Brain in eclampsia: MR imaging with clinical correlation

Prediction of pre-eclampsia by using radiomics nomogram from gestational hypertension patients

Background

Pre-eclampsia (PE) is the main cause of death in maternal and prenatal morbidity. No effective clinical tools could be used for the prediction of PE. A radiomics nomogram based on diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps was established to predict PE from gestational hypertension (GH).

Materials and methods

A total of 138 patients with hypertensive disorders of pregnancy were continuously enrolled in the study prospectively, namely, 58 patients with PE and 80 patients with GH. The patients were randomly divided into a training cohort (n = 97) and a test cohort (n = 41). Radiomics features were extracted from DWI and ADC maps. The radiomics signature was constructed using a least absolute shrinkage and selection operator (LASSO) algorithm in the training cohort. A radiomics nomogram was developed by combining the radiomics signature with the selected clinical risk factors. The area under the receiver operating characteristic (ROC) curves (AUC), specificity, sensitivity, accuracy, positive predictive value, and negative predictive values of the radiomics signature, clinical risk factors, and radiomics nomogram were calculated. Decision curve analysis (DCA) was performed to determine the clinical usefulness of the radiomics nomogram.

Results

The LASSO analysis finally included 11 radiomics features, which were defined as the radiomics signature. The individualized prediction nomogram was constructed by integrating the radiomics signature, maternal age, and body mass index (BMI). The nomogram exhibited a good performance both in the training cohort [AUC of 0.89 (95% CI, 0.82–0.95)] and test cohort [AUC of 0.85 (95% CI, 0.73–0.97)] for predicting PE from GH. The DCA indicated that clinicians and patients could benefit from the use of radiomics nomogram.

Conclusion

The radiomics nomogram could individually predict PE from GH. The nomogram could be conveniently used to facilitate the treatment decision for clinicians and patients.

Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome: Distinct Clinical Entities with Overlapping Pathophysiology

The clinical and radiologic manifestations of posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome are reviewed. The relationship between these entities is discussed. A hypothesis of a common underlying pathophysiology is proposed and substantiated based on the current medical literature.

Hypertensive Encephalopathy: Clinical and Neuroradiological Findings

Hypertensive encephalopathy is a syndrome consisting of headache, seizures, visual changes, and other neurologic disturbances in patients with elevated systemic blood pressure. The purpose of this study was to analyse the clinical and neuroradiological findings in nine patients with hypertensive encephalopathy, observed in five years.

CT (n = 13), and MR (n = 12), examinations performed in these patients before and after resolution of symptoms were reviewed. Six had the preeclampsia-eclampsia syndrome, and three had hypertensive encephalopathy due to other causes. CT and MR findings in all patients having these examinations were indicative of oedema in the cortex and subcortical white matter in the occipital lobes. Two of the nine patients also had similar findings in the cerebellum and frontal lobes.

The findings on the CT and MR studies resolved on follow-up examinations performed after the hypertension was corrected.

Our results suggest that the radiological findings associated with hypertensive encephalopathy in the appropriate clinical setting are very useful to achieve an early diagnosis.

Childhood posterior reversible encephalopathy syndrome: Magnetic resonance imaging findings with emphasis on increased leptomeningeal FLAIR signal

PURPOSE

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiologic syndrome characterized clinically by headache, seizures, and altered sensorium and radiological changes which are usually reversible. The purpose of this study was to describe the spectrum of magnetic resonance imaging (MRI) findings in childhood PRES, to determine the common etiologies for childhood PRES, and to have an insight into the pathophysiology of PRES.

METHODS

The MRI results of 20 clinically diagnosed cases of PRES between July 2011 and June 2013 were reviewed. The final diagnosis of PRES was based on the clinical presentation and the MRI features at the time of presentation, which resolved on the follow-up imaging. The medical records of the patients were reviewed to determine the underlying medical disease.

RESULTS

Eight out of the 20 patients included in the study were on cyclosporine or tacrolimus based immunosuppressant therapy for kidney transplant. Four patients had severe hypertension at presentation. The most common MRI finding was high T2-fluid-attenuated inversion recovery (FLAIR) signal in the cortex and subcortical white matter of both cerebral hemispheres, particularly in the parietal and occipital lobes (n=16). The second most common MRI finding was increased leptomeningeal FLAIR signal (n=7). Out of seven patients with leptomeningeal signal, five demonstrated leptomeningeal enhancement as well. Four out of these seven patients had no other parenchymal findings.

CONCLUSION

Childhood PRES is commonly seen in the setting of immunosuppressant therapy for kidney transplant, severe hypertension and cancer treatment. There was high incidence of increased leptomeningeal FLAIR signal and leptomeningeal enhancement in our study. It supports the current theory of endothelial injury with increased microvascular permeability as the potential pathophysiology of PRES. Also, absence of elevated blood pressure in majority of the patients in our study supports the theory of direct endothelial injury by some agents leading to vasogenic edema.

Fatal posterior revesible leukoencephalopathy syndrome associated coma induced by bevacizumab in metastatic colorectal cancer and review of literature

Posterior reversible leukoencephalopathy syndrome (PRES) is a syndrome characterized by headache, hypertension, confusion, visual disturbance, and seizures accompanied by subcortical vasogenic edema, predominantly involving the parietal and occipital lobes. The syndrome is usually described in malignant hypertension, eclampsia, renal failure, immunosuppressive, and cytotoxic chemotherapies. Bevacizumab, a monoclonal antibody that binds to the vascular endothelial growth factor (VEGF) has been linked to PRES. We carried out review of reports documenting the occurrence of PRES in patients receiving bevacizumab. This literature review was conducted by utilizing PubMed Database. If early diagnosed, PRES is reversible. We present a case of fatal PRES-associated coma induced by bevacizumab in metastatic colorectal cancer.

Hypertensive encephalopathy and cerebral infarction

Introduction

Hypertensive encephalopathy is one cause of posterior reversible encephalopathy syndrome. Hypertensive encephalopathy and cerebral infarction have only been reported in a few individual case reports.

Case description

A 51-year-old woman presented with hypertensive encephalopathy. T2-weighted images from magnetic resonance imaging showed hyperintense lesions in both occipital and parietal lobes. Diffusion-weighted imaging showed that this represented cytotoxic oedema and perfusion magnetic resonance imaging revealed reduced blood volume and flow. The magnetic resonance imaging was repeated 5 months later and subtotal regression of theT2-hyperintensity had occurred. However, small bilateral infarcts were seen on T1-weighted images. Perfusion magnetic resonance imaging presented reduced blood volume and flow on the right side.

Discussion and evaluation

The patient in this report had posterior reversible encephalopathy syndrome caused by hypertensive encephalopathy. Magnetic resonance imaging of the brain showed bilateral cytotoxic oedema that partially resolved and resulted in small infarcts. The imaging findings are compatible with posterior reversible encephalopathy syndrome with subtotal resolution and infarct evolution.

Conclusion

The case report suggests that the presence of hypertensive encephalopathy and posterior reversible encephalopathy syndrome should alert clinicians and lead to prompt treatment in order to prevent cerebral damage.

Posterior reversible encephalopathy syndrome could be an underestimated variant of "reversible neurological deficits" in Systemic Lupus Erythematosus

Background

Posterior reversible encephalopathy syndrome (PRES) has been increasingly identified in patients with systemic lupus erythematosus (SLE) owing to the advance in neuroimaging techniques. Prompt diagnosis is pivotal to improve its outcome. To analyze the clinical and radiographic profile of PRES in patients with SLE and search for the appropriate treatment strategy PRES in SLE.

Methods

SLE patients who fulfilled the diagnostic criteria for PRES from August 2008 to January 2011 were evaluated at baseline, and followed to determine clinical outcomes. Data were analysis on clinical characteristics, laboratory abnormalities, treatment details, and outcomes.

Results

Ten episodes of PRES in patients with SLE were identified. All patients were female, mean age of onset was 22.93 ± 2.48 years, and SLEDAI at the onset of PRES were 25.8 ± 5.7. All cases had acute onset of headache, altered mental status, stupor, vomiting, cortical blindness and seizures. Neurological symptoms were the initial manifestation of SLE in three cases. Head magnetic resonance imaging (MRI) demonstrated posterior white matter edema involving the parietal, temporal and occipital lobes, which were more conspicuous on T2 weighted spin echo and diffusion-weighted MR imaging (DWI) than on computed tomography (CT) scan. Complete clinical and radiographic recovery was observed in 8 patients after prompt treatment with corticosteroids.

Conclusions

PRES might be due to lupus per se besides other traditional causative factors such as hypertension. PRES might be an underestimated variant of “reversible neurological deficits” in SLE. Prompt recognition and timely management is important to prevent permanent neurological deficits.

Posterior reversible encephalopathy syndrome in childhood: report of four cases and review of the literature

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a recently described disorder with typical radiological findings of bilateral gray and white matter abnormalities in the posterior regions of the cerebral hemispheres and cerebellum. Its clinical symptoms include headache, decreased alertness, mental abnormalities such as confusion, diminished spontaneity of speech, and changed behavior ranging from drowsiness to stupor, seizures, vomiting, and abnormalities of visual perception such as cortical blindness. In this study, the clinical and radiological findings of 4 children with this syndrome due to a variety of conditions are reported.

METHODS

The records of 4 children with a diagnosis of PRES were retrospectively analyzed.

RESULTS

PRES is associated with a disorder of cerebrovascular autoregulation of multiple etiologies. Four patients with PRES who had primary diagnoses of severe aplastic anemia, nephritic syndrome, Henoch-Schönlein purpura, and acute poststreptococcal glomerulonephritis are presented. This syndrome has been described in numerous medical conditions, including hypertensive encephalopathy, eclampsia, and with the use of immunosuppressive drugs.

CONCLUSIONS

Early recognition of PRES as a complication during different diseases and therapies in childhood may facilitate precise diagnosis and appropriate treatment.

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.

Posterior Reversible Encephalopathy Syndrome in severe preeclampsia: case report and literature review

We describe a 23 year old primigravid patient with severe preeclampsia complicated by posterior reversible encephalopathy syndrome (PRES), who presented with sensory and motor deficits and amnesia in the postpartum period Cranial magnetic resonance imaging (MRI) showed abnormal areas in the white matter of bilateral parieto-occipital lobes, indicating brain edema which disappeared completely on the follow-up scan taken four weeks after delivery together with complete symptom regression. The development of PRES in preeclampsia is discussed and the importance of prompt postpartum blood pressure control is emphasized.

Cerebral magnetic resonance imaging in eclampsia: a series of 12 cases

The object of this study was to assess the ability of magnetic resonance imaging (MRI) to detect the cerebral abnormalities associated with eclampsia and therefore to establish its place in our management of the condition. This study was of particular relevance to our institution because eclampsia is common in our patient population. This was a prospective study in which 13 patients with an initial diagnosis of eclampsia received MRI brain scans. Of 12 patients with a final diagnosis of eclampsia, seven (58.3%) showed the typical MRI changes of eclampsia, namely cerebral hyperintensities representing focal areas of oedema. In five patients (41.6%) the scans were normal. The rate of abnormality detection was surprisingly low. We conclude that the reason for this was the time delay in obtaining the scans. The cerebral changes in eclampsia can be rapidly reversible. Future studies must aim to perform MRI within 48 hours of seizure activity. MRI is more sensitive than computed tomography scanning but has no practical advantages over computed tomography except where the diagnosis is in doubt.

Reversible posterior leucoencephalopathy syndrome associated with anticancer drugs

BACKGROUND

Reversible posterior leucoencephalopathy syndrome (RPLS) is an underappreciated clinical-radiologic syndrome characterized by reversible cortical dysfunction preferentially involving the occipital lobes in conjunction with imaging findings of reversible subcortical oedema. As RPLS is being increasingly identified within the oncology population in association with cytotoxic chemotherapy and targeted agents, a review of the published work in English was carried out.

METHODS

A MEDLINE search of the published work in English was conducted to identify cases of RPLS in patients more than 16 years of age who were treated with anticancer drugs for documented malignancy. Only cases with adequate documentation regarding demographic and treatment data, cerebral magnetic resonance imaging and outcome were selected.

RESULTS

We identified 24 patients with RPLS associated with a variety of anticancer drugs, most commonly complicating polychemotherapy and/or bevacizumab-containing regimens. There was a female predominance: 18 females and 6 males (P= 0.023). Women were of premenopausal age and were younger than males: 49.3 +/- 16.4 years versus 60.7 +/- 6.4 years (P= 0.09). Most patients presented with acute headache (67%), seizures (63%), confusion (54%) or cortical blindness (46%) with mean systolic and diastolic blood pressure of 168 +/- 15 and 98 +/- 15 mm Hg, respectively. Findings on magnetic resonance imaging showed hyperintense lesions on T(2)-weighted images in all patients, which involved the occipital lobes in 75% of patients; all patients experienced clinical and radiologic resolution within days to weeks. No deaths were directly attributed to RPLS.

CONCLUSIONS

Combination and single-agent chemotherapy as well as novel anticancer drugs are associated with RPLS. We found RPLS to be overrepresented in premenopausal woman; the prevalence in this subgroup may be related to an anticancer drug-oestrogen interaction inducing altered cerebral vasoreactivity and endothelial dysfunction.

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.

Distinct imaging patterns and lesion distribution in posterior reversible encephalopathy syndrome

BACKGROUND AND PURPOSE

Although the term posterior reversible encephalopathy syndrome (PRES) was popularized because of the typical presence of vasogenic edema in the parietal and occipital lobes, other regions of the brain are also frequently affected. We evaluated lesion distribution with CT and MR in a large cohort of patients who experienced PRES to comprehensively assess the imaging patterns identified.

MATERIALS AND METHODS

The locations of the PRES lesion at toxicity were comprehensively identified and tabulated in 136 patients by CT (22 patients) and MR (114 patients) imaging including the hemispheric, basal ganglial, and infratentorial locations. Clinical associations along with presentation at toxicity including blood pressure were assessed.

RESULTS

Vasogenic edema was consistently present in the parietal or occipital regions (98%), but other locations were common including the frontal lobes (68%), inferior temporal lobes (40%), and cerebellar hemispheres (30%). Involvement of the basal ganglia (14%), brain stem (13%), and deep white matter (18%) including the splenium (10%) was not rare. Three major patterns of PRES were noted: the holohemispheric watershed (23%), superior frontal sulcal (27%), and dominant parietal-occipital (22%), with additional common partial or asymmetric expression of these primary PRES patterns (28%).

CONCLUSION

Involvement of the frontal lobe, temporal lobe, and cerebellar hemispheres is common in PRES, along with the occasional presence of lesions in the brain stem, basal ganglia, deep white matter, and splenium. Three primary PRES patterns are noted in the cerebral hemispheres, along with frequent partial or asymmetric expression of these PRES patterns. Awareness of these patterns and variations is important to recognize PRES neurotoxicity more accurately when present.

Spectrum of radiological changes in hypertensive children with reversible posterior leucoencephalopathy

We prospectively studied 19 children with severe hypertension to evaluate the spectrum of radiological changes, severity and reversibility of this entity. All of them were subjected to clinical and biochemical evaluation, followed by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). Headache was seen in 17 children, 13 had confusion and drowsiness, 12 had nausea and vomiting, 10 patients had visual disturbances, seizure and dyspnoea. Only two had focal neurological deficit (one with right facial palsy and another with right lateral rectus palsy). Of these 19 children, 15 patients had hypertensive retinopathy and four had normal fundi. The positive MRI findings in 17/19 patients were: bilateral leukoencephalopathic changes in occipitoparietal region (9/17), diffuse white/grey matter lesion (3/17) patients, brain stem hyperintensity (2/17) and haemorrhagic lesions (3/17). On MRA, 12/19 patients had attenuation of cerebral arteries of different degree. On follow up, MRI findings resolved in all except three patients. All patients had normal MRA on follow up, except one with persistent minimal attenuation of middle cerebral artery and another had spasm in anterior, middle and posterior cerebral arteries. The intracranial abnormalities in these patients with severe hypertension were reversible in many of the cases after control of blood pressure was achieved. We therefore conclude that severe hypertension may lead to leuoencephalopathy, which had a wide radiological spectrum. A better understanding of this complex syndrome may obviate unnecessary investigations and allow management of associated problems in prompt and appropriate ways.

Reversible posterior leukoencephalopathy syndrome: report of 2 simultaneous cases in children

Reversible posterior leukoencephalopathy syndrome (RPLS) is a rare complication of cancer chemotherapy. We have recently observed two cases occurred simultaneously in children receiving different chemotherapy regimens, for hepatoblastoma and acute lymphoblastic leukaemia, respectively. Both children presented with altered mental status, severe visual disturbances, headache, seizures, backpain and hypertension. Magnetic resonance imaging showed cortical and subcortical lesions especially in the occipital and parietal regions, strongly consistent with RPLS. Both patients completely recovered from their neuropsychologic deficits in about ten days only with anticonvulsant and antihypertensive therapy, and chemotherapy regimen was promptly restarted according to the planned protocol, without any neuropsychological sequela. A mild left midriasis was the only neurologic defect that persisted in the patient with acute lymphoblastic leukemia.

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.

Comparison of cerebral magnetic resonance and electroencephalogram findings in pre-eclamptic and eclamptic women

OBJECTIVE

To compare the cerebral magnetic resonance (MR) and electroencephalogram (EEG) findings in pre-eclamptic and eclamptic pregnant women.

METHODS

A total of 38 pregnant women with mild pre-eclampsia (n = 15), severe pre-eclampsia (n = 11) and eclampsia (n = 12) were included in this study. Cranial MR without contrast and EEG were performed in these women on admission or within 3 days of onset. Follow-up control MR or EEG evaluations were performed 4-6 weeks postpartum in women with MR or EEG abnormalities in the initial examination. To compare differences, X(2) test, Fisher exact or Mann-Whitney U-tests were used.

RESULTS

Abnormal cranial MR findings were found in one (6%) pre-eclamptic woman, in four (36%) severe pre-eclamptic women, and in 11 (92%) eclamptic women. Cranial MR findings were consistent with ischaemia in 15 (39%) patients and haemorrhage in one (3%) case. Two (5%) severe pre-eclamptic women showed cerebral infarction during the follow-up period. MR and EEG abnormalities were totally resolved in 88% of cases. The MR findings of 12 (71%) patients were located in the occipital lobes followed by the parietal lobes in six (40%) cases. Three (20%) mild pre-eclamptic women, four (36%) severe pre-eclamptic women and 10 (83%) eclamptic women had abnormal EEGs. The EEG changes were totally resolved in 13 of 14 (93%) patients after the first month. In one patient with cerebral haemorrhage, the EEG changes lasted for a duration of 6 months.

CONCLUSIONS

A correlation between EEG abnormalities and MR findings was found in this study. The combined use of MR and EEG may help to determine the prognosis for these patients, but the interictal EEG findings recorded in eclampsia were non-specific.

Upward transtentorial herniation, hydrocephalus, and cerebellar edema in hypertensive encephalopathy

BACKGROUND

Edema of the cerebellum with secondary obstructive hydrocephalus is a rare presentation of hypertensive encephalopathy. The authors report an unusual case of isolated posterior fossa swelling with upward transtentorial herniation and hydrocephalus causing neurologic deterioration. These patients are often initially evaluated by a neurologist because of the acute neurologic symptoms. Prompt diagnosis with aggressive blood pressure control may obviate the need for emergent cerebrospinal fluid (CSF) diversion.

REVIEW SUMMARY

This is a case report of a 26-year-old man who presented to the emergency room with confusion and somnolence over a 2-day period. His initial blood pressure was 175/110 mmHg. On examination he was disoriented, with a Glasgow Coma Scale score of 12 points, opening his eyes only to loud verbal stimuli, verbalizing inappropriately, and he was only able to follow simple commands. Neuroimaging revealed edema of the cerebellar folia with noncommunicating hydrocephalus and upward transtentorial herniation. Differential diagnoses of posterior fossa tumor, rhombencephalitis, and hypertensive encephalopathy were entertained. A thorough literature review is included with the discussion of this case. The patient underwent emergent ventriculostomy for CSF drainage and prompt blood pressure control with nitroprusside. After 48 hours of CSF drainage and correction of his hypertension, his neurologic examination normalized. Repeat imaging revealed near resolution of the obstructive hydrocephalus and cerebellar edema.

CONCLUSION

Isolated edema of the cerebellum with upward transtentorial herniation and obstructive hydrocephalus is a rare presentation of hypertensive encephalopathy and should be considered in patients with an acute hypertensive crisis and mental status changes. This entity responds to prompt blood pressure control; however, emergent ventriculostomy by a neurosurgical team should be entertained for neurologic deterioration secondary to significant obstructive hydrocephalus, as illustrated in this case.

Permanent visual deficits secondary to the HELLP syndrome

A 34-year-old woman with eclampsia and the hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome developed encephalopathy, cardiomyopathy, pulmonary edema, liver failure, and disseminated intravascular coagulation (DIC), all of which resolved. She also had retinal hemorrhages in both eyes and a hemorrhagic infarct in the left occipital lobe that resulted in a permanent right homonymous hemianopia and a persistently depressed acuity of 20/100 OS. This case is unusual in demonstrating permanent visual deficits. In nearly all cases of preeclampsia or eclampsia, visual deficits are reversible. The superimposition of the HELLP syndrome may create more neurologic damage. Clinicians should be alert to patients at risk for HELLP syndrome and manage them aggressively.

A case of late postpartum seizures after epidural analgesia

We present the case of a 29-year-old female who in her third pregnancy developed seizures seven days postpartum. The only symptoms preceding the seizures were headache and visual disturbance. There was no evidence of preeclampsia antepartum or postpartum. All clinical investigations were normal including computerised tomography, magnetic resonance imaging and lumbar puncture. All symptoms resolved within 24 h of the first seizure. In this case report we highlight the difficulties in establishing the cause of postpartum seizures.

Magnetic resonance imaging in Posterior Reversible Encephalopathy Syndrome: report of three cases and review of literature

INTRODUCTION

Eclampsia is one of the main causes of Posterior Reversible Encephalopathy Syndrome (PRES) a recent clinico-neuroradiological entity represented by characteristic MR findings of a symmetric bilateral subcortical/cortical hyperintensity in T2-weighted images, more often in parieto-occipital lobes, accompanied by clinical neurological alterations. Neuroradiological and clinical alterations are commonly completely reversible although ischemic evolution has been described. The pathophysiology is still a matter of debate. Specific magnetic resonance (MR) techniques, such as FLAIR (fluid attenuated inversion recovery) and DWI (diffusion weighted images) sequences, have improved the ability to detect subcortical/cortical lesions and helped to clarify the underlying pathophysiological mechanism of cerebrovascular involvement, which results important for an appropriate therapeutic decision.

CASE REPORT AND DISCUSSION

We report the MR imaging findings of three patients with eclampsia and PRES as well as a careful review of literature.

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.

Reversible posterior leukoencephalopathy syndrome in children with cancers

We report three cases of reversible posterior leukoencephalopathy syndrome (RPLS) in children with cancers. All patients presented with sudden confusional state, visual disturbance, and transient mild hypertension under the treatment of childhood cancers. Magnetic resonance imaging of the brain demonstrated cortical and subcortical lesions predominantly in the occipital region, which showed high intensity signal on fluid-attenuated inversion recovery images. All patients completely recovered from their neuropsychologic deficits only with antihypertensive therapy or discontinuation of the possible offending drugs. Early recognition of RPLS as a complication during cancer therapy in childhood may facilitate precise diagnosis and appropriate treatment.

Appropriate neurological evaluation and multimodality magnetic resonance imaging in eclampsia

HYPOTHESIS

Simultanagnosia is common in eclampsia and a visuospatial test may be the most appropriate method in assessing the degree and monitoring of neurological deficit.

AIM

To determine a sensitive clinical test for the degree of neurological deficit in eclampsia and in monitoring neurological change.

METHODS

Thirty women with eclampsia were evaluated by clinical neurological quantitative scales including the Canadian Neurological Scale, Glasgow Coma Scale, Mini-Mental State Examination, a validated Cookie Theft Picture Test (CTPT), magnetic resonance imaging (MRI) (T1/T2), diffusion weighted imaging (DWI) and magnetic resonance angiography (MRA).

RESULTS

The CTPT, used to measure simultanagnosia, had a sensitivity of 100% (95% CI: 84.5-100), specificity of 33.3% (95% CI: 1.8-87.5) with positive predictive value of 93.1% (95% CI: 75.8-98.8) and negative predictive value of 100% (95% CI: 5.5-100). The degree of agreement between simultanagnosia as measured by CTPT and DWI was 93.3% (Kappa=0.474; P=0.001). Standard MRI compared with DWI had a sensitivity of 77.8% (95% CI: 57.3-90.6), specificity of 100% (95% CI: 31-100), positive predictive value of 100% (95% CI: 80.8-100) and negative predictive value of 33.3% (95% CI: 9-69.1). The degree of agreement between standard MRI and DWI was 90%, this was statistically significant (Kappa=0.412: P=0.001).

CONCLUSIONS

The validated CTPT for simultanagnosia was abnormal in the majority (n=29; 96.7%) of eclamptic patients with other neurological scales normal. Standard MRI and DWI showed excellent correlation with this simple bedside clinimetric evaluation. The oedema in eclampsia is primarily of vasogenic origin.

Two cases of malignant hypertension with reversible diffuse leukoencephalopathy exhibiting a reversible nocturnal blood pressure "riser" pattern

We report two cases of malignant hypertension with reversible diffuse leukoencephalopathy demonstrating a nocturnal blood pressure (BP) rising pattern ("riser" pattern). Case 1 was a 54-year-old man diagnosed with malignant hypertension who presented with diffuse leukoencephalopathy and nocturnal BP rise during the acute phase. These abnormal findings diminished after treatment of hypertension. Case 2 was a 50-year-old woman diagnosed with malignant hypertension in association with leukoencephalopathy, heart failure and acute renal failure. She also presented with a "riser" pattern during the acute phase. In contrast to case 1, the leukoencephalopathy and "riser" pattern in case 2 were not improved even after 1 month of treatment. Following intensive antihypertensive treatment, renal failure was improved in case 1, but renal failure was not improved after 1 month in case 2. In conclusion, a possible explanation of this phenomenon is that a causative volume overload due to renal dysfunction produced the temporal leukoencephalopathy-like brain edema and "riser" pattern in these cases.

Diagnostic value of apparent diffusion coefficient hyperintensity in selected patients with acute neurologic deficits

BACKGROUND AND PURPOSE

A pattern of decreased intensity on apparent diffusion coefficient (ADC) maps is useful in the early detection of ischemic brain injury. Less information exists with regard to patients with acute neurologic deficits in whom there is abnormal conventional magnetic resonance imaging (MRI) and increased ADC intensity.

METHODS

The authors identified 13 patients with acute neurologic deficits who underwent diffusion MRI and had calculated ADC maps demonstrating hyper-intensity in regions characterized by computed tomography hypodensity and MRI T2 hyperintensity. The initial and follow-up imaging characteristics and clinical syndromes were recorded.

RESULTS

Clinical syndromes included hypertensive encephalopathy, posterior leukoencephalopathy, hyperperfusion following carotid endarterectomy, venous sinus thrombosis, HIV encephalopathy, and brain tumor. Diffusion-weighted imaging (DWI) was hyperintense in 3 of 13 patients, isointense in 4 of 13 patients, heterogeneous in 3 of 13 patients, and hypointense in 3 of 13 patients. The ADC values in these regions were significantly higher than those in control regions (P < .0001). At early follow-up, MRI abnormalities resolved completely in 3 of 13 patients and partially in 9 of 13 patients. MRI abnormalities were unchanged in 1 patient.

CONCLUSIONS

In the evaluation of patients with acute neurologic deficits, ADC hyperintensity may identify a subset of patients with vasogenic edema of nonischemic etiology. Frequently, these conditions are potentially reversible if appropriately managed. DWI and conventional images alone are not sufficient to identify these neurologic conditions.

Clinical spectrum of reversible posterior leukoencephalopathy syndrome

Reversible posterior leukoencephalopathy syndrome is a recently recognized disorder with characteristic radiologic findings that mainly involve the white/gray matter of the parieto-occipital lobes. This complex syndrome is associated with cyclosporine A therapy or a variety of other conditions in which blood pressure rises acutely. Twelve patients from a variety of conditions who met the diagnostic criteria for this syndrome were studied. Interestingly, three of these patients had intra-abdominal neurogenic tumors, which have rarely been reported. Initial cranial magnetic resonance imaging scans revealed fairly symmetric areas of increased T(2) signal involving both white and gray matter of parieto-occipital lobes in the majority of the patients. However, the lesions were often located outside the parieto-occipital regions. Four patients had occipital region magnetic resonance spectroscopy during the acute phase, which revealed high lactate peak and normal N-acetyl aspartate/creatine and choline peaks. With appropriate treatment, most patients recovered from this syndrome and experienced almost complete resolution of brain lesions on follow-up magnetic resonance imaging. One patient, however, continued to have small residual hemosiderin deposits on a follow-up magnetic resonance imaging with neurologic sequellae. In conclusion, a better understanding of this complex syndrome may obviate unnecessary investigations and allow management of the associated problems in prompt and appropriate ways.

Visual loss in pregnancy

A 36-year-old preeclamptic woman presented with bilateral visual loss upon recovery from anesthesia following cesarean section. Visual acuity was hand motion OU. Pupillary responses to light were normal, without a relative afferent pupillary defect. Treatment consisted of control of blood pressure and the patient's vision improved to 20/25 OU within 3 days.

Cortical blindness in a preeclamptic patient after a cesarean delivery complicated by hypotension

IMPLICATIONS

Visual strokes can occur after prolonged hypotension or as a complication of preeclampsia-eclampsia. This case describes the diagnostic dilemma posed by a patient who developed transient blindness after a hypotensive episode during cesarean delivery for severe preeclampsia-eclampsia.

Dynamic susceptibility contrast enhanced MRI in reversible posterior leukoencephalopathy syndrome associated with haemolytic uraemic syndrome

We describe a case of reversible posterior leukoencephalopathy associated with haemolytic uraemic syndrome. Following remission confirmed on MRI, the patient relapsed several months later. Neuroimaging findings on conventional MRI and FLAIR sequences and dynamic susceptibility contrast enhanced MRI are described. White matter abnormalities may be shown on CT or MRI in this syndrome. However, dynamic susceptibility contrast enhanced MRI showed far more extensive abnormality within the brain. In addition, phase contrast angiographic measurement of flow in the carotid and basilar arteries indicated a significant elevation of cerebral blood flow, suggesting a decrease in global cerebrovascular resistance. These observations support existing theories that the disorder is manifested by autoregulatory disturbance in small cerebral vessels. Our findings suggest that this abnormality is far more extensive than is demonstrated on T2 weighted MR images and that it is associated with global abnormality of cerebrovascular autoregulation.

Hypertensive encephalopathy: complication in children treated for myeloproliferative disorders--report of three cases

We routinely perform echo-planar diffusion-weighted sequences in all brain magnetic resonance (MR) imaging studies. When three children undergoing chemotherapy for acute leukemia presented with seizures, conventional MR images demonstrated what appeared to be acute, posterior, parasagittal infarcts. However, diffusion-weighted images were normal. These MR imaging findings were consistent with those of hypertensive encephalopathy. Early recognition and treatment of minimal hypertension in these patients allows reversal of encephalopathy.

Cerebral edema complicating eclampsia

OBJECTIVE

This study was undertaken to describe and correlate clinical findings with computed tomographic and magnetic resonance imaging scan results in 10 women with eclampsia and widespread cerebral edema.

STUDY DESIGN

This was a clinical descriptive study of 10 women with eclampsia and symptomatic cerebral edema who were encountered at Parkland Hospital from 1986 through 1998. During this 13-year period nearly 175 women had eclampsia from a total of >160, 000 women delivered. The clinical courses of these 10 women with eclampsia and symptomatic cerebral edema are described, along with findings from computed tomographic and magnetic resonance imaging scans.

RESULTS

In 3 cases symptoms followed an acute and severe elevation of blood pressure while the patient was being treated for eclampsia. All 3 of these women had severe generalized edema with radiographic findings of impending transtentorial herniation. Herniation did occur in 1 of these women, and she died. The other 7 women had central nervous system symptoms that persisted after an initial eclamptic convulsion. Symptoms ranged from lethargy, confusion, and blurred vision to obtundation and blindness. Five of these women had multiple areas of edema mostly apparent at the gray matter-white matter junction. Two women demonstrated extensive unilateral brain involvement; however, their symptoms were similar to those of the women with multifocal areas of cerebral edema.

CONCLUSION

Symptomatic cerebral edema developed in almost 6% of women with eclampsia. Its genesis probably represents a continuum of central nervous system lesions that result from eclampsia. We postulate that women with symptoms of extensive cerebral edema have a cytotoxic edema caused by ischemia that is intensified by a vasogenic edema associated with sudden or severe hypertension.

Management of acute severe hypertension and encephalopathy

We still do not have an ideal drug to treat acute severe hypertension in pregnancy. Hydralazine and labetalol are the safest agents, but they are inadequate to control blood pressure in some women. Both hypertensive encephalopathy and eclampsia now appear to be forms of an acute process known as reversible posterior leukoencephalopathy syndrome.