Reversible posterior leukoencephalopathy syndrome: evaluation with diffusion-tensor MR imaging

[Posterior reversible encephalopathy syndrome in children with hematological diseases]

OBJECTIVE

To assess risk factors (RF) and severity grade of Posterior reversible encephalopathy syndrome (PRES) in children with hematological diseases.

MATERIAL AND METHODS

We analyzed cases of PRES in children during chemotherapy (CT) and after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We estimated the following RF: arterial hypertension, steroid therapy, CT, immunosuppressive therapy (IST), infection and renal injury.

RESULTS

Thirty-five cases of PRES occurred in 32 patients (8 after allo-HSCT and 27 during CT) were included in this study. In the most of cases (94.3%), there were 2 and more RF. An increase in blood pressure level (88.6%), CT and IST (82.8%) administration, steroid therapy (71.4%) were the most significant for PRES development. Infectious process and the decline in renal function played a lesser role in this syndrome (31.4% and 14%). At the initial presentation of PRES, there were seizures (94.3%), a decrease of consciousness (28.6%), headache, vision disturbances and stomachache (20%). In the most of cases (91.4%), the 2nd and 3d grade according to the Common Terminology Criteria for Adverse Events (CTCAE 5.0) were observed. Brain magnetic resonance imaging (MRI) revealed the vasogenic edema of temporal (88.6%), occipital (74.3%), frontal (40%) lobes and the cerebellum (22.9%) more often than the cytotoxic edema (p=0.03). The cytotoxic edema was observed in the thalamus and the basal ganglia (2.9%) more often than in other parts of the brain (p<0.01).

CONCLUSION

The majority of PRES cases are caused by more than two RF. Arterial hypertension does not have a leading role among its causes. There is a significant correlation between the grade of PRES according to CTCAE 5.0 score and RF number (p<0.05).

Posterior Reversible Encephalopathy Syndrome Following Intracranial Hypotension Due to Cerebrospinal Fluid (CSF) Leakage: A Report of Two Cases

Posterior reversible encephalopathy syndrome (PRES) in cases of intracranial hypotension is a life-threatening condition. Early suspicion, appropriate treatment, and tight control of possible contributing factors that may facilitate PRES in cerebrospinal fluid (CSF) leak patients may bring a more favorable outcome, lowering the morbidity and mortality rate.

Two cases of PRES with features of intracranial hypotension are presented.

We also discussed the possible pathogenesis of PRES in patients with intracranial hypotension. We emphasize the importance of the early diagnosis and treatment of ICH by repairing the leakage and further prompt attention to tight blood pressure control in those patients to avoid PRES development.

Neuroimaging findings of posterior reversible encephalopathy syndrome (PRES) following haematopoietic stem cell transplantation in paediatric recipients

BACKGROUND

Haematopoietic stem cell transplantation (HSCT) is used worldwide in various malignant and nonmalignant childhood diseases, including haematologic, genetic, autoimmune and metabolic disorders, and is the only curative treatment for many of these illnesses. The survival rates of many childhood diseases have been increased due to HSCT treatment. However, associated complications are still important for management. Central nervous system (CNS) complications in paediatric HSCT recipients can be associated with high morbidity and significantly contribute to mortality. Posterior reversible encephalopathy syndrome (PRES) is one of the most common CNS complications in patients with neurological symptoms following HSCT. Magnetic resonance imaging (MRI) is the modality of choice and shows typical bilateral vasogenic oedema at the posterior parts of the cerebral hemispheres; however, various atypical imaging manifestations can also occur. In this study, we retrospectively examined CNS complications in our paediatric HSCT recipients with a focus on the typical and atypical neuroimaging manifestations of PRES following HSCT.

METHODS

We retrospectively reviewed the medical records of 300 consecutive paediatric HSCT recipients from January 2014 to November 2018. A total of 130 paediatric HSCT recipients who experienced neurological signs and symptoms and were evaluated with neuroimaging studies following HSCT were enrolled in the study. The timing of CNS complications was defined according to immune status, including the pre-engraftment period (< 30 days after HSCT), the early postengraftment period (30-100 days after HSCT), and the late postengraftment period (> 100 days after HSCT), which were defined as phases 1, 2 and 3, respectively.

RESULTS

Overall, 130 paediatric HSCT recipients experienced neurological signs and symptoms and therefore underwent neuroimaging examinations. Among these 130 patients, CNS complications were present in 23 patients (17.6%, 23/130), including 13 (56.5%) females and 10 (43.5%) males with a median age of 8.0 years (range, 8 months to 18.0 years). Among these 23 patients, 14 cases of PRES (60.9%), 5 (21.7%) cases of leukoencephalopathy, 3 cases of acute subdural haemorrhage (ASDH) (13%) and 1 (4.3%) case of fungal CNS infection were identified by neuroimaging. On MRI, typical parietooccipital vasogenic oedema was present in 78.5% of the PRES cases (11/14). The following atypical neuroimaging manifestations were observed: isolated involvement of the bilateral frontal lobes in 1 case, isolated cerebellar vermis involvement in 1 case, and isolated basal ganglia involvement in 1 case. Restricted diffusion associated with cytotoxic damage was demonstrated in 2 of 14 cases, one of which also showed subacute cytotoxic injury with ADC pseudonormalization.

CONCLUSION

Paediatric HSCT recipients presenting with CNS signs and symptoms should be evaluated by neuroimaging studies for timely diagnosis and early management. PRES is the most common CNS complication and may present with atypical MRI manifestations, which should not dissuade a PRES diagnosis in appropriate clinical settings.

Autoimmune diseases of the brain, imaging and clinical review

There is an extensive spectrum of autoimmune entities that can involve the central nervous system, which has expanded with the emergence of new imaging modalities and several clinicopathologic entities. Clinical presentation is usually non-specific, and imaging has a critical role in the workup of these diseases. Immune-mediated diseases of the brain are not common in daily practice for radiologists and, except for a few of them such as multiple sclerosis, there is a vague understanding about differentiating them from each other based on the radiological findings. In this review, we aim to provide a practical diagnostic approach based on the unique radiological findings for each disease. We hope our diagnostic approach will help radiologists expand their basic understanding of the discussed disease entities and narrow the differential diagnosis in specific clinical scenarios. An understanding of unique imaging features of these disorders, along with laboratory evaluation, may enable clinicians to decrease the need for tissue biopsy.

Posterior reversible encephalopathy syndrome in the emergency department: A single center retrospective study

INTRODUCTION

Posterior Reversible Encephalopathy Syndrome (PRES) and the related term Reversible Posterior Leukoencephalopathy Syndrome (RPLS) denote a constellation of clinical symptoms paired with key radiological findings. These symptoms may include headache, altered mental status, visual changes, and seizures. PRES is a rare condition and remains a challenging diagnosis to make in the emergency department. Data on risk factors and clinical presentation are limited, and there is no recent literature-supported diagnostic criteria. Our primary objective was to identify initial symptoms, clinical presentation, and risk factors that should guide the emergency clinician to consider a diagnosis of PRES. A secondary objective was to identify associations between risk factors and the outcomes of mortality and ICU admissions.

METHODS

This was a retrospective, observational study that evaluated patients seen in the Emergency Department (ED) in an urban tertiary care center with the diagnosis of PRES or RPLS from 1/1/2008 to 1/1/2018. The Health System's Electronic Medical Record was used to collect data. Search criteria included any patient diagnosed with Posterior Reversible Encephalopathy Syndrome (PRES) or Reversible Posterior Leukoencephalopathy Syndrome (RPLS), and excluded patients under 18 years of age, transfer patients, or patients that were not evaluated in our emergency department.

RESULTS

We identified 98 patients based on our initial search criteria. After a chart review, 27 patients met our predefined eligibility criteria. In patients with confirmed diagnosis of PRES, the majority were female (70%) and 37% were either on an immunomodulator or undergoing chemotherapy at the time of presentation. 67% of patients presented with altered mental status, 41% had a focal neurologic deficit, and 37% had a witnessed seizure prior to diagnosis. Headache (48%), nausea (33%), and vision changes (30%) were the next most common reported symptoms. The majority of patients were hypertensive at time of presentation (82%) and many had a past medical history of hypertension (78%); twelve were given anti-hypertensive medications. 33% of the patients were admitted to the ICU and 26% died. There were no statistical associations found between documented ED interventions and the outcome of mortality.

CONCLUSION

PRES is difficult to identify and diagnose in the emergency department. Significant risk factors such as female gender, hypertension, and those currently undergoing active immunotherapy/chemotherapy are associated with PRES. Common presenting complaints and exam findings include headache, altered mental status, and neurologic deficits. Emergency providers should consider PRES in patients presenting with altered mental status with significant risk factors, especially with neurologic deficits for which stroke has been ruled out.

Neuropathophysiology of preeclampsia and eclampsia: A review of cerebral hemodynamic principles in hypertensive disorders of pregnancy

Preeclampsia and eclampsia are hypertensive disorders of pregnancy associated with abnormal placental vascular development. The systemic angiogenic imbalance, endothelial dysfunction and proinflammatory state caused by abnormal placental development results in abnormalities in renal, hepatic, pulmonary and neurologic function. Neurosensory symptoms related to pregnancy induced hypertension (PIH), the most devastating of which are intracranial hemorrhage and seizure, are among the leading causes of maternal and perinatal morbidity and mortality globally, yet risk stratification strategies and targeted therapies remain elusive. Current treatment for preeclampsia with severe features is limited to delivery, antihypertensive therapy, and magnesium sulfate seizure prophylaxis. Magnesium sulfate reduces seizure rates among severe preeclamptics, but predisposes patients to weakness, uterine atony, pulmonary edema and respiratory depression. Therefore, this drug should ideally be administered only to the subset of preeclamptics who are at increased risk for neurologic complications. While there are no objective methods validated to predict eclampsia, we hypothesize that measurement of optic nerve sheath diameters, optic disc height and middle cerebral artery transcranial doppler resistance indices may be useful in identifying subclinical cerebral edema, potentially allowing us to recognize those patients at highest risk for seizures. This summary of the current literature provides an initial framework for developing more sophisticated and noninvasive methods for identifying, monitoring and treating parturients who are at highest risk for neurologic complications from preeclampsia.

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.

Neurological Complications in Patients with Systemic Lupus Erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is commonly associated with neurological manifestations. Rapid recognition and treatment of these complications may improve outcomes. In this article, we review the neurological conditions associated with SLE, their diagnosis and management strategies.

RECENT FINDINGS

Recent meta-analysis showed that patients with neuropsychiatric manifestations of SLE were more likely to have positive antiphospholipid, antiribosomal P, and antineuronal antibodies. Another meta-analysis showed an association between SLE and antiphospholipid antibodies with cognitive impairment. Two large retrospective studies have shown that the peripheral nervous system is commonly involved in SLE frequently alongside the central nervous system. Neurological manifestations occur in most of SLE patients. Antiphospholipid antibodies are common in patients with SLE and increase the odds of neurological complications. Management typically involved a combination of treatments directed toward the neurological complication and therapies directed toward SLE itself. The efficacy of these treatment protocols, however, has not been rigorously studied and deserves further investigation.

Posterior reversible encephalopathy syndrome in pediatric patients: pathophysiology, diagnosis, and management

Posterior reversible encephalopathy syndrome (PRES) is well-described in adults, but has been reported with relative rarity in children, usually occurring in the context of chemotherapy for acute leukemia. Pathogenesis involves perturbed cerebral autoregulation leading to vasogenic edema predominantly affecting the parieto-occipital white matter, though involvement of the frontal and temporal lobes, as well as posterior fossa, is also described. We review the literature on the pathophysiology, diagnosis, and management of PRES in pediatric patients.

Posterior Reversible Encephalopathy Syndrome: Three Ethiopian Hypertensive Patients Presented with Recurrent Seizure: Case Series and Literature Review

Background

Posterior Reversible Encephalopathy Syndrome (PRES) is a potentially reversible neurological disorder of acute to subacute onset characterized by headache, nausea and vomiting, visual disturbance, seizure and altered mental status. Neuroimaging findings are characteristic, which allow early diagnosis in the appropriate clinical setting and enable to institute appropriate therapy timely.

Case Presentation

We report 3 adult patients with a history of hypertension presented with recurrent episode of seizure and altered mentation. While all the 3 patients were preliminarily diagnosed with Ischemic stroke, they were subsequently diagnosed with posterior reversible encephalopathy syndrome after neuroimaging revealed the typical features of the syndrome. They were started on antihypertensive and anticonvulsant drugs. On follow-up examination after 3–4 weeks, the patients showed marked clinical and neuro-imaging improvements.

Conclusion

Posterior reversible encephalopathy syndrome is a rare condition. The presenting clinical symptoms are non-specific and may mimic other neurological disorders. Therefore, early recognition of classic radiographic features is vital to the diagnosis. Timely diagnosis and treatment of this syndrome is important as the treatment outcome is mostly favorable.

Posterior Reversible Encephalopathy Syndrome Secondary to Hypertensive Encephalopathy Brought on by a MAO Inhibitor: A Case Report

An elderly woman was admitted to the Family Medicine inpatient service for altered mental status after being brought to the emergency room by a concerned neighbor, who had come across the patient speaking incoherently. Initial evaluation was notable for elevated blood pressures, but extensive lab testing and head computed tomographic imaging were within normal limits. However, subsequent magnetic resonance imaging showed white matter changes consistent with posterior reversible encephalopathy syndrome (PRES), a neurologic syndrome characterized by headache, altered mental status, loss of vision, and seizures as well as radiographic findings of posterior cerebral white matter edema. Multiple etiologies of PRES have been described and include hypertensive encephalopathy, immunosuppressant medications, and eclampsia. This case describes an episode of PRES secondary to hypertensive encephalopathy brought about by an inappropriate dose of a monoamine oxidase (MAO) inhibitor. The patient had significant improvement in symptoms with removal of the offending agent and control of her blood pressure. While PRES generally has a good prognosis, prompt recognition, and management are important in preventing significant disease morbidity and mortality.

Functional and Radiologic Assessment of the Brain after Reduced-Intensity Unrelated Donor Transplantation for Severe Sickle Cell Disease: Blood and Marrow Transplant Clinical Trials Network Study 0601

Stroke and cognitive decline are hallmarks of sickle cell disease (SCD). The natural history of SCD predicts progressive loss of 1 IQ point per year attributable to disease-related pathology. Hematopoietic cell transplantation (HCT) is curative by reverting to donor-derived erythropoiesis, but evidence that HCT can positively influence disease-induced cognitive decline is lacking. The Sickle Cell Unrelated Transplant Trial prospectively evaluated cognition and brain magnetic resonance imaging (MRI) findings at 2 years after reduced-intensity conditioning followed by unrelated donor HCT. Thirteen study participants completed pre-HCT and post-HCT assessments of intelligence. The mean age of participants was 12.5 ± 3.3 years (range, 6.7 to 17.4 years). Eleven of the 13 recipients completed imaging studies at baseline and post-HCT. Seven had overt stroke pre-HCT, and 1 had an elevated transcranial Doppler velocity with abnormal MRI. The mean Full-Scale IQ was stable: 90.9 ± 13 at baseline and 91.2 ± 13 post-HCT. The mean Performance IQ was 89.9 ± 13 at baseline versus 90.9 ± 13 post-HCT, and mean Verbal IQ was 93.4 ± 13 at baseline versus 93.2 ± 13 post-HCT, respectively. Six recipients had stable MRI; 2 showed resolution of all areas of infarction. Three had additional infarcts post-HCT noted at the 2-year time point. This is the first report describing stabilization of IQ and central nervous system outcomes after unrelated donor HCT despite previous central nervous system morbidity and post-HCT posterior reversible encephalopathy syndrome. These preliminary results post-HCT suggest that HCT may stabilize the cognitive decline of SCD and should continue to be followed over the long term.

Immunosuppression-associated posterior reversible encephalopathy syndrome in an acute leukemia case

Posterior reversible encephalopathy syndrome (PRES) was described in 1996. Herein, we aimed to report an immunosuppression- related PRES case. A 34-year-old woman was diagnosed as t-cell acute lymphoblastic leukemia and allogeneic hematopoietic stem cell transplantation (HSCT) was performed. Cyclosporine was given for GVHD prophylaxis in addition to the other routine medications of HSCT. She was hospitalized for acute renal failure and due to the possible contribution of acute renal failure cyclosporine was stopped. Tacrolimus was started for GVHD prophylaxis at a dose of 1 mg/day. However, fifteen days after the initiation of tacrolimus, blurred vision occurred in our patient. Petechial bleeding sites were detected in bilateral cerebral and cerebellar hemisphere by MR imaging. Tacrolimus dosage was reduced to 0.5 mg/day. She had hypertension which was difficult to control and followed-up in the intensive care unit. She had seizures. Control cranial MR resulted as diffusion limitation in bilateral cerebellar hemisphere, bilateral occipital and frontal-parietal regions with vasogenic edema findings; contrast involvement in left frontal-parietal and right cerebellar regions. She had vision loss and lethargy. Control cranial MR favored PRES syndrome secondary to immunosuppression. Hypertensive state was taken under control with antihypertensive treatment and all immunosuppressive agents were stopped. Two weeks later her clinical condition was slightly improved. MR test which was conducted 2 weeks after the diagnosis revealed the regression of PRES lesions. The characteristic signs on neuroimaging are the symmetrical white matter edema in the posterior cerebral hemispheres, particularly the parietal- occipital regions. In conclusion, PRES rarely develops secondary to the immunosuppressive agents and the clinicians should suspect and promptly diagnose PRES which might cause otherwise serious irreversible clinical complications.

Assessment of cerebral perfusion and edema in preeclampsia with intravoxel incoherent motion MRI

INTRODUCTION

Cerebral complications are the main reasons for morbidity and mortality in preeclampsia and eclampsia. As yet, we do not know whether the pathophysiology entails hypo- or hyperperfusion of the brain, or how and when edema emerges, due to the difficulty of examining the cerebral circulation.

MATERIAL AND METHODS

We have used a non-invasive diffusion weighted-magnetic resonance imaging technique, intravoxel incoherent motion, to study cerebral perfusion on the capillary level and cerebral edema in women with preeclampsia (n = 30), normal pregnancy (n = 32), and non-pregnant women (n = 16). Estimates of cerebral blood volume, blood flow, and edema were measured in 5 different regions. These points were chosen to represent blood supply areas of both the carotid and vertebrobasilar arteries, and to include both white and gray matter.

RESULTS

Except for the caudate nucleus, we did not detect any differences in cerebral perfusion measures on a group level. In the caudate nucleus, we found lower cerebral blood volume and lower blood flow in preeclampsia than in either normal pregnancy (P = .01 and P = .03, respectively) or non-pregnant women (both P = .02). No differences in edema were detected between study groups.

CONCLUSION

The cerebral perfusion measures were comparable between the study groups, except for a portion of the basal ganglia where hypoperfusion was detected in preeclampsia but not in normal pregnancy or non-pregnant women.

Posterior reversible encephalopathy syndrome secondary to asymptomatic poststreptococcal glomerulonephritis in a child with sickle cell anemia: a case report

BACKGROUND

Posterior reversible encephalopathy syndrome is a neurotoxic condition that occurs as a result of the failure of posterior circulatory autoregulation in response to acute changes in blood pressure. Overperfusion with resultant disruption of the blood-brain barrier results in vasogenic edema, but not infarction. Posterior reversible encephalopathy syndrome can be the presenting feature of postinfectious glomerulonephritis, which has been reported in approximately 5% of hospitalized children, and it has been reported in very few cases of adult patients with sickle cell anemia. We report a very rare case of posterior reversible encephalopathy syndrome that occurred in a child with sickle cell anemia. This presentation should be differentiated from other neurologic manifestations that occur in patients with sickle cell anemia, because management is totally different.

CASE PRESENTATION

We report what is to our knowledge the first reported case of a 9-year-old Saudi girl with sickle cell anemia who developed posterior reversible encephalopathy syndrome secondary to asymptomatic poststreptococcal glomerulonephritis. This occurred after full recovery from acute chest syndrome and severe vaso-occlusive crisis.

CONCLUSIONS

The purpose of this report is to emphasize that all efforts should be made to explore the causes of different neurologic manifestations that occur in patients with sickle cell anemia, because this will require different pathways of management.

Quantitative Magnetic Resonance Diffusion-Weighted Imaging Evaluation of the Supratentorial Brain Regions in Patients Diagnosed with Brainstem Variant of Posterior Reversible Encephalopathy Syndrome: A Preliminary Study

BACKGROUND AND PURPOSE

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity with several causes, characterized by rapid onset of symptoms and typical neuroimaging features, which usually resolve if promptly recognized and treated. Brainstem variant of PRES presents with vasogenic edema in brainstem regions on magnetic resonance (MR) images and there is sparing of the supratentorial regions. Because PRES is usually caused by a hypertensive crisis, which would likely have a systemic effect and global manifestations on the brain tissue, we thus proposed that some microscopic abnormalities of the supratentorial regions could be detected with diffusion-weighted imaging (DWI) using apparent diffusion coefficient (ADC) analysis in brainstem variant of PRES and hypothesized that "normal-looking" supratentorial regions will increase water diffusion.

METHODS

We retrospectively identified patients with PRES who underwent brain magnetic resonance imaging studies. We identified 11 brainstem variants of PRES patients, who formed the study cohort, and 11 typical PRES patients and 20 normal control subjects as the comparison cohorts for this study. Nineteen regions of interest were drawn and systematically placed. The mean ADC values were measured and compared among these 3 groups.

RESULTS

ADC values of the typical PRES group were consistently elevated compared with those in normal control subjects. ADC values of the brainstem variant group were consistently elevated compared with those in normal control subjects. ADC values of the typical PRES group and brainstem variant group did not differ significantly, except for the pons area.

CONCLUSIONS

Quantitative MR DWI may aid in the evaluation of supratentorial microscopic abnormalities in brainstem variant of PRES patients.

Various Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) on Magnetic Resonance Imaging (MRI)

Background

Posterior reversible encephalopathy syndrome (PRES), also called the acute hypertensive encephalopathy and reversible posterior leukoencephalopathy syndrome (RPLS), is a neurotoxic syndrome of cerebral vasoregulation classically characterized by bilaterally symmetrical parieto-occipital edema. However, the imaging findings are variable and may occur in other locations such as the frontal lobes, thalami, basal ganglia and brainstem. Most commonly, PRES presents with hyperintense signals on T2 and FLAIR sequences. Restricted diffusion and hemorrhage are rare. This study presents the typical and atypical manifestations of PRES on 3T MR images.

Material/Methods

It is a retrospective study analyzing a radiology report database and MR images of 92 patients with a clinical and radiological diagnosis of PRES. The brain MRI images of these patients were evaluated. The regions involved and the signal intensity of the affected areas on T1, T2, FLAIR and DW sequences were recorded. The location of the abnormal signal intensity as well as the presence or absence of atypical features such as diffusion restriction and hemorrhage were also recorded.

Results

The most commonly affected region was the parieto-occipital lobes (100%), however, other atypical regions involved were the frontal lobes (30.4%), temporal lobes (8.69%), basal ganglia (22%), cerebellum(17.39%), brainstem(9%) and thalamus(4%). Some of the cases showed restricted diffusion (43%) and hemorrhage (9%).

Conclusions

The involvement of the parieto-occipital, frontal and temporal lobes is common in PRES. Occasionally, there may be an involvement of the basal ganglia, cerebellum and brainstem, with or without hemorrhage and restricted diffusion. Radiologists should be aware of the typical and atypical imaging manifestations of PRES in order to make an accurate diagnosis.

Atypical presentation of posterior reversible encephalopathy syndrome: Clinical and radiological characteristics in eclamptic patients

Posterior reversible encephalopathy syndrome (PRES) is an obstetric emergency frequently occurring in a pregnant or puerperal woman, manifested with an acute headache, consciousness impairment, seizures, and visual deficits and is associated with white matter changes predominantly affecting the posterior parietal and occipital lobes of the brain. Apart from the above-described typical location of the changes, the most common atypical location involves the brain stem and basal ganglia. Since magnetic resonance imaging (MRI) is more sensitive and specific imaging technique compared to computerized tomography, establishing the diagnosis and follow-up in patients with PRES is based mainly on MRI findings. It is particularly important not to exclude PRES as a possible diagnosis when we have the appropriate clinical presentation accompanied by the atypical radiological findings, since this clinical-radiological syndrome can often be manifested with an atypical MRI image.

Perioperative posterior reversible encephalopathy syndrome in a patient with no history of hypertension: a case report

Background

Posterior reversible encephalopathy syndrome is characterized by reversible neurological symptoms with leukoencephalopathy detectable by computed tomography (CT) and magnetic resonance (MR) imaging.

Case presentation

We here present a patient with no history of hypertension who, after being transferred back to the ward after undergoing total hysterectomy under general anesthesia, had several seizures and lost consciousness. Posterior reversible encephalopathy syndrome was suspected on the basis of brain CT images and clinical findings. She was treated with respiratory support, sedative drugs, and anticonvulsants, and MR imaging confirmed a diagnosis of posterior reversible encephalopathy syndrome. She regained consciousness and responsiveness the following day.

Conclusions

Clinically, posterior reversible encephalopathy syndrome resembles cerebral infarction or intracranial hemorrhage; MR imaging is useful for differentiating it from these conditions. Including this condition in the differential diagnosis and instituting appropriate treatment is important in minimizing the risk of development of irreversible neurological damage during the perioperative period.

Utility and Significance of Gadolinium-Based Contrast Enhancement in Posterior Reversible Encephalopathy Syndrome

BACKGROUND AND PURPOSE

Posterior reversible encephalopathy syndrome is a clinicoradiologic syndrome. Literature regarding associated factors and the prognostic significance of contrast enhancement in posterior reversible encephalopathy syndrome is sparse. This study set out to evaluate an association between the presence of enhancement in posterior reversible encephalopathy syndrome and various clinical factors in a large series of patients with this syndrome.

MATERIALS AND METHODS

From an MR imaging report search that yielded 176 patients with clinically confirmed posterior reversible encephalopathy syndrome between 1997 and 2014, we identified 135 patients who had received gadolinium-based contrast. The presenting symptoms, etiology, clinical follow-up, and maximum systolic and diastolic blood pressures within 1 day of MR imaging were recorded. MRIs were reviewed for parenchymal hemorrhage, MR imaging severity, and the presence and pattern of contrast enhancement. Statistical analyses evaluated a correlation between any clinical features and the presence or pattern of enhancement.

RESULTS

Of 135 included patients (67.4% females; age range, 7-82 years), 59 (43.7%) had contrast enhancement on T1-weighted MR imaging, the most common pattern being leptomeningeal (n = 24, 17.8%) or leptomeningeal plus cortical (n = 21, 15.6%). Clinical outcomes were available in 96 patients. No significant association was found between the presence or pattern of enhancement and any of the variables, including sex, age, symptom, MR imaging severity, blood pressure, or outcome (all P > .05 after Bonferroni correction).

CONCLUSIONS

The presence or pattern of enhancement in posterior reversible encephalopathy syndrome is not associated with any of the tested variables. However, an association was found between MR imaging severity and clinical outcome.

Clinical and neuroimaging findings in children with posterior reversible encephalopathy syndrome

OBJECTIVE

To clarify the clinical and radiological spectrum of posterior reversible encephalopathy syndrome (PRES) in children, and to identify the prognostic factors.

METHODS

The records of 40 children with PRES were reviewed. Acute clinical symptoms, MRI including apparent diffusion coefficient (ADC) maps in the acute and follow-up periods and neurological sequelae, including epilepsy, were noted.

RESULTS

Age at onset ranged from 2 to 16 years. Underlying disorders were hematological or neoplastic disorders (n = 20), renal diseases (n = 14) and others (n = 6). In the acute period, 31 patients had seizures, 25 had altered consciousness, 11 had visual disturbances and 10 had headache. Of 29 patients who had ADC maps in the acute period, 13 had reduced diffusivity as shown by ADC within PRES lesions. Of 26 patients with follow-up MRI, 13 had focal gliosis or cortical atrophy. No patients had motor impairment, and four patients had focal epilepsy. No clinical variables were associated with focal gliosis or cortical atrophy on follow-up MRI, but lesional ADC reduction in the acute period was prognostic for focal gliosis or cortical atrophy on follow-up MRI (p = 0.005).

CONCLUSIONS

To the best of our knowledge, this is the largest cohort study to date involving PRES in children. Acute symptoms in pediatric patients are similar to those reported in adults, but altered consciousness was more frequent in children. Lesional ADC reduction in the acute period was common and was a good predictor of later, irreversible MRI lesions.

Temporal Evolution of Parotid Volume and Parotid Apparent Diffusion Coefficient in Nasopharyngeal Carcinoma Patients Treated by Intensity-Modulated Radiotherapy Investigated by Magnetic Resonance Imaging: A Pilot Study

Purpose

To concurrently quantify the radiation-induced changes and temporal evolutions of parotid volume and parotid apparent diffusion coefficient (ADC) in nasopharyngeal carcinoma (NPC) patients treated by intensity-modulated radiotherapy by using magnetic resonance imaging (MRI).

Materials and Methods

A total of 11 NPC patients (9 men and 2 women; 48.7 ± 11.7 years, 22 parotid glands) were enrolled. Radiation dose, parotid sparing volume, severity of xerostomia, and radiation-to-MR interval (RMI) was recorded. MRI studies were acquired four times, including one before and three after radiotherapy. The parotid volume and the parotid ADC were measured. Statistical analysis was performed using SPSS and MedCalc. Bonferroni correction was applied for multiple comparisons. A P value less than 0.05 was considered as statistically significant.

Results

The parotid volume was 26.2 ± 8.0 cm³ before radiotherapy. The parotid ADC was 0.8 ± 0.15 × 10⁻³ mm²/sec before radiotherapy. The parotid glands received a radiation dose of 28.7 ± 4.1 Gy and a PSV of 44.1 ± 12.6%. The parotid volume was significantly smaller at MR stage 1 and stage 2 as compared to pre-RT stage (P < .005). The volume reduction ratio was 31.2 ± 13.0%, 26.1 ± 13.5%, and 17.1 ± 16.6% at stage 1, 2, and 3, respectively. The parotid ADC was significantly higher at all post-RT stages as compared to pre-RT stage reciprocally (P < .005 at stage 1 and 2, P < .05 at stage 3). The ADC increase ratio was 35.7 ± 17.4%, 27.0 ± 12.8%, and 20.2 ± 16.6% at stage 1, 2, and 3, respectively. The parotid ADC was negatively correlated to the parotid volume (R = -0.509; P < .001). The parotid ADC was positively associated with the radiation dose significantly (R² = 0.212; P = .0001) and was negatively associated with RMI significantly (R² = 0.203; P = .00096) significantly. Multiple regression analysis further showed that the post-RT parotid ADC was related to the radiation dose and RMI significantly (R² = 0.3580; P < .0001). At MR stage 3, the parotid volume was negatively associated with the dry mouth grade significantly (R² = 0.473; P < .0001), while the parotid ADC was positively associated with the dry mouth grade significantly (R² = 0.288; P = .015).

Conclusion

Our pilot study successfully demonstrates the concurrent changes and temporal evolution of parotid volume and parotid ADC quantitatively in NPC patients treated by IMRT. Our results suggest that the reduction of parotid volume and increase of parotid ADC are dominated by the effect of acinar loss rather than edema at early to intermediate phases and the following recovery of parotid volume and ADC toward the baseline values might reflect the acinar regeneration of parotid glands.

Posterior Reversible Encephalopathy Syndrome (PRES): Restricted Diffusion does not Necessarily Mean Irreversibility

Background

Restricted diffusion is the second most common atypical presentation of PRES. This has a very important implication, as lesions with cytotoxic edema may progress to infarction. Several studies suggested the role of DWI in the prediction of development of infarctions in these cases. Other studies, however, suggested that PRES is reversible even with cytotoxic patterns. Our aim was to evaluate whether every restricted diffusion in PRES is reversible and what factors affect this reversibility.

Material/Methods

Thirty-six patients with acute neurological symptoms suggestive of PRES were included in our study. Inclusion criteria comprised imaging features of atypical PRES where DWI images and ADC maps show restricted diffusion. Patients were imaged with 0.2-T and 1.5-T machines. FLAIR images were evaluated for the severity of the disease and a FLAIR/DWI score was used. ADC values were selectively recorded from the areas of diffusion restriction. A follow-up MRI study was carried out in all patients after 2 weeks. Patients were classified according to reversibility into: Group 1 (reversible PRES; 32 patients) and Group 2 (irreversible changes; 4 patients). The study was approved by the University’s research ethics committee, which conforms to the declaration of Helsinki.

Results

The age and blood pressure did not vary significantly between both groups. The total number of regions involved and the FLAIR/DWI score did not vary significantly between both groups. Individual regions did not reveal any tendency for the development of irreversible lesions. Similarly, ADC values did not reveal any significant difference between both groups.

Conclusions

PRES is completely reversible in the majority of patients, even with restricted diffusion. None of the variables under study could predict the reversibility of PRES lesions. It seems that this process is individual-dependent.

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

Posterior reversible encephalopathy syndrome (PRES) is an uncommon clinico-radiological condition that can result in severe brain injury. The pathogenesis of cerebral vasogenic edema, the hallmark of PRES, is not fully understood. Despite its name, there is substantial heterogeneity both in terms of imaging findings and outcome. Relatively little is known about PRES in kidney disease despite the clustering of risk factors including hypertension, autoimmune disease and immunosuppression. In a retrospective observational study of incident end-stage kidney disease patients in Southwest Ireland over a ten year period, we discovered five cases of PRES representing an incidence of 0.84% in this patient population. These five cases highlight the variability in clinical presentation and the potentially life-threatening nature of this condition. We provide an in-depth review of the existing literature regarding PRES in terms of its pathogenesis and heterogeneity, as well as the experience of PRES in ESKD patients. PRES appears to be rare in the ESKD population but could be under-recognized. Marked hypertension is a cardinal risk factor in this population, associated with extracellular fluid volume expansion. Neuroimaging findings can be diverse involving both anterior and posterior circulation territories. Three of the five patients described had commenced haemodialysis within four weeks of their presentation. These patients may be particularly vulnerable to microvascular brain injury, which can be devastating. This emphasises the need for clinicians to pay meticulous attention to extracellular fluid volume control during this potentially hazardous period.

How I treat and manage strokes in sickle cell disease

Neurologic complications are a major cause of morbidity and mortality in sickle cell disease (SCD). In children with sickle cell anemia, routine use of transcranial Doppler screening, coupled with regular blood transfusion therapy, has decreased the prevalence of overt stroke from ∼11% to 1%. Limited evidence is available to guide acute and chronic management of individuals with SCD and strokes. Current management strategies are based primarily on single arm clinical trials and observational studies, coupled with principles of neurology and hematology. Initial management of a focal neurologic deficit includes evaluation by a multidisciplinary team (a hematologist, neurologist, neuroradiologist, and transfusion medicine specialist); prompt neuro-imaging and an initial blood transfusion (simple followed immediately by an exchange transfusion or only exchange transfusion) is recommended if the hemoglobin is >4 gm/dL and <10 gm/dL. Standard therapy for secondary prevention of strokes and silent cerebral infarcts includes regular blood transfusion therapy and in selected cases, hematopoietic stem cell transplantation. A critical component of the medical care following an infarct is cognitive and physical rehabilitation. We will discuss our strategy of acute and long-term management of strokes in SCD.

A case of posterior reversible encephalopathy syndrome associated with acute pancreatitis and chronic alcoholism

Posterior reversible encephalopathy syndrome (PRES) is known to be caused by a variety of clinical disorders. The authors encountered a case of PRES associated with acute pancreatitis and chronic alcoholism. A 49-year-old man presented with altered mental status. Magnetic resonance imaging (MRI) displayed vasogenic edema at the bilateral posterior temporal and parieto-occipital lobes and cerebellum. Laboratory tests and abdominal computed tomography (CT) revealed acute pancreatitis. The patient recovered completely, and follow-up brain MRI and abdominal CT exhibited resolution of the previous lesions. We suggest that acute pancreatitis might be an etiology of PRES.

Risk of subsequent dementia in patients with hypertensive encephalopathy: a nationwide population-based study in Taiwan

BACKGROUND/AIMS

We investigated the association of hypertensive encephalopathy (HE) with subsequent dementia.

METHODS

Using universal insurance claims data, we identified a study cohort of 5,504 participants with HE newly diagnosed between 1997 and 2010 and a comparison cohort of 22,016 healthy participants. Incidence and risks of dementia were estimated for both cohorts until the end of 2010.

RESULTS

The dementia incidence was 1.45-fold [95% confidence interval (CI) = 1.27-1.66] higher in the study cohort than in the comparison cohort, with an adjusted hazard ratio (HR) of 1.38 (95% CI = 1.19-1.59) for the study cohort. The risk was higher for males than for females and elderly patients. With an incidence of 13.4 per 1,000 person-years, the HR of dementia increased to 2.09 (95% CI = 1.18-3.71) for the HE patients with the comorbidities of head injury and diabetes compared to those without HE and comorbidities. The risk of developing dementia declined with the follow-up time.

CONCLUSION

Hypertensive patients with HE displayed a significantly higher risk for dementia than those without HE. The risk increased further in those with the comorbidities of head injury and diabetes. Physicians should be aware of the link between HE and dementia when assessing patients with HE.

Sudden Bilateral Choroidal Detachment in a Patient with Posterior Reversible Encephalopathy Syndrome

BACKGROUND: Pre-eclampsia is one of the most important causes of a rare cliniconeuroradiological entity called posterior reversible encephalopathy syndrome. The syndrome is characterized by headacke, visual disturbances, seizures, altered mental status and radiological findings of edema in the white matter of the brain areas perfused by the posterior brain circulation.CASE REPORT: Here we present a patient with sudden bilateral visual loss and deafness in early postnatal period without any other neurological deficits, but with affiliated ophthalmological pathology. The correct diagnosis was made 3 days after the Cesarean section.The patient was diagnosed with posterior reversible encephalopathy syndrome and bilateral choroidal detachment.CONCLUSION: Vascular changes in posterior reversible encephalopathy syndrome can cause visual disturbances not only by brain edema, but combined brain and ocular pathology.

Neurologic complications following pediatric renal transplantation

We reviewed neurologic complications after renal transplantation in children over a 20-year period. Neurologic complications were classified as early (within 3 months) and delayed (beyond 3 months). Of 115 children, 10 (8.7%) had complications. Early complications were found in 4.35% of patients: seizures in 4 (posterior reversible leukoencephalopathy syndrome due to immunosuppressant toxicity, sepsis/presumed meningitis, and indeterminate) and headaches in 1. One patient with seizures received levetiracetam for 6 months and 1 with headaches received amitriptyline prophylaxis. Late complications were noted in 4.35% of patients: seizures in 3 (posterior reversible leukoencephalopathy syndrome due to hypertension, hypertensive encephalopathy), headaches in 2, and tremors in 1. Two patients with seizures were treated with anti-epilepsy medications; 1 with migraine received cyproheptadine prophylaxis. Neurologic complications develop in children after renal transplantation. Seizures due to posterior reversible leukoencephalopathy syndrome were the commonest complication. Early detection and appropriate management of these complications is important.

Post-dural puncture headache and posterior reversible encephalopathy syndrome: a misdiagnosis or co-presentation?

Posterior reversible encephalopathy syndrome (PRES) is a rare neurological condition associated with a variety of underlying conditions, including preeclampsia. The headache associated with PRES may be indistinguishable from post-dural puncture headache, which may result in diagnostic delay. We report a case of PRES that was initially diagnosed as post-dural puncture headache. The case was unique because there were no features of preeclampsia, initial presentation was typical of post-dural puncture headache, and there was a five-day interval between the onset of headache and the development of seizures and cortical blindness, pathognomonic of PRES. It remains unclear whether this was an atypical presentation of PRES, initially misdiagnosed as post-dural puncture headache, or whether delayed treatment of headache triggered PRES.

Sickle cell disease and posterior reversible leukoencephalopathy

Sickle cell disease can present with neurological manifestations. One such presentation is with posterior reversible leukoencephalopathy also known as reversible posterior leukoencephalopathy. The condition is classically described as reversible over time; it commonly presents with oedematous changes involving the white matter of the occipital and parietal regions. Only a few patients with the association between sickle cell disease and posterior reversible leukoencephalopathy have been described in the adult literature. We present two patients from our institutions to emphasise the association between the two conditions and summarise the published cases in the literature.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a recently proposed cliniconeuroradiologic entity with several well-known causes, such as hypertensive encephalopathy, eclampsia, and the use of cytotoxic and immunosuppressive drugs, as well as some causes more recently described. PRES is characterized by neuroimaging findings of reversible vasogenic subcortical edema without infarction. The pathogenesis is incompletely understood. Two opposing hypotheses are commonly cited, but the issue is controversial: (1) the current more popular theory suggests that severe hypertension exceeds the limits of autoregulation, leading to breakthrough brain edema; (2) the earlier original theory suggests that hypertension leads to cerebral autoregulatory vasoconstriction, ischemia, and subsequent brain edema. The clinical syndrome of PRES typically involves headache, encephalopathy, visual symptoms, and seizures. The clinical presentation is often nonspecific, and therefore the diagnosis of PRES has come to increasingly rely on magnetic resonance imaging (MRI) abnormalities consistent with PRES with documented recovery clinically and on repeated neuroimaging. The diagnosis has important therapeutic and prognostic implications because the reversibility of the clinical and radiologic abnormalities is contingent on the prompt control of blood pressure and/or discontinuing the offending drug.

Hypertensive encephalopathy and cerebral infarction

Introduction

Hypertensive encephalopathy is one cause of posterior reversible encephalopathy syndrome. Hypertensive encephalopathy and cerebral infarction have only been reported in a few individual case reports.

Case description

A 51-year-old woman presented with hypertensive encephalopathy. T2-weighted images from magnetic resonance imaging showed hyperintense lesions in both occipital and parietal lobes. Diffusion-weighted imaging showed that this represented cytotoxic oedema and perfusion magnetic resonance imaging revealed reduced blood volume and flow. The magnetic resonance imaging was repeated 5 months later and subtotal regression of theT2-hyperintensity had occurred. However, small bilateral infarcts were seen on T1-weighted images. Perfusion magnetic resonance imaging presented reduced blood volume and flow on the right side.

Discussion and evaluation

The patient in this report had posterior reversible encephalopathy syndrome caused by hypertensive encephalopathy. Magnetic resonance imaging of the brain showed bilateral cytotoxic oedema that partially resolved and resulted in small infarcts. The imaging findings are compatible with posterior reversible encephalopathy syndrome with subtotal resolution and infarct evolution.

Conclusion

The case report suggests that the presence of hypertensive encephalopathy and posterior reversible encephalopathy syndrome should alert clinicians and lead to prompt treatment in order to prevent cerebral damage.

Posterior leukoencephalopathy syndrome: Postpartum focal neurologic deficits: A report of three cases and review of the literature

Posterior reversible encephalopathy syndrome presents with a variety of neurologic features, which, although devastating at some point, are potentially reversible on prompt recognition and institution of appropriated treatment. We report the management of three cases occurring in the last 4 years in our tertiary university hospital.

Toxic leukoencephalopathies

Leukoencephalopathy is a syndrome of neurologic deficits, including alteration of mental status, caused by pathologic changes in the cerebral white matter. The term, toxic leukoencephalopathy, encompasses a wide variety of exposures and clinical presentations. The diagnosis in these Frontiers in Clinical Neurotoxicology syndromes is made by careful attention to the history, clinical features, and radiologic findings. This article details three of the best-defined toxic leukoencephalopathies: delayed posthypoxic leukoencephalopathy, including delayed neurologic sequelae after carbon monoxide poisoning; heroin inhalation leukoencephalopathy; and posterior reversible encephalopathy syndrome.

[Unusual acute encephalopathy in a young patient with end-stage renal disease]

Posterior reversible encephalopathy represents a neurotoxic state which can be associated to different pathological situations. The key to diagnosis are characteristic features on magnetic resonance imaging and rapidly evolving neurological symptoms if recognized and treated rapidly. Arterial hypertension and preeclampsia are the main causes of posterior reversible encephalopathy. Metabolic disorders including renal failure can also be associated with this syndrome. We report the clinical observation of an 18-year-old young patient on chronic hemodialysis who presented a status epilepticus associated with hypertensive crisis, two weeks after his transfer to peritoneal dialysis. Magnetic resonance imaging showed a typical aspect of posterior reversible encephalopathy with intracerebral haemorrhage. The evolution was favorable with a clear improvement of encephalic lesions.