Posterior Reversible Encephalopathy Syndrome (PRES): Pathophysiology and Neuro-Imaging

Structural connectivity modifications following deep brain stimulation of the subcallosal cingulate and nucleus accumbens in severe anorexia nervosa

PURPOSE

Anorexia nervosa (AN) is a mental health disorder characterized by significant weight loss and associated medical and psychological comorbidities. Conventional treatments for severe AN have shown limited effectiveness, leading to the exploration of novel interventional strategies, including deep brain stimulation (DBS). However, the neural mechanisms driving DBS interventions, particularly in psychiatric conditions, remain uncertain. This study aims to address this knowledge gap by examining changes in structural connectivity in patients with severe AN before and after DBS.

METHODS

Sixteen participants, including eight patients with AN and eight controls, underwent baseline T1-weigthed and diffusion tensor imaging (DTI) acquisitions. Patients received DBS targeting either the subcallosal cingulate (DBS-SCC, N = 4) or the nucleus accumbens (DBS-NAcc, N = 4) based on psychiatric comorbidities and AN subtype. Post-DBS neuroimaging evaluation was conducted in four patients. Data analyses were performed to compare structural connectivity between patients and controls and to assess connectivity changes after DBS intervention.

RESULTS

Baseline findings revealed that structural connectivity is significantly reduced in patients with AN compared to controls, mainly regarding callosal and subcallosal white matter (WM) tracts. Furthermore, pre- vs. post-DBS analyses in AN identified a specific increase after the intervention in two WM tracts: the anterior thalamic radiation and the superior longitudinal fasciculus-parietal bundle.

CONCLUSIONS

This study supports that structural connectivity is highly compromised in severe AN. Moreover, this investigation preliminarily reveals that after DBS of the SCC and NAcc in severe AN, there are WM modifications. These microstructural plasticity adaptations may signify a mechanistic underpinning of DBS in this psychiatric disorder.

Posterior reversible encephalopathy syndrome (PRES) on the second postpartum day: learning experience from a case report and literature review

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is an uncommon neurological disorder which is characterised by variable symptoms. The transient clinical condition may be underestimated and misdiagnosed as other conditions, especially, among pregnant women with severe preeclampsia, eclampsia, and HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome in the puerperium. We hereby contribute to the literature this rare complication and hightlight the appropriate management of PRES .

PRESENTATION CASE

A pregnant woman (gravida 3, parity 2) had a normal antenatal course. However, she was diagnosed with severe preeclampsia and HELLP syndrome at 29 weeks and 5 days of gestation. Therefore, she was indicated for a medical termination of pregnancy following a patient's consent at our tertiary referral hospital. Severely, the patient developed rapidly with altered mental health in early puerperium. In result, PRES was diagnosed based on a brain magnetic resonance imaging (MRI) evidence with typical findings. After a strict multidisciplinary management, the clinical condition improved after 5 days of onset and recovered completely after a 4-month follow-up without any sequelae.

CONCLUSION

In summary, despite its rarity, clinicians ought to be knowledgeable and raise an aware of PRES during pregnancy. Importantly, a brain imaging modalities should be taken into account among pregnant women with neurological symptoms subsequent to severe preeclampsia. In addition to early diagnosis, a timely appropriate treatment with multidisciplinary team is strongly indicated. Further studies with a large case series are required for this uncommon entity.

Magnetic resonance imaging patterns and perfusion changes of posterior reversible encephalopathy syndrome in children with clinical outcome correlation

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) in children has a propensity towards atypical features on magnetic resonance (MR) imaging, with limited literature on perfusion changes and clinicoradiological correlation.

OBJECTIVE

We aimed to comprehensively study MR imaging patterns of pediatric PRES, including cerebral blood flow variations on arterial spin labeling, and looked for any MR biomarkers of poor clinical outcome.

MATERIALS AND METHODS

In this retrospective observational study conducted in a tertiary hospital setting, MR records over a 4-year period (May 2019 to May 2023) were systematically searched along with their clinical details. Patients with an age less than 18 years and a clinicoradiological constellation consistent with PRES were included. MR scans were analyzed by two neuroradiologists with 8 years' and 10 years' experience. Association was sought with poor clinical outcome (defined as modified Rankin Scale score at discharge of > 2).

RESULTS

A total of 45 patients (29 boys) were included in the study, with a mean age (± standard deviation) of 11.19 (± 4.53) years. On MR imaging, 95.6% of patients (n = 43) showed atypical features and/or atypical areas of involvement. The superior frontal sulcus (n = 18) was the most predominant MR pattern, and cerebellar involvement was not uncommon (n = 15). Unilateral involvement (n = 3), isolated central pattern (n = 1), and spinal cord involvement (PRES-SCI: n = 1) were also encountered. Brainstem involvement (n = 4) showed a characteristic "V-sign" of anterior medullary hyperintensity. Patchy restricted diffusion (46.6%), punctate hemorrhages (37.7%), and leptomeningeal contrast enhancement (36%) were not uncommon. Arterial spin labeling sequence (available in 24 patients) showed increased cerebral blood flow in the involved areas in 79.2% of patients. Univariate analysis showed a significant association of the presence of hemorrhage (P = 0.003), involvement of brainstem (P = 0.007), deep white matter (P = 0.008), and thalamus (P = 0.026) with poor clinical outcome. Multivariate regression analysis found that hemorrhage on MRI (P = 0.011, odds ratio 8) was an independent factor associated with poor clinical outcome.

CONCLUSIONS

The conventionally described atypical features in PRES are common in children and therefore may no longer be considered exceptions. Raised perfusion on arterial spin labeling sequence was seen in the majority of cases. Hemorrhage on MRI was an independent predictor of poor clinical outcome in pediatric PRES.

Approach to Altered Mental Status in Pregnancy and Postpartum

The evaluation and diagnosis of altered mental status in the pregnant or postpartum patient largely parallels the approach used for any other patient; however, there are several critical differences including that some neuroobstetric diagnoses require emergent delivery of the fetus. Being familiar with the physiological changes and medical complications of pregnancy and delivery is therefore essential. This review first addresses pregnancy-specific disorders that may result in altered mental status, such as the hypertensive disorders of pregnancy and pregnancy-related metabolic and endocrinopathies. The focus then shifts to the complex physiologic changes in pregnancy and how these changes contribute to the distinct epidemiology of pregnancy-related cerebrovascular complications like intracranial hemorrhage, ischemic stroke, and reversible cerebral vasoconstriction syndrome. Medical disorders that are not unique to pregnancy, such as infections and autoimmune conditions, may present de novo or worsen during pregnancy and the peripartum period and require a thoughtful approach to diagnosis and management. Finally, the unique nervous system complications of obstetric anesthesia are explored. In each section, there is a focus not only on diagnosis and syndrome recognition but also on the emergent treatment needed to reverse these complications, bearing in mind the unique physiology of the pregnant patient.

Atypical posterior reversible encephalopathy syndrome: A lentiform fork sign following transplantation

Key Clinical Message

Posterior Reversible Encephalopathy Syndrome, typically characterized by parieto-occipital vasogenic edema, can present atypically, as a bilateral symmetrical vasogenic edema in the basal ganglia, featuring the called "lentiform fork sign." Prompt recognition of such variations is crucial for accurate diagnosis and tailored management, highlighting the complexity of this syndrome's manifestations.

Abstract

Posterior Reversible Encephalopathy Syndrome (PRES) manifests as transient neurological symptoms and cerebral edema, commonly associated with immunosuppressive drugs (ISDs) in transplant recipients. ISDs can lead to endothelial dysfunction and compromise the blood-brain barrier. Typically, PRES exhibits identifiable MRI patterns, often demonstrating vasogenic edema in the bilateral parieto-occipital white matter. Identifying unique presentations, such as the recently observed "lentiform fork sign," commonly seen in uremic encephalopathy, emphasizes this syndrome's broad spectrum manifestations. A 19-year-old male, who underwent bilateral lung and liver transplantation, experienced a bilateral tonic-clonic seizure of unknown onset 47 days post-surgery. MRI findings revealed an unconventional PRES pattern, featuring the "lentiform fork sign" as bilateral symmetrical vasogenic edema in the basal ganglia, surrounded by a hyperintense rim outlining the lentiform nucleus bilaterally. Subsequent management, including ISD modification and magnesium supplementation, resulted in clinical and neuroimaging resolution. An almost complete clinical and radiological resolution was achieved after 14 days. The occurrence of PRES in transplant recipients highlights the intricate interplay among ISDs, physiological factors, and cerebrovascular dynamics, potentially involving direct neurovascular endothelial toxicity and disruption of the blood-brain barrier. Neuroimaging plays a pivotal role in diagnosis. The distinctive "lentiform fork sign" was observed in this patient despite the absence of typical metabolic disturbances. Management strategies usually involve reducing hypertension, discontinuing ISDs, correcting electrolyte imbalances, and initiating antiseizure drugs if necessary. Identifying the presence of the "lentiform fork sign" alongside typical PRES edema in a patient lacking renal failure emphasizes that this manifestation is not solely indicative of uremic encephalopathy. Instead, it might represent the final common pathway resulting from alterations in the blood-brain barrier integrity within the deep white matter. Understanding such atypical imaging manifestations could significantly aid earlier and more precise diagnosis, influencing appropriate management decisions.

Early onset of posterior reversible encephalopathy syndrome (PRES) following postpartum eclampsia-A case report

Early screening and management of postpartum posterior reversible encephalopathy syndrome (PRES) can reduce hospital stay and complications. Obstetricians, gynecologists, ophthalmologists, and even general physicians should be aware of PRES since its presentation is variable.

Clinical Presentation and Imaging Findings of Irreversible Cerebral Amyloid Angiopathy-Related Inflammation (CAA-ri): A Case Report and Literature Review

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a rare condition primarily driven by an autoimmune reaction against cerebrovascular amyloid beta protein. Accurate diagnosis hinges on recognizing characteristic clinical symptoms and imaging features, such as asymmetric cerebral white matter lesions often linked to angioedema. We report the case of a woman in her 70s with progressive, irreversible CAA-ri who initially presented with left homonymous hemianopia and experienced significant psychiatric and neurological deterioration following an epileptic seizure. Despite initiating corticosteroid therapy seven months after onset, her condition continued to worsen, ultimately leading to her death in the 11th month due to general decline. This report reviews the clinical progression and imaging findings of the case, discusses the diagnostic process for CAA-ri, differentiates it from related conditions, and evaluates the timing of corticosteroid treatment.

Tacrolimus-induced posterior reversible encephalopathy syndrome following liver transplantation

In this editorial, we talk about a compelling case focusing on posterior reversible encephalopathy syndrome (PRES) as a complication in patients undergoing liver transplantation and treated with Tacrolimus. Tacrolimus (FK 506), derived from Streptomyces tsukubaensis, is a potent immunosuppressive macrolide. It inhibits T-cell transcription by binding to FK-binding protein, and is able to amplify glucocorticoid and progesterone effects. Tacrolimus effectively prevents allograft rejection in transplant patients but has adverse effects such as Tacrolimus-related PRES. PRES presents with various neurological symptoms alongside elevated blood pressure, and is primarily characterized by vasogenic edema on neuroimaging. While computed tomography detects initial lesions, magnetic resonance imaging, especially the Fluid-Attenuated Inversion Recovery sequence, is superior for diagnosing cortical and subcortical edema. Our discussion centers on the incidence of PRES in solid organ transplant recipients, which ranges between 0.5 to 5 +ACU-, with varying presentations, from seizures to visual disturbances. The case of a 66-year-old male status post liver transplantation highlights the diagnostic and management challenges associated with Tacrolimus-related PRES. Radiographically evident in the parietal and occipital lobes, PRES underlines the need for heightened vigilance among healthcare providers. This editorial emphasizes the importance of early recognition, accurate diagnosis, and effective management of PRES to optimize outcomes in liver transplant patients. The case further explores the balance between the efficacy of immunosuppression with Tacrolimus and its potential neurological risks, underlining the necessity for careful monitoring and intervention strategies in this patient population.

Current State of Evidence for Neuroimaging Paradigms in Management of Acute Ischemic Stroke

Stroke is the chief differential diagnosis in patient presenting to the emergency room with abrupt onset focal neurological deficits. Neuroimaging, including non-contrast computed tomography (CT), magnetic resonance imaging (MRI), vascular and perfusion imaging, is a cornerstone in the diagnosis and treatment decision-making. This review examines the current state of evidence behind the different imaging paradigms for acute ischemic stroke diagnosis and treatment, including current recommendations from the guidelines. Non-contrast CT brain, or in some centers MRI, can help differentiate ischemic stroke and intracerebral hemorrhage (ICH), a pivotal juncture in stroke diagnosis and treatment algorithm, especially for early window thrombolytics. Advanced imaging such as MRI or perfusion imaging can also assist making a diagnosis of ischemic stroke versus mimics such as migraine, Todd's paresis, or functional disorders. Identification of medium-large vessel occlusions with CT or MR angiography triggers consideration of endovascular thrombectomy (EVT), with additional perfusion imaging help identify salvageable brain tissue in patients who are likely to benefit from reperfusion therapies, particularly in the ≥6 h window. We also review recent advances in neuroimaging and ongoing trials in key therapeutic areas and their imaging selection criteria to inform the readers on potential future transitions into use of neuroimaging for stroke diagnosis and treatment decision making. ANN NEUROL 2024;95:1017-1034.

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.

A case study of posterior reversible encephalopathy syndrome: Not always reversible with detrimental consequences

ABSTRACT

Posterior reversible encephalopathy syndrome, or PRES, is often an unrecognized sequela of uncontrolled hypertension that is associated with a significant risk of mortality. It is poorly understood and can lead to endothelial dysfunction with disturbance of the blood-brain barrier and subsequent brain edema. Headache, seizures, encephalopathy, and visual disturbances are among the most common symptoms associated with PRES. Testing and evaluation should be quickly initiated not only to solidify the diagnosis but also to rule out others such as infection or stroke. Prompt identification of the symptoms of PRES can potentially reverse long-term side effects such as life-long seizures or visual deficits.

Posterior Reversible Encephalopathy Syndrome in a Late Postpartum Patient With a Rare Complication of Subarachnoid Hemorrhage

Posterior reversible encephalopathy syndrome (PRES) is considered a neuroclinical syndrome of headache, confusion, visual changes, and seizures associated with neuroimaging findings of posterior cerebral white matter edema. Although the incidence of the syndrome is largely unknown, this condition is becoming increasingly recognized. The prognosis is generally good with most symptoms resolving within one week and lesions on imaging resolving in two weeks. Death and significant neurological disability have been reported but are relatively rare. In this report, we present a 10-day postpartum patient with an atypical history of headache and seizure-like activity. Neuroimaging revealed findings consistent with PRES as well as a rare complication of subarachnoid hemorrhage. This case highlights the importance of clinicians considering preeclampsia/eclampsia-induced PRES when encountering a postpartum patient with headache and hypertension to further reduce morbidity and mortality in this patient population.

Hemorrhagic Posterior Reversible Encephalopathy Syndrome in a Pediatric Patient With Acute Lymphoblastic Leukemia: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is an uncommon yet severe neurological disorder characterized by a combination of clinical and radiological features. Common clinical presentations of PRES include headaches, seizures, altered mental status ranging from lethargy to coma, visual disturbances, and behavior changes.  This case report outlines the occurrence of hemorrhagic PRES in an 11-year-old girl with B-cell acute lymphoblastic leukemia (ALL) relapse. Hospitalized for ALL relapse, the patient underwent reinduction chemotherapy. On the ninth day of admission, she had a generalized tonic-clonic seizure with a blood pressure peak of 170/120 mmHg. Magnetic resonance imaging (MRI) and a seizure episode suggested PRES. Initially, after the first tonic-clonic seizure, the neurological examination was normal, but after the second seizure, the meningeal symptoms were negative, and gaze palsy and right-sided homonymous hemianopsia were observed; muscle strength was symmetrically reduced in the upper and lower extremities and reflexes were symmetrical and diminished. A bilateral Babinski reflex was observed at the time of examination; the patient had mild motor aphasia, and she opened her eyes only in response to tactile stimulation. A follow-up MRI four days after the second seizure episode showed extensive PRES damage with hemorrhagic changes. Over two weeks, the patient's neurological status and blood pressure gradually improved, with persistent changes in the visual field. Subsequent MRI revealed a significant reduction in PRES lesions, but residual hemorrhage measuring 6x4 cm remained evident.

Neuropsychiatric manifestations associated with Juvenile Systemic Lupus Erythematosus: An overview focusing on early diagnosis

Juvenile systemic lupus erythematosus (jSLE) is a chronic multisystem inflammatory disease that manifests before the age of 16 years, following a remitting - relapsing course. The clinical presentation in children is multifaceted, most commonly including constitutional, hematological, cutaneous, renal, and neuropsychiatric symptoms. Neuropsychiatric manifestations range widely, affecting approximately 14-95 % of jSLE patients. They are associated with high morbidity and mortality, particularly at a younger age. Headaches, seizures, cognitive dysfunction, and mood disorders are the most frequent neuropsychiatric manifestations. The pathophysiological mechanism is quite complex and has not yet been fully investigated, with autoantibodies being the focus of research. The diagnosis of neuropsychiatric jSLE remains challenging and exclusionary. In this article we review the clinical neuropsychiatric manifestations associated with jSLE with the aim that early diagnosis and prompt treatment is achieved in children and adolescents with the disease.

Cocaine-Induced Toxic Leukoencephalopathy: A Case Report

We present a case here where a 57-year-old South Asian male with disturbed mental status developed multifocal leukoencephalopathy, which we believe was caused by cocaine usage. Cocaine was detected in the urine toxicological sample. Non-acute CT head, with a follow-up brain MRI demonstrating hyperintensity of the T2 FLAIR signal corresponding to diffusion restriction throughout the whole supratentorial white matter, involving semiovale and subcortical U fibres in the occipital lobes as well as posterior frontal and parietal centrum. It was less likely that the patient had posterior reversible encephalopathy syndrome (PRES), which can potentially manifest similarly in a clinical and imaging context because there was no abrupt rise of blood pressure at presentation or during the patient's stay. Extensive examinations were conducted to exclude additional factors that may contribute to the patient's appearance, including autoimmune, vasculitis, and infectious diseases. Levamisole, a significant chemical that is frequently used to increase the volume of cocaine samples and has been linked to neuronal damage, should be examined in individuals who use cocaine and exhibit these kinds of clinical symptoms. The patient was prescribed 250 mg of methylprednisolone twice daily for five days after it was determined that cocaine-induced neuronal toxicity was the cause of his symptoms. Although no improvement was seen right away, over the course of the next few days, he did exhibit a gradual, albeit slight, improvement in his mental status while residing in the nursing home. It is crucial to comprehend the possible connection between cocaine usage, a commonly abused drug, and people exhibiting similar clinical symptoms. To have a better understanding of the pathophysiology and possible treatment approach, more research is necessary as there is now no recommended therapy regimen.

[Posterior reversible encephalopathy syndrome in autoimmune disorders]

Posterior reversible encephalopathy syndrome (PRES) is characterized by nonspecific symptoms, including not only pronounced non-focal and various focal neurological signs but also specific neuroimaging features, including vasogenic edema affecting predominantly the posterior area. PRES usually develops in the setting of acute arterial hypertension. However, it is not uncommon for PRES to develop in non-hypertensive patients, including people with autoimmune disorders (multiple sclerosis, neuromyelitis optica spectrum disorder, etc). PRES could also be due to the toxic effects of drugs or other substances. The pathophysiological mechanisms of PRES include impaired autoregulation of cerebral blood flow due to acute arterial hypertension and toxic endotheliotropic effects of endogenous and exogenous factors.

Case report: PRES associated with fruquintinib in a patient with metastatic colon cancer

Posterior reversible encephalopathy syndrome (PRES) is a rare, reversible neurological disease that is frequently associated with the use of targeted therapy agents. In this case study, we examine the development of posterior reversible encephalopathy syndrome (PRES) in a 44-year-old woman with metastatic colon cancer following 1 month of treatment with the vascular endothelial growth factor receptor (VEGFR) inhibitor, fruquintinib. The occurrence of PRES after 1 month of VEGFR inhibitor administration is a common phenomenon. However, it is noteworthy that this is the first reported case of PRES associated with fruquintinib. The patient's neurological function improved upon discontinuing the drug for a week, but worsening was observed following a lower-dose fruquintinib treatment. This patient's experience highlights the potential for neurological deterioration in those treated with fruquintinib, prompting physicians to consider the possibility of PRES. Notably, this may be the first reported case linking fruquintinib to the syndrome, underscoring the importance of recognizing the association between PRES and fruquintinib.

Posterior Reversible Leukoencephalopathy With Hemorrhagic Features: A Case Series

Introduction Posterior reversible leukoencephalopathy syndrome (PRES) is a clinical-radiological condition characterized by reversible subcortical vasogenic cerebral edema of acute or subacute onset in circumstances that disrupt capillary permeability, unfrequently accompanied by cytotoxic and/or hemorrhagic lesions. We describe a case series of PRES with hemorrhagic features. Subjects and methods Electronic medical records of hospitalized patients diagnosed with PRES from January 2009 to December 2021 were collected. Demographic data, medical history, clinical presentation, and outcome were recorded. Variables were compared between patients with and without hemorrhagic features using the Wilcoxon-Mann-Whitney test with a statistical significance level of p<0.05. Results Over a 12-year period, 33 patients were diagnosed with PRES, of whom 10 had hemorrhagic features: seven cortical microbleeds, two intraparenchymal hematomas, and one subarachnoid hemorrhage. Half of the patients were women, with a median age of 45.8 years (interquartile range (IQR) 21.8), and were admitted for non-neurological reasons. The sample included nine transplant recipients (six solid organa, three bone marrowa), with four patients in the immediate post-transplant period. PRES occurred in the context of infections and blood pressure fluctuations under cytotoxic drugs, such as immunosuppressants. Seventy percent showed improvement/resolution on neuroimaging at a median of 70 days (IQR 62.9). The three major hemorrhages occurred in the context of thrombocytopenia. The recorded in-hospital mortality was 10%. When compared to PRES without hemorrhagic features, patients with hemorrhagic features had a lower use of corticosteroids (50% vs. 78.8%; p=0.02) and a higher presence of restrictive lesions on neuroimaging (60% vs. 17%; p=0.04), with no differences in the other analyzed variables. Conclusion Patients with PRES and hemorrhagic features had a lower use of corticosteroids and a higher presence of restrictive lesions on neuroimaging. Further studies are needed to better understand the clinical implications and management of PRES with hemorrhagic manifestations.

A Case of Reversible Posterior Leukoencephalopathy Syndrome (PRES) With a History of Migraine and Onset With Initial Visual Aura and Migraine-Like Headache, With a Significant Response to Lasmiditan: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a neurological disease that presents with various neurological symptoms and is often accompanied by elevated blood pressure at onset. Neuroimaging, especially magnetic resonance imaging (MRI), often shows a characteristic parieto-occipital pattern with a symmetrical distribution of changes, reflecting vasogenic edema. Hypertension and endothelial cell damage are the most common causes of PRES. An association between migraine and endothelial cell damage has been suggested, but the relationship between migraine and PRES is unknown. Reports on PRES triggered by migraines are scarce. We report a case of PRES in a 59-year-old woman with migraine without aura. At the onset, the patient experienced a first-ever visual aura and a migraine-like headache. In this case, it was also difficult to distinguish between PRES headache and headache caused by a pre-existing migraine; however, lasmiditan, an acute migraine treatment without vasoconstrictive properties, was remarkably effective for headaches.

Case report: Reversible encephalopathy caused by dyskinesia-hyperpyrexia syndrome

Parkinson's disease (PD) is a common neurodegenerative disorder. Some patients with advanced-stage disease are accompanied by emergencies and critical issues such as dyskinesia-hyperpyrexia syndrome (DHS), parkinsonism-hyperpyrexia syndrome (PHS), and serotonin syndrome (SS). In this study, we report a patient with reversible encephalopathy caused by DHS who presented with an acute onset of fidgetiness, dyskinesia, and hyperpyrexia after antiparkinsonian drug abuse. In the present case, brain magnetic resonance imaging (MRI) showed multiple abnormal signals in the cortex and subcortex of the bilateral parietal and occipital lobes that resolved within weeks, which coincided with the characteristic MRI findings in posterior reversible encephalopathy (PRES). Our report expands on the neuroimaging features of DHS and highlights the importance of early identification, diagnosis, and treatment to improve patient prognosis.

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.

Alcohol-related posterior reversible encephalopathy syndrome: a case report of a patient managed with a benzodiazepine-sparing regimen for alcohol withdrawal

We report a case of posterior reversible encephalopathy syndrome (PRES) during treatment for alcohol withdrawal syndrome with gabapentin and clonidine. The patient developed severe hypertension, confusion and tremor, culminating in bilateral vision loss and a seizure. Imaging revealed posterior cerebral edema. Treatment with benzodiazepines, antihypertensives, and anti-seizure medications led to resolution. One year later, imaging showed resolution of the findings. We review the associated literature and propose the recognition of a PRES sub-entity, Alcohol-Related PRES (ARPRES), which can appear in the setting of alcohol withdrawal syndrome, chronic alcohol use, and acute alcohol intoxication, with or without hypertension.

Comprehensive Update and Review of Clinical and Imaging Features of SMART Syndrome

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a delayed complication of cranial irradiation, with subacute onset of stroke-like symptoms including seizures, visual disturbance, speech impairment, unilateral hemianopsia, facial droop, and aphasia, often associated with migraine-type headache. The diagnostic criteria were initially proposed in 2006. However, the diagnosis of SMART syndrome is challenging because clinical symptoms and imaging features of SMART syndrome are indeterminate and overlap with tumor recurrence and other neurologic diseases, which may result in inappropriate clinical management and unnecessary invasive diagnostic procedures. Recently, various imaging features and treatment recommendations for SMART syndrome have been reported. Radiologists and clinicians should be familiar with updates on clinical and imaging features of this delayed radiation complication because recognition of this entity can facilitate proper clinical work-up and management. This review provides current updates and a comprehensive overview of the clinical and imaging features of SMART syndrome.

Malignant Hypercalcemia: A Rare Etiology of Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome (PRES) is a rare and severe neurotoxic encephalopathic state characterized by variable neurologic manifestations ranging from headache and confusion to seizures, coma, and reversible subcortical vasogenic edema on imaging. PRES is commonly induced by chronic renal failure, hypertension, chemotherapeutic drugs, and eclampsia. PRES induced by hypercalcemia is uncommon and not widely underlined in the literature. We underline a case of a 61-year-old female diagnosed with advanced breast carcinoma presented with altered sensorium and generalized limb weakness. She was found to have malignant hypercalcemia, and brain imaging demonstrated subcortical vasogenic edema in the occipital and frontal lobe, suggestive of PRES. Her condition gradually improved after the treatment of hypercalcemia.

Posterior reversible encephalopathy syndrome: A rare complication of rituximab therapy in rheumatoid arthritis

Rituximab, a murine-human chimeric monoclonal antibody targeting CD20-positive B lymphocytes, has established itself as an effective and relatively safe biologic therapy for patients with refractory rheumatoid arthritis. Most common side effects associated with its use include infusion related reactions and cytopenia. Rare adverse effects such as progressive multifocal leukoencephalopathy and posterior reversible encephalopathy syndrome (PRES) have also been reported. Diagnosis of PRES following rituximab treatment requires a high index of suspicion correlated with clinical and radiological features in individuals at risk. Early diagnosis and prompt treatment is associated with a favorable prognosis. We present a case of a young man who developed PRES following rituximab administration on account of active rheumatoid arthritis. Timely diagnosis and prompt treatment ensured his uneventful recovery without residual neurological deficit.

Posterior Reversible Encephalopathy Syndrome in an Adult Male With Uncontrolled Blood Pressure and Cocaine Use: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a subacute syndrome that is diagnosed by neurologic symptoms and radiologic findings. PRES is predominantly caused by uncontrolled hypertension though it has been associated with illicit drug use, specifically cocaine use. We describe a case of a 68-year-old male who developed visual disturbances and gait abnormalities. Imaging was confirmed with head CT that showed hypoattenuation in the posterior aspects of the occipital lobes. The patient was managed with anti-hypertensive medication and blood pressure monitoring during his hospital course. Therefore, the patient's neurological symptoms resolved once the blood pressure was well-controlled. MRI of the brain was completed prior to discharge and confirmed resolution. Hypertension and cocaine use has been documented as causative agents of PRES. It is most likely due to the inability of the posterior circulation of the brain to auto-regulate with acute changes in blood pressure resulting in hypoperfusion and disruption of the blood-brain barrier with resultant vasogenic edema without infarction.

Parieto-Occipital Injury on Diffusion MRI Correlates with Poor Neurologic Outcome following Cardiac Arrest

BACKGROUND AND PURPOSE

MR imaging of the brain provides unbiased neuroanatomic evaluation of brain injury and is useful for neurologic prognostication following cardiac arrest. Regional analysis of diffusion imaging may provide additional prognostic value and help reveal the neuroanatomic underpinnings of coma recovery. The purpose of this study was to evaluate global, regional, and voxelwise differences in diffusion-weighted MR imaging signal in patients in a coma after cardiac arrest.

MATERIALS AND METHODS

We retrospectively analyzed diffusion MR imaging data from 81 subjects who were comatose for >48 hours following cardiac arrest. Poor outcome was defined as the inability to follow simple commands at any point during hospitalization. ADC differences between groups were evaluated across the whole brain, locally by using voxelwise analysis and regionally by using ROI-based principal component analysis.

RESULTS

Subjects with poor outcome had more severe brain injury as measured by lower average whole-brain ADC (740 [SD, 102] × 10-6 mm2/s versus 833 [SD, 23] × 10-6 mm2/s, P < .001) and larger average volumes of tissue with ADC below 650 × 10-6 mms/s (464 [SD, 469] mL versus 62 [SD, 51] mL, P < .001). Voxelwise analysis showed lower ADC in the bilateral parieto-occipital areas and perirolandic cortices for the poor outcome group. ROI-based principal component analysis showed an association between lower ADC in parieto-occipital regions and poor outcome.

CONCLUSIONS

Brain injury affecting the parieto-occipital region measured with quantitative ADC analysis was associated with poor outcomes after cardiac arrest. These results suggest that injury to specific brain regions may influence coma recovery.

Imaging of Suspected Stroke in Children, From the AJR Special Series on Emergency Radiology

Pediatric stroke encompasses different causes, clinical presentations, and associated conditions across ages. Although it is relatively uncommon, pediatric stroke presents with poor short- and long-term outcomes in many cases. Because of a wide range of overlapping presenting symptoms between pediatric stroke and other more common conditions, such as migraine and seizures, stroke diagnosis can be challenging or delayed in children. When combined with a comprehensive medical history and physical examination, neuroimaging plays a crucial role in diagnosing stroke and differentiating stroke mimics. This review highlights the current neuroimaging workup for diagnosing pediatric stroke in the emergency department, describes advantages and disadvantages of different imaging modalities, highlights disorders that predispose children to infarct or hemorrhage, and presents an overview of stroke mimics. Key differences in the initial approach to suspected stroke between children and adults are also discussed.

Posterior reversible encephalopathy syndrome associated with mild COVID-19 infection in a 9-year-old child: A case report and literature review

The neurologic complications associated with the coronavirus disease 2019 (COVID-19) is becoming more prevalent in children after the appearance of the Omicron strain. An association between COVID-19 and posterior reversible encephalopathy (PRES) has been consistently reported in adults, but little information is available in the pediatric age group. There are only few case reports of COVID-19-related PRES in children, and all of these patients were either on some type of immunomodulatory medications or whose general condition was severe. The present case, a 9-year-old Japanese boy, who had no fever but vomited several times from days 1-4 of a COVID-19 infection had an afebrile seizure on the 8th day of his illness. The patient had no history of hypertension, and had not previously been administered any immunosuppressive drugs before or during the period of his COVID-19 infection. On admission, his physical findings were unremarkable, except for a high blood pressure. The results obtained by brain computed tomography and magnetic resonance imaging were consistent with PRES. The patient recovered with no sequelae after treatment with antihypertensive drugs. Further investigations did not suggest any underlying disease that could have caused the transient hypertension. Although PRES is relatively rare in children, pediatricians should keep in mind that this syndrome can be complicated, even in children with mild COVID-19 infections.

Medical emergencies in pediatric blood & marrow transplant and cellular therapies

Hematopoietic stem cell transplant (HCT) is used for many pediatric malignant and non-malignant diseases. However, these patients are at a high risk for emergencies post-transplant, related to prior comorbidities and treatments for the underlying disease, high dose chemotherapy regimen related toxicities, prolonged myelosuppression, and opportunistic infections due to their immunocompromised state. Emergencies can be during preparative regimen and hematopoietic progenitor cell (HPC) infusion, acute post-transplant (pre-engraftment) and late during post engraftment. Infectious complications are the most common cause of morbidity and mortality in the peri-transplant period. Sinusoidal obstructive syndrome is another life-threatening emergency seen in children undergoing HCT, especially in infants. Timely recognition and administration of defibrotide with/without steroids is key to the management of this complication. Another complication seen is transplant associated thrombotic microangiopathy. It can cause multiorgan failure if left untreated and demands urgent identification and management with complement blockade agents such as eculizumab. Cytokine release syndrome and cytokine storm is an important life-threatening complication seen after cellular therapy, and needs emergent intervention with ICU supportive care and tocilizumab. Other complications in acute period include but are not limited to: seizures from busulfan or other chemotherapy agents, PRES (posterior reversible encephalopathy syndrome), diffuse alveolar hemorrhage, idiopathic pulmonary syndrome and allergic reaction to infusion of stem cells. Acute graft versus host disease (GvHD) is a major toxicity of allogeneic HCT, especially with reduced intensity conditioning, that can affect the skin, liver, upper and lower gastrointestinal tract. There has been major development in new biomarkers for early identification and grading of GvHD, which enables application of treatment modalities such as post-transplant cyclophosphamide and JAK/STAT inhibitors to prevent and treat GvHD. Myelosuppression secondary to the chemotherapy increases risk for engraftment syndrome as well as coagulopathies, thus increasing the risk for clotting and bleeding in the pediatric population. The purpose of this article is to review recent literature in these complications seen with pediatric hematopoietic cell transplant (HCT) and cellular therapies and provide a comprehensive summary of the major emergencies seen with HCT.

Visual Hallucinations as a Major Manifestation of Posterior Reversible Encephalopathy Syndrome: Case Report and Literature Review

We evaluated a 48-year-old woman who had visual hallucinations (VHs) as a major presenting sign of posterior reversible encephalopathy syndrome (PRES). Despite her mild loss of vision, she described various hallucinations after awakening from a comatose state days after a motorcycle collision. VHs are usually accompanied by more severe loss of vision, yet our case and literature review indicate that sudden onset of formed VHs should suggest a possible diagnosis of PRES in patients who have large fluctuations in blood pressure, renal failure, or autoimmune dysfunction, as well as in patients taking cytotoxic agents.

Paediatric posterior reversible encephalopathy syndrome: is there an association of blood pressure with imaging severity and atypical magnetic resonance characteristics?

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is relatively uncommon in paediatric patients; however, its pathophysiology remains obscure.

OBJECTIVE

The aims of this study were to find an association or correlation between (1) blood pressures and (2) imaging severity and the presence of atypical imaging features in children with PRES.

MATERIALS AND METHODS

We performed a retrospective cross-sectional evaluation in children diagnosed with PRES. We reviewed radiologic findings along with each patient's clinical profile and outcome. We categorised imaging severity into mild, moderate and severe, and assessed the MR imaging pattern, enhancement and diffusion restriction for each child. We assessed both associations and correlations between variables using the chi-square test, Cramer V and Kendall tau b.

RESULTS

A total of 63 children met the inclusion criteria (31 boys; mean age 9.7 years). A total of 42 children (67%) had an elevated blood pressure. Imaging showed parieto-occipital lobe involvement pattern in 24 (38%) children, frontal lobe pattern in 25 (40%) and cerebellar involvement in 12 (19%). Three (5%) had haemorrhage, 15 (24%) had contrast enhancement and 19 (30%) had positive diffusion restriction (cytotoxic oedema). We found no statistically significant association between imaging severity and blood pressures (P=0.11), nor any association between blood pressure and atypical imaging findings such as diffusion restriction (P=0.1), enhancement (P=0.11) or haemorrhage (P=0.33).

CONCLUSION

According to our results, there is no statistically significant association or correlation between blood pressure and either imaging severity or atypical imaging features in children with PRES. Further prospective studies are warranted.

Hepatic cortical blindness

Hepatic cortical blindness is an unusual clinical complication of hepatic encephalopathy, and its epidemiology has not been studied in detail. Herein, we present a case report of a 37-year-old male with liver cirrhosis and immunoglobulin A nephropathy who noted visual impairment after eating high-protein food. In addition to the case report, all previously documented cases of hepatic cortical blindness occurring across the globe published from inception until August 2019 were reviewed. The incidence of hepatic cortical blindness is low, and diagnoses are easily missed. The diagnosis of hepatic cortical blindness is dependent on symptoms, and patients may experience several attacks of vision loss. Most patients experience complete blindness, but vision loss recovers within 10 min to one month. Early detection and therapy for hepatic encephalopathy may improve patient outcome.

Posterior Reversible Encephalopathy Syndrome Occurred During the Use of Pseudoephedrine: A Case Report

INTRODUCTION

Posterior reversible encephalopathy syndrome (PRES) is a syndrome that is manifested by a variety of clinical findings, like headache, seizure, loss of vision and change in consciousness, and characterized by bilateral vasogenic edema, which is usually located in the posterior part of the hemispheres, but sometimes located in atypical localization.

CASE PRESENTATION

A 56-year-old man with no known systemic disease with generalized tonic clonic seizure was evaluated. He had oral paracetamol + pseudoephedrine HCl for runny nose, sore throat, and headache. After the second dosage, he had a seizure during sleeping. In flair sequence of magnetic resonance imaging, bilateral cortical and subcortical hyperintensities were observed in the posterior parts of the hemispheres and the cerebellar hemispheres, which demonstrated PRES.

CONCLUSION

We presented a PRES case with seizures after using 2 doses of pseudoephedrine. In addition to hypertension, several factors have been blamed, such as eclampsia-preeclampsia, some immunosuppressive and chemotherapeutic drugs, some kidney diseases. Although the patient had no known risk factors for PRES, he was diagnosed with hypertension and diabetes mellitus during follow-up.

MR Imaging for Acute Central Nervous System Pathologies and Presentations in Emergency Department

Although evaluation of suspected stroke is a major driver of MRI use in the emergency department (ED), the exquisite contrast resolution and flexibility provided by MRI are valuable in the workup of a broad variety of acute neurologic complaints. This article provides an overview, focused primarily on "non-stroke" neurologic emergencies encountered in ED brain MRI that emergency radiologists should be familiar with.

Role of MRI and CT in the Evaluation of Headache in Pregnancy and the Postpartum Period

Approximately 35% of acute headaches in pregnant women are secondary to an underlying condition. Headaches are also common in the postpartum period where they occur in 30% to 40% of patients. The majority of secondary headaches are due to hypertensive disorders: preeclampsia-eclampsia, posterior reversible encephalopathy syndrome, and acute arterial hypertension. Other causes include reversible cerebral vasoconstriction syndrome and pituitary apoplexy, as well as life-threatening conditions such as cerebral venous thrombosis. In this article, we review general recommendations for imaging the pregnant patients and discuss the imaging findings of common causes of headaches in pregnancy and the postpartum period.

Neurological Manifestations of Acute Porphyrias

PURPOSE OF REVIEW

Porphyrias constitute a group of rare metabolic disorders that result in a deficiency of the heme biosynthetic pathway and lead to the accumulation of metabolic intermediaries. Patients with porphyria can experience recurrent neurovisceral attacks which are characterized by neuropathic abdominal pain and acute gastrointestinal symptoms, including nausea, vomiting, and constipation. Depending on the type of porphyria, patients can present with cutaneous manifestations, such as severe skin photosensitivity, chronic hemolysis, or evidence of neurologic dysfunction, including alterations in consciousness, neurovascular involvement, seizures, transient sensor-motor symptoms, polyneuropathy, and behavioral abnormalities.

RECENT FINDINGS

More recently, cases of posterior reversible encephalopathy syndrome, cerebral vasoconstriction, and acute flaccid paralysis have also been described. While the exact pathogenic mechanisms linking the accumulation of abnormal heme biosynthetic intermediaries to neurologic manifestations have not been completely elucidated, it has been proposed that these manifestations are more common than previously thought and can result in permanent neurologic injury. This article reviews the basic principles of heme synthesis as well as the pathogenic mechanism of disease, presentation, and treatment of acute hepatic porphyrias with emphasis on those with neurologic manifestations.

Cerebral perfusion in posterior reversible encephalopathy syndrome measured with arterial spin labeling MRI

BACKGROUND AND PURPOSE

The pathophysiologic basis of posterior reversible encephalopathy syndrome (PRES) remains controversial. Hypertension (HTN)-induced autoregulatory failure with subsequent hyperperfusion is the leading hypothesis, whereas alternative theories suggest vasoconstriction-induced hypoperfusion as the underlying mechanism. Studies using contrast-based CT and MR perfusion imaging have yielded contradictory results supporting both ideas. This work represents one of the first applications of arterial spin labeling (ASL) to evaluate cerebral blood flow (CBF) changes in PRES.

MATERIALS AND METHODS

After obtaining Institutional Review Board approval, MRI reports at our institution from 07/2015 to 09/2020 were retrospectively searched and reviewed for mention of "PRES" and "posterior reversible encephalopathy syndrome." Of the resulting 103 MRIs (performed on GE 1.5 Tesla or 3 Tesla scanners), 20 MRIs in 18 patients who met the inclusion criteria of clinical and imaging diagnosis of PRES and had diagnostic-quality pseudocontinuous ASL scans were included. Patients with a more likely alternative diagnosis, technically non-diagnostic ASL, or other intracranial abnormalities limiting assessment of underlying PRES features were excluded. Perfusion in FLAIR-affected brain regions was qualitatively assessed using ASL and characterized as hyperperfusion, normal, or hypoperfusion. Additional quantitative analysis was performed by measuring average gray matter CBF in abnormal versus normal brain regions.

RESULTS

HTN was the most common PRES etiology (65%). ASL showed hyperperfusion in 13 cases and normal perfusion in 7 cases. A hypoperfusion pattern was not identified. Quantitative analysis of gray matter CBF among patients with visually apparent hyperperfusion showed statistically higher perfusion in affected versus normal appearing brain regions (median CBF 100.4 ml/100 g-min vs. 61.0 ml/ 100 g-min, p < 0.001).

CONCLUSION

Elevated ASL CBF was seen in the majority (65%) of patients with PRES, favoring the autoregulatory failure hypothesis as a predominant mechanism. Our data support ASL as a practical way to assess and noninvasively monitor cerebral perfusion in PRES that could potentially alter management strategies.

Breath-Hold Diving-Related Decompression Sickness with Brain Involvement: From Neuroimaging to Pathophysiology

Central nervous system involvement related to decompression sickness (DCS) is a very rare complication of breath-hold diving. So far, it has been postulated that repeated dives with short surface intervals represent a key factor in the development of breath-holding-related DCS. We report the case of a breath-hold diver who, after repeated immersion, developed DCS with brain involvement. After treatment in a hyperbaric chamber, there was a clinical improvement in the symptoms. Magnetic resonance imaging of the brain showed hyperintense lesions in long-time repetition sequences (FLAIR, T2WI) in the left frontal and right temporal lobes. Diffusion-weighted imaging (DWI) sequences and the apparent diffusion coefficient (ADC) map were characteristic of vasogenic edema, allowing us to exclude the ischemic nature of the process. These findings, together with the acute clinical presentation, the resolution of lesions in evolutionary radiological controls and the possible involvement of blood–brain barrier/endothelial dysfunction in DCS, could suggest a new form of posterior reversible encephalopathy syndrome (PRES)-like presentation of DCS. This would represent a novel mechanism to explain the pathophysiology of this entity. We conducted a literature review, analyzing the pathophysiological and neuroimaging characteristics of DCS in breath-hold diving based on a case of this rare disease.

Posterior Reversible Encephalopathy Syndrome with Postoperative Hematoma After C4-C6 Spinal Fusion: A Case Report

CASE

A 71-year-old woman with a 2-year history of spondylosis and radiculopathy presented with progressively worsening cervical spine pain and neurological dysfunction for 2 years. The patient developed posterior reversible encephalopathy syndrome (PRES) after postoperative hematoma in the retroesophageal and retropharyngeal areas. This occurred status post anterior cervical diskectomy and fusion (ACDF) of C4-C6. One year postoperatively, the patient recovered with full ambulation, neurological improvement, and resolution of all PRES signs and symptoms.

CONCLUSION

We present a case of a previously undescribed outcome of PRES as a complication of ACDF likely related to postoperative hypertension and fragile blood vessels.

Posterior Reversible Encephalopathy Syndrome and Pre-eclampsia/Eclampsia: Anesthetic Implications and Management

Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic disorder that has recently become more frequently diagnosed. While the exact etiology of PRES remains unclear, multiple diseases are associated with PRES. Moreover, there is increasing recognition of the association of PRES in pre-eclampsia/eclampsia with advancements in imaging techniques and increased awareness of the disorder. While pre-eclampsia/eclampsia alone presents unique perioperative challenges, PRES further complicates anesthetic management. Unfortunately, the anesthetic management for these critically ill and complex patients is not well elucidated and it is unclear whether the anesthetic choice may actually worsen neurologic symptoms. We describe two different presentations of PRES with pre-eclampsia/eclampsia, their anesthetic implications, and management.

White matter integrity is disrupted in adolescents with acute anorexia nervosa: A diffusion tensor imaging study

Anorexia nervosa (AN) is a highly debilitating mental illness with multifactorial etiology. It oftentimes begins in adolescence, therefore understanding the pathophysiology in this period is important. Few studies investigated the possible impact of the acute state of illness on white matter (WM) tissue properties in the developing adolescent brain. The present study expands our understanding of the implications of AN and starvation on WM integrity. 67 acutely ill adolescent patients suffering from AN restricting type were compared with 32 healthy controls using diffusion tensor imaging assessing fractional anisotropy (FA) and mean diffusivity (MD). We found widespread alterations in the vast majority of the WM regions with significantly decreased FA and increased MD in the AN group. In this highly selective sample in the acute stage of AN, the alterations are likely to be the consequence of starvation. Still, we cannot rule out that some of the affected regions might play a key role in AN-specific psychopathology.

Prevalence and Risk Factors of Posterior Reversible Encephalopathy Syndrome in Isfahan, Iran

Background:

Posterior reversible encephalopathy syndrome (PRES) is a rare clinical-radiological syndrome characterized by such symptoms as headaches, altered consciousness, blurred vision, seizure, and focal neurological deficits. We herein present well-documented PRES cases and discuss the risk factors and characteristic imaging patterns of this syndrome.

Materials and Methods:

We prospectively examined 31 patients with PRES in Alzahra Hospital, Isfahan, Iran, and compared the underlying diseases of PRES in terms of their clinical features and cranial magnetic resonance imaging (MRI) findings.

Results:

The most common underlying disease was hypertension (90.3%), followed by systemic lupus erythematosus (32.3%), preeclampsia (25.8%), chronic renal failure (22.6%), and rheumatoid arthritis (22.6%). Interestingly, we also reported heroin abuse as a possible risk factor for PRES (9.7%). The most frequent clinical signs were headaches (54.8%), seizure (54.8%), and blurred vision (35.5%). The most frequent lesions on cranial MRI were in the parieto-occipital area (87.1%), followed by the cerebellum (19.4%) and the frontal lobe (12.9%). Other abnormalities on MRI were less common. In addition, 16.1% of the study population had vasospasm on magnetic resonance arteriography (MRA). Clinical recovery was followed by radiological resolution in all the patients.

Conclusions:

The clinical presentation is nonspecific, most patients present with a combination of symptoms, particularly headaches and seizure. MRI is crucial for the diagnosis of PRES, and MRA is useful in that it can identify associated vasospasm. Timely diagnosis and treatment are required to avoid a devastating outcome.

[Manifestations of the central nervous system after COVID-19]

Numerous diseases of the central nervous system (CNS), especially in the postacute phase after an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described. These include neuroimmunologically mediated diseases, such as encephalopathy, encephalitis, myelitis, acute disseminated encephalomyelitis (ADEM), acute necrotizing hemorrhagic leukoencephalitis (ANHLE) and neuromyelitis optica spectrum disorder (NMOSD) as well as others, such as posterior reversible encephalopathy syndrome (PRES), opsoclonus myoclonus ataxia (OMA) and cerebrovascular diseases. A parainfectious or postinfectious association is discussed but the pathophysiological mechanisms are so far unknown. Underlying mechanisms could be a virus-triggered overactivation of the immune system with hyperinflammation and cytokine storm but possibly also the development of specific autoantibodies against CNS tissue. Direct damage due to the invasion of SARS-CoV‑2 into the brain or spinal cord does not seem to play a relevant role. An exact clinical phenotyping and initiation of additional diagnostics are recommended, also to rule out other causes. To date no medicinal treatment options for CNS manifestations of long COVID exist; however, first results regarding inflammation and autoimmunity are promising and could lead to new treatment approaches.

IgA nephropathy with posterior reversible encephalopathy with spinal cord involvement in a young male: A case report

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological phenomenon commonly associated with kidney diseases, especially chronic kidney disease. A consequence of endothelial dysfunction, PRES is usually associated with uncontrolled blood pressures and can rarely have atypical radiological findings involving the brain stem and spinal cord, called posterior reversible encephalopathy with spinal cord involvement (PRES-SCI). These atypical features may be confused with other etiologies causing a delay in diagnosis and management. We describe a young male patient who presented with neurological symptoms suggestive of PRES; however, the atypical radiological findings along with concomitant rapidly progressive glomerulonephritis led to a diagnostic dilemma. Repeat neuro-imaging after appropriate blood pressure control showed disappearance of the lesions confirming the diagnosis of PRES-SCI, and kidney biopsy showed advanced IgA nephropathy. Knowledge of atypical features of PRES is crucial amongst nephrologists as it is a common association with kidney disease and prompt identification and management avoid irreversible sequelae and unnecessary investigations.

EYE DISEASE IN KIDNEY TRANSPLANTATION: CLINICAL CHALLENGES IN A UNIQUE PATIENT POPULATION

Eye disease is common among kidney transplant recipients and their management is challenging. Chronic kidney disease is associated with ocular complications, both independently and in the context of various systemic disorders. In addition, chronic immunosuppression predisposes kidney transplant recipients to an array of long-term ocular issues. This may be broadly categorized into infections, malignancies, and other immunosuppression-specific side effects. The interdependence of kidney disease, transplant pharmacotherapy and ocular health therefore requires a multispecialty approach. Although the kidney transplant population has grown along with the burden of associated oculopathies, systematic guidelines targeting this patient group are lacking. This evidenced-based narrative review summarizes the pertinent issues that may present in the ophthalmic and optometric clinical settings, with emphasis on collaborative management and directions for future research.