Spectrum and Potential Pathogenesis of Reversible Posterior Leukoencephalopathy Syndrome

Frequency of ischaemic stroke and intracranial haemorrhage in patients with reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) - A systematic review

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) may cause ischaemic stroke and intracranial haemorrhage. The aim of our study was to assess the frequency of the afore-mentioned outcomes.

METHODS

We performed a PROSPERO-registered (CRD42022355704) systematic review and meta-analysis accessing PubMed until 7 November 2022. The inclusion criteria were: (1) original publication, (2) adult patients (≥18 years), (3) enrolling patients with PRES and/or RCVS, (4) English language and (5) outcome information. Outcomes were frequency of (1) ischaemic stroke and (2) intracranial haemorrhage, divided into subarachnoid haemorrhage (SAH) and intraparenchymal haemorrhage (IPH). The Cochrane Risk of Bias tool was used.

RESULTS

We identified 848 studies and included 48 relevant studies after reviewing titles, abstracts and full text. We found 11 studies on RCVS (unselected patients), reporting on 2746 patients. Among the patients analysed, 15.9% (95% CI 9.6%-23.4%) had ischaemic stroke and 22.1% (95% CI 10%-39.6%) had intracranial haemorrhage. A further 20.3% (95% CI 11.2%-31.2%) had SAH and 6.7% (95% CI 3.6%-10.7%) had IPH. Furthermore, we found 28 studies on PRES (unselected patients), reporting on 1385 patients. Among the patients analysed, 11.2% (95% CI 7.9%-15%) had ischaemic stroke and 16.1% (95% CI 12.3%-20.3%) had intracranial haemorrhage. Further, 7% (95% CI 4.7%-9.9%) had SAH and 9.7% (95% CI 5.4%-15%) had IPH.

CONCLUSIONS

Intracranial haemorrhage and ischaemic stroke are common outcomes in PRES and RCVS. The frequency reported in the individual studies varied considerably.

Perfusion Deficits in Patients with Posterior Reversible Encephalopathy Syndrome: a Retrospective, Two-Center Study

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is manifested by acute neurological symptoms in patients with varied predisposing factors and characteristic findings on brain imaging. Cerebrovascular autoregulation is thought to be altered in PRES. However, it remains unclear whether cerebral hypoperfusion or hyperperfusion is the initiating event. We aimed to describe the brain perfusion status in untreated patients with PRES.

METHODS

Patients with PRES who underwent cerebral perfusion studies on presentation were retrospectively identified from (1) a prospective database of patients with PRES admitted to Saint Mary's Hospital, Mayo Clinic, Rochester from January 2005 to December 2021 and (2) University of Nebraska Medical Center electronic database from January 2010 to December 2021. Demographics, past medical history, presenting symptoms, cause of PRES, and clinical outcomes were recorded. Brain imaging studies were reviewed. We recorded the location of brain lesions, the time from symptoms onset to perfusion study, blood pressure at the time of the perfusion study, and blood pressure lowering treatments.

RESULTS

Five patients (four women, median age 66 years) were included. Causes of PRES were acute hypertension (n = 3), perioperative blood pressure fluctuations, and treatment with pazopanib. Four patients had chronic hypertension. Presenting symptoms were encephalopathy (n = 5), focal neurological symptoms (n = 4), and seizures (n = 2). All patients underwent computed tomography (CT) perfusion performed within 12 h of symptoms onset. All but one patient was hypertensive at the time of CT perfusion. Scans showed diffuse cerebral hypoperfusion, more pronounced in the corona radiata and areas with brain edema. No patient had critical cerebral ischemia or arterial vasoconstriction on CT angiogram.

CONCLUSIONS

Patients with PRES can have cerebral hypoperfusion despite severe hypertension. A perfusion study in the acute setting may be helpful to better understand the perfusion status and guide blood pressure treatment.

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.

Improving diagnostic approaches to cerebrovascular disorders in patients with hypertensive encephalopathy

BACKGROUND

Modern research today proves an increase in the incidence of ischemic stroke. Risk factors for vascular disease have become more common among young people. Clinical studies have shown that hypertension, dyslipidemia, and diabetes are traditional risk factors among the elderly. The aim of the study was to improve diagnostic approaches to cerebrovascular disorders in patients with hypertensive encephalopathy (НE) by clarifying the development of pathogenesis mechanisms, based on a comprehensive clinical study.

MATERIALS AND METHODS

This qualitative study was carried by clinical and neurological examination; neuropsychological examination (Mini-Mental State Examination, abbreviated multifactorial personality questionnaire, Beck depression scale, Spielberger scale).

RESULTS

The study was examined 351 patients (150 men, 201 women) with НE in hypertension of 2 degrees. The clinical examination was performed according to a two-stage method, which involves the establishment or exclusion of symptomatic hypertension. The study did not include patients with secondary hypertension, diabetes mellitus, cardiac arrhythmias, and conduction disorders, heart failure who suffered from acute cerebrovascular accident and myocardial infarction.

CONCLUSION

The necessity of obligatory examination by a neurologist of patients with arterial hypertension for detection of manifestations of НE with the use of modern research methods, which allows to prevent damage to target organs, and first of all - brain damage, has been proved.

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.

A Case of Pediatric Posterior Reversible Encephalopathy Syndrome (PRES) Secondary to Post-streptococcal Glomerulonephritis: A Literature Review and Assessment of Treatment Modalities

Posterior reversible encephalopathy syndrome (PRES) is a disorder that most commonly affects adults, and is characterized by neurologic symptoms such as encephalopathy, seizures, headaches, and visual disturbances. It usually occurs in the context of other systemic disturbances that result in hypertensive crises, such as renal failure, cytotoxic drugs, and autoimmune conditions. In children, it rarely manifests following chemotherapy induction or hematopoietic stem cell transplantation. No cases have been reported in the English literature connecting renal dysfunction and hypertensive emergency secondary to post-streptococcal glomerulonephritis (PSGN) with PRES. We present a case of an eight-year-old boy, who developed a constellation of symptoms suggestive of PSGN and later developed PRES. PRES is often confirmed upon suspicion through brain MRI showing subcortical edema of various brain regions including occipital, temporal, or parietal cortices. Our patient demonstrated subcortical edema of the bilateral occipital lobes and right cerebellar hemisphere, with positive antistreptolysin O (ASO) titers demonstrating PSGN as the likely etiology for his hypertensive emergency. Management included antihypertensive and anticonvulsant treatment, which allowed the resolution of the offending hypertensive emergency that resulted in PRES. Our case adds to the growing body of literature on PRES and describes a new etiology of pediatric PRES secondary to PSGN.

Posterior reversible leukoencephalopathy syndrome associated with acute postinfectious glomerulonephritis: systematic review

BACKGROUND

Kidney diseases are a recognized cause of posterior reversible leukoencephalopathy syndrome, usually abbreviated as PRES. The purpose of this review was to systematically address the association between acute postinfectious glomerulonephritis and PRES.

METHODS

We performed a systematic review of the literature on acute postinfectious glomerulonephritis associated with PRES. The principles recommended by the Economic and Social Research Council guidance on the conduct of narrative synthesis and on the Preferred Reporting Items for Systematic Reviews and Meta-analyses were used. Databases searched included Excerpta Medica, US National Library of Medicine, and Web of Science.

RESULTS

For the final analysis, we evaluated 47 reports describing 52 cases (32 males and 20 females). Fifty patients were ≤ 18 years of age. Blood pressure was classified as follows: normal-elevated (n = 3), stage 1 hypertension (n = 3), stage 2 hypertension (n = 5), and severe hypertension (n = 41). Acute kidney injury was classified as stage 1 in 32, stage 2 in 16, and stage 3 in four cases. Neuroimaging studies disclosed a classic posterior PRES pattern in 28 cases, a diffuse PRES pattern in 23 cases, and a brainstem-cerebellum PRES pattern in the remaining case. Antihypertensive drugs were prescribed in all cases and antiepileptic drugs in cases presenting with seizures. A resolution of clinical findings and neuroimaging lesions was documented in all cases with information about follow-up.

CONCLUSIONS

The main factor associated with PRES in acute postinfectious glomerulonephritis is severe hypertension. Prompt clinical suspicion, rapid evaluation, and management of hypertension are crucial. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Posterior Reversible Encephalopathy Syndrome and brain haemorrhage as COVID-19 complication: a review of the available literature

Background

SARS-CoV-2 infection has been associated with various neurological manifestations. Since patients affected by SARS-CoV-2 infection present coagulation and immune system dysregulation, ischemic or haemorragic stroke is not uncommon, irrespective of respiratory distress. However, the occurrence of focal neurological deficits together with other symptoms like headache, cortical blindness, seizure and altered mental status should prompt the diagnosis of Posterior Reversible Encephalopathy Syndrome (PRES). Antithrombotic treatment, the alteration of endothelial function, and coagulopathy due to COVID-19 and PRES leading to the breakdown of blood–brain barrier may then contribute to the occurrence of a brain haemorrhage.

Methods

We describe the case of a COVID-19 patient who developed bilateral occipital lobe haemorrhages suggestive of haemorrhagic PRES. We then reviewed the available literature about haemorrhagic evolution of PRES in COVID-19.

Results

We describe the clinical and radiological features of five COVID-19 patients who developed haemorrhagic PRES.

Conclusions

Coagulopathy and endothelial dysfunction resulting from the massive release of cytokines during the host immune response may be key factors in the pathogenesis of COVID-19-related PRES. Antithrombotic therapy and the leakage of the blood–brain barrier can subsequently increase the risk of haemorrhagic transformation of the lesioned brain tissue. A prompt diagnosis of PRES is mandatory, since the timely interruption/reversal of antithrombotic therapy may be a key determinant for a good prognosis.

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.

Clinical characteristics and outcomes of patients admitted to hospitals for posterior reversible encephalopathy syndrome: a retrospective cohort study

Background

Posterior reversible encephalopathy syndrome (PRES) is usually a benign, yet underdiagnosed clinical condition associated with subacute to acute neurological manifestations primarily affecting white matter. PRES is reversible when recognized promptly and treated early by removal of the insulting factor; however, can lead to irreversible and life-threatening complications such as cerebral hemorrhage, cerebellar herniation, and refractory status epilepticus.

Methods

We utilized the National Inpatient Sample database provided by the Healthcare Cost and Utilization Project (HCUP-NIS) 2017 to investigate the demographic variables (age, sex, and race) for patients with PRES, concomitant comorbidities and conditions, inpatient complications, inpatient mortality, length of stay (LOS), and disposition.

Results

A total of 635 admissions for patients aged 18 years or older with PRES were identified. The mean age was 57.2 ± 0.6 years old with most encounters for female patients (71.7%, n = 455) and white as the most prevalent race. Half the patients in our study presented with seizures (50.1%, n = 318), sixty-three patients (9.9%) presented with vision loss, and sixty-four patients (10.1%) had speech difficulty. In addition, 45.5% of patients had hypertensive crisis (n = 289). 2.2% of hospitalizations had death as the outcome (n = 14). The mean LOS was 8.2 (±0.3) days, and the mean total charges were $92,503 (±$5758). Inpatient mortality differed between males and females (1.7% vs. 2.4%) and by race (3.6% in black vs. 1.8% in white) but was ultimately determined to be not statistically significant. Most patients who present with vision disturbance have a high risk of intracranial hemorrhage. Furthermore, end-stage renal disease, atrial fibrillation, and malignancy seemed to be linked with a very high risk of mortality.

Conclusion

PRES, formerly known as reversible posterior leukoencephalopathy, is a neurological disorder with variable presenting symptoms. Although it is generally a reversible condition, some patients suffer significant morbidity and even mortality. To the best of our knowledge, this is the largest retrospective cohort of PRES admissions that raises clinician awareness of clinical characteristics and outcomes of this syndrome.

Posterior Reversible Encephalopathy Syndrome

Purpose of Review

This review provides an updated discussion on the clinical presentation, diagnosis and radiographic features, mechanisms, associations and epidemiology, treatment, and prognosis of posterior reversible encephalopathy syndrome (PRES). Headache is common in PRES, though headache associated with PRES was not identified as a separate entity in the 2018 International Classification of Headache Disorders. Here, we review the relevant literature and suggest criteria for consideration of its inclusion.

Recent Findings

COVID-19 has been identified as a potential risk factor for PRES, with a prevalence of 1–4% in patients with SARS-CoV-2 infection undergoing neuroimaging, thus making a discussion of its identification and treatment particularly timely given the ongoing global pandemic at the time of this writing.

Summary

PRES is a neuro-clinical syndrome with specific imaging findings. The clinical manifestations of PRES include headache, seizures, encephalopathy, visual disturbances, and focal neurologic deficits. Associations with PRES include renal failure, preeclampsia and eclampsia, autoimmune conditions, and immunosuppression. PRES is theorized to be a syndrome of disordered autoregulation and endothelial dysfunction resulting in preferential hyperperfusion of the posterior circulation. Treatment typically focuses on treating the underlying cause and removal of the offending agents.

Recurrent Posterior Reversible Encephalopathy Syndrome in an Adolescent Boy with End-Stage Renal Disease

Posterior reversible encephalopathy syndrome (PRES), also known as reversible posterior leukoencephalopathy syndrome, is a neurological entity characterized by acute change in consciousness, visual impairment, headache, and seizures. It is associated with autoimmune disease, immunosuppressive agents, organ transplantation, acute glomerulonephritis, and sepsis. Typically, vasogenic edema is seen in the white matter of parieto-occipital lobes but can also involve atypical locations such as frontal lobes, thalamus, basal ganglia, and gray matter. While occurring extensively in adults, few cases, especially recurrent episodes, have been described in children. We report a case of recurrent PRES in a 17-year-old boy with end-stage renal disease on a peritoneal dialysis program who initially presented with hypertension and seizures. He emergently received intravenous antihypertensive medication with immediate and sustained improvement in his mental status. Information about recurrent PRES in children is limited because it is not commonly seen. We examine the clinical features of PRES and highlight important points for the diagnosis and management of this rare syndrome. This report demonstrates the importance of pediatricians to consider PRES in the differential diagnosis in children presenting with acute altered mental status. Blood pressure measurements, which are often overlooked in pediatric care, may assist in correctly diagnosing patients.

Posterior reversible encephalopathy syndrome: A neuropsychiatric manifestation of systemic lupus erythematosus

Posterior Reversible Encephalopathy Syndrome (PRES) is an acute neurological syndrome clinically characterized by seizures, altered mental status, headache, and visual disturbances. It is caused by a variety of abnormalities in the endothelial function that ultimately result in vasogenic edema in the circulation of the central nervous system. This is reflected by the neuroimaging findings, that most often show reversible parieto-occipital edema. An important proportion of patients with PRES present with Systemic Lupus Erythematosus (SLE), and its complications, as their sole risk factors. This review describes the relationship between these two clinical entities and explains the pathophysiological models that have been proposed to describe the development of PRES. We explain how SLE can cause alterations in every pathway implicated in the development of PRES. Given the relatively high frequency and the distinct clinical course, PRES in the setting of SLE might be best described as a distinct neuropsychiatric syndrome associated with SLE.

Etiologies, Cerebral Vasomotion, and Endothelial Dysfunction in the Pathophysiology of Posterior Reversible Encephalopathy Syndrome in Pediatric Patients

The posterior reversible encephalopathy syndrome was characterized by Hinchey and colleagues in the 1990s. The condition frequently afflicts patients suffering from hematologic and solid organ malignancy and individuals undergoing transplantation. Cases are more frequently described in the adult population compared with children. In the pediatric population, malignancy, transplantation, renal disease, and hypertension represent the most common etiologies. Theories on pathogenesis have centered upon cerebrovascular dysautoregulation with increases in blood–brain barrier permeability. This generates vasogenic edema of the cerebral parenchyma and consequent neurologic deficits. The parietal and occipital lobes are affected with greatest prevalence, though frontal and temporal lobe involvement is frequent, and that of the contents of the infratentorial posterior cranial fossa are occasionally described. The clinical presentation involves a characteristic constellation of neurologic signs and symptoms, most typically inclusive of headache, visual-field disturbances, abnormalities of visual acuity, and seizures. Supportive care, withdrawal of the offending agent, antihypertensive therapy, and prophylactic anticonvulsants affect convalescence in majority of cases. The principal challenge lies in identifying the responsible agent precipitating the condition in patients with malignancy and those having undergone transplantation and thus deciding which medication among a multidrug treatment regimen to withhold, the duration of drug cessation required to effect clinical resolution, and the safety of resuming treatment with the compound. We accordingly reviewed and evaluated the literature discussing the posterior reversible encephalopathy syndrome in children.

Posterior reversible leukoencephalopathy syndrome: Case series and review of the literature

OBJECTIVE

To describe clinical manifestations, antecedents, comorbidities and associated treatments, imaging findings, and follow-up in patients with posterior reversible encephalopathy syndrome.

METHODS

A retrospective, descriptive analysis of admitted patients was performed between June 2009 and May 2014 in a third-level care hospital. We evaluated age, sex, comorbidities, symptoms, values of blood pressure at admission, renal function, medication and time elapsed until the disappearance of symptoms.

RESULTS

Thirteen patients were included. In all, 77% of them had a history of hypertension at baseline and 85% had impaired renal function. The most prevalent comorbidity was renal transplantation, and 85% had deterioration of renal function. Five of the patients had undergone renal transplantation. The most common clinical manifestation was seizures. All had subcortical lesions and bilateral parietooccipital involvement was the finding most frequently observed.

CONCLUSION

This syndrome should be taken into account in the differential diagnoses of patients presenting with acute neurological syndromes and the abovementioned risk factors.

Posterior reversible encephalopathy syndrome induced by intracranial hypotension in a postpartum patient

Objective: A number of hormonal, physiologic, immunologic, and hemodynamic changes can cause a series of central nervous system-related problems in pregnant and postpartum women. Posterior reversible encephalopathy syndrome (PRES) is commonly seen in these conditions. However, PRES during pregnancy and the postpartum period are not always due to pregnancy.Methods: We describe a patient who presented with headache followed by an epileptic seizure after cesarean section and whose computed tomography (CT) showed bilateral low-density lesions in the frontal lobe. To explore the pathogenesis, we further examined the patient with brain magnetic resonance imaging (MRI) and lumbar puncture.Results: Brain MRI revealed vasogenic edema in the frontal lobe and temporal-occipital regions of both hemispheres. MRI of the brain with contrast showed diffuse enhancement of the supratentorial dura mater and decreased of bilateral lateral ventricles. There was no abnormality in brain magnetic resonance angiography and magnetic resonance venography. Bloody cerebrospinal fluid flowed very slowly during lumbar puncture.Conclusion: These findings suggest that, although rare, intracranial hypotension in postpartum patients may be a cause of PRES.

A rare case of pediatric moyamoya disease with reversible white matter lesions in a 3-year-old Chinese girl

Moyamoya disease is a chronic cerebral vascular disease characterized by progressive occlusion of the cerebral arteries and resulting in the development of abnormal collateral circulation. We report a case of moyamoya disease in a 3-year-old Chinese girl with partly reversible white matter lesions. This case indicates that, in pediatric moyamoya disease, white matter lesions may be associated with cerebral ischemia, and they may be reversible after treatment.

Hypertensive brainstem encephalopathy: a diagnosis often overlooked

Hypertensive encephalopathy (HE) is a subset of posterior reversible encephalopathy syndrome. It typically involves the posterior supratentorial structures, but variations do occur. However, isolated brainstem involvement in HE is rare, with a few cases reported in the literature. Herein, we report a case of acute hypertensive brainstem encephalopathy in which the patient had mild symptoms with very high blood pressure and normal neurological examination. The computed tomography of the brain showed diffuse hypodensity at brainstem. The patient's symptoms improved drastically after hypertension had been controlled. Marked clinical-radiologic dissociation in this particular case was highly suggestive of hypertensive brainstem encephalopathy. Prompt recognition of the condition and aggressive treatment of hypertension in such patients is crucial to relieve oedema and to prevent life-threatening progression. Nevertheless, there is still a lack of awareness among physicians and radiologists regarding this rare clinical entity.

Clinical Correlates of Periodic Discharges and Nonconvulsive Seizures in Posterior Reversible Encephalopathy Syndrome (PRES)

IMPORTANCE

The pathophysiological mechanisms of Posterior Reversible Encephalopathy Syndrome (PRES) and related seizures remain poorly understood. The prevalence and clinical significance of nonconvulsive seizures (NCSz) and related epileptiform patterns during continuous electroencephalography monitoring (CEEG) in PRES have not been well described.

OBJECTIVE

To report the prevalence, characteristics and risk factors for NCSz and related highly epileptiform patterns in patients with PRES, and to determine their relation to imaging abnormalities and outcome.

DESIGN, SETTING AND PARTICIPANTS

From a prospective CEEG database, we retrospectively identified patients with PRES and reviewed their medical charts. Based on CEEG findings, we designed a retrospective cohort study comparing two groups defined based on the presence or the absence of NCSz and/or periodic discharges (PDs).

MAIN OUTCOMES AND MEASURES

The prevalence and risk factors for PDs and NCSz, description of EEG and magnetic resonance imaging (MRI) abnormalities and functional outcome as measured by the Glasgow Outcome Scale (GOS) at hospital discharge.

RESULTS

Among 37 eligible patients, 23 (62%) had PDs or NCSz. The presence of NCSz was associated with the presence of PDs (15/22 vs. 1/15; p = 0.0002). NCSz and PDs were usually either lateralized or bilateral independent and predominated in the posterior regions. No clinical features were associated with the occurrence of PDs or NCSz. Cortical restricted diffusion on MRI was more frequent in the PDs/NCSz group (17/23 vs. 1/14; p < 0.001). PDs/NCSz were associated with worse outcome, with 3 deaths vs. 0 in the no PDs/NCSz group and fewer cases with low disability (4 vs. 9 cases with GOS = 5, p < 0.04).

CONCLUSIONS AND RELEVANCE

Our results reveal a high prevalence of NCSz and PDs in critically ill patients with PRES and an association with restricted diffusion and worse outcome, whether treating or preventing these EEG findings can improve outcome requires further research.

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.

Influential factors and clinical significance of an atypical presentation of posterior reversible encephalopathy syndrome in patients with eclampsia

BACKGROUND AND PURPOSE

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiologic entity for which eclampsia is one of the most common predisposing conditions. Despite the imaging changes typically reported, the predisposing factors and clinical implications of atypical presentations have yet to be fully clarified.

METHODS

A total of 56 patients with PRES were selected for study. Demographic, clinical, and laboratory data were analyzed, focusing on atypical presentations of PRES. Multiple logistic regression was applied to identify factors impacting such atypical presentations, and functional outcomes were assessed upon patient discharge.

RESULTS

Overall, 22 of the 56 patients (39.3%) displayed features of atypical PRES. By multiple logistic regression, headache (OR = 5.39; 95% CI, 1.24-23.51; p = 0.025) and frequent convulsions (OR = 4.41; 95% CI, 1.09-17.91; p = 0.038) proved to be independent factors associated with atypical PRES. Ultimately, outcomes of 18 patients were gauged as poor, based on the modified Rankin Scale (mRS). Logistic regression indicated that visual disturbances (OR = 9.02; 95% CI, 1.37-59.35; p = 0.02), frequent convulsions (OR = 9.47; 95% CI, 1.67-53.63; p = 0.01), and restricted diffusion on imaging (OR = 11.96; 95% CI, 1.76-81.11; p = 0.01) were independently associated with poor outcomes in patients with eclampsia-related PRES.

CONCLUSION

Headache and frequent convulsions are independently associated with atypical presentations of PRES. If present, restricted diffusion may help in predicting poor outcomes of such patients upon discharge.

Posterior reversible encephalopathy syndrome with extensive cytotoxic edema after blood transfusion: a case report and literature review

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is described as a clinical-radiological disease entity with good prognosis. In brain MRI, PRES generally presents with vasogenic edema. Although PRES is induced by various causes, a small number of PRES cases have occurred after red cell blood transfusion. It is unclear whether there are characteristic features in PRES after blood transfusion.

CASE PRESENTATION

Here, we report a case of 75-year-old Japanese woman who had acute exacerbation of subacute anemia by bleeding from gastric ulcer. After receiving a red cell blood transfusion, she showed disturbance of consciousness with extensive cytotoxic and small vasogenic edema in the occipitoparietal area on brain MRI. She was diagnosed as PRES and suffered irreversible impairments of visual acuity and fields in both eyes. We summarized and discussed clinical features of cases with PRES after blood transfusion.

CONCLUSIONS

A total of 21 cases including the present one have been reported as PRES after blood transfusion. Of the cases, 20 of 21 were female, and 15 of 17 developed PRES in the course of chronic anemia lasting over 1 month. Anemia was severe in 15 of 20 cases, with hemoglobin levels < 3.5 g/dl. In 14 of 17 cases, hemoglobin levels increased to 5 g/dl by red cell blood transfusion until the onset of PRES. On brain MRI, 2 of 21 cases showed cytotoxic edema and 3 of 21 cases showed irreversible neurological disturbance. In this patient, the occurrence of PRES in subacute anemia and the presence of extensive cytotoxic brain edema with irreversible neurological deficits were characteristic points. When treating severe anemia, even with a subacute progression, we should consider a possibility that PRES occurs after blood transfusion with extensive cytotoxic brain edema and irreversible neurological changes.

Unusual Aspect of Posterior Reversible Encephalopathy Syndrome in an Elderly Adult

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) classically occurs in patients presenting with a sudden increase of arterial pressure or eclampsia, but the range of etiologies is very wide. Although the mechanisms underlying PRES remain unclear, research suggests that when the extent of hypertension exceeds the threshold of cerebral blood flow autoregulation, this induces blood-brain barrier disruption that leads to brain edema. Unusual presentations on magnetic resonance imaging (MRI) are possible, including the involvement of frontal or temporal lobes, cerebellar hemispheres, basal ganglia, brainstem, or deep white matter. However, in these atypical locations, edema is mostly accompanied by the classical parieto-occipital region involvement.

CASE REPORT

We report the case of an elderly adult presenting with an unusual presentation of PRES with exclusive involvement of the frontal lobes, associated with severe hypertension. In our case, computed tomography and MRI abnormalities were exclusively localized in the frontal regions without involvement of the classical parieto-occipital regions. A favorable clinical course after hypertension management and complete clearance on an MRI scan at 3 months' follow-up confirmed the diagnosis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: PRES is a condition potentially encountered by many doctors, especially in the emergency department. However, atypical clinical or imaging presentations are possible and could delay the diagnosis. These must be known to begin adequate treatment as quickly as possible.

Posterior reversible encephalopathy syndrome following elevated mean arterial pressures for cervical spinal cord injury

BACKGROUND

Increasing the mean arterial pressure (MAP) is an accepted treatment modality to minimize the risk for irreversible neurologic damage secondary to spinal cord ischemia. Posterior reversible encephalopathy syndrome (PRES) is a rare complication occurring after transplantation surgery, in persons having an autoimmune disorder or after abrupt increases in blood pressure of various etiologies.

STUDY DESIGN

Case report.

METHODS

Retrospective evaluation of medical records.

RESULTS

A 68-year-old female with long-standing diabetes, and rheumatoid arthritis (treated with methotrexate) presented with bilateral upper extremity weakness and numbness developing several days after a motor vehicle accident. Physical examination confirmed decreased upper extremity motor strength and decreased sensation to light touch and pinprick in the C5-C6 dermatomal distribution. Magnetic resonance imaging (MRI) demonstrated C5-C6 subluxation with spinal cord compression. The patient had traction applied and mean arterial pressures were elevated greater than 85 mmg. The following day the patient underwent anterior and posterior cervical spine fusion and decompression. Immediately post-operatively, the patient developed status epilepticus. Head MRI revealed areas of high T2 signal intensity in the bilateral occipital lobes, consistent with a diagnosis of PRES. Two weeks later, the patient had resolution of her symptoms and resolution of PRES on imaging.

CONCLUSION

This is the first report of posterior reversible encephalopathy syndrome secondary to therapeutic blood pressure increase in the setting of cervical spine fracture with neurological deficits. The patients had resolution of symptoms following discontinuation of the MAP goals. Posterior reversible encephalopathy syndrome (PRES) is a life-threatening condition characterized by seizures, confusion, visual disturbance, and headaches alongside neuroradiological findings indicative of posterior cerebral hemispheric white matter edema.^1,2 PRES has been described in association with abrupt blood pressure elevation, autoimmune disorders, or transplantation.^1-4 In this case report PRES presented with typical status epilepticus⁵ but in an unexpected clinical setting, immediately after anterior cervical decompression and fusion (ACDF) and posterior cervical fusion (PCF) with laminectomy of C5-C6.

The imaging spectrum of posterior reversible encephalopathy syndrome: A pictorial review

Posterior reversible encephalopathy syndrome (PRES) is characterized by the acute onset of neurologic symptoms (headache, altered mental status, visual changes, seizures) with accompanying vasogenic edema on brain imaging. Risk factors for PRES include infection, uremia, malignancy, autoimmune disorders, the peripartum state and hypertension. PRES is classically described as being posterior (i.e. parieto-occipital) but radiologic variants are increasingly recognized. This pictorial review demonstrates the heterogeneity of the different radiologic presentations of PRES in reference to lesion distribution, hemorrhage, diffusion restriction, contrast enhancement, and other associated findings.

Posterior reversible encephalopathy syndrome presenting in the anterior circulation with malignant intracranial hypertension requiring surgical decompression: a case report and literature review

Posterior reversible encephalopathy syndrome (PRES) is thought to result from endothelial dysfunction and breakdown of the blood-brain barrier with subsequent vasogenic edema. Abrupt hypertension has been identified as one of its risk factors. We present a rare case of PRES in the anterior circulation with sudden onset of left hemiparesis and rapid neurological deterioration on the basis of hypertensive crisis. Due to refractory intracranial hypertension, the patient required emergent right decompressive craniectomy. Further investigations, including a biopsy, revealed an atypical form of PRES. This case illustrates the importance of aggressive medical and early surgical management to prevent permanent neurological deficits.

Corticosteroid therapy and severity of vasogenic edema in posterior reversible encephalopathy syndrome

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a variable cerebrovascular syndrome associated with hypertension and autoregulatory failure. Steroids have been reported to both precipitate and treat PRES. We sought to determine the prevalence of steroid therapy at the time of PRES and to assess the relationship between steroid therapy and extent of vasogenic edema.

METHODS

We performed a retrospective review of radiology reports between 2008 and 2014 from two academic medical centers to identify cases of PRES. Clinical and radiographic data were collected. Descriptive statistics were used to determine the prevalence of corticosteroid therapy at the time of PRES onset and the latency from steroid initiation to PRES onset. The association between steroid therapy and extent of vasogenic edema was assessed in multiple regression models.

RESULTS

We identified 99 cases of PRES in 96 patients. The median age was 55years (IQR 30-65) and 74% were women. Steroid therapy at time of PRES onset was identified in 44 of 99 cases. Excluding patients on chronic therapy, the median duration of steroid exposure before PRES onset was 6 (IQR, 3-10) days. Steroid therapy was not associated with extent of vasogenic edema in unadjusted or linear and logistic regression models adjusted for age, sex, and maximum systolic blood pressure on day of onset.

CONCLUSION

Corticosteroid therapy, often of brief duration, frequently preceded the onset of PRES and was not associated with severity of vasogenic edema.

Posterior Reversible Encephalopathy Syndrome: A Review

Radiologists may be the first to suggest the diagnosis of posterior reversible encephalopathy syndrome (PRES). PRES is associated with many diverse clinical entities, the most common of which are eclampsia, hypertension, and immunosuppressive treatment. Radiologists should be aware of the spectrum of imaging findings in PRES. When promptly recognized and treated, the symptoms and radiological abnormalities can be completely reversed. When unrecognized, patients can progress to ischemia, massive infarction, and death. In this review, we present an overview of the unique signs observed on computed tomography and magnetic resonance images in PRES that can help in the early diagnosis and treatment that is highly effective in this syndrome.

Posterior reversible encephalopathy syndrome in a postpartum hemorrhagic woman without hypertension: A case report

RATIONALE

Posterior reversible encephalopathy syndrome (PRES), which diagnosis is based on clinical symptoms and radiological features, is a neurotoxic disease characterized by a set of clinical manifestations, such as seizure, headache, visual, and/or consciousness disturbance. It is the first case of PRES followed by postpartum hemorrhage (PPH) without underlying disease.

PATIENT CONCERNS

A 37-year-old healthy woman had PPH after caesarean section. Six days after delivery, headache occurred suddenly, followed by episodes of clonus seizure.

DIAGNOSES

Brain computed tomography showed ischemic stroke. However, magnetic resonance imaging revealed characteristics consistent with PRES.

INTERVENTIONS

The patient received phenytoin for seizure control.

OUTCOMES

Seizure was under good control over the following days. Three months later, repeated magnetic resonance imaging showed complete remission.

LESSONS

PRES may be triggered by PPH and is not necessarily secondary to typical predisposing factors such as hypertension or pre/eclampsia. Hormone fluctuation, increased blood pressure variation, and massive blood transfusion may be contributed to the development of PRES in our case. Also, it is necessary to rule out those life-threatening diseases, such as cavernoma hemorrhage, cerebral venous thrombosis, and ischemic stroke before the diagnosis of PRES.

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.

Posterior reversible encephalopathy in the intensive care unit

Posterior reversible encephalopathy syndrome (PRES) is increasingly diagnosed in the emergency department, and medical and surgical intensive care units. PRES is characterized by acute onset of neurologic symptoms in the setting of blood pressure fluctuations, eclampsia, autoimmune disease, transplantation, renal failure, or exposure to immunosuppressive or cytotoxic drugs, triggers known to admit patients to the intensive care unit (ICU). Although the exact pathophysiology remains unknown, there is growing consensus that PRES results from endothelial dysfunction. Because of the heterogeneous nature of the disorder, it is probable that different mechanisms of endothelial injury are etiologically important in different clinical situations. The presence of bilateral vasogenic edema on brain imaging, particularly in parieto-occipital regions, is of great diagnostic utility but PRES remains a clinical diagnosis. Although largely reversible, PRES can result in irreversible neurologic injury and even death. The range of clinical and radiographic manifestations of the syndrome is probably broader than previously thought, and it is imperative that clinicians become familiar with the full spectrum of the disorder, as prompt recognition and elimination of an inciting factor improve outcome. PRES may be the most frequent toxic-metabolic encephalopathy seen in the ICU.

Acute Kidney Injury, Recurrent Seizures, and Thrombocytopenia in a Young Patient with Lupus Nephritis: A Diagnostic Dilemma

Introduction. Posterior reversible encephalopathy syndrome (PRES) is a constellation of clinical and radiologic findings. Fluctuations in blood pressure, seizures, and reversible brain MRI findings mainly in posterior cerebral white matter are the main manifestations. PRES has been associated with multiple conditions such as autoimmune disorders, pregnancy, organ transplant, and thrombotic microangiopathy (TMA). Case Presentation. A 22-year-old woman with history of Systemic Lupus Erythematous complicated with chronic kidney disease secondary to lupus nephritis class IV presented with recurrent seizures and uncontrolled hypertension. She was found to have acute kidney injury and thrombocytopenia. Repeat kidney biopsy showed diffuse endocapillary and extracapillary proliferative and membranous lupus nephritis (ISN-RPS class IV-G+V) and endothelial swelling secondary to severe hypertension but no evidence of TMA. Brain MRI showed reversible left frontal and parietal lesions that resolved after controlling the blood pressure, making PRES the diagnosis. Conclusion. PRES is an important entity that must be recognized and treated early due to the potential reversibility in the early stages. Physicians must have high suspicion for these unusual presentations. We present a case where performing kidney biopsy clinched the diagnosis in our patient with multiple confounding factors.

Posterior Reversible Encephalopathy Syndrome: A Comparative Study of Pediatric Versus Adult Patients

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is an acute neurotoxic syndrome that, although characteristically reversible, can result in long-term disability. Our aim was to identify the clinical and radiological factors that are unique to children with PRES compared with adults with the syndrome in a single center.

METHODS

We retrospectively reviewed the clinical and radiological records of all patients with PRES admitted at a tertiary care medical center from 2007 to 2014. All patients who met the clinical and radiological criteria for PRES were dichotomized into children (less than 18 years) and adults (18 years or older) based on their age groups, and comparison of their baseline variables, clinical, laboratory, and imaging features was performed.

RESULTS

During this study period, 19 pediatric patients and 100 adult patients with PRES were identified. On univariate analysis, factors significantly associated with pediatric patients with the syndrome were multiorgan failure (84.2% vs 50%, P = 0.006), temporal lobe involvement (63.3% vs 39%, P = 0.04), restricted diffusion (42.1% vs 18%, P = 0.02), and less likelihood of cerebellar involvement (21.1% vs 57%, P = 0.004). On bivariate logistic regression analysis, all these factors remained significantly associated with pediatric PRES; multiorgan failure (odds ratio: 5.80, 95% confidence interval: 1.45 to 29.41, P = 0.03), temporal lobe involvement (odds ratio: 5.08, 95% confidence interval: 1.17 to 22.17, P = 0.03), restricted diffusion (odds ratio: 2.48, 95% confidence interval: 1.61 to 10.10, P = 0.02), and less likely to have cerebellar involvement (odds ratio: 0.08, 95% confidence interval: 0.002 to 0.39, P = 0.002).

CONCLUSIONS

Factors unique to PRES in children compared with adults include a greater propensity with multi-organ failure, involvement of the temporal lobe, and restricted diffusion on imaging.

Diagnosis of Acute Neurologic Emergencies in Pregnant and Postpartum Women

Acute neurologic symptoms in pregnant and postpartum women may be caused by exacerbation of a preexisting neurologic condition, the initial presentation of a non-pregnancy-related problem, or a new neurologic problem. Pregnant and postpartum patients with headache and neurologic symptoms are often diagnosed with preeclampsia or eclampsia; however, other etiologies must also be considered. A team approach with close communication between emergency physicians, neurologists, maternal-fetal medicine specialists, and radiologists is the key to obtaining best outcomes. This article reviews the clinical features and differential diagnosis of acute serious neurologic conditions in pregnancy and the puerperium, focusing on diagnosis.

[Research advances of posterior reversible encephalopathy syndrome in children]

Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological entity affecting the posterior brain, i.e. occipital and parietal lobes. The syndrome are characterized by headaches, altered mental status, seizures, and visual disturbances. Although the pathogenesis remains unclear, endothelial dysfunction may be a key factor. The basic disease may play a crucial role in the incidence of PRES. In most cases, PRES resolves spontaneously and patients show both clinical and radiological improvements. In severe forms, PRES might cause substantial morbidity with sequel and even mortality, as a result of acute hemorrhage or massive posterior fossa edema causing obstructive hydrocephalus or brainstem compression. Early identification, active and appropriate treatment is very important.

Incidence of posterior reversible encephalopathy syndrome in eclamptic and patients with preeclampsia with neurologic symptoms

BACKGROUND

Posterior reversible encephalopathy syndrome is observed frequently in patients with eclampsia; however, it has also been reported in some patients with preeclampsia.

OBJECTIVES

The aim of this study was to determine the incidence of posterior reversible encephalopathy syndrome in patients with preeclampsia and eclampsia and to assess whether these 2 patient groups share similar pathophysiologic backgrounds by comparing clinical and radiologic characteristics.

STUDY DESIGN

This was a retrospective cohort study of 4849 pregnant patients. A total of 49 patients with eclampsia and preeclampsia and with neurologic symptoms underwent magnetic resonance imaging and magnetic resonance angiography; 10 patients were excluded from further analysis because of a history of epilepsy or dissociative disorder. The age, parity, blood pressure, and routine laboratory data at the onset of symptoms were also recorded.

RESULTS

Among 39 patients with neurologic symptoms, 12 of 13 patients with eclampsia (92.3%) and 5 of 26 patients with preeclampsia (19.2%) experienced the development of posterior reversible encephalopathy syndrome. Whereas age and blood pressure at onset were not significantly different between patients with and without encephalopathy, hematocrit, serum creatinine, aspartate transaminase, alanine transaminase, and lactate dehydrogenase values were significantly higher in patients with posterior reversible encephalopathy syndrome than in those without magnetic resonance imaging abnormalities. In contrast, patients with eclampsia with posterior reversible encephalopathy syndrome did not show any significant differences in clinical and laboratory data compared with patients with preeclampsia with posterior reversible encephalopathy syndrome. In addition to the parietooccipital regions, atypical regions (such as the frontal and temporal lobes), and basal ganglia were also involved in patients with eclampsia and patients with preeclampsia with posterior reversible encephalopathy syndrome. Finally, intraparenchymal hemorrhage was detected in 1 patient with eclampsia, and subarachnoid hemorrhage was observed in 1 patient with preeclampsia.

CONCLUSIONS

Although the incidence of posterior reversible encephalopathy syndrome was high in patients with eclampsia, nearly 20% of the patients with preeclampsia with neurologic symptoms also experienced posterior reversible encephalopathy syndrome. The similarities in clinical and radiologic findings of posterior reversible encephalopathy syndrome between the 2 groups support the hypothesis that these 2 patient groups have a shared pathophysiologic background. Thus, magnetic resonance imaging studies should be considered for patients with the recent onset of neurologic symptoms, regardless of the development of eclampsia.

Uremic Encephalopathy: MR Imaging Findings and Clinical Correlation

BACKGROUND AND PURPOSE

Uremic encephalopathy is a metabolic disorder in patients with renal failure. The purpose of this study was to describe the MR imaging findings of uremic encephalopathy.

MATERIALS AND METHODS

This study retrospectively reviewed MR imaging findings in 10 patients with clinically proved uremic encephalopathy between May 2005 and December 2014. Parameters evaluated were lesion location and appearance; MR signal intensity of the lesions on T1WI, T2WI, and T2 fluid-attenuated inversion recovery images; the presence or absence of restricted diffusion on diffusion-weighted images and apparent diffusion coefficient maps; and the reversibility of documented signal-intensity abnormalities on follow-up MR imaging.

RESULTS

MR imaging abnormalities accompanying marked elevation of serum creatinine (range, 4.3-11.7 mg/dL) were evident in the 10 patients. Nine patients had a history of chronic renal failure with expansile bilateral basal ganglia lesions, and 1 patient with acute renal failure had reversible largely cortical lesions. Two of 6 patients with available arterial blood gas results had metabolic acidosis. All basal ganglia lesions showed expansile high signal intensity (lentiform fork sign) on T2WI. Varied levels of restricted diffusion and a range of signal intensities on DWI were evident and were not correlated with serum Cr levels. All cortical lesions demonstrated high signal intensity on T2WI. Four patients with follow-up MR imaging after hemodialysis showed complete resolution of all lesions.

CONCLUSIONS

The lentiform fork sign is reliable in the early diagnosis of uremic encephalopathy, regardless of the presence of metabolic acidosis. Cytotoxic edema and/or vasogenic edema on DWI/ADC maps may be associated with uremic encephalopathy.

Late postpartum eclampsia complicated with posterior reversible encephalopathy syndrome: a case report and a literature review

Posterior reversible encephalopathy syndrome (PRES) is a rare but serious clinical-neuroradiological entity characterized by headache, vomiting, visual disturbances, altered mental status, seizures, and unconsciousness associated with the characteristic imaging findings including sub-cortical vasogenic edema at the bilateral parietal and occipital lobes. We describe a case of 28-year-old PRES patient secondary to delayed maternal postpartum eclampsia. This patient was not initially diagnosed with pre-eclampsia and PRES. The diagnosis was established after magnetic resonance imaging. After treatment this patient's PRES resolved. Early diagnosis and treatment are the keys to reverse PRES. A literature review for PRES is provided in this report.

Risk of Stroke After the International Classification of Diseases-Ninth Revision Discharge Code Diagnosis of Hypertensive Encephalopathy

BACKGROUND AND PURPOSE

Although chronic hypertension is a well-established risk factor for stroke, little is known about stroke risk after hypertensive encephalopathy (HE), when neurologic sequelae of hypertension become evident. Therefore, we evaluated the risk of stroke after a diagnosis of HE.

METHODS

We identified all patients discharged from California, New York, and Florida emergency departments and acute care hospitals between 2005 and 2012 with a primary International Classification of Diseases, Ninth Edition, Clinical Modification discharge diagnosis of HE (437.2). Patients discharged with a primary diagnosis of seizure (345.x) served as negative controls, whereas patients with a primary diagnosis of transient ischemic attack (435.x) were positive controls. Our primary outcome was the composite of subsequent ischemic stroke or intracerebral hemorrhage. Kaplan-Meier survival statistics were used to calculate cumulative outcome rates, and Cox proportional hazard analysis was used to examine the association between index disease types and outcomes while adjusting for vascular risk factors.

RESULTS

We identified 8233 patients with HE, 191 091 with seizure, and 308 680 with transient ischemic attack. The 1-year cumulative rate of ischemic stroke or intracerebral hemorrhage after HE was 4.90% (95% confidence interval [CI], 4.45-5.40) when compared with 0.92% (95% CI, 0.88-0.97) after seizure and 4.49% (95% CI, 4.42-4.57) after transient ischemic attack. The risk of intracerebral hemorrhage was significantly elevated in those with HE (hazard ratio, 2.0; 95% CI, 1.7-2.5) but not in those with transient ischemic attack (hazard ratio, 1.0; 95% CI, 0.9-1.1), when compared with seizure patients.

CONCLUSIONS

Patients discharged with a diagnosis of HE face a high risk of future cerebrovascular events, particularly intracerebral hemorrhage.

The spectrum of posterior reversible encephalopathy in systemic lupus erythematosus

Our aim was to compare our South African cohort of systemic lupus erythematosus (SLE) and posterior reversible encephalopathy syndrome (PRES) with other published series. We reviewed the records of 10 patients with SLE and PRES seen over a 10-year period and their demographic data, clinical manifestations, laboratory tests, imaging findings, and outcome were recorded. We identified 10 females who included six Indians, three mixed ethnicity, and one African Black. Three patients had PRES at the onset of SLE. The most common manifestations at presentation were seizures (100 %), hypertension (80 %), and altered mental state (50 %). On neuroimaging, nine patients had bilateral involvement, and the occipital (90 %), parietal (90 %), and frontal lobes (50 %) were most commonly involved. The risk factors for PRES were disease activity (90 %), renal disease (80 %) and hypertension (80 %). Ninety percent of the patients were on immunosuppressive therapy. Immunosuppressive therapy was increased in six patients (60 %), continued in two and reduced in two patients after the diagnosis of PRES. Seven patients recovered completely and three patients died from co-morbidities. A review of the larger case series of SLE and PRES showed that the presentation and neuroimaging findings were similar; most patients had active disease at the time of PRES and the majority of patients required intensification of immunosuppressive therapy. We have shown that the majority of patients with SLE have active disease at the time of PRES, and they require an increase in their immunosuppressive therapy.

Posterior reversible encephalopathy syndrome: clinical and radiological manifestations, pathophysiology, and outstanding questions

Almost two decades have elapsed since posterior reversible encephalopathy syndrome (PRES) was described in an influential case series. This usually reversible clinical syndrome is becoming increasingly recognised, in large part because of improved and more readily available brain imaging. Although the pathophysiological changes underlying PRES are not fully understood, endothelial dysfunction is a key factor. A diagnosis of PRES should be considered in the setting of acute neurological symptoms in patients with renal failure, blood pressure fluctuations, use of cytotoxic drugs, autoimmune disorders, or eclampsia. Characteristic radiographic findings include bilateral regions of subcortical vasogenic oedema that resolve within days or weeks. The presence of haemorrhage, restricted diffusion, contrast enhancement, and vasoconstriction are all compatible with a diagnosis. In most cases, PRES resolves spontaneously and patients show both clinical and radiological improvements. The range of symptoms that can comprise the syndrome might be broader than usually thought. In its mild form, this disorder might cause only one clinical symptom (headache or seizure) and radiographically might show few areas of vasogenic oedema or even normal brain imaging in some rare cases. In severe forms, PRES might cause substantial morbidity and even mortality, most often as a result of acute haemorrhage or massive posterior fossa oedema causing obstructive hydrocephalus or brainstem compression.