Posterior reversible encephalopathy syndrome in end-stage kidney disease: not strictly posterior or reversible

A case of bilateral cortical blindness followed by generalised tonic-clonic seizure epilepsy in a patient with posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) in end-stage kidney disease (ESKD) is rare, with ocular symptoms as the first manifestation being even rarer. Here, we report a case of PRES in a patient with ESKD, characterized by sudden binocular blurred vision followed by epilepsy, to improve the understanding of this syndrome among nephrologists and ophthalmologists. A 50-year-old female requested an ophthalmic consultation due to bilateral vision loss followed by generalised tonic-clonic seizures. One month before onset of current illness, she developed ESKD secondary to rapid progression of previous ANCA vasculitis associated renal damage. Latter magnetic resonance imaging confirmed the diagnosis of PRES. Two weeks later, the patient's vision fully recovered. Conclusion: PRES is not an etiological diagnosis but a neuroimaging sign. In addition, PRES is a danger signal that is usually reversible if recognized and treated early, and can be life-threatening if treatment is delayed.

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.

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 (PRES) associated with SARS-CoV-2 infection in a patient under maintenance haemodialysis: a case report

BACKGROUND

Endothelial dysfunction is common in patients undergoing chronic haemodialysis, and is a major cause of posterior reversible encephalopathy syndrome (PRES). Recently, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been shown to cause endothelial dysfunction by infecting vascular endothelial cells. Several cases of neurological complications in patients without kidney dysfunction, and only a few cases in patients with chronic kidney disease, have been reported in the literature. However, no previous report has yet described PRES associated with SARS-CoV-2 infection among patients undergoing maintenance dialysis.

CASE PRESENTATION

A 54-year-old woman undergoing maintenance haemodialysis was admitted to our hospital for status epilepticus. She had developed end-stage kidney disease (ESKD) secondary to diabetic nephropathy. Seven days prior to admission, she had developed fever and was diagnosed with COVID-19. Subsequently her blood pressure increased from 160/90 mmHg to 190/100 mmHg. On admission, she presented with severe hypertension (> 220/150 mmHg), unconsciousness, and epilepticus. CT tomography revealed no signs of brain haemorrhage. Cranio-spinal fluid (CSF) examination revealed no signs of encephalitis, and CSF polymerase chain reaction (PCR) for SARS-CoV-2 was negative. MRI findings revealed focal T2/FLAIR hyperintensity in the bilateral parietooccipital regions, leading to the diagnosis of PRES. Deep sedation and strict blood pressure control resulted in a rapid improvement of her symptoms, and she was discharged without sequelae.

CONCLUSIONS

We report the first case of PRES associated with SARS-CoV-2 infection in a patient undergoing maintenance haemodialysis. Patients undergoing maintenance haemodialysis are at high risk of PRES because of several risk factors. SARS-CoV-2 infection causes direct invasion of endothelial cells by binding to angiotensin-converting enzyme 2 (ACE2), initiating cytokine release, and hypercoagulation, leading to vascular endothelial cell injury and increased vascular leakage. In the present case, SARS-CoV-2 infection possibly be associated with the development of 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 (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.

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.

Unusual Presentation of a Posterior Reversible Encephalopathy Syndrome With Brainstem Involvement and Subarachnoid Haemorrhage

Posterior reversible encephalopathy syndrome is an increasingly recognized disorder characterized by a headache, visual disturbances, and seizures. It is a reversible neurotoxic state, with multiple risk factors in which endothelial injury and compromised brain perfusion are the common characteristics. Diagnosis is usually made by cerebral magnetic resonance imaging that typically shows early-stage bilateral symmetrical parieto-occipital hyperintensities on T2 and fluid-attenuated inversion recovery (FLAIR) sequences. However, other locations have been described where the disease may appear less frequently. We describe the case of a 62-year-old man, with a medical history of hypertension, who presented with anisocoria with mydriatic non-reactive pupil and ptosis of the left eye. CT head showed a slightly hypodense brainstem, in relation to vasogenic edema. This was confirmed with magnetic resonance imaging. The angiography did not identify cerebral artery aneurysms. The symptoms and radiological findings were almost completely reversible after improving the patient's blood pressure. This case highlights a rare single presentation of posterior reversible encephalopathy syndrome associated with subarachnoid hemorrhage. A high index of suspicion, careful examination, and exploration with imaging techniques were essential to reach this diagnosis.

Chronic Kidney Disease and Cerebrovascular Disease: Consensus and Guidance From a KDIGO Controversies Conference

The global health burden of chronic kidney disease is rapidly rising, and chronic kidney disease is an important risk factor for cerebrovascular disease. Proposed underlying mechanisms for this relationship include shared traditional risk factors such as hypertension and diabetes, uremia-related nontraditional risk factors, such as oxidative stress and abnormal calcium-phosphorus metabolism, and dialysis-specific factors such as cerebral hypoperfusion and changes in cardiac structure. Chronic kidney disease frequently complicates routine stroke risk prediction, diagnosis, management, and prevention. It is also associated with worse stroke severity, outcomes and a high burden of silent cerebrovascular disease, and vascular cognitive impairment. Here, we present a summary of the epidemiology, pathophysiology, diagnosis, and treatment of cerebrovascular disease in chronic kidney disease from the Kidney Disease: Improving Global Outcomes Controversies Conference on central and peripheral arterial disease with a focus on knowledge gaps, areas of controversy, and priorities for research.

Posterior Reversible Encephalopathy Syndrome: Tips for Diagnosis and Treatment

Often described as a clinico-radiological entity, posterior reversible encephalopathy syndrome (PRES) is being increasingly diagnosed nowadays. However, mystery still surrounds its exact etiology. Though there are no standardized diagnostic criteria for this syndrome, there is a consistent feature associated with it: brain vasogenic edema in combination with neurotoxicity. The nonspecific nature of this condition leaves room for the diagnosis to be overlooked, leading to delays in providing appropriate treatment and unfavorable patient outcomes. PRES is associated with a variety of medical conditions including hypertension, eclampsia, autoimmune conditions, renal failure, sepsis, and an immunocompromised state, such as that secondary to the use of immunosuppressive therapy, human immunodeficiency virus (HIV), and organ transplants. Treatment by a multidisciplinary team and prompt identification and reversal of the underlying cause can lead to beneficial outcomes, as in the case we present in this report.

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.

Peak blood pressure and prediction of posterior reversible encephalopathy syndrome in children

BACKGROUND

Hypertension is a risk factor for posterior reversible encephalopathy syndrome (PRES), but the timing and severity of hypertension relative to PRES are unknown. The objective was to identify a clinically meaningful blood pressure (BP) threshold that predicts PRES development in high-risk children.

METHODS

We recorded peak systolic BP, diastolic BP, BP z-scores, and mean arterial pressure over the 14 days preceding clinical concern for PRES in 35 subjects who developed PRES, compared to 14 controls who had normal brain magnetic resonance imaging and similar underlying disease, renal function, and medications. We used multivariable logistic regression models adjusted for fluid overload and obesity to estimate the association of peak BP with PRES. We used receiver operating characteristic curves to determine which peak BP thresholds best predicted PRES and calculated the corresponding sensitivity, specificity, and positive and negative predictive values.

RESULTS

Peak systolic BP z-score was most strongly associated with PRES (OR 3.97, 95% CI 1.62-9.74), and peak systolic BP z-score ≥ 3.0 predicted PRES (area under the curve 0.95, 95% CI 0.88-1.0) with 91% sensitivity and 85% specificity, indicating 94% positive predictive value and 79% negative predictive value.

CONCLUSIONS

We demonstrated that peak systolic BP z-score ≥ 3.0 in the preceding 14 days predicted PRES development in cases compared with controls in children at high risk. Our study suggests that stage 2 hypertension, corresponding to a z-score ≥ 3.0, could help define hypertensive emergency in high-risk children and indicate when more aggressive treatment is warranted to prevent neurologic injury.

Posterior reversible encephalopathy syndrome in the setting of trauma: A case report

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Posterior reversible encephalopathy syndrome (PRES) in the setting of trauma and acute care surgery.

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Posterior reversible encephalopathy syndrome (PRES) in trauma patients with a specific pattern of neuroimaging and clinical symptoms.

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T2 weighted diffusion hyperintensities were present on MRI of the brain in both cases.

Reports of posterior reversible encephalopathy syndrome (PRES) in the setting of trauma and acute care surgery are scarce. PRES presents rapidly with a variety of symptoms including headaches, visual disturbances, altered consciousness, and seizures. It is associated with acute hypertensive episodes. PRES is diagnosed with a specific neuroimaging pattern and a constellation of clinical symptoms. This case report presents two traumatically injured patients with one confirmed case of PRES and the other with a potential case of PRES. The diagnosis was made through neuroimaging showing patchy T2 and diffusion hyperintensity in the periphery of both occipital lobes and adjacent cerebellar hemispheres on MRI in one case. The other case highlights extensive stable white matter disease without evidence of acute infarct on MRI, as well as diminished attenuation within the cerebral white matter in the occipital lobes on CT scan. There was resolution of visual symptoms in one patient while the other patient's neurologic status did not allow for evaluation of symptom resolution. This report aims to emphasize the possibility of PRES in trauma patients with a specific pattern of neuroimaging and clinical symptoms, and to increase the index of suspicion in acute care providers.

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.

Concurrent pituitary apoplexy and posterior reversible encephalopathy syndrome in a patient with end-stage renal disease on hemodialysis: A case report

RATIONALE

Pituitary apoplexy (PA) and posterior reversible encephalopathy syndrome (PRES) are rare neurologic diseases that show acute neuro-ophthalmologic symptoms such as headache, decreased visual acuity, and altered consciousness. These diseases are rarely found in patients with end-stage renal disease (ESRD) on hemodialysis, and simultaneous occurrence of these 2 diseases has not been reported.

PATIENT CONCERNS

The patient was a 75-year-old man with a history of hypertension, diabetes mellitus, and non-functioning pituitary macroadenoma. He had been receiving hemodialysis for ESRD for 3 months before his presentation to the emergency room. The patient complained of headache, vomiting, and dizziness that started after the previous day's hemodialysis. The patient had voluntarily discontinued his antihypertensive medication 2 weeks before presentation and had high blood pressure with marked fluctuation during hemodialysis. Complete ptosis and ophthalmoplegia on the right side suggested 3rd, 4th, and 6th cranial nerve palsies.

DIAGNOSES

Magnetic resonance imaging of the brain revealed a pituitary tumor, intratumoral hemorrhage within the sella, and symmetric vasogenic edema in the subcortical white matter in the parieto-occipital lobes. Based on these findings, the patient was diagnosed with PA and PRES.

INTERVENTIONS

Intravenous administration of hydrocortisone (50 mg every 6 hours after a bolus administration of 100 mg) was initiated. Although surgical decompression was recommended based on the PA score (5/10), the patient declined surgery.

OUTCOMES

Headache and ocular palsy gradually improved after supportive management. The patient was discharged on the 14th day of hospitalization with no recurrence 5 months post-presentation. Current therapy includes antihypertensive agents, oral prednisolone (7.5 mg/day), and maintenance hemodialysis.

LESSONS

Neurologic abnormalities developed in a patient with ESRD on hemodialysis, suggesting the importance of prompt diagnosis and treatment in similar instances.

Blood pressure and the brain: the neurology of hypertension

Hypertension affects more than one in four adults. The brain is an early target of hypertension-induced organ damage, and may manifest as stroke, subclinical cerebrovascular abnormalities and dementia. Hypertension-related small vessel disease can cause vascular dementia and can potentiate Alzheimer’s pathology, lowering the threshold at which signs and symptoms manifest. Many hypertensive emergencies may also have a neurological presentation, such as hypertensive encephalopathy, haemorrhagic stroke or pre-eclampsia. Here we highlight the importance of blood pressure in maintaining brain health and the brain’s role in controlling blood pressure.

Chemotherapy-induced posterior reversible encephalopathy syndrome: Three case reports

RATIONALE

Posterior reversible encephalopathy syndrome (PRES) has been associated with the use of several medications, including chemotherapeutic agents.

PATIENT CONCERNS

A 65-year-old woman was diagnosed with adenocarcinoma of the ovary, after sixth-line treatment with topotecan, at the beginning of the fourth cycle, she was admitted to the emergency room for presenting tonic-clonic seizures, visual disturbance, and hypertension. A 66-year-old woman was diagnosed with bilateral breast cancer; due to disease progression, treatment with paclitaxel and gemcitabine was started, 1 month after the last dose of chemotherapy, she was admitted to the emergency room for suffering severe headache, altered mental status, tonic-clonic seizures, and hypertension. A 60-year-old patient diagnosed with breast cancer on the left side, underwent second-line chemotherapy with gemcitabine, carboplatin, and bevacizumab, and 1 month after the last dose of chemotherapy, she was also admitted to the emergency room due to altered mental status, vomiting, tonic-clonic seizures, and hypertension.

DIAGNOSIS

They were diagnosed as PRES based on physical examination, laboratory findings, and imaging techniques that revealed diffuse lesions and edema within the parieto-occipital regions.

INTERVENTIONS

They received support treatment with blood pressure (BP) control, seizures were controlled with a single anti-epileptic agent, and chemotherapeutic agents from the onset of PRES to its resolution were discontinued.

OUTCOMES

All these patients improved after medical treatment was started.

LESSONS

Medical personnel and therapeutic establishments need to be made aware about this chemotherapy-induced neurologic complication.

Arginine Vasopressin and Posterior Reversible Encephalopathy Syndrome Pathophysiology: the Missing Link?

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity characterized by a typical brain edema. Its pathogenesis is still debated through hypoperfusion and hyperperfusion theories, which have many limitations. As PRES occurs almost exclusively in clinical situations with arginine vasopressin (AVP) hypersecretion, such as eclampsia and sepsis, we hypothesize that AVP plays a central pathophysiologic role. In this review, we discuss the genesis of PRES and its symptoms through this novel approach. We theorize that AVP axis stimulation precipitates PRES development through an increase in AVP secretion or AVP receptor density. Activation of vasopressin V_1a receptors leads to cerebral vasoconstriction, causing endothelial dysfunction and cerebral ischemia. This promotes cytotoxic edema through hydromineral transglial flux dysfunction and may increase endothelial permeability, leading to subsequent vasogenic brain edema. If our hypothesis is confirmed, it opens new perspectives for better patient monitoring and therapies targeting the AVP axis in PRES.

Clinical Profile and Outcome of Posterior Reversible Encephalopathy Syndrome in Hemodialysis Patients

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiologic entity characterized by headache, altered level of consciousness, seizures, visual disturbances, and reversible vasogenic subcortical edema. Hypertension and renal failure are well known principal risk factors for the development of PRES. However, risk factors and outcome of PRES has not been studied in patients on maintenance hemodialysis (MHD). The objective of this study is to characterize the factors predisposing to the development of PRES in patients on MHD. We performed a retrospective analysis in patients of MHD who were diagnosed with PRES between August 1, 2013, and July 31, 2015. Those with a history of cerebrovascular accidents/stroke, and epilepsy were excluded. We analyzed the clinical details, course, and laboratory data. One year follow-up data were noted in recurrence of PRES and mortality. A total of 18 patients were included for the final analysis. Of these, 13 (72%) patients were males. Majority of these patients were young and mean age was 21.1 years (6–50 years). Most of the PRES episodes developed shortly after initiation of MHD with mean duration of 2 months after initiation of MHD (1 month–3 years). All 18 patients had resistant hypertension. Eight (45%) patients had infection at the time of PRES episodes. Four patients had catheter-related bloodstream infection, 1 had pneumonia and 3 patients were recently diagnosed with pulmonary tuberculosis. Four (22%) patients developed recurrence of PRES and all these episodes developed within 2 months of index event. Seven (39%) patients underwent renal transplantation, and all received triple immune suppression and had uncontrolled hypertension in the perioperative period. However, none of these patients developed PRES after transplantation. All these patients had been maintaining stable graft function in the follow-up. All episodes of PRES were of generalized tonic–clonic seizure type and 6 of them presented as status epilepticus. None of them had any neurological sequel and no mortality at the end of 1 year. PRES is not uncommon in patients on MHD. Uncontrolled hypertension and infection are common predisposing factors. Renal transplantation is safe and not adversely affected by prior episodes of PRES in MHD.

Peritoneal dialysis: A factor of risk or protection for posterior reversible encephalopathy syndrome? review of the literature

Posterior reversible encephalopathy syndrome is a clinical and radiological entity with acute or subacute neurological presentation associated with brain lesions that primarily affect the white matter of the posterior regions. It is often associated with the rapid onset of severe hypertension and/or with kidney failure (acute and chronic), but it has also been reported as a neurological complication in several medical conditions. In recent years, there has been an increase in the number of cases and related publications due to the advance of diagnostic imaging techniques. The characteristic radiological finding includes hyperintense lesions in T2- and FLAIR-weighted magnetic resonance imaging, which are often bilateral and located in the posterior cerebral regions and correspond to areas of vasogenic oedema. Little is known about the pathophysiology of posterior reversible encephalopathy syndrome. The most accepted theory, especially in cases with associated hypertension, is the loss of cerebral self-regulation which leads to the onset of vasogenic oedema. The main feature of this syndrome is the reversibility of both symptoms and cerebral lesions with an early and appropriate diagnosis. Despite the frequent association with kidney failure and severe hypertension, there are few cases reported in patients on peritoneal dialysis. This article presents a review of PRES in peritoneal dialysis patients in the published literature.

Posterior reversible encephalopathy syndrome in an HIV-infected patient on antiretroviral treatment: what is the risk factor?

Posterior reversible encephalopathy syndrome (PRES) is a rare but well-described syndrome associated with a high morbidity and a substantial mortality. We present an illustrative case of an HIV-infected but virologically suppressed patient who complained of visual impairment accompanied by severe headache and epileptic seizures. The cerebral CT scan and the follow-up cranial MRI confirmed the diagnosis of PRES. Unlike the cases of HIV-infected patients with PRES published so far, our patient suffered neither from advanced immunodeficiency nor from opportunistic infection or from any other evident predisposing factor. This case highlights that the absence of classical risk factors does not exclude the diagnosis of PRES. We discuss the hypothesis that in accordance with the new pathophysiological theory, persistent HIV-associated cerebrovascular reactivity in combination with endothelial dysfunction may represent an undetected risk factor for the development of PRES in virologically and immunologically stable patients.

The clinical characteristics of posterior reversible encephalopathy syndrome in patients with chronic renal failure

Few studies have investigated posterior reversible encephalopathy syndrome (PRES) in patients with chronic renal failure (CRF). The present study analyzed the clinical manifestations, laboratory examinations and imaging features of PRES in patients with CRF. A total of 42 patients with CRF with or without PRES were recruited in the current retrospective case-control study. Patient data taken prior to the onset of PRES in patients with CRF and PRES (n=21) were collected and analyzed. At the same time, data from patients with CRF but without PRES (n=21) were also analyzed. Brain magnetic resonance imaging (MRI) scans were collected from patients in the PRES group. The mean blood pressure of patients in the PRES group was significantly higher than that of the control group (systolic blood pressure: 172±15 mmHg vs. 135±14 mmHg, P<0.01; diastolic blood pressure: 95±16 mmHg vs. 64±13 mmHg, P<0.01). Furthermore, compared with the control group, mean serum albumin (Alb) and hemoglobin (Hb) concentrations in the PRES group were significantly lower (Alb: 29.1±5.3 g/l vs. 34.6±6.1 g/l, P=0.001; Hb: 74±16 g/l vs. 89±28 g/l, P=0.037). By contrast, mean LDH concentration was significantly higher in the PRES group (LDH: 336±141 U/l vs. 235±89 U/l, P=0.004). In the PRES group, 24 h urine volume was significantly lower in the PRES group than in the control group (24 h urine volume: 651±520 ml vs. 982±518 ml, P=0.046). No significant differences in levels of serum potassium (4.5±0.6 mmol/l vs. 4.4±0.5 mmol/l, P=0.377), sodium (138.3±4.9 mmol/l vs. 139.0±6.8 mmol/l, P=0.325), calcium (2.0±0.24 mmol/l vs. 1.9±0.24 mmol/l, P=0.673), alanine aminotransferase; (24±14 U/l vs. 18±8 U/l, P=0.975); aspartate aminotransferase (29±11 U/l vs. 24±9 U/l, P=0.619) and uric acid (448±148 µmol/l vs. 378±116 µmol/l, P=0.599) were found between the two groups. PRES is a relatively common nervous system complication arising in patients with CRF. Certain biochemical markers, including Hb and Alb, may be associated with PRES. Diagnosing PRES is difficult as computed tomography (CT) brain scans may be normal and MRI scans, which are more sensitive than CT scans at diagnosing PRES, are not always performed in patients with CRF. Thus, brain MRI scans should be taken first in such patients when PRES is suspected.

Three cases of posterior reversible encephalopathy syndrome with chronic kidney disease triggered by infection

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological condition with diverse neurological manifestations. Many clinical factors are known causes of PRES, but only a few cases of PRES have been reported in patients with chronic kidney disease (CKD) and infectious disease. We describe three cases of PRES in patients with CKD triggered by various infectious diseases. Characteristic hyperintense signals on magnetic resonance imaging (MRI) indicating reversible vasogenic brain oedema in various parts of the brain were observed. To explain the pathophysiology of PRES, the hypertension/hyperperfusion and hypoperfusion/vasoconstriction theories have been proposed. Patients with CKD have many complications including uraemia, hypertension, and immunosuppression. Therefore, physicians should recognize that patients with CKD are at high risk of PRES triggered by infectious diseases and promptly diagnose PRES because immediate treatment of the triggers often leads to complete resolution.

Neurological consults on the renal unit

Neurological symptoms commonly occur in chronic kidney disease and may result from its treatments and complications. Impaired renal function also influences treatments for other neurological conditions, requiring various cautions, dose adjustments and timing considerations, particularly in the context of renal replacement therapy. In this review, we present six illustrative clinical vignettes to highlight these challenges.

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.

An unusual presentation of a rare disease: posterior reversible encephalopathy syndrome following abdominal sepsis

Posterior reversible encephalopathy syndrome (PRES) is an unusual disease of unknown incidence and cause. There are a wide range of associated, predisposing medical causes to include pregnancy, renal failure, immunosuppressive medication administration and hypertension. The diagnosis is made following the radiographic identification of characteristic vasogenic edema in the setting of neurologic impairment. A significant portion of patients will have long-term, if not permanent, sequelae of the disease. We present a patient who developed PRES following a hemicolectomy that was complicated by an anastomotic leak. She went on to a complete recovery following surgical treatment of the leak and supportive care.

Posterior Reversible Encephalopathy Syndrome Resolving Within 48 Hours in a Normotensive Patient Who Underwent Thoracic Spine Surgery

Posterior reversible encephalopathy syndrome (PRES) usually manifests with severe headaches, seizures, and visual disturbances due to uncontrollable hypertension. A patient (age in the early 60s) with a history of renal cell cancer presented with lower-extremity weakness and paresthesias. Magnetic resonance imaging (MRI) of the thoracic spine revealed a T8 vertebral body metastatic lesion with cord compression at that level. The patient underwent preoperative embolization of the tumor followed by posterior resection and placement of percutaneous pedicle screws and rods. Postoperatively, the patient experienced decreased visual acuity bilaterally. Abnormal MRI findings consisted of T2 hyperintense lesions and fluid-attenuated inversion recovery changes in both occipital lobes, consistent with the unique brain imaging pattern associated with PRES. The patient’s blood pressure was normal and stable from the first day of hospitalization. The patient was kept on high-dose steroid therapy, which was started intraoperatively, and improved within 48 hours after symptom onset.