Ischemic stroke related to an amniotic fluid embolism during labor

Amniotic fluid embolism: a reappraisal

OBJECTIVES

Using cases from our own experience and from the published literature on amniotic fluid embolism (AFE), we seek to improve on existing criteria for diagnosis and discern associated risk factors. Additionally, we propose a novel theory of pathophysiology.

METHODS

This retrospective case review includes eight cases of AFE from two hospital systems and 21 from the published literature. All cases were evaluated using the modified criteria for research reporting of AFE by Clark et al. in Am J Obstet Gynecol, 2016;215:408-12 as well as our proposed criteria for diagnosis. Additional clinical and demographic characteristics potentially correlated with a risk of AFE were included and analyzed using descriptive analysis.

RESULTS

The incidence of AFE was 2.9 per 100,000 births, with five maternal deaths in 29 cases (17.2 %) in our series. None of the cases met Clark's criteria while all met our criteria. 62.1 % of patients were over the age of 32 years and two out of 29 women (6.9 %) conceived through in-vitro fertilization. 6.5 % of cases were complicated by fetal death. Placenta previa occurred in 13.8 %. 86.2 % of women had cesarean sections of which 52.0 % had no acute maternal indication.

CONCLUSIONS

Our criteria identify more patients with AFE than others with a low likelihood of false positives. Clinical and demographic associations in our review are consistent with those previously reported. A possible relationship between cesarean birth and risk of AFE was identified using our criteria. Additionally, we propose a new hypothesis of pathophysiology.

Stroke in Women: A Review Focused on Epidemiology, Risk Factors, and Outcomes

Stroke is a particularly important issue for women. Women account for over half of all persons who experienced a stroke. The lifetime risk of stroke is higher in women than in men. In addition, women have worse stroke outcomes than men. Several risk factors have a higher association with stroke in women than in men, and women-specific risk factors that men do not have should be considered. This focused review highlights recent findings in stroke epidemiology, risk factors, and outcomes in women.

Pregnancy and stroke risk in women

Stroke associated with pregnancy and post-partum occurs in about 30 per 100,000 deliveries, and includes subtypes of ischemic and hemorrhagic stroke as well as cerebral venous sinus thrombosis (CVST). There are a wide variety of underlying causes and risk factors, some that are common to both pregnant and non-pregnant women, and others that are unique to pregnancy. Although some of the strokes that occur may be a direct result of the pregnancy itself, such as hypertensive disorders of pregnancy, others could be anticipated or prevented by understanding the risk factors. These may include the presence of pre-pregnancy clotting disorders, aneurysms or arteriovenous malformations, hypertension, diabetes, or advanced maternal age. Treatment of stroke during pregnancy is based on the current recommendations for non-pregnant stroke patients, assuming the benefit of these treatments is likely higher than the risks. These decisions must be made with the appropriate specialists in stroke and endovascular treatment, as well as high-risk obstetrician/gynecologists, and most importantly, patient and family preferences.

Cerebrovascular disease in pregnancy and postpartum

PURPOSE OF REVIEW

Cerebrovascular disorders during pregnancy and puerperium are uncommon but potentially serious entities. This review aims to provide guidance on the diagnosis and management of these diseases, according to the most recent findings.

RECENT FINDINGS

Proteinuria is no longer a mandatory criterion for the diagnosis of preeclampsia. Favourable long-term foetal and maternal outcomes are achieved in most patients with ruptured cerebral arterial malformations during pregnancy receiving interventional treatment prior to delivery. Despite the recent recommendations, physicians still hesitate to administer thrombolysis in pregnant women. In women with a history of cerebral venous thrombosis, prophylaxis with low molecular weight heparin during pregnancy and puerperium is associated with lower rates of recurrent thrombotic events and miscarriage.

SUMMARY

Hypertensive disorders of pregnancy are a continuum of failure of autoregulation mechanisms that may lead to eclampsia, posterior reversible encephalopathy syndrome, reversible cerebral vasoconstriction syndrome and stroke. MRI is the preferred imaging modality of choice. In the absence of specific contraindications, treatment of cerebrovascular complications should not be withheld from pregnant women, including reperfusion therapies in acute ischemic stroke and treatment of ruptured cerebral aneurysms. Previous history of stroke alone does not contraindicate future pregnancy, but counselling and implementation of prevention strategies are needed.

Neurological Emergencies During Pregnancy

This article serves as a comprehensive review of neurologic emergencies in pregnancy. Common initial presentations of neuroemergencies are reviewed with a clinical algorithm. Neurovascular disorders in pregnancy are reviewed, including acute ischemic strokes with data on tPA and thrombectomy; cerebral venous sinus thrombosis diagnosis and management; posterior reversible encephalopathy syndrome management; reversible cerebral vasoconstriction syndrome; and intracerebral hemorrhage. Attention is paid to management of cerebral edema and safety of osmotic therapies. A review of seizures in pregnancy is provided, including new-onset causes and decreased seizure thresholds. For status epilepticus, a low teratogenicity risk medication protocol in pregnancy is provided.

Stroke in Pregnancy: A Focused Update

Ischemic stroke (IS) and hemorrhagic stroke (HS) can be devastating complications during pregnancy and the puerperium that are thought to occur in approximately 30 in 100,000 pregnancies. In high-risk groups, such as women with preeclampsia, the incidence of both stroke subtypes, combined, is up to 6-fold higher than in pregnant women without these disorders. IS or HS may present in young women with atypical symptoms including headache, seizure, extremity weakness, dizziness, nausea, behavioral changes, and visual symptoms. Obstetric anesthesiologists who recognize these signs and symptoms of pregnancy-related stroke are well positioned to facilitate timely care. Acute stroke of any type is an emergency that should prompt immediate coordination of care between obstetric anesthesiologists, stroke neurologists, high-risk obstetricians, nurses, and neonatologists. Historically, guidelines have not addressed the unique situation of maternal stroke, and pregnant women have been excluded from the large stroke trials. More recently, several publications and professional societies have highlighted that pregnant women suspected of having IS or HS should be evaluated for the same therapies as nonpregnant women. Vaginal delivery is generally preferred unless there are obstetric indications for cesarean delivery. Neuraxial analgesia and anesthesia are frequently safer than general anesthesia for cesarean delivery in the patient with a recent stroke. Potential exceptions include therapeutic anticoagulation or intracranial hypertension with risk of herniation. General anesthesia may be appropriate when cesarean delivery will be combined with intracranial neurosurgery.

Neurologic Complications of Fat Embolism Syndrome

PURPOSE OF REVIEW

Fat embolism syndrome (FES) is a rare disorder with potentially devastating neurologic complications. This article reviews the history, pathophysiology, clinical features, diagnosis, and treatment of FES with a focus on its neurologic aspects.

RECENT FINDINGS

The neurologic complications of FES are more commonly recognized with current diagnostic testing and increase awareness of the disorder. FES may present initially with neurologic manifestations. Prompt diagnosis of FES and of its neurologic manifestations could be lifesaving. This includes respiratory support and management of neurological complications. The classic clinical triad of pulmonary insufficiency, neurologic disturbances, and petechial skin rash typically presents 24 to 72 h following an initial insult, most commonly a traumatic long bone fracture. Early onset (< 24 h) and delayed onset (> 72 h) have been described. Neurologic manifestations may include ischemic/hemorrhagic strokes, retinal ischemia, seizures, autonomic dysfunction, and diffuse brain injury. Diagnosis remains clinical. Management consists mainly of supportive care.

Causes and Treatment of Acute Ischemic Stroke During Pregnancy

PURPOSE OF REVIEW

Treatment recommendations for pregnancy associated ischemic stroke are scarce. This may be due to the fact that, in general, obstetricians tend not to make recommendations for stroke patients and neurologists are not commonly involved in the care of pregnant women. Herein, we review the multiple etiologies of ischemic stroke during pregnancy, considerations for diagnostic testing, and acute treatment and prevention options, including associated risks specific to the pregnant and puerperal state.

RECENT FINDINGS

Intravenous tissue plasminogen activator (tPA) and endovascular thrombectomy have been used successfully to treat pregnant women with acute ischemic stroke. Recent national guidelines recommend considering tPA use during pregnancy for moderate and severe strokes if the potential benefits offset the risks of uterine hemorrhage. Pregnancy-associated ischemic stroke is rare, but can be devastating, and recanalization therapy should not be systematically withheld. Women who are at risk for stroke should be followed carefully, and providers caring for pregnant women should be educated regarding stroke signs and symptoms. Many of the standard post stroke diagnostic modalities may be used safely in pregnancy, and primary and secondary stroke prevention therapy must be tailored to avoid fetal toxicity.

A Systematic Review of the Causes and Management of Nonthrombotic Embolic Stroke of Tissue Origin

Introduction

Various bodily tissues have been reported to enter the arterial circulation and embolize to the brain resulting in ischemic stroke. Most frequently nonthrombotic embolic stroke (NTES) of tissue origin is iatrogenic or related to an underlying disease process. With the increase in elective surgery and intravascular procedures, NTES may increase in prevalence.

Aim

To compile a summary of the background, incidence, presentation, and treatment of NTES of tissue origin, by conducting a systematic review of the current literature.

Summary of Review

We searched EMBASE and MEDLINE for articles on NTES of tissue origin published in English with no restriction on publication date (search date June 2017). 800 articles were identified and screened and 159 articles were ultimately reviewed in full text and included in qualitative analysis. Articles deemed relevant were assessed by a second reviewer to confirm compatibility with the inclusion criteria. References of included articles were reviewed for relevant publications. We categorized the pathology of the emboli into the following groups: amniotic fluid (4 publications), tumour (60 publications), fat (43 publications), cholesterol (19 publications), and intravascular debris (12 publications). We then summarized the available literature on each cause of NTES.

Conclusions

NTES of tissue origin is an uncommon but important diagnosis to consider particularly in younger stroke patients and in certain clinical settings. Treatment for NTES is currently anecdotal and based on small case series. Embolectomy may emerge as the therapy of choice due to the longer treatment timeframe and heterogeneity of the emboli.