema, and an increase in BBB permeability, but not anti-angiogenic imbalance in the brain.

Optic nerve ultrasound for fluid status assessment in patients with severe preeclampsia

Background There are no data on usefulness of optic nerve sheath diameter (ONSD) as a marker of patient's fluid status in preeclampsia. The objective was to examine potential correlation between ONSD and lung ultrasound estimates of extravascular lung water in severe preeclampsia. Patients and methods Thirty patients with severe preeclampsia were included. Optic and lung ultrasound were performed within 24 hours from delivery. ONSD was measured 3 mm behind the globe. Lung ultrasound Echo Comet Score (ECS) was obtained summing B-lines ("comet tails") in parasternal intercostal spaces bilaterally. Pearson's correlation analysis was used to assess the relationship between ONSD and ECS (p < 0.05 significant). Results Median ONSD was 5.7 mm (range 3.8-7.5 mm). Median ECS value was 19 (range 0-24). Statistically significant correlation was found between ONSD and ECS (r2 = 0.464; p < 0.001). Conclusions Significant correlation between ONSD and ECS suggests optic ultrasound could be used for assessing fluid status and guiding peripartum fluid therapy in patients with severe preeclampsia.

A headache-free reversible cerebral vasoconstriction syndrome (RCVS) with symptomatic brain stem ischemia at late pregnancy as a rare manifestation of RCVS resolved with termination of pregnancy by semi-urgent cesarean section

A 32-year-old pregnant woman in her 39th week of pregnancy presented at the emergency room complaining of sudden-onset dizziness with gaze disturbance and was admitted to our hospital. Her past medical history included hypertension, diabetes mellitus and infarction in the right medulla oblongata 18 months prior to this event. Magnetic resonance (MR) angiography showed multiple irregular stenosis of the intracranial arterial system. Although MR images revealed no fresh ischemic or hemorrhagic lesions, she was diagnosed with reversible cerebral vasoconstriction syndrome (RVCS) associated with pregnancy. Cesarean section immediately resolved the headache-free ischemic RCVS. The postpartum course of the patient was uneventful as well as that of her baby. Follow-up MR angiography showed improvement of intracranial vasoconstriction and follow-up MR imaging showed improvement of a left medial pontine ischemic lesion on diffusion-weighted image. This report describes a rare manifestation of pregnancy-related RCVS.

Effects of perinatal blood pressure on maternal brain functional connectivity

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.

Imaging neurological emergencies in pregnancy and puerperium

The altered physiologic state of female patients during and just after pregnancy places them at an increased risk for several potentially life-threatening neurologic disorders. Swift diagnosis of such pathology and related complications is critical in order to reduce risk of morbidity and mortality to both the mother and the fetus. Neuroimaging plays an important role in the emergent diagnosis of pathology associated with pregnancy and puerperium, and it is critical for the radiologist to be cognizant of correlative imaging findings. Furthermore, given concerns regarding risks of neuroimaging to the fetus, it is important for the radiologist to act as an informed consultant regarding balancing fetal risks and the mother's health. The purpose of this review is to elucidate the underlying pathophysiology and neuroimaging findings associated with diagnoses that are unique to or highly associated with pregnancy and puerperium, as well as to understand the role that CT and MR play in diagnosis during and just after pregnancy, and their respective risks to the fetus.

Ocular ultrasonography for diagnosing increased intracranial pressure in patients with severe preeclampsia

BACKGROUND

Ultrasound measurements of optic nerve sheath diameter (ONSD) and optic disc height (ODH) measured outside pregnancy correlate with intracranial hypertension. Data on the usefulness of ocular ultrasonography in preeclampsia are limited.

OBJECTIVE

To determine whether ONSD and ODH are greater in patients with features of severe preeclampsia compared to healthy controls.

METHODS

Consecutively admitted patients with severe preeclampsia (according to the ACOG Task Force on Hypertension in Pregnancy) and healthy term control pregnant women were included in this prospective observational study. Optic nerve sheath diameter measured 3 mm behind the globe and ODH were assessed using ocular ultrasonography. Patients with severe preeclampsia were compared to controls before delivery, and at one and four days post-delivery.

RESULTS

We included 30 patients with severe preeclampsia and 30 controls. Optic nerve sheath diameter was significantly higher in patients with severe preeclampsia compared to controls before delivery, and one day and four days post-delivery (P <0.001). Optic disc height was significantly greater in patients with severe preeclampsia compared to controls before delivery (P <0.001), and one day (P <0.001) but not four days, post-delivery (P=0.66). Before delivery, 43% of patients with severe preeclampsia had an ONSD >5.8 mm and 77% an ODH ≥1 mm: compatible with intracranial hypertension. None of the control patients had an ONSD of >5.8 mm or an optic disc height of ≥1 mm before or after delivery.

CONCLUSIONS

Severe preeclampsia was associated with a significantly higher ONSD and increased ODH, which could be ultrasonographic evidence of papilledema.

Risk factors for poor outcome in posterior reversible encephalopathy syndrome: systematic review and meta-analysis

Background

The roles of clinical etiology and symptoms, imaging findings and biochemical parameters in predicting the prognosis of posterior reversible encephalopathy syndrome (PRES) have not been well-characterized. We perform a meta-analysis of all published studies to assess the value of various risk factors in predicting the prognosis of PRES.

Methods

Searches of the PubMed, EMBASE, Cochrane Library, and Web of Science databases were performed to identify the eligible studies. The odds ratios (ORs) with their corresponding 95% confidence interval (CI) for related risk factors were used to calculate the pooled estimates of the outcomes.

Results

Six studies with 448 cases were included in the meta-analysis. Hemorrhage was associated with high risk for poor outcome in patients with PRES. Toxemia of pregnancy (pre-eclampsia/eclampsia) was associated with improved outcome in PRES patients. Cytotoxic edema was noted to be related to poor outcome, but did not show statistical significance. The pooled OR for hemorrhage, pre-eclampsia/eclampsia, cytotoxic edema was 4.93 (95% CI: 3.94-6.17; P<0.00001), 0.24 (95% CI: 0.15-0.40; P<0.00001) and 2.59 (95% CI: 0.84-7.99; P=0.10), respectively.

Conclusions

PRES patients with hemorrhage or cytotoxic edema are likely to have poor outcomes. Pre-eclampsia/eclampsia is associated with reduced risk of poor outcome in patients with PRES.

Neurofilament as Neuronal Injury Blood Marker in Preeclampsia

Preeclampsia has been shown to be associated with changes in cerebral structure and cognitive function later in life. Nf (neurofilaments) are specific scaffolding proteins of neurons, and their quantification in serum has been proposed as a biomarker for neuroaxonal injury. We performed a prospective, longitudinal, single-center study at the University Hospital of Basel to determine serum Nf concentrations in pregnant women with singleton pregnancies and with high risk of preeclampsia or with early signs of preeclampsia. Enrollment started at 21 weeks of gestation, followed up with multiple visits until delivery. Sixty out of 197 women developed preeclampsia (30.5%). NfL (Nf light chain) was measured with a highly sensitive single molecule array (Simoa) assay, in addition to the established preeclampsia markers sFlt-1 (soluble fms-like tyrosine kinase-1) and PlGF (placental growth factor). The most important independent predictors of NfL were maternal age, number of pregnancies, and proteinuria. NfL levels increased during pregnancy and were significantly higher in women developing preeclampsia. The discriminatory accuracy of NfL, PlGF, and sFlt-1 in receiver operating characteristic curves analysis (area under the curve) of the overall group was 0.68, 0.81, and 0.84, respectively, and in women older than 36 years 0.7, 0.62, and 0.79, respectively. We conclude that increased axonal injury serum marker NfL predicts preeclampsia particularly in older women, with an accuracy similar to the established angiogenic factors. NfL may serve as an early indicator of preeclampsia-induced changes in cerebral structure and may help to stratify disease management.

Preeclampsia and the brain: neural control of cardiovascular changes during pregnancy and neurological outcomes of preeclampsia

Preeclampsia (PE) is a form of gestational hypertension that complicates ∼5% of pregnancies worldwide. Over 70% of the fatal cases of PE are attributed to cerebral oedema, intracranial haemorrhage and eclampsia. The aetiology of PE originates from abnormal remodelling of the maternal spiral arteries, creating an ischaemic placenta that releases factors that drive the pathophysiology. An initial neurological outcome of PE is the absence of the autonomically regulated cardiovascular adaptations to pregnancy. PE patients exhibit sympathetic overactivation, in comparison with both normotensive pregnant and hypertensive non-pregnant females. Moreover, PE diminishes baroreceptor reflex sensitivity (BRS) beyond that observed in healthy pregnancy. The absence of the cardiovascular adaptations to pregnancy, combined with sympathovagal imbalance and a blunted BRS leads to life-threatening neurological outcomes. Behaviourally, the increased incidences of maternal depression, anxiety and post-traumatic stress disorder (PTSD) in PE are correlated to low fetal birth weight, intrauterine growth restriction (IUGR) and premature birth. This review addresses these neurological consequences of PE that present in the gravid female both during and after the index pregnancy.

Immune system activation in the pathogenesis of posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological syndrome characterized by a variable combination of headaches, seizures, altered mental status, visual impairment, focal neurological signs and symmetric vasogenic edema in bilateral posterior cerebral circulation territory. The pathogenesis of PRES is still controversial. Most of the clinical conditions associated with PRES involve a systemic toxicity response in the entire organism with activation of the cells of the immune system and cytokines. These PRES related conditions induce T cell activation, cytokine release, and subsequent leukocyte adhesion and activation, resulting in endothelial damage and fluid leakage. This potential mechanism of immune system activation and endothelial dysfunction may play a critical role in the pathogenesis of PRES. In this review, the role of immune system activation and endothelial dysfunction in the pathogenesis of PRES is discussed, with the aim to improve our understanding of this disorder.

Quantitative Magnetic Resonance Diffusion-Weighted Imaging Evaluation of the Supratentorial Brain Regions in Patients Diagnosed with Brainstem Variant of Posterior Reversible Encephalopathy Syndrome: A Preliminary Study

BACKGROUND AND PURPOSE

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity with several causes, characterized by rapid onset of symptoms and typical neuroimaging features, which usually resolve if promptly recognized and treated. Brainstem variant of PRES presents with vasogenic edema in brainstem regions on magnetic resonance (MR) images and there is sparing of the supratentorial regions. Because PRES is usually caused by a hypertensive crisis, which would likely have a systemic effect and global manifestations on the brain tissue, we thus proposed that some microscopic abnormalities of the supratentorial regions could be detected with diffusion-weighted imaging (DWI) using apparent diffusion coefficient (ADC) analysis in brainstem variant of PRES and hypothesized that "normal-looking" supratentorial regions will increase water diffusion.

METHODS

We retrospectively identified patients with PRES who underwent brain magnetic resonance imaging studies. We identified 11 brainstem variants of PRES patients, who formed the study cohort, and 11 typical PRES patients and 20 normal control subjects as the comparison cohorts for this study. Nineteen regions of interest were drawn and systematically placed. The mean ADC values were measured and compared among these 3 groups.

RESULTS

ADC values of the typical PRES group were consistently elevated compared with those in normal control subjects. ADC values of the brainstem variant group were consistently elevated compared with those in normal control subjects. ADC values of the typical PRES group and brainstem variant group did not differ significantly, except for the pons area.

CONCLUSIONS

Quantitative MR DWI may aid in the evaluation of supratentorial microscopic abnormalities in brainstem variant of PRES patients.

Neurologic complications in critically ill pregnant patients

Neurologic complications in a critically ill pregnant woman are uncommon but some of the complications (such as eclampsia) are unique to pregnancy and the puerperal period. Other neurologic complications (such as seizures in the setting of epilepsy) may worsen during pregnancy. Clinical signs and symptoms such as seizure, headache, weakness, focal neurologic deficits, and decreased level of consciousness require careful consideration of potential causes to ensure prompt treatment measures are instituted to prevent ongoing neurologic injury. Clinicians should be familiar with syndromes such as pre-eclampsia, eclampsia, stroke, posterior reversible encephalopathy syndrome, and reversible cerebral vasoconstriction syndrome. Necessary imaging studies can usually be performed safely in pregnancy. Scoring systems for predicting maternal mortality are inadequate, as are recommendations for neurorehabilitation. Tensions can arise when there is conflict between the interests of the mother and the interests of the fetus, but in general maternal health is prioritized. The complexity of care requires a multidisciplinary and multiprofessional approach to achieve best outcome in an often unexpected situation.

Other cerebrovascular occlusive disease

In this chapter we review the optimal imaging modalities for subacute and chronic stroke. We discuss the utility of computed tomography (CT) and multimodal CT imaging. Further, we analyze the importance of specific magnetic resonance imaging sequences, such as diffusion-weighted imaging for acute ischemic stroke, T2/fluid-attenuated inversion recovery for subacute and chronic stroke, and susceptibility imaging for detection of intracranial hemorrhages. Different ischemic stroke mechanisms are reviewed, and how these imaging modalities may aid in the determination of such. Further, we analyze how topographic patterns in ischemic stroke may provide important clues to the diagnosis, in addition to the temporal evolution of the stroke. Lastly, specific cerebrovascular occlusive diseases are reviewed, with emphasis on the optimal imaging modalities and their findings in each condition.