The neurologic consequences of eclampsia

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.

Gestational treatment of folic acid attenuates blood-brain barrier leakage in pregnant- and prepubertal rats after pentylenetetrazole-induced seizure

OBJECTIVES

Folic acid (FA) is physiologically important in mammals and is a common vitamin supplement used during pregnancy and lactation. Numerous studies have reported that FA significantly improves endothelial function. The blood-brain barrier (BBB) plays an important role in maintaining the microenvironment required for neuronal function, but its unique structure is damaged by epileptic seizures. The aim of this study was to evaluate the potential protective role of FA on BBB leakage, as well as on the reactive astrogliosis in pregnant rats and their prepubertal offspring during pentylenetetrazole (PTZ)-induced epileptic seizure.

METHODS

Pregnant rats were treated with FA (5 mg/kg) and PTZ on gestational days 0-19 and 19, respectively. The pups were treated with PTZ at puberty. Evans blue was used to evaluate BBB integrity. Reactive astrogliosis was defined using immunohistochemical analysis for glial fibrillary acidic protein (GFAP). Mean arterial blood pressure (MABP) was measured at the femoral artery.

RESULTS

A moderate decrease in BBB leakage was observed in FA-treated pregnant and prepubertal animals (P < 0.05). MABP was decreased significantly in pregnant rats (P < 0.05). The epilepsy-induced increase in MABP was less prominent in pregnant animals (P < 0.05). GFAP intensity decreased in PTZ-treated pregnant animals (P < 0.01) and FA-treated prepubertal rats.

DISCUSSION

Our findings suggest that FA, which is used as a maternal vitamin to promote normal fetus development, may be beneficial against seizure-induced neuronal damage by decreasing BBB leakage and reactive astrogliosis in pregnant and prepubertal rats.

Use of antiepileptic drugs in pregnancy

Babies born to mothers exposed to antiepileptic drugs (AEDs) are at increased risk for major congenital malformations, cognitive impairment and fetal death. For the millions of women with epilepsy, maintaining the safest drug that will successfully prevent seizures during pregnancy remains a primary consideration. The recent development of collaborative international registries to examine the differential and dose-dependent effects of the expanding number of old and new AEDs, have shed light upon potential differences during pregnancy. Valproic acid appears to be associated with the highest risk of overall, as well as AED-specific, birth defects, becoming more evident as doses exceed 1000 mg/day. Lamotrigine may be less teratogenic to humans than other AEDs, although orofacial clefts have recently been reported. The effects of polytherapy appear to carry greater risks compared with monotherapy. Limited data exist for many of the newer AEDs. Furthermore, AED effects may persist during postnatal development. Although no class 1 outcome data are available, prepregnancy counseling to optimize patient-specific treatment is recommended for women of childbearing potential with epilepsy.

Isolated reversible hypoglossal nerve palsy as the initial manifestation of pre-eclampsia

Isolated hypoglossal nerve lesions often reflect sinister neoplastic or vascular pathology. Rarely, reversible lesions occur, perhaps via mechanisms similar to Bell's palsy. We report a patient with reversible isolated hypoglossal nerve palsy as the first and predominant early manifestation of pre-eclampsia and speculate on the pathogenesis behind this abnormality.

Microangiopathic disorders in pregnancy

Microangiopathic disorders present with thrombocytopenia, hemolytic anemia, and multiorgan damage. In pregnancy, these disorders present a challenge both diagnostically and therapeutically, with widely overlapping clinical scenarios and disparate treatments. Although rare, a clear understanding of these diseases is important because devastating maternal and fetal outcomes may ensue if there is misdiagnosis and improper treatment. Microangiopathic disorders presenting in pregnancy are thus best assessed and treated by both obstetric and hematology teams. As a better understanding of the pathophysiology underlying each of the disease processes is gained, new diagnostic testing and therapies will be available, which will lead to improved outcomes.

Proteinuria in status epilepticus or eclampsia; a diagnostic dilemma

A 36-year-old primigravida with a history of temporal lobe epilepsy presented at 25 weeks of pregnancy with generalized tonic clonic seizures. The clinical picture was confused with eclampsia because of rising blood pressure and proteinuria. Clinical investigations, which included a lumbar puncture, were carried out to rule out an infective cause for the seizures. A computed tomography of the brain was performed for evidence of intracranial hemorrhage. The patient was intubated and ventilated in the intensive care unit. The labile blood pressure settled in 2 days, and the transient heavy proteinuria also resolved after 3 days. Eclampsia would have warranted operative delivery of the preterm fetus with the attendant problems of prematurity. Delivery would have been hazardous in such an acutely unwell patient. The management also would have required magnesium sulfate with its potential for toxicity. Transient proteinuria may occur in status epilepticus. The blood pressure can be labile during epileptic seizures and, in the absence of an intracranial hemorrhage, generally settles without treatment after control of the seizures. This case highlights the importance of differentiating eclampsia in a patient with known epilepsy that may also mask other disease entities such as intracranial hemorrhage, meningitis, or encephalopathy. We have also discussed the importance of various signs associated with eclampsia and their clinical significance. The differential diagnosis of seizures in pregnancy are broad as symptoms of the various disease entities including eclampsia, intracranial hemorrhage, status epilepticus, meningitis, stroke overlap creating a dilemma in an acute emergency. We present a case whereby the clinical picture of status epilepticus was confused with eclampsia because of the presence of a rising blood pressure and proteinuria.

Maternal mortality due to arterial hypertension in São Paulo City (1995-1999)

AIM

To describe the case profile of maternal death resulting from hypertensive disorders in pregnancy and to propose measures for its reduction.

METHODS

The Committee on Maternal Mortality of São Paulo City has identified 609 cases of obstetric maternal death between 1995 and 1999 with an underreporting rate of 52.2% and a maternal mortality rate of 56.7/100,000 live births. Arterial hypertension was the main cause of maternal death, corresponding to 142 (23.3%) cases.

RESULTS

Ninety-five (66.9%) of the deaths occurred during the puerperal period and 34 (23.9%) occurred during pregnancy. The time of death was not reported in 13 (9.2%) cases. Seizures were observed in 41 cases and magnesium sulfate was used in four of them. The causes of death were ruled to be cerebrovascular accident (44.4%), acute pulmonary edema (24.6%), and coagulopathies (14.1%). Cesarean section was performed in 85 (59.9%) cases and vaginal delivery in 15 (16.0%).

CONCLUSION

Complications of arterial hypertension are responsible for the high rates of pregnancy-related maternal death in São Paulo City. Quality prenatal care and appropriate monitoring of the hypertensive pregnant patient during and after delivery are important measures for better control of this condition and are essential to reduce disorders in pregnancy.

Pre-eclampsia: clinical manifestations and molecular mechanisms

Preeclampsia affects 3-5% of pregnancies and can have a significant impact on health for both mother and fetus. Risk factors include maternal co-morbidities such as obesity and chronic hypertension, paternal factors, and genetic factors. New hypertension and proteinuria during the second half of pregnancy are key diagnostic criteria, but the clinical features and associated prognostic implications are somewhat heterogeneous and may reflect different mechanisms of disease. Renal dysfunction and proteinuria correspond to the pathologic finding of glomerular endotheliosis, and generally resolve after cure of preeclampsia through fetal and placenta delivery. The molecular mechanisms behind this disease are being discovered and refined. The initial etiologic agents are currently unknown. Pathologic studies show abnormal development of an ischemic placenta with a high-resistance vasculature, which cannot deliver an adequate blood supply to the fetoplacental unit. Endothelial dysfunction plays a central role in the pathogenesis of the maternal syndrome. Dysfunctional endothelial cells produce altered quantities of vasoactive mediators, which lead to a tip in the balance towards vasoconstriction. An imbalance in circulating angiogenic factors is emerging as a prominent mechanism that mediates the endothelial dysfunction and the clinical signs and symptoms of preeclampsia. Soluble fms-like tyrosine kinase 1 (sFlt1), an endogenous anti-angiogenic factor that is a potent vascular endothelial growth factor (VEGF) antagonist, is highly elevated in preeclampsia. VEGF is not only important in angiogenesis, but also in maintaining endothelial health including the formation of endothelial fenestrae (a hallmark of the glomerular vascular endothelium). sFlt1 overexpression in animals induces glomerular endotheliosis with the loss of endothelial fenestrae that resembles the renal histological lesions of preeclampsia. More severe forms of preeclampsia, including the HELLP syndrome, may be explained by a concomitant elevation in both sFlt1 and soluble endoglin, another anti-angiogenic factor. Unraveling of the molecular mechanisms behind preeclampsia may help to expand our armamentarium to treat patients in a more directed fashion, as current management consists of supportive care and expedited delivery. Finally, long-term outcomes of women with preeclampsia include a significantly increased risk for hypertension and cardiovascular disease, including mortality, which may warrant more aggressive screening and treatment in this population.

Resistance artery vasodilation to magnesium sulfate during pregnancy and the postpartum state

This study compared the vasodilatory responses to magnesium sulfate (MgSO(4)) of cerebral and mesenteric resistance arteries and determined whether the responses varied between different gestational groups. Third-order branches (<200 microm) of the posterior cerebral (PCA) and mesenteric arteries (MA) were dissected from nonpregnant (NP; n = 6), late pregnant (LP; day 19, n = 6), and postpartum (PP; day 3, n = 6) Sprague-Dawley rats. A concentration-response curve was performed by replacing the low-MgSO(4) (1.2 mM) HEPES buffer solution with increasing concentrations of MgSO(4) (4, 6, 8, 16, and 32 mM) and measuring lumen diameter at each concentration. All groups exhibited concentration-dependent dilation to MgSO(4), decreasing the amount of tone in the vessels. However, MA were significantly more sensitive to MgSO(4) than PCA. Whereas there was no difference in the response between different gestational groups in MA, the PCA from the LP and PP groups showed a significantly diminished response to MgSO(4). The percent dilation at 32 mM MgSO(4) for PCA versus MA in NP, LP, and PP animals was 36 +/- 2 vs. 51 +/- 7% (P < 0.05), 19 +/- 9 vs. 54 +/- 6% (P < 0.01 vs. PCA and NP), and 12 +/- 5 vs. 52 +/- 11% (P < 0.01 vs. PCA and NP). These results demonstrate that MgSO(4) is a vasodilator of small resistance arteries in the cerebral and mesenteric vascular beds. The refractory responses of the PCA in LP and PP groups demonstrate changes in the cerebrovascular vasodilatory mechanisms with gestation. The greater sensitivity of the MA to MgSO(4)-induced vasodilation suggests that the prophylactic effect of MgSO(4) on eclamptic seizures may be more closely related to the lowering of systemic blood pressure than to an effect on cerebral blood flow.