Posterior Reversible Encephalopathy Syndrome: Clinicoradiological Spectrum and Therapeutic Strategies

Clinical and Radiological Features of Unilateral Posterior Reversible Encephalopathy Syndrome (PRES): A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity characterized by reversible vasogenic edema predominantly affecting the posterior regions of the cerebral hemispheres. However, unilateral presentation of PRES is an exceptionally rare manifestation. We describe the case of a 34-year-old woman who presented with left-sided hemiparesis, hemisensory loss, headache, and focal motor seizures. Brain CT revealed right anterior and posterior hypodensities in the right frontal and parietal subcortical locations, brain MRI showed vasogenic edema in the subcortical right cerebral hemisphere, and cerebral angiogram revealed diffuse narrowing of the left internal carotid artery just distal to the carotid bifurcation with no flow of contrast beyond the ophthalmic segment. The patient's symptoms resolved during her admission, MRI findings improved on repeated imaging, and she was ultimately diagnosed with unilateral PRES. Unilateral PRES is a complex and challenging diagnosis, and this case sheds light on the atypical radiological features of unilateral PRES possibly intricately linked with contralateral steno-occlusive disease of the carotid artery. It is essential to maintain the atypical variants of PRES as part of the differential diagnosis when encountering acute neurological symptoms and vasogenic edema on imaging in the context of contralateral steno-occlusive disease of the carotid artery.

Potential voriconazole associated posterior reversible leukoencephalopathy in children with malignancies: Report of two cases

INTRODUCTION

The fungal infection has become severe morbidity amongst patients with malignancy. Voriconazole, a new generation of triazole, has shown excellent results in treating invasive fungal infections.

CASE REPORT

Herein, we report two cases of posterior reversible encephalopathy syndrome (PRES), which induced after voriconazole exposure.Management and outcome: Magnetic resonance imaging, and the serum level of voriconazole were investigated in both patients to assess toxicity. The role of methotrexate, as one of the possible causes of PRES, is weakened significantly through precise assessing diffusion-weighted images on magnetic resonance imaging.

DISCUSSION

These unique cases emphasize that voriconazole can induce PRES even at therapeutic levels. Therefore, in the case of neurotoxicity, PRES must be considered, and voriconazole should discontinue. The prognosis seemed promising when voriconazole stopped immediately after clinical suspicion.

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

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

Acute Respiratory Distress Syndrome and Posterior Reversible Encephalopathy Syndrome following Rituximab Therapy

The anti-CD20 monoclonal antibody rituximab is associated with rare but significant adverse events, notably posterior reversible encephalopathy syndrome (PRES) and acute respiratory distress syndrome (ARDS). We report a case of concomitant ARDS and PRES developing after rituximab therapy for treatment of cryoglobulinaemic vasculitis. There are 7 reported cases of PRES complicating rituximab use. PRES onset varied from immediate to 21 days after administration. All patients recovered completely, and rituximab was reintroduced in half of the cases. The occurrence of ARDS in association with rituximab is rarer. Only 3 confirmed cases exist, and ARDS may occur as a delayed reaction.

Clinical spectrum of Posterior Reversible Encephalopathy Syndrome (PRES) in patients with eclampsia

Objective:

To identify the prevalence, demographic details and clinical features of PRES in women suffering from eclampsia.

Methods:

Women admitted in the labor room suite with diagnosis of eclampsia were studied. The study period was from October 15. 2011 to March 15. 2012, in the department of obstetrics & gynecology unit 3, Civil hospital Karachi. Of all patients with diagnosis of eclampsia, 22 underwent neuro imaging by computerized tomography. Demographic details, clinical findings and maternal and perinatal outcome were entered on a predesigned Performa.

Results:

Thirty four women were identified, with eclampsia. Neuro imaging was done in 22 women. Posterior reversible encephalopathy syndrome was recognized in 9 (22) patients. The mean systolic blood pressure was 161(±11) mm Hg, and mean diastolic blood pressure was 111(±10) mm Hg. Mean number of fits were three, and the mean gestational age of patients were 35 weeks. Gestational age was found significantly associated with PRES (p <0.3) Mean leukocyte count in patients with eclampsia was 20,083±16,165/cu mm.

Conclusion:

Our study shows presence of Posterior reversible encephalopathy syndrome (PRES) in women who are identified with eclampsia. There is need for awareness and long term neurological follow up in this group of women.

Clinical Management of Posterior Reversible Encephalopathy Syndrome after Allogeneic Hematopoietic Stem Cell Transplantation: A Case Series and Review of the Literature

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a rare but serious complication after allogeneic hematopoietic stem cell transplantation (alloHSCT). Among others, calcineurin inhibitors (CNI) for prophylaxis of graft-versus-host disease (GvHD) may promote the development of PRES, but the pathomechanism is still controversial. Discontinuation of CNI facilitates remission of symptoms but might contribute to the unfavorable prognosis of PRES due to an elevated incidence of GvHD.

METHODS

This is a case series of 7 patients with PRES from a retrospective analysis of 146 consecutive patients who received alloHSCT for hematologic malignancies.

RESULTS

At the onset of PRES, all patients presented a systemic infection, while no influence was seen for underlying disease, conditioning regimen, donor type, or GvHD. Discontinuation of CNI and control of the blood pressure reversed neurological symptoms in 6 patients, while 1 patient died from septic multiorgan failure. After bridging with prednisolone and/or mycophenolic acid, replacement of CNI by the mammalian target of rapamycin (mTOR) inhibitor everolimus effectively prevented severe GvHD without recurrence of PRES.

CONCLUSIONS

A systemic infection/inflammation may be an important cause of PRES. Prophylaxis of GvHD by the mTOR inhibitor everolimus in case of PRES after alloHSCT demonstrated promising results but needs to be validated in larger cohorts.

Reversible confluent deep white matter abnormalities: a new variant of posterior reversible encephalopathy syndrome

We describe a confluent deep white matter abnormalities variant of PRES, further strengthening the notion that PRES is a disorder of radiological heterogeneity. We present 2 cases of PRES with findings of diffuse but reversible vasogenic edema located in the deep periventricular white matter regions of bilateral hemispheres without a clearly posterior distribution. We feel that this represents a rare variant of PRES on imaging, thus adding to the existing radiological spectrum for this entity. Both of our patients presented with malignant hypertension (mean arterial blood pressure of 200 mmHg) and developed neurological symptoms that included encephalopathy, seizure, headache, and vision changes. Additionally, both patients presented with significant subcortical white matter edema that improved dramatically on follow-up imaging. The clinical and radiological improvement in both patients occurred following successful blood pressure management. It is possible that the deep white matter changes of PRES are seen exclusively in the setting of severe accelerated hypertension. Our case reports reveal that, in patients with hypertensive encephalopathy, a deep white matter pattern of diffuse signal changes may not necessarily indicate chronic ischemic changes and follow-up imaging studies are essential to rule out a diagnosis of PRES.