Posterior reversible encephalopathy syndrome

Abstract

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.

Clinical and MRI Features of Posterior Reversible Encephalopathy Syndrome With Atypical Regions: A Descriptive Study With a Large Sample Size

“…Although we excluded the three primary variations of typical PRES, we found that the occipital (278, 50.0%), parietal (234, 42.1%), and frontal (150, 27.0%) lobes were still commonly involved. This suggests that PRES with atypical region involvement is often accompanied by typical region involvement (3,29). Vasogenic edema, which is an essential pathological feature of PRES, is usually hypointense on T1WI, hyperintense on T2WI and FLAIR, and isointense or hyperintense on DWI and ADC maps.…”

“…Posterior reversible encephalopathy syndrome (PRES) is a reversible clinico-radiological entity associated with various conditions (e.g., renal failure, blood pressure fluctuations, cytotoxic drugs, autoimmune disorders, and pre-eclampsia or eclampsia), and the diverse clinical manifestations mainly include acute and subacute onset of headache, nausea, vomiting, seizures, altered mental status, visual disturbances, and focal neurological signs (1)(2)(3)(4). The typical MRI feature of PRES is characterized by reversible vasogenic edema affecting the subcortical white matter of supratentorial lobes, especially in the parieto-occipital lobes (5).…”

Clinical Spectrum of Posterior Reversible Encephalopathy Syndrome in Children

“…The cytotoxic theory proposes that the endothelial dysfunction of PRES is due to exogenic toxins, such as drugs for chemotherapy or immunosuppression, or endogenic toxins, such as those generated during sepsis or eclampsia [2,6,12,13]. The immunogenic theory proposes that endotheliopathy, mediated by T-cell activation and the release of cytokines such as tumor necrosis factor-α (TNF) and interleukin-1 (IL-1), increases endothelial permeability and subsequent vasogenic edema [3,4,10,14]. In addition, TNF-α and IL-1 induce astrocytes to produce vascular endothelial growth factor, which disintegrates tight junction and increases vascular permeability.…”

“…As in adult cases, primary or secondary hypertension and renal disease are the most significant predisposing factors in chil-dren and adolescents [6,9]. In addition, the use of immunosuppressive agents after organ transplantation or bone marrow transplantation, including tacrolimus, cyclosporine A, mycophenolate, and corticosteroids, has been a major risk factor [4,6,15,19,20]. PRES has also been reported in children with cancers, such as acute lymphoblastic leukemia or lymphoreticular malignancy, and/or the use of chemotherapeutic drugs such as vincristine, cyclophosphamide, cytarabine (Ara-C), cisplatin, methotrexate, and L-asparaginase [6,9].…”

“…PRES was first recognized in 1996 in patients who had renal insufficiency or hypertension or who were immunosuppressed [1]. PRES is characterized by a sudden onset of neurological symptoms, such as seizures, headache, visual disturbances, and reversible, cortical/subcortical vasogenic edema, commonly involving the parieto-occipital region of the brain [2][3][4]. Although the patho-tations, and outcomes from a pediatric perspective.…”