Early relapse of severe chronic active Epstein-Barr virus infection with posterior reversible encephalopathy syndrome after reduced intensity stem cell transplantation with umbilical cord blood

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 encephalopathy syndrome concurrent with human herpesvirus-6B encephalitis after allogeneic hematopoietic stem cell transplantation

Posterior reversible encephalopathy syndrome (PRES) and human herpesvirus (HHV)-6 encephalitis are both serious neurological complications post hematopoietic stem cell transplantation. Although infection is one of the important causes of PRES, only few cases have reported the relation between PRES and viral infection. Herein, we report the first adult case of PRES concurrent with HHV-6 encephalitis after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia. This case suggests that HHV-6 reactivation is associated with the pathogenesis of PRES. Also, PRES and HHV-6 encephalitis cause similar symptoms, and switching the immunosuppressant from calcineurin inhibitor to prednisolone for treating PRES may worsen HHV-6 encephalitis. Therefore, we should pay attention to the complication of HHV-6 encephalitis even after PRES is diagnosed.

Posterior reversible encephalopathy syndrome (PRES) and infection: a systematic review of the literature

Posterior reversible encephalopathy syndrome (PRES) is an encephalopathy characterized by a rapid onset of symptoms including headache, seizures, confusion, blurred vision, and nausea associated with a typical magnetic resonance imaging appearance of reversible subcortical vasogenic edema prominent and not exclusive of parieto-occipital lobes. Vasogenic edema is caused by a blood-brain barrier leak induced by endothelial damage or a severe arterial hypertension exceeding the limits of cerebral blood flow autoregulation. Although the exact pathophysiological mechanism is still unclear, frequent conditions that may induce PRES include severe hypertension, eclampsia/pre-eclampsia, acute kidney diseases and failure, immunosuppressive therapy, solid organ, or bone marrow transplantation. Conversely to other conditions, which may induce PRES, the link between severe infection or sepsis and PRES, often associated with gram-positive bacteria, is still poorly understood and less well known. Clinicians from multiple disciplines, such as neurologists and internists, may encounter during their profession patients with severe infection or sepsis and should consider the possible association between PRES and these conditions. We systematically reviewed the literature about this association in order to provide a helpful clinical insight of such complex pathophysiological mechanism, highlighting the importance of recognizing PRES in such a complex clinical scenario.