A multi-disciplinary model of risk factors for fatal outcome in posterior reversible encephalopathy syndrome

Hemolysis, Elevated Liver Enzymes and Low Platelet Count Syndrome Complicated by Disseminated Intravascular Coagulation and Posterior Reversible Encephalopathy Syndrome: A Case Report

A 22-year-old pregnant woman was transferred from an external medical facility after experiencing an eclamptic seizure linked to hemolysis, elevated liver enzymes and low platelet count syndrome (HELLP) syndrome, and posterior reversible encephalopathy syndrome (PRES). Her situation was further complicated by intrauterine fetal demise and disseminated intravascular coagulation, necessitating a comprehensive multidisciplinary approach. This report details the diagnostic process and challenges in managing this complex patient with diverse medical requirements. Emphasis is placed on the observed hemostatic abnormalities, and we delineate the nuances in our approach compared to managing a similar condition in a nonpregnant patient. Heightened awareness among healthcare professionals is imperative for prompt diagnosis and effective intervention in such uncommon neurological complications during pregnancy.

Posterior Reversible Encephalopathy Syndrome With Hemorrhagic Transformation in the Postoperative Period of a Kidney Transplant

Patients with end-stage renal disease (ESRD) who undergo kidney transplantation are at an increased risk of developing surgical and/or medical complications. Posterior reversible encephalopathy syndrome (PRES) is a rare complication that occurs in 0.34% of kidney transplant patients. It is characterized by a combination of neurological manifestations, risk factors, and characteristic radiological findings in neuroimaging studies. The development of PRES has been associated with various medical conditions and factors, including hypertension, the use of cytotoxic and immunosuppressive drugs, acute or chronic kidney disease, pre-eclampsia/eclampsia, autoimmune diseases, and solid organ and bone marrow transplantation. This report presents the case of a 19-year-old woman diagnosed with ESRD on hemodialysis due to lupus nephritis who experienced an episode of PRES with intraparenchymal hemorrhage during the postoperative period of kidney transplantation. The case emphasizes the importance of closely monitoring these patients during this period to enable early diagnosis and timely treatment of complications, ensuring a favorable prognosis.

Imaging of Reversible Cerebral Vasoconstriction Syndrome and Posterior Reversible Encephalopathy Syndrome

PRES and RCVS are increasingly recognized due to the wider use of brain MRI and increasing clinical awareness. Imaging plays a crucial role in confirming the diagnosis and guiding clinical management for PRES and RCVS. Imaging also has a pivotal role in determining the temporal progression of these entities, detecting complications, and predicting prognosis. In this review, we aim to describe PRES and RCVS, discuss their possible pathophysiological mechanisms, and discuss imaging methods that are useful in the diagnosis, management, and follow-up of patients.

Posterior Reversible Encephalopathy Syndrome (PRES) and the Uncommon Sequela: Mesial Temporal Sclerosis

Posterior reversible encephalopathy syndrome is often linked to conditions like hypertension and is characterized by reversible brain edema. The development of mesial temporal sclerosis as a consequence of posterior reversible encephalopathy syndrome is an uncommon clinical outcome.  We report a 48-year-old female who initially presented with severe iron deficiency anemia, hypertension, and septic tenosynovitis requiring surgical drainage with subsequent development of posterior reversible encephalopathy syndrome accompanied by endocarditis. Although there was a question of one seizure episode during one of her hospital days, the patient experienced multiple seizure episodes three months after she left the hospital. Subsequent MRI demonstrated atrophy of the left mesial temporal lobe suggesting mesial temporal sclerosis.  The temporal development of mesial temporal sclerosis in a patient with posterior reversible encephalopathy syndrome highlights mesial temporal sclerosis as a potential long-term consequence of posterior reversible encephalopathy syndrome, and the need for imaging surveillance in patients diagnosed with posterior reversible encephalopathy syndrome.

Pediatric Posterior Reversible Encephalopathy Syndrome: A Review With Emphasis on Neuroimaging Characteristics

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by the sudden onset of seizures, headaches, and visual disturbances. Its exact cause is unknown, but several triggers and associated conditions are identified, including high blood pressure, kidney dysfunction, and various medications. Magnetic resonance imaging (MRI) plays a crucial role in diagnosis due to its high sensitivity and specificity for detecting characteristic features. Pediatric PRES exhibit age-dependent differences in triggers, radiological findings, and clinical course. The lesions typically involve the posterior cortical and subcortical white matter, but atypical locations and features are also observed. While generally reversible with appropriate treatment, PRES carries a risk of permanent neurological damage. Despite increasing cases, the current literature on pediatric PRES remains limited. This review highlights the need for further research to understand the mechanisms, delineate distinct clinical and radiological features, and develop precise diagnostic and management strategies for pediatric patients.

Posterior reversible encephalopathy syndrome in children with malignancies - a single-center retrospective study

Background

Posterior reversible encephalopathy syndrome (PRES) diagnosis relies on clinical and radiological characteristics. Clinical manifestations include focal neurologic deficits, hemiparesis, seizures with symptoms of intracranial hypertension, headache, nausea, vomiting, and visual field disturbances. The majority of patients have typical changes in magnetic resonance imaging. The epidemiology and outcomes of PRES in the pediatric cancer population have not been well described. Most of the available data are from retrospective analyses.

Objective

The aim of our study was to evaluate the clinical and radiological presentation as well as the outcome of PRES in children treated for cancers in a single center.

Methods

We analyzed data from 1,053 patients diagnosed with malignancies in a single center over 15 years to determine the incidence of PRES.

Results

19/1053 (1.8%) patients developed PRES. The diagnosis was accompanied by a range of clinical symptoms including hypertension, seizures, altered mental status, and headaches. Magnetic resonance imaging was performed in all patients, and 14/19 (73.7%) exhibited typical findings consistent with PRES. Four patients (21.0%) required treatment in the Intensive Care Unit.

Conclusion

Posterior reversible encephalopathy syndrome (PRES) is a rare but significant complication in children with cancer.There is a clear need to establish clinical criteria for PRES to improve the diagnosis and treatment of patients with PRES, particularly in the pediatric oncological population.Further studies are needed to identify the risk factors for recurrent PRES, particularly in pediatric cancer patients undergoing chemotherapy or immunosuppressive treatment.

Posterior Reversible Leukoencephalopathy With Hemorrhagic Features: A Case Series

Introduction Posterior reversible leukoencephalopathy syndrome (PRES) is a clinical-radiological condition characterized by reversible subcortical vasogenic cerebral edema of acute or subacute onset in circumstances that disrupt capillary permeability, unfrequently accompanied by cytotoxic and/or hemorrhagic lesions. We describe a case series of PRES with hemorrhagic features. Subjects and methods Electronic medical records of hospitalized patients diagnosed with PRES from January 2009 to December 2021 were collected. Demographic data, medical history, clinical presentation, and outcome were recorded. Variables were compared between patients with and without hemorrhagic features using the Wilcoxon-Mann-Whitney test with a statistical significance level of p<0.05. Results Over a 12-year period, 33 patients were diagnosed with PRES, of whom 10 had hemorrhagic features: seven cortical microbleeds, two intraparenchymal hematomas, and one subarachnoid hemorrhage. Half of the patients were women, with a median age of 45.8 years (interquartile range (IQR) 21.8), and were admitted for non-neurological reasons. The sample included nine transplant recipients (six solid organa, three bone marrowa), with four patients in the immediate post-transplant period. PRES occurred in the context of infections and blood pressure fluctuations under cytotoxic drugs, such as immunosuppressants. Seventy percent showed improvement/resolution on neuroimaging at a median of 70 days (IQR 62.9). The three major hemorrhages occurred in the context of thrombocytopenia. The recorded in-hospital mortality was 10%. When compared to PRES without hemorrhagic features, patients with hemorrhagic features had a lower use of corticosteroids (50% vs. 78.8%; p=0.02) and a higher presence of restrictive lesions on neuroimaging (60% vs. 17%; p=0.04), with no differences in the other analyzed variables. Conclusion Patients with PRES and hemorrhagic features had a lower use of corticosteroids and a higher presence of restrictive lesions on neuroimaging. Further studies are needed to better understand the clinical implications and management of PRES with hemorrhagic manifestations.

Is decompressive craniectomy necessary in malignant posterior reversible encephalopathy syndrome with brain edema caused uncal herniation? A case report of reversible coma without surgical decompression

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is considered a benign entity and is usually reversible with only medical management, but persistent neurologic deficits and disability or death can occur without adequate treatment. Favorable outcomes have been associated with surgical decompression in malignant-type PRES in which hemorrhagic transformation or brain stem compression has developed.

CASE DESCRIPTION

Here we report a case of malignant PRES in a 61-year-old female of Asian descent in which the disease rapidly progressed to coma and a near-fatal condition with uncal herniation caused by severe brain edema; however, this patient achieved a dramatic recovery without surgical decompression.

CONCLUSION

After reviewing previous reports regarding malignant PRES, we propose that hemorrhagic transformation is a crucial indicator for surgical decompression and an important prognostic factor in malignant PRES.

Posterior Reversible Leucoencephalopathy Syndrome: Case Series, Comments, and Diagnostic Dilemma

PURPOSE OF REVIEW

To report a series of patients with clinical and radiological features suggestive of posterior reversible encephalopathy syndrome (PRES) related to diverse etiologies emphasizing its pathophysiological basis.

RECENT FINDINGS

Posterior reversible encephalopathy syndrome (PRES) may present with a broad range of clinical symptoms from headache and visual disturbances to seizure and altered mentation. Typical imaging findings include posterior-circulation predominant vasogenic edema. Although there are many well-documented diseases associated with PRES, the exact pathophysiologic mechanism has yet to be fully elucidated. Generally accepted theories revolve around disruption of the blood-brain barrier secondary to elevated intracranial pressures or endothelial injury induced by ischemia from a vasoconstrictive response to rising blood pressure or toxins/cytokines. While clinical and radiographic reversibility is common, long-standing morbidity and mortality can occur in severe forms. In patients with malignant forms of PRES, aggressive care has markedly reduced mortality and improved functional outcomes. Various factors that have been associated with poor outcome include altered sensorium, hypertensive etiology, hyperglycemia, longer time to control the causative factor, elevated C reactive protein, coagulopathy, extensive cerebral edema, and hemorrhage on imaging. Reversible cerebral vasoconstriction syndromes (RCVS) and primary angiitis of the central nervous system (PACNS) are invariably considered in the differential diagnosis of new cerebral arteriopathies. Recurrent thunderclap headache (TCH), and single TCH combined with either normal neuroimaging, border zone infarcts, or vasogenic edema, have 100% positive predictive value for diagnosing RCVS or RCVS-spectrum disorders. Diagnosis of PRES in some circumstances can be challenging and structural imaging may not be sufficient to distinguish it from other differential diagnostic considerations like ADEM. Advanced imaging techniques, such as MR spectroscopy or positron emission tomography (PET) can provide additional information to determine the diagnosis. Such techniques are more useful to understand the underlying vasculopathic changes in PRES and may answer some of the unresolved controversies in pathophysiology of this complex disease. Eight patients with PRES resulting from different etiologies varying from pre-eclampsia/eclampsia, post-partum headache with seizures, neuropsychiatric systemic lupus erythematosus, snake bite, Dengue fever with encephalopathy, alcoholic liver cirrhosis with hepatic encephalopathy, and lastly reversible cerebral vasoconstriction syndrome (RCVS). Additionally, a diagnostic dilemma between PRES and acute disseminated encephalomyelitis (ADEM) was notable in one patient. Some of these patients did not have or only very transiently had arterial hypertension. PRES may underlie the clinical conundrum of headache, confusion, altered sensorium, seizures, and visual impairment. PRES need not necessarily be always associated with high blood pressure. Imaging findings may also be variable. Both clinicians and radiologists need to familiarize themselves with such variabilities.

Posterior Reversible Encephalopathy Syndrome in a Pediatric Patient with End-Stage Renal Disease

Posterior reversible encephalopathy syndrome (PRES) is a clinical and neuroimaging syndrome that can affect both children and adults and has variable etiology. It is clinically defined by headaches, consciousness disorders, seizures and visual disturbances. Early recognition (clinical and imaging) can lead to appropriate general measures to correct the underlying cause of PRES. In this paper, we report a case of PRES in an eight-year-old boy with bilateral renal hypoplasia and end-stage renal disease (ESRD).

Seizures in patients with kidney diseases: a neglected problem?

Nephrologists may encounter many systemic problems in their patients, including involvement of the neurological system and the development of seizures. Seizures are defined as abnormal neurological functions that cause overstimulation of neurons in the cerebral cortex or limbic system. Seizures may be focal or generalized depending on their origin and may have tonic, clonic, tonic-clonic or myoclonic character depending on the level of involvement of the motor movements. Patients with kidney disease may develop seizures due to etiologies seen in the general population (such as intracranial bleeding, cerebrovascular events, tumors, infections and intoxications) or due to kidney-related etiologies (such as uremic encephalopathy, dialysis disequilibrium syndrome and hyponatremia). Management of seizures in kidney patients is challenging for proper determination of the type and dosage of antiepileptic drugs due to varying renal clearances. This review covers the major causes of new-onset seizures in patients with acute kidney injury, electrolyte imbalances, chronic kidney disease, dialysis, renal transplantation or hypertension, and the available management approaches.

Drugs associated with posterior reversible encephalopathy syndrome, a worldwide signal detection study

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) can occur in a variety of clinical conditions, such as severe hypertension, pregnancy, inflammatory diseases, hematopoietic stem cells or solid organ transplantation. Apart increased blood pressure levels and altered renal function, several drugs have been reported as potential triggering factor. These descriptions are nevertheless limited to case reports or small case series. Systematic analysis of drugs associated with PRES using global pharmacovigilance database is lacking and can be useful.

METHODS

We performed a disproportionality analysis using VigiBase, the World Health Organization pharmacovigilance database, using the information component (IC). The IC compares observed and expected values to find associations between drugs and PRES using disproportionate Bayesian reporting. An IC_0.25 (lower end of the IC 95% credibility interval) > 0 is considered statistically significant.

RESULTS

Here we present an analysis of 3278 cases of PRES reported in VigiBase. These results identified 73 molecules statistically associated with PRES using full database as background with an IC_0.25 > 0. Only 34% (N = 25/73) of them had this information written in the summary of product characteristics. The main drug classes involved were antineoplastic and immunomodulating agents and the drugs with the greatest number of cases were tacrolimus, cyclosporin, bevacizumab, methotrexate, and vincristine. An overall mortality of 8.1% (N = 267/3278) was identified in cases of drug-associated PRES.

CONCLUSION

These results will help clinicians identify potential suspected drugs associated with PRES and decide which drug to discontinue and eventually lead to a re-evaluation of drug labels for some molecules.

Clinical Features and Risk Factors of Mortality in Patients with Posterior Reversible Encephalopathy Syndrome

Objective. Although the prognosis of posterior reversible encephalopathy syndrome (PRES) is usually favourable and most patients wholly recover, the disorder can result in death in some patients. To date, the data on clinical features and risk factors for death are still lacking; therefore, we aim to investigate the clinical features and long-term prognostic risk factors of PRES in the present study. Methods. The patients with PRES were identified from the First Affiliated Hospital of Zhengzhou University from June 2011 to June 2020. Clinical characteristics, laboratory tests, magnetic resonance imaging examinations, and treatment of all patients were analyzed retrospectively. All patients were followed up by telephone. Finally, the patients were divided into the survival group and death group for prognosis analysis. Results. A total of 92 patients with PRES were included; 84.8% of whom were female, with an average age of 25.4 (5–66) years at the onset of PRES. Epilepsy was the main clinical manifestation (72.8%). The in-hospital mortality rate was 2.17%. The 3-year all-cause survival rate for PRES patients was 86%. In univariate analysis, patients with systemic lupus erythematosus ( $P=0.027$ ) and blood transfusion history within 1 month before onset ( $P=0.027$ ), need for dialysis ( $P\le 0.001$ ), nephritis ( $P=0.010$ ), stroke ( $P=0.016$ ), and heart failure ( $P=0.016$ ) were associated with death. In multivariate analysis, we found that heart failure ( $\text{OR}=0.095$ , 95% CI 0.020 to 0.441) and stroke ( $\text{OR}=0.033$ , 95% CI 0.002 to 0.467) were independent risk factors for death in PRES patients, while pregnancy was a protective factor for death in PRES patients ( $\text{OR}=7.978$ , 95% CI 1.446 to 44.006). Conclusions. Our results indicate that PRES could be considered as a sign of a very high-risk patient. We also demonstrated that heart failure and stroke were independent risk factors for death in patients with PRES; moreover, pregnancy was a protective factor.

Factors associated with acute symptomatic seizure occurrence among patients with posterior reversible encephalopathy syndrome

OBJECTIVES

We aimed to define the factors associated with acute symptomatic seizure occurrence in posterior reversible encephalopathy syndrome (PRES) in the Thai-Asian population.

MATERIALS AND METHODS

We conducted a retrospective cohort study enrolling patients with PRES admitted to the hospital between 2006 and 2019. In addition to seizure characteristics, baseline characteristics, clinical presentations, precipitating factors, neuroimaging characteristics, hospital complications, and hospital outcomes were compared between the seizure and non-seizure groups. Factors with p-value <0.05 in the univariate analysis were entered into the first model of multivariate logistic regression analysis to determine the factors associated with seizure occurrence if the p-value <0.05. The interaction of associated factors was also analyzed in the final multiple logistic regression analysis model.

RESULTS

Acute symptomatic seizure, which is mainly based on the clinical documentation without electroencephalography, occurred in 50.0% of 136 patients with PRES. Of these, early seizures within 14 days of PRES occurred in 98.5% which mostly developed at presentation (82.4%) with a single seizure attack (55.9%). Convulsive seizures (77.9%) were the most common seizure semiology. The seizure group was significantly younger (median [interquartile range: IQR] 36.00 years old (21.75-48.50) vs 46.50 years old (31.25-61.00), p = 0.003). In univariate analysis, the seizure group had a higher prevalence of consciousness impairment (61.76% vs 26.47%, p < 0.001), Glasgow coma scale (GCS) score of 0-13 (42.46% vs 13.23%, p < 0.001), preeclampsia (20.58% vs 4.41%, p = 0.004), autoimmune disease (17.65% vs 5.88%, p = 0.033), and frontal lesions (25.00% vs 11.76%, p = 0.046) than those in the non-seizure group. In contrast, the seizure group had a lower prevalence of headache (27.94% vs 61.76%, p < 0.001). In the final multivariate logistic regression analysis which included the interaction terms, the acute symptomatic seizure occurrence directly associated with preeclampsia (adjusted odds ratio (aOR) 6.426, 95% confidence interval (CI) 1.450-27.031, p = 0.016) and autoimmune disease (aOR 4.962, 95% CI 1.283-18.642, p = 0.025), while headache showed a reverse association (aOR 0.310, 95% CI = 0.158-0.721, p = 0.008).

CONCLUSIONS

Acute symptomatic seizure occurred in a half of patients with PRES in this cohort. Preeclampsia and autoimmune disease were directly associated with seizure occurrence, while headache showed a reverse association.

Foreign accent syndrome and other neuropsychological sequelae of a parieto-occipital lesion following COVID-19 associated posterior reversible encephalopathy syndrome

OBJECTIVE

We describe a previously fit and well 54-year-old female who acquired a range of severe and persisting neuropsychological impairments following a posterior reversible encephalopathy syndrome (PRES) complication of COVID-19. The initial presentation included aphasia, a neurogenic foreign accent syndrome (FAS) and a persisting complete cortical blindness from the underpinning parieto-occipital brain injury.

METHOD

Neuropsychological single clinical case report.

RESULTS

The patient retained insight and made good early progress with their adjustment to the numerous losses caused by the COVID-19 associated acquired brain injury. Comprehensive neuropsychological investigation characterised an acalculia, along with deficits in focused, sustained and divided attention impacting on verbal memory, working memory and executive functioning, amongst numerous relative strengths.

CONCLUSION

Similar to PRES from other aetiologies, COVID-19 associated PRES can in some cases cause irreversible acquired brain injury. The diverse neuropsychological effects need to be comprehensively investigated and managed. This case adds to the neuropsychological literature on PRES, FAS and acquired brain injury as a rare complication of SARS-CoV-2.

Predictors of hospital outcomes among patients with posterior reversible encephalopathy syndrome

OBJECTIVES

We aimed to identify independent predictors of the clinical outcomes of posterior reversible encephalopathy syndrome (PRES) in the Thai-Asian population.

MATERIALS AND METHODS

This retrospective cohort study recruited PRES patients admitted in the hospital between 2006 and 2019. The baseline characteristics, clinical presentations, precipitating factors, neuroimaging characteristics, hospital complications, and hospital outcomes were compared between the groups with favourable (modified Rankin scale [mRS] score, 0-2) and unfavourable (mRS score, 3-6) clinical outcomes. Factors presenting with p-values < 0.5 in univariate analysis were analysed in the multiple logistic regression model to determine independent predictors of outcome.

RESULTS

Among 136 PRES patients, 22.80% experienced unfavourable outcomes (mRS score, 3-6), and the mortality rate was 7.35%. The common presenting symptoms in the unfavourable clinical outcome group were impairment of consciousness (90.32%) and seizures (67.74%). Sepsis as a hospital complication (adjusted odds ratio [aOR], 32.95; 95% confidence interval [CI], 4.44-244.22, p = 0.001), acute kidney injury as a hospital complication (aOR, 9.94; 95% CI, 1.71-57.66; p = 0.010), and impairment of consciousness (aOR, 10.85; 95% CI, 1.72-68.53, p = 0.011) were independent predictors of unfavourable outcomes. On the other hand, headache was an independent protective factor (aOR, 0.164; 95% CI, 0.03-0.91; p = 0.039).

CONCLUSIONS

Impairment of consciousness, sepsis as a hospital complication, and acute kidney injury were independent predictors of unfavourable clinical outcomes, whereas headache showed a preventive effect.

Clinical features and prognostic analysis of posterior reversible encephalopathy syndrome in children

BACKGROUND

We aimed to investigate the clinical features and prognosis of posterior reversible encephalopathy syndrome (PRES) in children.

METHODS

Clinical data of children with PRES diagnosed at the Children's Hospital of Chongqing Medical University from June 2015 to May 2019 were retrospectively analyzed.

RESULTS

The study enrolled 47 patients with a mean age at diagnosis of 8.79 ± 3.72 years (range, 2-15 years). PRES causes included renal disorder (29/47), hematological disease (13/47), and hypertension (5/47). PRES manifested as seizure (43/47), headache (28/47), visual impairment (18/47), dizziness (18/47), vomiting (18/47), and mental and behavioral abnormalities (17/47). Forty-six children had hypertension (46/47) at PRES onset. Magnetic resonance imaging (MRI) mainly involved the parietal and occipital lobes (42/47), 38 cases were mild (38/47), 7 were moderate (7/47), and 2 were severe (2/47). The clinical symptoms of 41 patients (41/47) were relieved within 1-2 weeks. Thirty-seven children were followed up for 7-54 months (modified Rankin Scale). Twenty-five children had favorable outcomes (25/37). Twelve children had adverse outcomes (12/37), including epilepsy, disorders of consciousness, visual impairment, and mental decline. Analysis of single factors revealed that severity on MRI, length of in-hospital stay, and mental and behavioral abnormalities were related to adverse outcomes after PRES. Analysis of multiple factors revealed that severity on MRI and length of in-hospital stay were independent risk factors for PRES.

CONCLUSION

Pediatric PRES is a clinical radiographic syndrome with multiple etiologies. Most patients have a good prognosis. Severity on MRI and length of in-hospital stay are independent risk factors.

Posterior Reversible Encephalopathy Syndrome with Postoperative Hematoma After C4-C6 Spinal Fusion: A Case Report

CASE

A 71-year-old woman with a 2-year history of spondylosis and radiculopathy presented with progressively worsening cervical spine pain and neurological dysfunction for 2 years. The patient developed posterior reversible encephalopathy syndrome (PRES) after postoperative hematoma in the retroesophageal and retropharyngeal areas. This occurred status post anterior cervical diskectomy and fusion (ACDF) of C4-C6. One year postoperatively, the patient recovered with full ambulation, neurological improvement, and resolution of all PRES signs and symptoms.

CONCLUSION

We present a case of a previously undescribed outcome of PRES as a complication of ACDF likely related to postoperative hypertension and fragile blood vessels.

Posterior reversible encephalopathy syndrome: characteristics, diagnostic accuracy, prognostic factors and long-term outcome in a paediatric population

Posterior reversible leukoencephalopathy syndrome (PRES) is a rare entity among children, characterised by acute neurological symptoms and radiological findings. The role of clinical symptoms and neuroimaging in predicting the prognosis of PRES have not been well-characterised. A retrospective descriptive study of children with PRES, admitted to a Paediatric Intensive Care Unit during a 10-year period, was performed to describe its characteristics, compare the accuracy of computed tomography (CT) scan and MRI on diagnosis and identify prognostic factors on paediatric population. Sixteen cases were identified. Most patients (13; 81%) presented underlying disorders, including malignancies (5; 31%), chronic kidney disease (3; 19%) and post-transplant status (3; 19%). Hypertension (15; 94%) was the most common trigger. All patients had seizures, 9 patients (56%) altered state of consciousness, 8 (50%) headache. CT scan was performed in 15 patients (94%) and MRI in 13 (81%); 1 patient underwent only MRI. MRI allows the identification of new areas of vasogenic oedema and a correct diagnosis of PRES when CT scan was inconclusive. Two patients (13%) remained with neurological sequelae and one died. In two patients (13%) cognitive disorders (specific learning disorder, intellectual disability, motor tic disorder) were diagnosed during follow-up period. Clinical presentation was not statistically associated with outcome. Also, atypical neuroimaging (haemorrhagic and unilateral lesions) were not statistically related with poor neurological or cognitive outcome. However, prospective studies with a larger cohort are needed to establish prognostic factors of PRES in the paediatric population.

Maternal and Perinatal Outcome of Posterior Reversible Encephalopathy Syndrome (PRES) in Patients with Eclampsia at Tertiary Health Care Centre

Introduction

Posterior reversible encephalopathy syndrome (PRES) and the related term reversible posterior leukoencephalopathy syndrome (RPLS) denote a constellation of clinical symptoms paired with key radiological findings. Eclampsia associated with PRES is a rare condition and remains a challenging diagnosis to make. There are only a few studies regarding PRES syndrome with a limited sample size. Our institution is a tertiary referral centre; hence, a good sample size of patients with eclampsia complicated with PRES syndrome is seen in our study. The objective was to identify the maternal and neonatal outcomes in PRES with eclampsia.

Methods

This study is a prospective observational study done in Government Medical College, Aurangabad, India from October 2018 to September 2020. In the present study, we have enrolled 63 cases, who satisfied inclusion and exclusion criteria during two years. All women admitted in the labour room of tertiary health care centre diagnosed with eclampsia with neurological symptoms during the study period were studied. Relevant data were obtained from the case file and compiled by common proforma. Analysis was done by SPSS (Statistical package for social sciences) Version 25th.

Results

In patients with a confirmed diagnosis of PRES with eclampsia(n = 63), the mean age of the patient was 20.74 ± 2.04 years, 23 (36.5%) patients had headache as premonitory symptoms, whereas 13(20.6%)patients had visual disturbances as the premonitory symptom. The mean gestational age at presentation was 34.4 ± 2 weeks. 40(63.5%) patients were showing parieto-occipital region changes, and 24(38.1%) subjects were showing only occipital region involvement in CT brain. 12 (19.04%) subjects were diagnosed with HELLP syndrome as a maternal complication, 07 (11.1%) subjects had Abruptio placentae. 26(41.3%) babies needed NICU admission, and 4 (6.3%) babies had neonatal death.

Conclusion

In pregnant patients presenting with seizure and neurological symptoms, a possibility of PRES should be considered. Proper diagnosis requires careful attention to clinical and radiographic presentation. In eclampsia with PRES patients, a timely intervention with anti-hypertensive, anti-cerebral oedema measures as well as management of other associated symptoms are required.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13224-021-01585-9.

Posterior reversible encephalopathy syndrome (PRES): diagnosis and management

Posterior reversible encephalopathy syndrome (PRES) may present with diverse clinical symptoms including visual disturbance, headache, seizures and impaired consciousness. MRI shows oedema, usually involving the posterior subcortical regions. Triggering factors include hypertension, pre-eclampsia/eclampsia, renal failure, cytotoxic agents and autoimmune conditions. The mechanism underlying PRES is not certain, but endothelial dysfunction is implicated. Treatment is supportive and involves correcting the underlying cause and managing associated complications, such as seizures. Although most patients recover, PRES is not always reversible and may be associated with considerable morbidity and even mortality.

Posterior Reversible Encephalopathy Syndrome: A Review of the Literature

Posterior reversible encephalopathy syndrome (PRES) is a group of clinical syndromes typically characterized by bilateral reversible vasogenic edema of the subcortical white matter in the parieto-occipital region on neuroimaging that causes a wide variety of acute or subacute neurological symptoms, including headache, mental status alteration, seizures, and visual dysfunction. PRES is classically suspected in patients with severe hypertension, renal failure, autoimmune disorders, eclampsia, or immunosuppressant medications. Frequent neurological evaluations and neuroimaging examinations by computed tomography or magnetic resonance imaging are required for both the diagnosis and assessment of the condition. Early detection of the disease is key for a rapid recovery and good prognosis.

Cerebrovascular Disease in the Setting of Posterior Reversible Encephalopathy Syndrome

Overlap between the pathogenesis of posterior reversible encephalopathy syndrome and that of cerebrovascular disease can confound their clinical and radiological presentations, posing a diagnostic challenge. This article presents a literature review and discussion of the clinical manifestations, pathological mechanisms, and imaging manifestations of subarachnoid hemorrhage and vasculitis leading to posterior reversible encephalopathy syndrome, coexistence of posterior reversible encephalopathy syndrome with reversible cerebral vasoconstriction syndrome, and hemorrhage and infarction secondary to posterior reversible encephalopathy syndrome. The findings show that posterior reversible encephalopathy syndrome shares some overlapping pathophysiological mechanisms with cerebrovascular disease. Importantly, neuroimaging plays an important role in identifying this entity in a timely manner and differentiating it from other diseases.

A broad spectrum of posterior reversible encephalopathy syndrome - a case series with clinical and paraclinical characterisation, and histopathological findings

Background

Posterior reversible encephalopathy syndrome (PRES) is clinical-neuroradiologically defined and potentially reversible, so there are limited data about histopathological findings. We aimed to describe the clinical and paraclinical features of patients with PRES with regard to its reversibility.

Methods

This retrospective case series encompasses 15 PRES cases out of 1300 evaluated patients from a single German center between January 1, 2010, and June 15, 2020. PRES was established according to the diagnostic criteria as proposed by the Berlin PRES Study 2012. One of the cases studied was subject to brain autopsy.

Results

From the 15 patients studied (median age 53 years, range 17–73; 11 female), 67 % presented with epileptic seizures, 40 % suffered from encephalopathy with reduced consciousness and 53 % developed delirium, while 47 % had headache and visual disturbances. Subcortical brain MRI abnormalities related to PRES were observed in all patients. One patient developed spinal ischemia and another Guillain-Barré syndrome in addition to PRES. Hypertensive blood pressure was the main underlying/trigger condition in all patients. Clinical symptoms and MRI changes were not reversible in 42 %, even progressive in 3 out of these 5 patients. Median time from symptom onset to diagnosis in these non-reversible cases was 7 days (range 0–13), while the median delay in diagnosis in the reversible group was 1 day (range 0–3). Cerebellar/brain stem involvement and status epilepticus were more frequently in patients with non-reversible disease course. Mortality due to PRES occurred in 13 % of these patients. Neuropathological examination of the brain of a 57-year-old female patient revealed major leukencephalopathic changes, fibrinoid necrosis of endothelial cells and fresh petechial hemorrhages in accordance with PRES.

Conclusions

Our case series demonstrates that PRES was not reversible in 42 % of the studied patients. Delay in diagnosis seems to contribute to limited reversibility and poor outcome.

Clinical Presentation and Risk Factors for Poor Outcomes Among Adult Patients With Posterior Reversible Encephalopathy Syndrome: A Retrospective Cohort Study

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is an acute neurological condition with unknown global incidence, variable clinical presentation, and prognosis.

OBJECTIVES

To describe a cohort of patients with PRES with a focus on brain magnetic resonance imaging (MRI) patterns and their relationship with short-term clinical outcomes.

METHODS

Retrospective cohort study. The authors included patients if they were older than 15 years and had a PRES diagnosis on the basis of a positive brain MRI at any time during the in-hospital stay.

RESULTS

Forty-four patients were included in the present analysis. The median age was 57 years (interquartile range, 32.0-68.5) and 70.5% were women. Hypertension (59.1%), history of transplantation (27.3%), previous chemotherapy (27.3%), chronic renal failure (38.6%), and autoimmune disease (15%) were the main comorbid conditions present. The classic triad of seizures, headache, and visual impairment was present in 18.0% of the cases. Eighty-six percent of patients were admitted to the intensive care unit, with 36.0% needing invasive life support. Brain MRI showed a dominant parieto-occipital pattern in 26 patients, whereas cytotoxic edema and bleeding were present in 27.3% and 29.6%, respectively. In-hospital mortality was 11.4%. The median modified Rankin Scale at hospital discharge was 1 (0-2.5). Risk factors associated with low modified Rankin Scale scores were: headache, visual impairment, and parieto-occipital pattern. Decreased level of consciousness and mechanical ventilation requirement were associated with greater discharge disability.

CONCLUSIONS

Characteristic symptoms and signs of PRES and classic MRI patterns are associated with better clinical outcomes.

Posterior Reversible Encephalopathy Syndrome Following Blood Transfusion: A Rare Case Report with Literature Review

Background:

Posterior reversible encephalopathy syndrome (PRES) is clinicoradiological disease entity characterized by headache, seizures, altered sensorium and corticalvisual loss with characteristic MRI features of subcortical white matter hyperintensities on T2W imaging. Though hypertension is a traditional hallmark of PRES, uncommon causes without hypertension have been described. We report an unusual such case without hypertension, precipitated by red cell transfusion.

Case Presentation:

A 40 years female received six units of packed cell transfusion for severe anemia (Hemoglobin 3.0 Gm %) transfused over 8 hours. She was having menorrhagia and was operated on for a hysterectomy. She developed a headache on the second postoperative day for five days and no cause was revealed in spite of extensive workup, including MRI brain and CSF study. On the sixth day, she had recurrent seizures followed by altered sensorium in the absence of hypertension. Her repeat MRI brain findings were consistent with PRES.

Conclusion:

We reviewed 25 cases, including the present one as PRES after the blood transfusion. 24 were females, and 16 of 19 developed PRES in the course of chronic anemia lasting over 1 month. Anemia was severe in 18 of 25 cases, with haemoglobin (Hb) levels < 4.0 Gm%. In 16 of 20 cases, Hb levels increased to 5 g/dl by red cell blood transfusion until the onset of PRES. On MRI brain, 23 of 25 cases showed vasogenic edema and 3 of 25 cases showed an irreversible neurological deficit. When treating severe chronic anemia rapid correction of Hb with blood transfusion, one should consider a possibility of PRES in post-transfusion neurological symptoms in spite of normal diagnostic workup.

Detecting the Uncommon Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) in Adults: a Comprehensive Illustrated Guide for the Trainee Radiologist

Posterior reversible encephalopathy syndrome (PRES) has traditionally been described as a reversible leukoencephalopathy with a distinct pattern of posteriorly distributed vasogenic oedema involving the subcortical regions of parietal and occipital lobes. PRES commonly occurs in the setting of hypertensive emergencies, pre-eclampsia/eclampsia, impaired renal function, and immunosuppressive therapy. The various clinical presentations of PRES include encephalopathy, seizures, headache, visual, and focal neurological deficits. As knowledge of this entity grows, the range of clinical, and radiological features is seen to be much broader than originally described. The brain oedema may not always be posteriorly distributed and the syndrome may not be uniformly reversible. Of special note are some uncommon imaging features (unilateral cerebral involvement, and isolated posterior fossa involvement) and also some uncommon complications (haemorrhage, cytotoxic oedema, and vasoconstriction). These red herrings may lead to potential diagnostic challenges and pitfalls especially for trainee radiologists, who often read these scans in an emergency setting. Early and accurate diagnosis is crucial for prompt optimum management, thereby avoiding residual morbidity. This review article focusses on the atypical radiological features of PRES in adults with extensive case-based imaging examples. A brief description of the pathophysiology, clinical, and classic radiological features of PRES has also been included. A tabulated summary of potential mimics with diagnostic pearls is provided to highlight pertinent take home points and to serve as an easy guide for day-to-day clinical practice.

Patterns, risk factors and outcome predictors of posterior reversible encephalopathy syndrome in pediatric cancer patients

The purpose of this study was to assess the clinical and radiological patterns and outcome predictors of posterior reversible encephalopathy syndrome (PRES) in pediatric cancer patients. A retrospective study included patients who developed PRES during their treatment at the Children's Cancer Hospital Egypt. A total of 50 patients developed PRES. Leukemia and lymphoma were the commonest diagnoses (64%). Regarding the MRI findings, occipital affection was the most common (92%), followed by frontal and temporal lobes involvement in 32% and 22% respectively and advanced PRES was described in 8 patients. Of the whole patients, 80% had complete clinical resolution and 60% showed complete radiological resolution at 2 weeks' evaluation and 2 patients died out of PRES. Unfavorable outcome was associated with those who had motor dysfunction, status epilepticus at presentation, frontal lobe and thalamic affection and atypical PRES. PRES might present in atypical sites with poor outcome including death.

Atypical posterior reversible encephalopathy syndrome with albuminocytological dissociation and late emerging neuroradiological findings: A case report

Posterior reversible encephalopathy syndrome (PRES) is a central nervous system disorder accompanied by vasogenic edema in white matter that is usually located in temporo-parieto-occipital area. Typically, PRES is presented with headaches, seizures, and change of consciousness. The most common etiologic factor is fluctuations in blood pressure. An eighty-eight-year-old female patient was evaluated because of her acute confused state. Medical history revealed hypertension. Blood pressure was 190/100 mmHg. The initial examination showed impaired consciousness. Radiological investigations of brain showed chronic ischemic lesions. Albuminocytological dissociation was detected in CSF examination. On the 6^th day of admission, cranial MRI was repeated. Radiological findings were typical for PRES. The cranial MRI is a valuable diagnostic tool for the diagnosis of the PRES but, as in our case, despite the subtle clinical and radiological findings presented during admission, repeated MRI and CSF examination may contribute to a definite diagnosis. This case is remarkable for severe protein elevation in CSF, irreversible fatal course and radiographic evidence of vasogenic edema occurred subsequently.

Posterior reversible encephalopathy syndrome (PRES): presentation, diagnosis and treatment

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder which is characterised by variable symptoms, which include visual disturbances, headache, vomiting, seizures and altered consciousness. The exact pathophysiology of PRES has not been completely explained, but hypertension and endothelial injury seem to be almost always present. Vasoconstriction resulting in vasogenic and cytotoxic edema is suspected to be responsible for the clinical symptoms as well as the neuro-radiological presentation. On imaging studies, Symmetrical white matter abnormalities suggestive of edema are seen in the computer tomography (CT) and magnetic resonance imaging (MRI) scans, commonly but not exclusively in the posterior parieto-occipital regions of the cerebral hemispheres. The management is chiefly concerned with stabilization of the patient, adequate and prompt control of blood pressure, prevention of seizures and timely caesarean section in obstetric cases with pre-eclampsia/eclampsia. In conclusion, persistently elevated blood pressures remain the chief culprit for the clinical symptoms as well as the neurological deficits. Early diagnosis by diffusion weighted MRI scans, and differentiation from other causes of altered sensorium i.e. seizures, meningitis and psychosis, is extremely important to initiate treatment and prevent further complications. Although most cases resolve successfully and carry a favorable prognosis, patients with inadequate therapeutic support or delay in treatment may not project a positive outcome.

Advanced Imaging Techniques in Diagnosis of Posterior Reversible Encephalopathy Syndrome (PRES)

Diagnosis of Posterior Reversible Encephalopathy Syndrome (PRES) in some circumstances can be challenging and structural imaging may not be sufficient to distinguish it from other differential diagnostic considerations. Advanced imaging techniques, such as MR spectroscopy or positron emission tomography (PET) can provide additional information to determine the diagnosis. Other techniques, such as susceptibility weighted imaging (SWI) improves detection of hemorrhage which has prognostic role. CT or MR Perfusion as well as Single-Photon Emission Computed Tomography (SPECT) are more useful to understand the underlying vasculopathic changes in PRES and may answer some of the unresolved controversies in pathophysiology of this complex disease. In this review we summarized the findings of previous studies using these advanced methods and their utilities in diagnosis or prognosis of PRES.

Posterior Reversible Encephalopathy Syndrome: Clinical Features and Outcome

Background: Posterior reversible encephalopathy syndrome (PRES) is an acute neurotoxic syndrome that is characterized by a spectrum neurological and radiological feature from various risk factors. Common neurological symptoms includes headache, impairment in level of consciousness, seizures, visual disturbances, and focal neurological deficits. Common triggering factors include blood pressure fluctuations, renal failure, eclampsia, exposure to immunosuppressive or cytotoxic agents and autoimmune disorders. The classic radiographic findings include bilateral subcortical vasogenic edema predominantly affecting the parieto-occipital regions but atypical features include involvement of other regions, cortical involvement, restricted diffusion, hemorrhage, contrast enhancement. This review is aimed to summarize the updated knowledge on the typical and atypical clinical and imaging features, prognostic markers and identify gaps in literature for future research.

Methods: Systematic literature review using PUBMED search from 1990 to 2019 was performed using terms PRES was performed.

Results: While clinical and radiographic reversibility is common, long-standing morbidity and mortality can occur in severe forms. In patients with malignant forms of PRES, aggressive care has markedly reduced mortality and improved functional outcomes. Although seizures were common, epilepsy is rare. Various factors that have been associated with poor outcome include altered sensorium, hypertensive etiology, hyperglycemia, longer time to control the causative factor, elevated C reactive protein, coagulopathy, extensive cerebral edema, and hemorrhage on imaging.

Conclusion: Large prospective studies that accurately predict factors that are associated with poor outcomes, determine the pathophysiology, and targeted therapy are required.

Childhood Posterior Reversible Encephalopathy Syndrome: Clinicoradiological Characteristics, Managements, and Outcome

Posterior reversible encephalopathy syndrome (PRES) is a novel clinicoradiological syndrome characterized by convulsions, headache, altered mentality, and impaired vision, which are usually accompanied by hypertension. As its nomination, PRES is usually diagnosed according to the presence of typical neuroimage showing vasogenic edema predominately involving the posterior brain area. With the widespread utilization of magnetic resonance imaging (MRI), PRES is becoming more perceptible in different medical fields. Compared to adult cases, childhood PRES seems to have a broader clinical and neuroradiological spectrum. PRES can be associated with various underlying comorbidities, medication use, and therapeutic modalities in children with diverse neurological manifestations. Moreover, pediatric patients with PRES have a more significant propensity for atypical MRI findings beyond the typically posterior cerebral areas. The knowledge of typical and atypical presentations in children is essential to avoid misdiagnosing or missing PRES, which is a potentially treatable entity. Early supportive care is the mainstay of treatment, with particular attention to the treatment of hypertension with rigorous attention to all body systems. Prompt identification and symptom-directed management are imperative to achieve a reversible prognosis in childhood PRES. Future studies specially designed for the child population are required to determine potential outcome predictors, and further, to develop novel strategies of neuroprotection in childhood PRES.

Childhood Posterior Reversible Encephalopathy Syndrome: Clinicoradiological Characteristics, Managements, and Outcome

Posterior reversible encephalopathy syndrome (PRES) is a novel clinicoradiological syndrome characterized by convulsions, headache, altered mentality, and impaired vision, which are usually accompanied by hypertension. As its nomination, PRES is usually diagnosed according to the presence of typical neuroimage showing vasogenic edema predominately involving the posterior brain area. With the widespread utilization of magnetic resonance imaging (MRI), PRES is becoming more perceptible in different medical fields. Compared to adult cases, childhood PRES seems to have a broader clinical and neuroradiological spectrum. PRES can be associated with various underlying comorbidities, medication use, and therapeutic modalities in children with diverse neurological manifestations. Moreover, pediatric patients with PRES have a more significant propensity for atypical MRI findings beyond the typically posterior cerebral areas. The knowledge of typical and atypical presentations in children is essential to avoid misdiagnosing or missing PRES, which is a potentially treatable entity. Early supportive care is the mainstay of treatment, with particular attention to the treatment of hypertension with rigorous attention to all body systems. Prompt identification and symptom-directed management are imperative to achieve a reversible prognosis in childhood PRES. Future studies specially designed for the child population are required to determine potential outcome predictors, and further, to develop novel strategies of neuroprotection in childhood PRES.

Blood-Brain Barrier Disruption as a Potential Target for Therapy in Posterior Reversible Encephalopathy Syndrome: Evidence From Multimodal MRI in Rats

Background: To explore blood-brain barrier disruption in hypertensive posterior reversible encephalopathy syndrome. Methods: The hypertension rat models were successfully established and scanned on 7T micro-MRI. MRI parameter maps including apparent diffusion coefficient, T1 value, and perfusion metrics such as cerebral blood volume, cerebral blood flow, mean transit time and time to peak maps, were calculated. Results: The ADC values of the experimental group were higher than those of the control group both in cortical (P < 0.01) and subcortical (P < 0.05) regions. Voxel-wise analysis of ADC maps localized vasogenic edema primarily to the posterior portion of the brain. The increase in cerebral blood volume and cerebral blood flow values were found in the cortical and subcortical regions of rats with acute hypertension. No correlation was found between perfusion metrics and mean arterial pressure. The Evans blue dye content was higher in the posterior brain region than the anterior one (P < 0.05). Conclusions: Cerebral vasogenic edema resulting from acute hypertension supports the hypothesis of posterior reversible encephalopathy syndrome as the result of blood-brain barrier disruption, which maybe the potential therapeutic target for intervention.

[Posterior reversible encephalopathy syndrome: a case report]

L'encéphalopathie postérieure réversible (EPR) est une entité radio-clinique associant une atteinte réversible du système nerveux central à une imagerie encéphalique typique. Il existe une grande variabilité dans la présentation clinique de ce syndrome et des aspects en imagerie parfois atypiques. L'EPR est une complication neurologique inhabituelle survenant au cours de la grossesse ou en post-partum, en dehors de toute pathologie préexistante de la grossesse dont l'œdème vasogénique par rupture de la barrière hémato encéphalique paraît être l'acteur principal. Nous rapportons l'observation d'une patiente primipare présentant des crises convulsives généralisées tonico-cloniques associées à un pic hypertensif, survenant au cours du troisième trimestre de grossesse. L'imagerie par résonance magnétique (IRM) cérébrale était en faveur d'une encéphalopathie postérieure réversible. L'EPR doit être évoqué devant tout signe d'appel neurologique, vu l'évolution favorable sans séquelles sous un traitement précoce et rapide.

Posterior reversible encephalopathy syndrome

PURPOSE OF REVIEW

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome characterized by acute cerebral endotheliopathy with consecutive disruption of the blood-brain barrier and vasogenic edema. Since its first description in 1996, PRES is increasingly recognized. However, many aspects of this syndrome with its wide spectrum of clinical and radiological features are still incompletely understood. In this review, possible pathophysiological mechanisms, approaches to diagnosis, recent study results on outcome, and future directions of research are described.

RECENT FINDINGS

Clinical manifestations of PRES include seizures, headache, visual disturbances, altered mental state, and more rarely hemiparesis or aphasia. Vasogenic edema predominantly occurs in the parieto-occipital region, but lesions affecting formerly called 'atypical' regions such as frontal lobe, cerebellum, or basal ganglia are common. If treated early and adequately, that is by removal of the underlying cause, PRES has a favorable prognosis, but neurological residual symptoms and even mortality can occur, particularly in patients with complications such as intracranial hemorrhage.

SUMMARY

In summary, validated diagnostic criteria and algorithms are warranted to standardize the diagnosis of PRES. This is essential for further research and future prospective studies that should investigate risk factors for unfavorable outcome and identify the roles of imaging features, clinical symptoms, and other biomarkers in predicting outcome.

Acute radiological pattern and outcome in posterior reversible encephalopathy syndrome patients

OBJECTIVE

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder of acute or subacute onset characterized by varied neurological symptoms including headache, impaired visual acuity or visual field deficits, confusion, disorders of consciousness, seizures, and motor neurological deficits. Even if recognition of severe forms of PRES has improved, mainly due to magnetic resonance imaging, pathogenesis is still unclear and management of these patients remains challenging. Moreover, prognosis is unpredictable varying from complete recovery to death and factors related to prognosis are still lacking. We studied early magnetic resonance imaging characteristics and their relationships with prognosis.

PATIENTS AND METHODS

We performed a retrospective analysis in patients with clinical and neuroradiological charateristics of PRES performing magnetic resonance of the brain within 2 days of symptoms onset.

RESULTS

After reviewing site database of magnetic resonance imaging and clinical records compatible with PRES, 157 patients were selected. After imaging reviewing, 25 patients with clinical and neuroradiological diagnosis of PRES were enrolled, 22 (88%) females. Mean age of enrolled patients at presentation was 44.4+18.4 years (range, 21-84 years). Patients were classified according to neuroradiological characteristics such as ischemic lesions, distribution and severity of edema, hemorrhage and contrast enhancement. In our group 23 patients (92%) showed an almost complete recovery but 2 patients (8%) died during hospitalization. Outcome was significantly related with hypointensity on ADC (p = 0.002) and CE (p < 0.001).

CONCLUSION

Early MR features may be helpful in suggesting prognosis. Moreover, neuroimaging at the early stage of PRES may give new insights in pathophysiological mechanisms underlying brain damage and neurological impairment.

Posterior reversible encephalopathy syndrome complicated with subarachnoid hemorrhage in an eclamptic pregnant patient: case report

Background

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic condition which comprises various neurological symptoms. This syndrome could be complicated by intracranial hemorrhage including subarachnoid hemorrhage (SAH). However, SAH is rarely seen in eclamptic patients with PRES.

Case presentation

A 34-weeks-pregnant woman at the age of 33 was admitted to the obstetrics department because of an episode of generalized tonic-clonic seizure. Before the seizure, the patient had a headache and was found to have an abnormal systolic blood pressure of 160 mmHg. On admission, systolic and diastolic blood pressures were up to 182 and 99 mmHg, respectively. Emergent cesarean section was then performed. On hospital day (HD) 2, cranial non-contrast computed tomography (CT) revealed the existence of SAH. Multiple areas of high signals on T2-weighted and fluid attenuated inversion recovery (FLAIR) sequences were shown by cranial magnetic resonance imaging (MRI) performed 2 days later. CT-angiography studies didn’t reveal intracranial aneurysm. After anti-hypertensive treatment, arterial blood pressure of the patient was gradually tapered to normal values. Eventually, the patient was discharged without any residual symptoms.

Conclusions

SAH is a rare complication of PRES in eclamptic patients. In patients with PRES, occurrence of SAH is related to increased morbidity and mortality especially when the hemorrhage is diffuse or massive. Our patient had a minor hemorrhage. The good prognosis might also be due to immediate elimination of the risk factor of PRES by emergent delivery.

Cerebrospinal Fluid in Posterior Reversible Encephalopathy Syndrome: Implications of Elevated Protein and Pleocytosis

Background and Purpose

Patients with posterior reversible encephalopathy syndrome (PRES) sometimes undergo analysis of cerebrospinal fluid (CSF) to exclude alternative diagnoses. This study's objectives were to describe the CSF characteristics in patients with PRES and to identify clinical and radiologic findings associated with distinct CSF abnormalities.

Methods

We identified a retrospective cohort of patients with PRES. We compared clinical and radiographic characteristics of those who did versus did not undergo lumbar puncture, described the observed range of CSF findings, and analyzed clinical and radiographic features associated with specific CSF abnormalities.

Results

A total of 188 patients were included. Patients with (n = 77) and without (n = 111) CSF analysis had similar clinical and radiographic characteristics. Cerebrospinal fluid protein was elevated in 46 (60%) of 77, with median CSF protein 53 mg/dL (upper limit of normal 45 mg/dL). Protein elevation was significantly associated with radiographic severity (P = .0058) but not with seizure, time from symptom onset, radiographic evidence of diffusion restriction, or contrast enhancement. Five (7%) patients had elevated CSF white blood cells, all of whom had infarction and/or hemorrhage on neuroimaging, and 4 of whom had eclampsia.

Conclusion

The CSF of most patients with PRES shows a mild protein elevation commensurate with radiographic severity. Cerebrospinal fluid pleocytosis may mark a distinct subtype of PRES with predisposition toward infarction and/or hemorrhage. These findings help clinicians interpret CSF findings in these patients and generate new hypotheses about the pathophysiology of this syndrome.

Risk factors for poor outcome in posterior reversible encephalopathy syndrome: systematic review and meta-analysis

Background

The roles of clinical etiology and symptoms, imaging findings and biochemical parameters in predicting the prognosis of posterior reversible encephalopathy syndrome (PRES) have not been well-characterized. We perform a meta-analysis of all published studies to assess the value of various risk factors in predicting the prognosis of PRES.

Methods

Searches of the PubMed, EMBASE, Cochrane Library, and Web of Science databases were performed to identify the eligible studies. The odds ratios (ORs) with their corresponding 95% confidence interval (CI) for related risk factors were used to calculate the pooled estimates of the outcomes.

Results

Six studies with 448 cases were included in the meta-analysis. Hemorrhage was associated with high risk for poor outcome in patients with PRES. Toxemia of pregnancy (pre-eclampsia/eclampsia) was associated with improved outcome in PRES patients. Cytotoxic edema was noted to be related to poor outcome, but did not show statistical significance. The pooled OR for hemorrhage, pre-eclampsia/eclampsia, cytotoxic edema was 4.93 (95% CI: 3.94-6.17; P<0.00001), 0.24 (95% CI: 0.15-0.40; P<0.00001) and 2.59 (95% CI: 0.84-7.99; P=0.10), respectively.

Conclusions

PRES patients with hemorrhage or cytotoxic edema are likely to have poor outcomes. Pre-eclampsia/eclampsia is associated with reduced risk of poor outcome in patients with PRES.

Controversy of posterior reversible encephalopathy syndrome: what have we learnt in the last 20 years?

Over two decades have passed since posterior reversible encephalopathy syndrome (PRES) was first described in 1996. It has becoming increasingly recognised because of improved and more readily available imaging modality. The exact pathophysiological mechanism is not completely understood and remains controversial at present. Precise diagnosis is essential to guide prompt, proper management. Our ability of differentiating it from other acute neurological disorders is likely to improve as we learnt more about the spectrum of this entity in the last 20 years. We emphasise the importance of recognising its diagnostic criteria and biomarker, which would be of great relevance to either outcome evaluation or study design. PRES has a favourable prognosis generally, but neurological sequelae and even fatalities can occur, especially in severe forms that might cause substantial morbidity and even mortality, particularly when the syndrome is complicated by intracranial haemorrhage or brain infarction. In this review, the pathophysiology, approach to diagnosis, some controversies as to the prognosis, as well as the future research direction of PRES are described.

[Posterior reversible encephalopathy syndrome: Report of a fatal case and analysis of predictive factors of a poor prognosis]

Posterior reversible encephalopathy syndrome is an illness with multiple causes and distinctive clinicalradiological characteristics that should be known by intensivists and emergency room physicians for a timely diagnosis and treatment. A fatal case of posterior reversible encephalopathy syndrome is presented, and the risk factors related to the outcome are identified.A 60-year-old man without a relevant medical history arrived at the emergency room presenting with depressed consciousness, seizures, and high blood pressure. Tomographic images revealed a posterior cerebellar hematoma. Resonance images showed ischemic zones, vasogenic edema from the thalamus to the brain stem, middle cerebellar peduncles, deep white matter of the cerebral hemispheres, and zones of hemorrhagic transformation. Despite medical-surgical management, the patient died. The risk factors described as the cause of the fatal outcome were identified. This case demonstrates that posterior reversible encephalopathy syndrome can occur without triggering risk factors and highlights the need for early recognition to establish an appropriate intervention to avoid injury or a fatal outcome. Cases of posterior reversible encephalopathy syndrome provide opportunities to investigate the susceptibility for the development of this condition and to establish appropriate preventive measures.

Imaging characteristics associated with clinical outcomes in posterior reversible encephalopathy syndrome

PURPOSE

Posterior reversible encephalopathy syndrome (PRES) is a disorder of cerebrovascular autoregulation that can result in brain edema, hemorrhage, and infarction. We sought to investigate whether certain imaging characteristics in PRES are associated with clinically significant patient outcomes.

METHODS

We retrospectively reviewed all cases of PRES occurring between 2008 and 2014 at two major academic medical centers. Demographic, clinical, and radiographic data were collected. We analyzed imaging studies for vasogenic edema, hemorrhage, and diffusion restriction. We performed univariate analysis and stepwise logistic regression to assess the association between our radiologic findings of interest and clinical outcomes as defined by hospital discharge disposition and modified Rankin scale (mRS) at time of discharge.

RESULTS

We identified 99 cases of PRES in 96 patients. The median age was 55 years (IQR 30-65) and 74% were women. In 99 cases, 60% of patients had active cancer, 19% had history of bone marrow or organ transplantation, 14% had autoimmune disease, and 8% were peripartum. Imaging at clinical presentation showed extensive vasogenic edema in 39%, hemorrhage in 36%, hemorrhage with mass effect in 7%, and restricted diffusion in 16%. In our final logistic regression models, the presence of extensive vasogenic edema, hemorrhage with mass effect, or diffusion restriction was associated with worse clinical outcome as defined by both discharge disposition (OR = 4.3; 95% CI: 1.4-36.3; p = 0.047) and mRS (OR = 3.6; 95% CI: 1.2-10.7; p = 0.019).

CONCLUSIONS

Extensive vasogenic edema, hemorrhage, and restricted diffusion on initial imaging in PRES are associated with worse clinical outcomes.