Blindness in eclampsia: CT and MR imaging

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.

Specialized Diagnostic Investigations to Assess Ocular Status in Hypertensive Diseases of Pregnancy

This review describes specialized diagnostic investigations to assess ocular status in hypertensive diseases of pregnancy. Ocular assessment can aid in early detection for prompt multidisciplinary treatment, obstetric intervention and follow-up. The investigations accurately predict the possible causes of blindness in hypertensive diseases of pregnancy. The investigations include fluorescein angiography, ophthalmodynamometry, fluorophotometry, imaging modalities, OCT, ultrasonography, doppler velocimetry and blood chemistry analysis. The review includes a summary of imaging techniques and related recent developments to assess the neuro-ophthalmic aspects of the disease. The imaging modalities have been instrumental in understanding the complex neuropathophysiological mechanisms of eclamptic seizures. The importance of blood chemistry analysis in hypertensive diseases of pregnancy has been emphasized. The investigations have made a significant contribution in improving the standards of antenatal care and reducing maternal and fetal morbidity and mortality.

Posterior Reversible Encephalopathy Syndrome: Clinical Differences in Patients with Exclusive Involvement of Posterior Circulation Compared to Anterior or Global Involvement

INTRODUCTION

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiologic syndrome not yet fully understood and characterized by transient neurologic symptoms in addition to typical radiological findings. There are only a few articles that describe the clinical differences between patients with PRES that involve carotid and vertebrobasilar circulations. Our study aims to further evaluate the differences between predominantly anterior and posterior circulation PRES.

METHODS

We review 54 patients who had received the diagnosis of PRES from 2009 to 2015. The patients were divided into 2 groups: (1) exclusively in posterior zones; and (2) anterior plus posterior zones or exclusively anterior zones. Several clinical characteristics were evaluated, including the following: age, sex, previous diseases, the neurologic manifestations, the highest blood pressure in the first 48 hours of presentation, highest creatinine level during symptoms, and the neuroimaging alterations in brain magnetic resonance imaging.

RESULTS

Mean age at diagnosis was 28.5 years old (9 men and 45 women) and mean systolic blood pressure among patients with lesions only in posterior zones was 162.1 mmHg compared to 179.2 mmHg in the anterior circulation. The most common symptoms in the 2 groups were headache and visual disturbances.

DISCUSSION

PRES may have several radiological features. A higher blood pressure seems to be 1 of the factors responsible for developing widespread PRES, with involvement of carotid vascular territory. This clinical-radiological difference probably occurs because of the larger number of autonomic receptors in the carotid artery in comparison to the vertebral-basilar system.

Toxic leukoencephalopathies

Leukoencephalopathy is a syndrome of neurologic deficits, including alteration of mental status, caused by pathologic changes in the cerebral white matter. The term, toxic leukoencephalopathy, encompasses a wide variety of exposures and clinical presentations. The diagnosis in these Frontiers in Clinical Neurotoxicology syndromes is made by careful attention to the history, clinical features, and radiologic findings. This article details three of the best-defined toxic leukoencephalopathies: delayed posthypoxic leukoencephalopathy, including delayed neurologic sequelae after carbon monoxide poisoning; heroin inhalation leukoencephalopathy; and posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome (PRES/RPLS) during pulse steroid therapy in macrophage activation syndrome

Posterior reversible encephalopathy syndrome (PRES)or Reversible posterior leukoencephalopathy syndrome (RPLS) is a neurological complication associated with various illnesses and medications(including rheumatological illnesses and their medications). Cyclosporine is the drug which is most commonly implicated in the causation of this condition. The authors report a 6 year old patient with systemic onset juvenile idiopathic arthritis (SoJIA) with macrophage activation syndrome who developed PRES during treatment with pulse methylprednsiolone therapy. In view of persitent SoJIA disease activity, the child was subsequently treated with Cyclosporine. The child made a complete neurological recovery. This case report highlights that, in accordance with recent literature, PRES is a complication of a unique set of conditions comprising of inflammation, hypertension, immunosupression and nephropathy in different degrees and does not necessarily preclude the use of drugs implicated as inciting agents. This has important implications in rheumatology where cyclosporine is a life saving medication used in macrophage activation syndrome.

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.

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.

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.

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.

[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.

Maternal transcranial Doppler in pre-eclampsia and eclampsia

Pre-eclampsia affects 3-7% of women and is associated with significant maternal and perinatal morbidity and mortality. Transcranial Doppler (TCD) has been used in pre-eclampsia/eclampsia to evaluate non-invasively the cerebrovascular hemodynamics in the maternal middle cerebral artery. TCD has demonstrated in pre-eclamptic women maternal cerebral vasospasm, which does not correlate with mean arterial pressure assessed simultaneously. Estimated cerebral perfusion pressure, assessed using a modified formula, has been shown to be increased in women with severe and non-severe pre-eclampsia. However, in severe pre-eclampsia, elevated cerebral perfusion pressure is counterbalanced by increases in cerebrovascular resistance and cerebral blood flow is unaffected. In eclampsia a significant fall in cerebral vascular resistance occurs which, in the presence of increases in cerebral perfusion pressure, leads to hyperperfusion. Cerebral vascular changes to date have not been sensitive enough to predict the development of pre-eclampsia or eclampsia. Longitudinal studies with the aim of predicting the onset of pre-eclampsia and to assess the effects of various drugs on the maternal cerebral circulation need to be designed.

Hypertensive brainstem encephalopathy: clinical and radiographic features

Reversible posterior leukoencephalopathy syndrome associated with hypertension rarely presents with predominant involvement of the brainstem and relative sparing of the supratentorial regions. We describe the clinical and neuroimaging features of three patients with reversible hypertensive brainstem encephalopathy. Headache and confusion in the setting of severe hypertension, with a relative paucity of brainstem signs and symptoms, despite extensive neuroimaging abnormalities in the brainstem support the diagnosis. The clinical findings and neuroimaging abnormalities resolve with treatment of the hypertension, further distinguishing this syndrome from brainstem infarction.

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.

Magnetic resonance imaging in preeclampsia and eclampsia complicated by visual disturbance and other neurological abnormalities

This study describes magnetic resonance imaging findings in women presenting with neurological complications associated with preeclampsia and eclampsia. One eclamptic and two preeclamptic women were studied after presenting with postpartum neurological events. In two women the brain increased in size on the initial follow-up images, following the same pattern seen in normal pregnancy. In the other woman, the brain was decreased in size at 13 days postpartum but increased in size at six weeks postpartum. This initial reduction in brain size may reflect the resolution of cerebral oedema resulting from underlying pathological processes.

The maternal cerebral circulation in pre-eclampsia: investigations using Laplace transform analysis of Doppler waveforms

OBJECTIVE

To compare the maternal cerebral circulation in pre-eclampsia and normal pregnancy using an alternative method of Doppler waveform analysis called the Laplace transform analysis, which provides haemodynamic data additional to standard Doppler indices.

DESIGN

A prospective cross-sectional study.

SETTING

Department of Obstetrics and Gynaecology, Nottingham University Hospital.

SAMPLE

The study involved 17 women in the third trimester of a normal pregnancy, 11 with pregnancy-induced hypertension and 26 with pre-eclampsia.

METHODS

Doppler recordings were obtained from the internal and external carotid and middle cerebral arteries, with the measurements in hypertensive women being carried out before any treatment was given. The waveforms were then subjected to Laplace transform analysis which provides information on vessel wall stiffness and upstream and downstream flow conditions.

MAIN OUTCOME MEASURES

The determination of the Laplace transform analysis parameters, including alpha, the natural frequency of oscillation and real pole, and pulsatility index.

RESULTS

Laplace transform analysis demonstrated a significant increase in vessel wall stiffness in all the arteries in hypertensive pregnancies, but this was more marked in pre-eclampsia. The data were also consistent with, but do not prove, increased downstream resistance in the middle cerebral artery in women with pre-eclampsia but not in those with pregnancy-induced hypertension.

CONCLUSIONS

The Laplace transform analysis of Doppler waveforms yields important physiological information concerning the cerebral circulation in pre-eclampsia, not detected using conventional Doppler indices. The results suggest that both pre-eclampsia and pregnancy-induced hypertension are associated with increased cerebral arterial wall stiffness and that, in addition, there may be cerebral vasoconstriction in pre-eclampsia.

Obstetrical anaesthesia for a parturient with preeclampsia, HELLP syndrome and acute cortical blindness

PURPOSE

To report the management of a multigravida presenting with preeclampsia, HELLP syndrome and acute cortical blindness for Caesarean section.

CLINICAL FEATURES

A 39-yr-old woman, with three past uncomplicated pregnancies presented at 33 wk with acute cortical blindness. Based on clinical and laboratory assessment, a diagnosis of preeclampsia with HELLP syndrome was made. A CT scan of her head demonstrated ischaemic lesions of her basal ganglia, extending superiorly to involve both posterior parietal and occipital regions. Infusions of magnesium sulphate and hydralazine were started and an urgent Caesarean section was performed under subarachnoid anaesthesia after insertion of an arterial line and intravenous hydration. The course of anaesthesia and surgery was uneventful and she delivered a live 1540 g female infant. By the following morning, she had recovered some vision and visual recovery was complete by 72 hr postpartum. She underwent an MRI with angiography on the first postpartum day. Ischaemic lesions were confirmed in the same sites identified on CT scan but all major cerebral vessels were patent and no significant vascular abnormality was noted. Her postoperative course was uneventful and she was discharged home seven days postpartum after being prescribed labetalol for continued hypertension.

CONCLUSION

The anaesthetic management of a parturient with acute cortical blindness and HELLP syndrome is modeled on the underlying preeclamptic condition. Invasive monitoring is not routinely indicated but is specifically indicated in some cases. Provided that it is not contraindicated because of prohibitive risk to the mother, regional anaesthesia has particular advantage in these patients. In particular, the use of spinal anaesthesia, which has been discouraged by some for this patient population, should be re-evaluated.

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.

Eclamptic encephalopathy: imaging and pathogenetic considerations

Eclampsia is a rare condition peculiar to pregnant and puerperal women, characterized by clinical pre-eclampsia (hypertension, proteinuria, edema) and generalized seizures. Three cases of eclamptic encephalopathy are reported: CT and MRI demonstrated transient abnormalities in the cortical and subcortical regions of the posterior areas of the brain - namely, parieto-occipital lobes - associated with occasional involvement of basal ganglia and/or brainstem. Pathogenesis is still unclear. Strict similarity with the pathological findings characterizing hypertensive encephalopathy suggests that a focal impairment in cerebral autoregulation may be the cause of vasodilation and fluid extravasation leading to hydrostatic edema; selective involvement of posterior areas could be explained by their lesser degree of adrenergic innervation supporting circulatory autoregulation mechanisms.

Single photon emission and cerebral computerised tomographic scan and transcranial Doppler sonographic findings in eclampsia

OBJECTIVE

To define more clearly the neuropathophysiology of eclampsia utilising single-photon emission computed tomography (SPECT), cerebral computerised tomography (CT) and transcranial Doppler (TCD) ultrasonography.

DESIGN

A prospective study

SETTING

The obstetric unit in King Edward VIII Hospital, a large tertiary referral centre in Kwa-Zulu Natal, South Africa.

PARTICIPANTS

Sixty-five women with eclampsia.

INTERVENTIONS

Imaging and ultrasonographic investigations were performed within 48 hours postpartum. Unenhanced cerebral CT scans were performed in all the women and SPECT scans were performed on 63 women using Technetium-99m-hexamethylpropyleneamineoxime (99mTc-HMPAO) as a tracer of regional cerebral blood flow. Middle cerebral artery blood flow velocity waveforms were measured using 2 MHz pulsed Doppler ultrasound via the transtemporal approach.

MAIN OUTCOME MEASURES

Abnormalities in SPECT scan, CT scan and TCD ultrasound findings.

RESULTS

SPECT scanning revealed perfusion deficits in the watershed areas in all women, 75% of whom had concomitant deficits in the parieto-occipital areas of the brain. Hypodensities (cerebral oedema) were reported in 38 CT scans (58.5%), with parieto-occipital involvement in 97.4% of cases. Increased flow velocity measurements in the middle and posterior cerebral arteries were recorded in 36 (85.7%) women in whom TCD ultrasound was performed.

CONCLUSION

The pathophysiological mechanism of eclamptic seizures is primary cerebral vasospasm with resultant ischaemia and cerebral oedema involving mainly the watershed areas and parieto-occipital lobes of the brain. SPECT scanning has been shown to be superior to CT scanning and TCD ultrasonography in detecting neuropathophysiologic alterations in eclampsia. However, each of the three investigative tools provide its own unique information and all three are necessary research techniques to improve our understanding of the neuropathophysiological mechanism of eclamptic seizures.

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.

Brain MRI findings in two cases with eclampsia

Neurological complications in patients with eclampsia are varied and include headache, visual disturbances, focal neurological deficits, altered mental status and coma. Occasionally, a focal neurological deficit includes a variety of visual disturbances. The pathophysiology of CNS abnormalities in patients with eclampsia is uncertain. Our cases, combined with a review of the literature, demonstrate that there is no correlation among severity of hypertension, parity, and location of lesions at initial magnetic resonance (MR) imaging findings or between the severity of hypertension and neurological symptoms. Two typical patterns are seen on MR images of patients with eclampsia. Lesions in the region of the posterior cerebral circulation are most common and are frequently associated with visual disturbances. Although there are lesions in the deep white matter or basal ganglia, a focal neurological deficit or alterations in mental status may not develop. This demonstrates the sensitivity of MR imaging in the detection of abnormalities in patients with eclampsia, even those without neurological deficits.

A reversible posterior leukoencephalopathy syndrome

BACKGROUND AND METHODS

In some patients who are hospitalized for acute illness, we have noted a reversible syndrome of headache, altered mental functioning, seizures, and loss of vision associated with findings indicating predominantly posterior leukoencephalopathy on imaging studies. To elucidate this syndrome, we searched the log books listing computed tomographic (CT) and magnetic resonance imaging (MRI) studies performed at the New England Medical Center in Boston and Hôpital Sainte Anne in Paris; we found 15 such patients who were evaluated from 1988 through 1994.

RESULTS

Of the 15 patients, 7 were receiving immunosuppressive therapy after transplantation or as treatment for aplastic anemia, 1 was receiving interferon for melanoma, 3 had eclampsia, and 4 had acute hypertensive encephalopathy associated with renal disease (2 with lupus nephritis, 1 with acute glomerulonephritis, and 1 with acetaminophen-induced hepatorenal failure). Altogether, 12 patients had abrupt increases in blood pressure, and 8 had some impairment of renal function. The clinical findings included headaches, vomiting, confusion, seizures, cortical blindness and other visual abnormalities, and motor signs. CT and MRI studies showed extensive bilateral white-matter abnormalities suggestive of edema in the posterior regions of the cerebral hemispheres, but the changes often involved other cerebral areas, the brain stem, or the cerebellum. The patients were treated with antihypertensive medications, and immunosuppressive therapy was withdrawn or the dose was reduced. In all 15 patients, the neurologic deficits resolved within two weeks.

CONCLUSIONS

Reversible, predominantly posterior leukoencephalopathy may develop in patients who have renal insufficiency or hypertension or who are immunosuppressed. The findings on neuroimaging are characteristic of subcortical edema without infarction.

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.

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.

Electroencephalogram and computerised cerebral tomography findings in eclampsia

OBJECTIVE

To define more clearly the neuropathophysiology of eclampsia.

DESIGN

A prospective study relating to computerised cerebral tomography (CAT) scan and electroencephalogram (EEG) findings in eclampsia.

SETTING

A large referral centre in a developing society.

SUBJECTS

Thirty-two women with eclampsia.

MAIN OUTCOME MEASURES

Abnormalities in EEG and CAT scan findings.

RESULTS

Approximately 45% of the women studied had CAT scan abnormalities, while 90% had EEG abnormalities. A burst suppression pattern on EEG examination was found in four women suggesting a temporary dissolution of cerebral function to the midbrain level as the cause of seizures.

CONCLUSIONS

EEGs are probably more sensitive than CAT scans in detecting the extent of the pathology in the brain in women with eclampsia.

Delayed peripartum vasculopathy: cerebral eclampsia revisited

Over a 2-year period, we treated 4 postpartum patients with acute neurologic problems appearing 4 to 9 days after delivery. Three patients either had no proteinuria or edema and therefore did not meet all accepted clinical criteria for the diagnosis of eclampsia. Magnetic resonance imaging (MRI) of the brain in all patients demonstrated high-signal foci most prominent in the parieto-occipital regions and the subcortical white matter. Cerebral angiogram in 2 patients revealed diffuse vasospasm. In 3 patients, MRI abnormalities resolved. MRI and angiographic abnormalities in our patients are identical to those of patients meeting accepted criteria for eclampsia. Our experience suggests that the current criteria for the diagnosis of eclampsia are too stringent, both in terms of clinical picture and days postpartum to cerebral manifestations.

Cortical visual impairment following bacterial meningitis: magnetic resonance imaging and visual evoked potentials findings in two cases

Cortical visual impairment (CVI) following bacterial meningitis is a very uncommon complication. Two children with CVI following bacterial meningitis are reported. Bacterial agents were Haemophilus influenzae type B in one and meningococci in the other child. Both children showed only insufficient recovery from CVI, mental retardation and residual neurological symptoms. Flash visual evoked potentials (VEP) showed preserved cortical response at onset of CVI. Re-evaluations several months later showed significantly reduced amplitudes, but normal latencies for P100. Thus, flash VEP does not allow prediction of visual outcome. MRI results have not been reported before. MRI at onset of diagnosis showed occipital parenchymal irregularities with enlarged sulci and subarachnoid spaces. Follow up MRI 15 months after onset of CVI in one patient showed marked atrophy of the occipital cortex, hyperintensities of the cortical white matter and no visible optic radiation. The MRI findings indicate hypoxic-ischaemic lesions in the border zone between the distribution of the great cerebral arteries.

Cerebral imaging in eclampsia: magnetic resonance imaging versus computed tomography

OBJECTIVES

Our objectives were to study the cerebral pathophysiology of eclampsia with the noninvasive technique of magnetic resonance imaging to compare the ability of magnetic resonance imaging to detect cerebral abnormalities in eclampsia with that of computed tomography.

STUDY DESIGN

Twenty-four patients with eclampsia received both magnetic resonance imaging and computed tomographic scanning.

RESULTS

Forty-six percent of the magnetic resonance imaging was abnormal and 33% of the computed tomography was abnormal. This higher incidence of abnormal magnetic resonance imaging scans was present in spite of the fact that they were obtained significantly longer after the patient's seizure activity. The most common abnormalities were cortisol, subcortical, and white matter edema.

CONCLUSION

Magnetic resonance imaging and computed tomographic scan abnormalities in eclampsia are usually similar. Cerebral imaging is not necessary in patients with uncomplicated eclampsia.

Magnetic resonance image abnormality in migraine with aura

Cerebral magnetic resonance imaging (MRI) was performed on 18 patients with migraine characterized by aura consisting of both visual symptoms and paresthesias. Fifteen headache-free individuals of the same age range were used as controls. Records were randomized and read in blind fashion by two neuroradiologists. Small subcortical white matter lesions were seen in three migraine cases and two controls. In one migraine case cortical infarctions were seen. In two controls, small areas of increased density similar to those in migraine were seen. No consistent correlation of migraine or its duration with cerebral atrophy was found. It is concluded that identification of both these MRI findings (small subcortical white lesions and cerebral atrophy) as significantly associated with migraine is doubtful.

Perioperative stroke. Part I: General surgery, carotid artery disease, and carotid endarterectomy

Although stroke, defined as a focal neurological deficit lasting more than 24 hr, is uncommon in the perioperative period, its associated mortality and long-term disability are high. No large-scale data are available to identify the importance of recognized risk factors for stroke in the perioperative period. A review of the literature shows that the incidence and mechanism of its occurrence are influenced by the presence of cardiovascular disease and the type of surgery. The most common cause of perioperative stroke is embolism. In non-cardiac surgery, the incidence of perioperative stroke is higher among the elderly. Properly administered, controlled hypotension is associated with minimal risk of stroke. Cerebral vasospasm may be the cause of focal cerebral ischaemia in eclamptic patients, and the aggressive treatment of hypertension may exacerbate the neurological damage. The risk of stroke associated with carotid endarterectomy is closely related to the preoperative neurological presentation, and the experience of the surgical/anaesthetic team. Symptomatic cerebrovascular disease, acute stroke, asymptomatic carotid lesions, preoperative assessment of risk, local and general anaesthesia, cerebral protection and monitoring during carotid endarterectomy are discussed with reference to reducing the risk of perioperative stroke. Adequate monitoring and protection have minimized the risk of ischaemia from carotid clamping, and the major mechanism of stroke is embolization.

Widespread cerebral ischaemia treated with nimodipine in a patient with eclampsia

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