CT and angiographic correlation of severe neurological disease in toxemia of pregnancy

Sudden Bilateral Choroidal Detachment in a Patient with Posterior Reversible Encephalopathy Syndrome

BACKGROUND: Pre-eclampsia is one of the most important causes of a rare cliniconeuroradiological entity called posterior reversible encephalopathy syndrome. The syndrome is characterized by headacke, visual disturbances, seizures, altered mental status and radiological findings of edema in the white matter of the brain areas perfused by the posterior brain circulation.CASE REPORT: Here we present a patient with sudden bilateral visual loss and deafness in early postnatal period without any other neurological deficits, but with affiliated ophthalmological pathology. The correct diagnosis was made 3 days after the Cesarean section.The patient was diagnosed with posterior reversible encephalopathy syndrome and bilateral choroidal detachment.CONCLUSION: Vascular changes in posterior reversible encephalopathy syndrome can cause visual disturbances not only by brain edema, but combined brain and ocular pathology.

Hepatic portal vein flow and three dimensional indices of hepatic perfusion in pre-eclampsia compared with normal pregnancy

It has been suggested that the origins of pre-eclampsia arise from the maternal venous system dysfunction. This study aimed to test this hypothesis by assessing hepatic perfusion in pre-eclampsia using three-dimensional (3D) ultrasound. The hepatic portal vein flow in 12 women with normal pregnancy and 11 women with pre-eclampsia was measured using standard Doppler ultrasound. The 3D indices of hepatic perfusion: flow index (FI), vascular index (VI) and vascularisation flow index (VFI), which are believed to reflect vascularity and flow intensity were also measured. Because of small numbers, a non-parametric test was used to test differences between groups. Hepatic portal vein flow was no different between women with normal pregnancy compared with women with pre-eclampsia (228.1 (215.5-270.6) vs. 283.0 (145.9-344.6); p = 0.90). The 3D indices of hepatic perfusion were as follows (FI: 36.3(30.7-42.5) vs. 39.7 (27.7-44.2), p = 1.00; VI: 11.7 (3.6-21.2) vs. 3.0 (0.5-7.6), p = 0.04; VFI: 4.7 (1.2-8.3) vs. 1.2 (0.1-3.2), p = 0.06, respectively). This study was not able to support or refute the suggestion that the genesis of pre-eclampsia arises from the maternal venous circulation. There may be biological differences in the 3D indices of hepatic perfusion in women with pre-eclampsia compared with normal pregnant women.

Posterior reversible encephalopathy syndrome: differences between pregnant and non-pregnant patients

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiologic entity not yet understood, that presents with transient neurologic symptoms and particular radiological findings. Few papers show the differences between pregnant and non-pregnant patients. We review the cases of 38 women diagnosed with PRES, in order to find significant differences between pregnant (18) and non-pregnant (20) patients. We found differences among the age of patients (25.83 years old in pregnant and 29.31 years old in non pregnant; P=0.001); in the mean of highest systolic blood pressure, that was higher in non-pregnant group (185:162 mmHg; P=0.121); and in creatinine levels that was higher in non-pregnant group (3.47:1.04 mg/dL; P=0.001). To our knowledge, just a few papers analyzed whether PRES syndrome presented in the same way in pregnant and non-pregnant patients. The differences and the possible pathophisiology of this syndrome still remain enigmatic.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a recently proposed cliniconeuroradiologic entity with several well-known causes, such as hypertensive encephalopathy, eclampsia, and the use of cytotoxic and immunosuppressive drugs, as well as some causes more recently described. PRES is characterized by neuroimaging findings of reversible vasogenic subcortical edema without infarction. The pathogenesis is incompletely understood. Two opposing hypotheses are commonly cited, but the issue is controversial: (1) the current more popular theory suggests that severe hypertension exceeds the limits of autoregulation, leading to breakthrough brain edema; (2) the earlier original theory suggests that hypertension leads to cerebral autoregulatory vasoconstriction, ischemia, and subsequent brain edema. The clinical syndrome of PRES typically involves headache, encephalopathy, visual symptoms, and seizures. The clinical presentation is often nonspecific, and therefore the diagnosis of PRES has come to increasingly rely on magnetic resonance imaging (MRI) abnormalities consistent with PRES with documented recovery clinically and on repeated neuroimaging. The diagnosis has important therapeutic and prognostic implications because the reversibility of the clinical and radiologic abnormalities is contingent on the prompt control of blood pressure and/or discontinuing the offending drug.

Gemcitabine monotherapy associated with posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome is a clinicoradiologic entity that may present with headaches, altered mental status, seizures and visual loss as well as specific neuroimaging findings. We report a case of a 74-year-old woman receiving adjuvant gemcitabine chemotherapy as monotherapy for a stage IIa pancreatic adenocarcinoma, who developed posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, altered mental status, visual disturbances, and seizures. Radiological features typically include edema of the posterior cerebral regions, especially of the parietooccipital lobes. Atypical imaging features, such as involvement of anterior cerebral regions, deep white matter, and the brain stem are also frequently seen. Vasoconstriction is common in vascular imaging. Different conditions have been associated with PRES, but toxemia of pregnancy, solid organ or bone marrow transplantation, immunosuppressive treatment, cancer chemotherapy, autoimmune diseases, and hypertension are most commonly described. The pathophysiology of PRES is unclear and different hypotheses are being discussed. Posterior reversible encephalopathy syndrome is best managed by monitoring and treatment in the setting of a neurointensive care unit. The prognosis is usually benign with complete reversal of clinical symptoms within several days, when adequate treatment is immediately initiated. Treatment of severe hypertension, seizures, and withdrawal of causative agents represent the hallmarks of specific therapy in PRES. Delay in diagnosis and treatment may lead to permanent neurological sequelae. Therefore, awareness of PRES is of crucial importance for the intensivist.

Cerebral infarction during hypertensive encephalopathy: Case report with pathologic and atypical radiographic findings

Neuroimaging of patients with hypertensive encephalopathy frequently reveals white matter changes that reverse with control of blood pressure. We report a young woman who presented with hypertensive encephalopathy but with unusual radiographic findings. Her course and atypical appearance on magnetic resonance imaging raised suspicion for encephalitis, but autopsy disclosed a large cerebral infarction, an uncommon complication during this clinical syndrome. The discovery of a pheochromocytoma at autopsy was also unexpected and may be associated with the unusual features of this case. The clinical, pathologic, and radiographic descriptions of this case may offer further insight into the pathophysiology of hypertensive encephalopathy.

The role of calcium channel blockers in the treatment of women with preeclampsia

Preeclampsia was originally known as a process whereby an unknown “toxin” was responsible for a variety of responses. While this toxin has yet to be determined, many theories have prevailed as to the appropriate therapy for this condition.

Recently, antihypertensive therapy has become increasingly regarded as an important component of the medical management of women with preeclampsia. Initially, the ideal therapy for peripartum acute hypertensive emergencies was felt to be a smooth muscle relaxant and the most commonly prescribed agent was hydralazine. This drug was felt to be beneficial because of its action on vascular smooth muscle, decreasing vasospasm. Outside of the United States diazoxide was also used for this purpose, although this drug has been replaced because of the high incidence of fetal distress. Another agent that was frequently used was α-methyldopa which was initially considered to be the treatment of choice in the treatment of patieats with moderate and severe preeclampsia. Recently, α-methyldopa has been reserved for the outpatient management of gestational hypertension, especially in women with mild preeclampsia or chronic hypertension.

The effect of magnesium sulfate on large cerebral artery blood flow in preeclampsia

OBJECTIVES

To determine the effect of a 6 gram intravenous bolus of magnesium sulfate on maternal cerebral blood flow in women with preeclampsia.

STUDY DESIGN

Velocity-encoded phase-contrast magnetic resonance imaging studies were performed on twelve preeclamptic women prior to and immediately after infusion of a 6 gram magnesium sulfate loading dose. Cerebral blood flow was determined at the bilateral proximal middle and posterior cerebral arteries. Study participants returned 6 weeks postpartum for a non-pregnant measurement of cerebral blood flow. The Wilcoxon paired-sample test was used with statistical significance defined as p<0.05.

RESULTS

There was no significant difference in cerebral vessel diameter nor blood flow for any of the examined arteries between the pre- and post magnesium sulfate therapy states.

CONCLUSIONS

The absence of a significant difference in cerebral blood flow of the middle and posterior cerebral arteries before and after infusion of a 6 gram loading dose of magnesium sulfate in women with preeclampsia could suggest the absence of vasoconstriction of the large cerebral arteries in preeclampsia and question the role of magnesium sulfate as a vasodilator of these arteries.

Overlapping features of eclampsia and postpartum angiopathy

INTRODUCTION

Postpartum cerebral angiopathy (PPA) is considered one of a diverse group of rare conditions termed "reversible cerebral vasoconstriction syndromes". Existing literature suggest considerable overlap in the manifestations of eclampsia and PPA.

METHODS

Retrospective case series review of PPA and eclampsia from a single neurosciences intensive care unit patient log identified over a consecutive 18-month period. A MEDLINE search (using OVID) of the English literature from 1950 through October 2008 was also performed.

RESULTS

Four patients who meet the obstetrical criteria for eclampsia and four patients whose clinical and radiographic features were consistent with PPA were identified. Twenty-eight patients with PPA were identified from the literature and showed significant clinical and radiographic overlap without cohort.

CONCLUSION

Given the overlapping clinical, laboratory, and radiographical features of eclampsia and PPA, it is probable they share a similar underlying pathophysiological mechanism and represent different clinical expressions of the same pregnancy-related disorder. The obstetrical definition of eclampsia may be to strict when applied in the neurosciences intensive care unit.

Hemorrhage in posterior reversible encephalopathy syndrome: imaging and clinical features

BACKGROUND AND PURPOSE

Hemorrhage is known to occur in posterior reversible encephalopathy syndrome (PRES), but the characteristics have not been analyzed in detail. The purpose of this study was to evaluate the imaging and clinical features of hemorrhage in PRES.

MATERIALS AND METHODS

Retrospective assessment of 151 patients with PRES was performed, and 23 patients were identified who had intracranial hemorrhage at toxicity. Hemorrhage types were identified and tabulated, including minute focal hemorrhages (<5 mm), sulcal subarachnoid hemorrhage, and focal hematoma. Clinical features of hemorrhage and nonhemorrhage PRES groups were evaluated, including toxicity blood pressure, coagulation profile/platelet counts, coagulation-altering medication, and clinical conditions associated with PRES. Toxicity mean arterial pressure (MAP) groups were defined as normal (<106 mm Hg), mildly hypertensive (106-116 mm Hg), or severely hypertensive (>116 mm Hg).

RESULTS

The overall incidence of hemorrhage was 15.2%, with borderline statistical significance noted between the observed clinical associations (P = .07). Hemorrhage was significantly more common (P = .02) after allogeneic bone marrow transplantation (allo-BMT) than after solid-organ transplantation. The 3 hemorrhage types were noted with equal frequency. A single hemorrhage type was found in 16 patients, with multiple types noted in 7. Patients undergoing therapeutic anticoagulation were statistically more likely to develop hemorrhage (P = .04). No difference in hemorrhage incidence was found among the 3 blood pressure subgroups (range, 14.9%-15.9%).

CONCLUSIONS

Three distinct types of hemorrhage (minute hemorrhage, sulcal subarachnoid hemorrhage, hematoma) were identified in PRES with equal frequency. The greatest hemorrhage frequency was seen after allo-BMT and in patients undergoing therapeutic anticoagulation. Hemorrhage rate was independent of the toxicity blood pressure.

New developments in pre-eclampsia

It is quite clear that pre-eclampsia is not simply pregnancy-induced hypertension; rather, it is a multisystem disease with pathophysiological changes secondary to reduced organ perfusion. This reduction can be explained by vasospasm secondary to increased sensitivity of the vasculature to usual circulating pressors, and vascular occlusion secondary to activation of the coagulation cascade. Although pre-eclampsia becomes clinically evident late in pregnancy, pathological and pathophysiological changes antedate the clinical syndrome by weeks to months. The syndrome occurs only in pregnancy and is cured by the removal of fetoplacental tissues.

Based on these findings, we have proposed that the inciting pathophysiological change of preeclampsia is reduced trophoblastic perfusion, which produces an agent that perturbs endothelial cells. The altered endothelial functions associated with this insult increase sensitivity to pressors, activate the coagulation cascade and produce the clinical and pathological findings of preeclampsia. Although we feel this hypothesis could explain pre-eclampsia, it is possible that its major value will be to stimulate others to approach this disorder by considering all facets of its pathophysiology rather than merely its hypertensive component.

The appreciation of pre-eclampsia as a disease present from early pregnancy and the potential role of vasodilator prostaglandins have already stimulated therapeutic trials of aspirin in women at very high risk with encouraging results. At present, information is insufficient to determine the risk/benefit ratio of this therapy in lower risk patients, and aspirin therapy should not be used in these women. Another potential modification of therapy, the substitution of phenytoin for magnesium sulphate, does not seem warranted on the basis of either currently available data or on theoretical grounds.

Fruitful directions for research in the near future will be the explanation of the abnormal trophoblastic invasion of pre-eclampsia and the determination of how reduced perfusion translates into a multisystem disease. In addition, aspirin therapy or other potential prophylactic therapies would be greatly aided by the development of new tests with reasonable positive predictive values, in order to identify preeclampsia prior to clinically evident disease.

Advances in the understanding of eclampsia

Preeclampsia, a serious hypertensive complication of pregnancy characterized by new-onset hypertension and proteinuria after midpregnancy, is a multisystem disorder that often involves the central nervous system. Neurologic signs and symptoms include hyperreflexia, headaches, visual disturbance, seizures, and cerebral hemorrhage. Eclampsia-new-onset seizures in the setting of preeclampsia-usually occurs before or within 48 hours of delivery, but can present as late as 1 month postpartum (late postpartum eclampsia). Magnesium sulfate is the drug of choice to prevent and treat eclampsia, a recommendation validated through large, randomized, and placebo-controlled trials. This review describes the pathogenesis, clinical features, and treatment of eclampsia, focusing on recent observations regarding roles of circulating antiangiogenic factors in the pathogenesis of the neurologic complications of eclampsia.

Posterior reversible encephalopathy syndrome, part 1: fundamental imaging and clinical features

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state coupled with a unique CT or MR imaging appearance. Recognized in the setting of a number of complex conditions (preeclampsia/eclampsia, allogeneic bone marrow transplantation, organ transplantation, autoimmune disease and high dose chemotherapy) the imaging, clinical and laboratory features of this toxic state are becoming better elucidated. This review summarizes the basic and advanced imaging features of PRES, along with pertinent features of the clinical and laboratory presentation and available histopathology. Many common imaging/clinical/laboratory observations are present among these patients, despite the perception of widely different associated clinical conditions.

Posterior reversible encephalopathy syndrome, part 2: controversies surrounding pathophysiology of vasogenic edema

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state accompanied by a unique brain imaging pattern typically associated with a number of complex clinical conditions including: preeclampsia/eclampsia, allogeneic bone marrow transplantation, solid organ transplantation, autoimmune diseases and high dose cancer chemotherapy. The mechanism behind the developing vasogenic edema and CT or MR imaging appearance of PRES is not known. Two theories have historically been proposed: 1) Severe hypertension leads to failed auto-regulation, subsequent hyperperfusion, with endothelial injury/vasogenic edema and; 2) vasoconstriction and hypoperfusion leads to brain ischemia and subsequent vasogenic edema. The strengths/weaknesses of these hypotheses are reviewed in a translational fashion including supporting evidence and current available imaging/clinical data related to the conditions that develop PRES. While the hypertension/hyperperfusion theory has been most popular, the conditions associated with PRES have a similar immune challenge present and develop a similar state of T-cell/endothelial cell activation that may be the basis of leukocyte trafficking and systemic/cerebral vasoconstriction. These systemic features along with current vascular and perfusion imaging features in PRES appear to render strong support for the older theory of vasoconstriction coupled with hypoperfusion as the mechanism.

Serum magnesium levels as related to symptomatic vasospasm and outcome following aneurysmal subarachnoid hemorrhage

INTRODUCTION

Recent evidence suggests that magnesium may be neuroprotective in the setting of cerebral ischemia, and therapeutic magnesium infusion has been proposed for prophylaxis and treatment of delayed ischemic neurological deficit (DIND) resulting from vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). We studied the association between serum magnesium levels, the development of DIND, and the outcomes of patients with SAH.

METHODS

We studied 128 consecutive patients with aneurysmal SAH treated at our institution between 1990 and 1997 who had a serum magnesium level measured at least once during the acute phase of their hospitalization. Delayed ischemic neurological deficit was defined as severe (major focal deficit or coma), moderate (incomplete focal deficit or decreased sensorium without coma), or none.

RESULTS

There was no significant difference in mean, minimum, or maximum serum magnesium levels between patients with and without DIND (1.93, 1.83, 2.02 versus 1.91, 1.84, 1.97 mg/dL, respectively). Similarly, no difference was found in mean serum magnesium levels among patients with severe (1.94 mg/dL), moderate (1.92 mg/dL), or no DIND (1.91 mg/dL). Analyses of serum magnesium levels before (0-4 days following SAH), during (4-14 days following SAH), and after (greater than 14 days following SAH) the period of highest risk for vasospasm revealed no association with the development or severity of DIND. Permanent deficit or death resulting from vasospasm and Glasgow Outcome Scale score at longest follow-up were similarly unaffected by serum magnesium levels overall or during any time interval. Forty (31.5%) patients were hypomagnesemic (less than 1.7 mg/dL) during hospitalization, but no difference in outcome (p = 0.185) or development of DIND (p = 0.785) was found when compared to patients with normal (1.7-2.1 mg/dL) or high (greater than 2.1 mg/dL) magnesium serum levels.

CONCLUSION

We identified no relationship between serum magnesium levels and the development of DIND or outcome following aneurysmal SAH. Based on these data, magnesium supplementation to normal or high-normal physiological ranges seems unlikely to be beneficial for DIND resulting from vasospasm. However, no inference can be made regarding the value of therapeutic infusion of magnesium to supraphysiological levels.

Imaging of acute neurological conditions in pregnancy and the puerperium

Eclampsia is one of the most common acute neurological events occurring during pregnancy. However, there are many other conditions that can present during pregnancy and the puerperium and that may either mimic eclampsia or produce other acute neurological manifestations. Frequently the symptoms and signs are non-specific, and it can be difficult to differentiate between these conditions on clinical grounds alone. Neuroradiological studies can provide valuable diagnostic information, and interventional radiological procedures may play a part in the subsequent management of these conditions. This review focuses on the imaging of acute neurological conditions which may be associated with, or present during, pregnancy and the puerperium.

Visual disturbances and seizures associated with pregnancy: a diagnostic dilemma and the role of radiological techniques as an aid to diagnosis

We present two cases of visual disturbances associated with tonic-clonic seizures during pregnancy and the associated radiological findings. We review the use of neuroimaging techniques as an aid to diagnosis and their role in elucidating the pathophysiology of cortical blindness.

Increased cerebral blood flow in preeclampsia with magnetic resonance imaging

OBJECTIVE

The purpose of this study was to compare third trimester and nonpregnant cerebral blood flow of women with preeclampsia to normotensive control subjects with the use of magnetic resonance imaging techniques.

STUDY DESIGN

Nine normotensive pregnant women and 12 untreated women with preeclampsia underwent velocity-encoded phase contrast magnetic resonance imaging of the bilateral middle and posterior cerebral arteries in the third trimester and at 6 to 8 weeks after delivery. The Student t test was used for comparison, with a probability value of <.05 considered significant.

RESULTS

Third-trimester large cerebral artery blood flow was significantly higher in preeclampsia. Mean vessel diameter was unchanged, except for the left posterior cerebral artery. There was no difference in mean vessel diameter or cerebral blood flow between the 2 groups while the women were not pregnant.

CONCLUSION

Cerebral blood flow is increased significantly in preeclampsia. We hypothesize that increased cerebral blood flow ultimately could lead to eclampsia through hyperperfusion and the development of vasogenic edema.

[Neurologic aspects of eclampsia]

The difficult types of preeclampsia and eclampsia are presented with the neurological symptoms. The break of cerebral autoregulation mechanism plays the most important role in pathogenesis of cerebral vasospasm. Nevertheless, eclampsia isn't just an ordinary hypertensive encephalopathy because other pathogenic mechanisms are involved in its appearance. The main neuropathologic changes are multifocal vasogenic edema, perivascular multiple microinfarctions and petechial hemorrhages. Neurological clinical manifestations are convulsions, headache, visual disturbances and rarely other discrete focal neurological symptoms. Eclampsia is a high-risk factor for onset of hemorrhagic or ischemic stroke. This is a reason why neurological diagnostic tests are sometimes needed. The method of choice for evaluation of complicated eclampsia is computerized brain topography that shows multiple areas of hypodensity in occipitoparietal regions. These changes are focal vasogenic cerebral edema. For differential diagnosis of eclampsia and stroke other diagnostic methods can be used--fundoscopic exam, magnetic resonance brain imaging, cerebral angiography and cerebrospinal fluid exam. The therapy of eclampsia considers using of magnesium sulfate, antihypertensive, anticonvulsive and antiedematous drugs.

Neuroimaging of delayed eclampsia. Report of 3 cases and review of the literature

Computed tomography and magnetic resonance imaging findings consistent with eclampsia were recently encountered in 3 patients who developed severe headache days to weeks after uncomplicated delivery. The neurologic presentation was nonspecific, and pre-eclamptic symptoms were not present, including significant hypertension. Variable expression of pre-eclampsia occurred during the course of their observation. Conventional angiography obtained in 2 patients because of a concern for aneurysm demonstrated central and peripheral vasospasm. Magnetic resonance angiography demonstrated central vasospasm in the third patient.

Adhesion molecules in Wilms tumor (part I)

Adhesion molekues are glicoprotees which have extracellular, transmembranous and intracytoplasmatic part. They show their basic role is in cell interaction in the tissue on one side and between cells and matrix on the other side. They have an important role in stabile integrity of tumor tissue, as well as in differenciation, prolifferation, apoptosis and metastatic spread of tumorous cells. Since there is very little known facts about adhesion molecule detection and about its significance in Wilms tumor, our intention was to collect all known achievements which could be of importance for better understanding of tumors nature and successful treatment. Especially because of well known fact that in 15% Wilms tumors there are b-catenin mutations, which indicates that there is a disorder in Wnt signal paththat plays an important role in Wilms tumor genesis.

Reversible posterior leukoencephalopathy syndrome: evaluation with diffusion-tensor MR imaging

PURPOSE

To characterize the changes in brain water diffusion caused by reversible posterior leukoencephalopathy syndrome (RPLS).

MATERIALS AND METHODS

Twelve patients with the clinical features and conventional magnetic resonance (MR) imaging findings of RPLS underwent diffusion-tensor echo-planar MR imaging. The isotropic diffusion coefficient (D) and diffusion anisotropy (A(sigma)) were measured in posterior regions of diffusion abnormality and in anterior areas of normal-appearing brain.

RESULTS

Across all 12 subjects, the mean D of (1.09 +/- 0.13 [SD]) x 10(-3) mm(2)/sec in affected posterior regions was 26% greater than its value of (0.87 +/- 0.07) x 10(-3) mm(2)/sec in normal-appearing anterior regions. The mean A(sigma) of 0.15 +/- 0.03 in posterior regions was 35% less than its value of 0.23 +/- 0.02 in anterior regions (t(11) = 9.58; P <.001). There was a significant inverse correlation between D and A(sigma) in posterior regions (r = -0.67; P <.018) but not in anterior regions (r = -0.12; P =.719). A follow-up study performed in one patient after resolution of symptoms documented reversal of elevated isotropic diffusion and at least partial recovery of anisotropy loss.

CONCLUSION

The increased magnitude of brain water diffusion characteristic of RPLS is accompanied by reduced A(sigma). The magnitudes of these two effects are correlated and may be reversible. These observations support the proposal that vasogenic edema due to cerebrovascular autoregulatory dysfunction is the underlying pathophysiologic mechanism in uncomplicated RPLS.

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

PURPOSE

To investigate the clinical parameters that are associated with the development of brain edema of hypertensive encephalopathy in patients with preeclampsia-eclampsia.

MATERIALS AND METHODS

Twenty-eight patients with preeclampsia-eclampsia and neurologic symptoms underwent magnetic resonance (MR) imaging. Clinical parameters recorded at the time of MR imaging included serum electrolytes and various indices of hematologic, renal, and hepatic function. Several data were available 1 week prior to the development of neurologic symptoms in 11 patients. Univariate analysis and multivariate logistic regression analyses were performed to study possible associations between these parameters and brain edema at MR imaging.

RESULTS

The 20 patients with brain edema at MR imaging had a significantly greater incidence of abnormal red blood cell morphology (14 [82%] of 17 patients vs two [25%] of eight, P: <.005) and higher levels of lactic dehydrogenase (LDH) (339 U/L +/- 65 [SD] vs 258 U/L +/- 65, P: =.007) than the eight with normal MR imaging findings; multivariate logistic regression analysis showed a strong association with red blood cell morphology only. Moreover, LDH levels were elevated before the development of neurologic abnormalities (P: <.05). Blood pressures were not significantly different between groups at any time.

CONCLUSION

Brain edema at MR imaging in patients with preeclampsia-eclampsia was associated with abnormalities in endothelial damage markers and not with hypertension level.

HELLP syndrome with haemaglobin vasospasm

The syndrome of haemolysis, elevated liver enzymes and low platelets (HELLP syndrome) is a life threatening, severe complication of pre-eclampsia with typical laboratory findings. An unusual case of a 36-year-old woman with HELLP syndrome and the initial complication of intracerebral haemorrhage is presented. The diagnosis of HELLP syndrome was confirmed by elevated liver enzymes, low platelets, increased total bilirubin and increased lactate dehydrogenase. The intracranial haematoma was removed with good neurological recovery ensuing. However, this case was complicated by cerebral vasospasm on the eleventh day, confirmed by cerebral angiography and computer tomographic findings. The patient died from brain swelling. Possible vasospam should be considered during the treatment of patients with HELLP syndrome.

Induction of eclampticlike changes by stimulation of the celiac ganglion in rats

OBJECTIVE

To examine the relation between the stimulation of the abdominal sympathetic nervous system and vasospasm of the brain in eclamptic seizures, we analyzed brain blood flow after stimulation of the celiac ganglion by lipopolysaccharide (LPS, 5, 50, or 500 mg/mL) or normal saline before and after denovation of sympathetic trunk in pregnant and nonpregnant rats.

METHODS

The brain blood flow was measured after stimulation of the celiac ganglion with 50 microL (5 mg/mL) LPS in group I, 50 microL (50 mg/mL) LPS in group II, 50 microL saline in group III, and 50 microL (500 mg/mL) LPS (after denovation of the sympathetic trunk) in group IV. A sham control experiment was also done by stimulation of the abdominal peritoneum with 50 microL (500 mg/mL) LPS in group V. Changes in water content and histological findings in the brain were also studied in this protocol.

RESULTS

A significant reduction in brain blood flow was observed in pregnant rats in groups I and II on stimulation of the celiac ganglion with LPS (p < 0.0001, p < 0.001) compared with before stimulation. Celiac ganglion stimulation with saline (group III) and LPS (group IV, after denovation of the sympathetic trunk) did not affect brain blood flow. Stimulation of the abdominal peritoneum with LPS (group V) could not induce any changes in brain blood flow. Repeated seizures occurred in 60% of pregnant rats and a remarkable increase in water content was observed after LPS stimulation of the celiac ganglion in groups I and II (p < 0.0001, p < 0.001). Histologically, we found that stimulation of the celiac ganglion with LPS caused widening of perivascular spaces with compression of the vessels leading to ischemic changes in brain tissues. There were no such findings observed in other groups. However, a lesser extent effect was noticed in nonpregnant than seen in pregnant rats.

CONCLUSION

Stimulation of the abdominal sympathetic ganglions could induce vasoconstriction of the brain vessels, thus decreasing brain blood flow, which results in eclampsialike changes in rats.

Changes in maternal middle cerebral artery blood flow velocity associated with general anesthesia in severe preeclampsia

In women with severe preeclampsia, significant increases in mean arterial pressures (MAP) are common after rapid induction of general anesthesia (GA) and tracheal intubation. The objectives of this prospective study were to assess the effects of the rapid induction-intubation technique on middle cerebral artery (MCA) flow velocity in severe preeclampsia and to examine the correlation between mean MCA flow velocity (Vm) and MAP. Eight women with severe preeclampsia (study group) and six normotensive women at term (control group) scheduled to undergo cesarean section under GA were studied. Before induction, patients in the study group received i.v. labetalol in divided doses to lower diastolic pressures to <100 mm Hg. Anesthesia was induced with pentothal 4-5 mg/kg, followed by succinylcholine 1.5 mg/kg to facilitate tracheal intubation. A transcranial Doppler was used to measure Vm. Both Vm and MAP were recorded before induction and every minute for 6 min after intubation. In the study group, after the administration of labetalol, MAP decreased from 129 +/- 9 to 113 +/- 9 mm Hg (P < 0.05), and Vm decreased from 59 +/- 11 to 54 +/- 10 cm/s (P < 0.05). After intubation, MAP increased from 113 +/- 9 to 134 +/- 5 mm Hg (P < 0.001), and Vm increased from 54 +/- 10 to 70 +/- 10 cm/s (P < 0.001). In the control group, while MAP increased significantly from 89 +/- 6 to 96 +/- 4 mm Hg (P < 0.05) after intubation, the concurrent increase in Vm from 49 +/- 5 to 54 +/- 7 cm/s was not significant. There was a significant positive pooled correlation between Vm and MAP (r = 0.5, P < 0.0006) in the study group but not in the control group (r = 0.24). After induction and intubation, both Vm and MAP values were significantly increased in the study group patients at all observation points compared with the control group patients. The findings indicate that Vm increases significantly after rapid-sequence induction of GA and tracheal intubation in women with severe preeclampsia, and there seems to be a direct relationship between MAP and Vm.

IMPLICATIONS

In women with severe preeclampsia, rapid-sequence induction of general anesthesia and tracheal intubation can cause severe hypertension. Our results indicate that the increase in blood pressure is associated with a significant increase in maternal cerebral blood flow velocity and that there is a significant correlation between these two variables.

Neurological aspects of eclampsia

Eclampsia accounts for a third of maternal mortality in developing countries. The neurological manifestations of eclampsia consist of seizures and alteration of sensorium or coma on a background of pre-eclampsia. Occasionally there can be focal neurological deficits too. Recent studies with CT scan and MRI have demonstrated the presence of cerebral edema and/or cerebral hemorrhage in eclampsia. EEG in patients with eclampsia has revealed evidence of diffuse cerebral dysfunction (delta waves) and epileptiform transients (spikes or sharp waves). There is also evidence of extensive vasculopathy within the brain parenchyma. A variety of mechanisms have been suggested to explain these changes, the most important being failure of autoregulation of cerebral blood flow that leads to cerebral edema and hemorrhage. There is considerable controversy regarding the treatment of seizures in eclampsia. Recent studies have shown that magnesium sulfate is superior to phenytoin or diazepam in the treatment of eclamptic seizures and prevention of eclamptic seizures in women with pre-eclampsia.

Comparative analysis of the vascular actions of diterpenes isolated from Euphorbia canariensis

We have analysed the effects of 2,3-diepiingol 7,12-diacetate-8-isobutyrate (compound 1), ingenol-3-angelate-17-benzoate (compound 2), ingenol-3-angelate-17-benzoate-20-acetate (compound 3) and 3,5,7,8,9,15-hexahydroxyjatropha-6(17),11-dien-14-one-5,8-bi s(2-methylbutyrate)-7-(2-methylpropionate) (compound 4), four diterpenes isolated from E. canariensis, on the isometric tension developed by isolated rabbit basilar and carotid arteries. Concentration-response curves to these compounds were obtained cumulatively in both arteries at resting tension and active tone (KCl, 50 mM). At resting tension a concentration-dependent contraction was induced by the four compounds. In the basilar artery the order of potency was 3=1>2=4, without significant differences between Emax values. In the carotid artery the order of potency was 3>2=1=4 and there were no significant differences between the Emax (maximum effect) values of compounds 1-3, all of which were higher than that of compound 4. In pre-contracted basilar artery compounds 1-3 induced concentration-dependent relaxation and compound 4 was almost ineffective; the order of potency was 3>2=1 without significant differences between Emax values. In the carotid artery with active tone the four compounds tested induced further contractions; the order of potency was 3>2=4>1 without significant differences between Emax values. These results show that the four diterpenes are potent active substances in rabbit basilar and carotid arteries and that there are regional differences between their action. The four compounds tested contract basilar and carotid arteries at resting tension. Compounds 1-3 relax pre-contracted basilar artery but not carotid artery.

Effects of magnesium sulphate on the noradrenaline-induced cerebral vasoconstrictor and pressor responses in the goat

OBJECTIVE

To examine the ability of magnesium sulphate to counteract the noradrenaline-induced cerebral vasoconstrictor and pressor responses in goats by using both in vivo and in vitro techniques.

DESIGN

Cerebral blood flow was measured in vivo by means of an electromagnetic flow probe around the internal maxillary artery. Isometric tension was recorded in vitro from rings of goat middle cerebral artery maintained in an organ bath.

RESULTS

1. In vivo. Continuous infusion of noradrenaline (10 micrograms/min) directly into the cerebral arterial supply elicited sustained decrease in cerebral blood flow (61% [SEM 3] of control values) and increase in cerebral vascular resistance (178% [SEM 9] of control values). Magnesium sulphate, injected directly into the cerebral arterial supply (10-300 mg) or infused intravenously (0.3 g and 3 g during 15 min) at the noradrenaline-induced steady state, increased cerebral blood flow by decreasing cerebral vascular resistance in a dose-dependent manner. A similar result was obtained when intravenous magnesium sulphate (3 g/15 min) was tested against the cerebral vasoconstrictor and pressor responses induced by intravenous infusion of noradrenaline (30 micrograms/min). 2. In vitro. When compared with the response obtained in a control medium (1 mmol/L Mg2+), 10 mmol/L Mg2+ significantly inhibited the maximum contraction elicited by noradrenaline (10(-8) to 3 x 10(-3) mol/L) from 45% [SEM 4] to 26% [SEM 4].

CONCLUSIONS

Magnesium sulphate reverses the noradrenaline-induced cerebral vasoconstrictor and pressor responses by a direct inhibitory action of Mg2+ on the actions of noradrenaline in the cerebral and peripheral vascular beds, which leads to a decrease in vascular resistance. These results could explain, at least in part, the beneficial effects of magnesium sulphate in the management of preeclampsia and eclampsia.

Diffusion-weighted imaging discriminates between cytotoxic and vasogenic edema in a patient with eclampsia

BACKGROUND

The pathophysiology of eclampsia remains unclear. While the majority of patients develop reversible T2 hyperintense signal abnormalities on MR scans and reversible neurological deficits, some patients do develop infarctions (permanent T2 hyperintense abnormalities) and permanent neurological impairment. Routine MRI cannot prospectively differentiate between these two patient groups. Echo-planar diffusion-weighted imaging, however, is a new technique that clearly differentiates between cytotoxic and vasogenic edema.

CASE DESCRIPTION

A 30-year-old woman developed symptoms consistent with eclampsia 24 hours after delivering premature twins. An MRI demonstrated extensive, diffuse T2 hyperintense signal abnormalities involving subcortical white matter and adjacent gray matter with a posterior predominance, consistent with either infarction or hypertensive ischemic encephalopathy. Diffusion-weighted images demonstrated increased diffusion, consistent with vasogenic edema and hypertensive ischemic encephalopathy.

CONCLUSIONS

Unlike routine MRI, diffusion-weighted imaging reliably differentiates between vasogenic edema and cytotoxic edema. Consequently, in eclamptic patients diffusion-weighted imaging can afford clear differentiation between hypertensive ischemic encephalopathy and infarction, two very different entities with very different treatment protocols. Diffusion-weighted imaging should be performed in all eclamptic patients and should greatly affect their management.

Randomised study assessing the effect of phenytoin and magnesium sulphate on maternal cerebral circulation in eclampsia using transcranial Doppler ultrasound

OBJECTIVE

To assess maternal middle cerebral artery flow velocity patterns as measured by transcranial Doppler ultrasound (TCD) in eclampsia and to investigate the effect of the anticonvulsants magnesium sulphate (MgSO4) and phenytoin on cerebral circulation.

DESIGN

Prospective randomised study.

SETTING

High care obstetric unit, King Edward VIII Hospital, Durban, South Africa.

PARTICIPANTS

Twenty-four eclamptic patients: 13 received MgSO4 and 11 phenytoin.

INTERVENTION

Middle cerebral artery flow velocity waveforms were measured using 2 MHz pulsed Doppler ultrasound via the transtemporal approach in eclamptic patients, before and 15 minutes after the loading dose of anticonvulsant.

RESULTS

Magnesium sulphate significantly reduced the pulsatility index (P = 0.002) and mean flow velocity (P = 0.02) in the middle cerebral artery, whereas phenytoin failed to produce any statistically significant effect. However, differences between groups were not statistically significant. Systolic and diastolic blood pressures were reduced in both the MgSO4 and phenytoin groups.

CONCLUSION

These findings provide firm evidence that MgSO4 relieves cerebral vasospasm, compared with phenytoin, and may therefore be the better drug for the prevention of eclamptic convulsion.

The feasibility of a control population for a randomized control trial of seizure prophylaxis in the hypertensive disorders of pregnancy

OBJECTIVE

To document the feasibility of a control population for a randomized controlled trial, we report our experience in managing hypertensive pregnancies without seizure prophylaxis.

STUDY DESIGN

An 8-year cross-sectional study in one institution was performed of all hypertensive patients.

RESULTS

Of 467 patients with preeclampsia or superimposed preeclampsia managed without seizure prophylaxis, 18 had seizure activity, 3.9% (95% confidence interval 2.3% to 6.0%). There was no seizure-related maternal mortality or major morbidity, and the perinatal mortality rate after 28 gestational weeks was the same in patients with or without seizures. By logistic regression seizures were 17.4 times more likely in preeclampsia and 8.1 times more likely in chronic hypertension with superimposed preeclampsia, compared with gestational or chronic hypertension alone.

CONCLUSION

The rate of seizures in patients with preeclampsia or superimposed preeclampsia managed without seizure prophylaxis was low and unassociated with an increase in maternal or perinatal mortality. A control arm is feasible in a randomized, controlled trial to address the issue of whether antiseizure medication can prevent eclampsia.

Interictal EEG changes in eclampsia

The pathogenesis of seizures and encephalopathy in eclampsia remains obscure even today. There are only a few reports on EEG findings in eclampsia. This is a report of the interictal EEG changes in 8 patients with eclampsia who were evaluated prospectively. The major EEG changes observed were (1) slowing of the background activity (generalized slowing in 4 patients and focal slowing in 3 patients) and (2) intermittent spike and sharp wave transients (5 patients). These abnormalities had disappeared in all except 2 patients when the EEG was repeated on the seventh day. A comparison is drawn between eclampsia and hypertensive encephalopathy for the clinical, EEG and CT/MRI findings. The pathogenesis of seizures and encephalopathy could be similar in these two conditions. It is worth while considering these EEG changes while planning the treatment of eclampsia.

Magnetic resonance evaluation of brainstem dysfunction in eclampsia and the HELLP syndrome

An unusual case of a 40-year-old woman with eclampsia and the HELLP syndrome associated with brainstem dysfunction is presented. The patient made a progressive neurological recovery. A follow-up magnetic resonance image (MRI) demonstrated complete resolution of the multiple foci. The MRI of the brainstem was found to correlate far more closely with neurological findings than with computed tomography (CT scan).

Nimodipine in the management of preeclampsia: maternal and fetal effects

OBJECTIVE

Our purpose was to determine the effects of orally administered nimodipine on selected maternal and fetal parameters in patients with preeclampsia.

STUDY DESIGN

Ten consecutive patients were given 30 mg of nimodipine orally every 4 hours from admission until 24 hours after delivery. Maternal and fetal cerebral blood velocity, umbilical artery blood velocity, fetal heart rate variability, maternal blood pressure and heart rate, and transplacental passage of the drug were studied. All 10 patients were delivered within 24 hours of the first dose of nimodipine.

RESULTS

There was an acute and significant reduction in the pulsatility index in the smaller diameter maternal cerebral arteries (ophthalmic and central retinal) and in the fetal middle cerebral artery. The umbilical artery systolic/diastolic ratio was also significantly reduced. Maternal blood pressure was controlled without the need for other antihypertensive medication, and although there was an increase in heart rate after administration of the drug, it was well tolerated. Nimodipine reached significant maternal and fetal levels within 2 hours.

CONCLUSIONS

Nimodipine is rapidly absorbed after oral administration and has significant maternal and fetal cerebral vasodilator activity. It is an effective, easily administered antihypertensive agent when used in patients with preeclampsia.

Occipital lobe epilepsy: a chronic condition related to transient occipital lobe involvement in eclampsia

Eleven hours and 6 days, respectively, after childbirth 2 women exhibited hypertension and paroxysmal visual disturbances followed by tonic-clonic seizures and no other preeclamptic signs. Both developed partial epilepsy with occipital lobe seizures with no other neurologic defects. Neuroimaging showed no lesion during either the acute episode or 3-5 year follow-up. Selective vulnerability of the occipital lobes during eclamptic hypertensive encephalopathy was the probable pathophysiologic mechanism. Aggressive antihypertensive treatment during the acute phase may have exacerbated the risk of permanent cerebral damage.