Experimental Models of Posterior Reversible Encephalopathy Syndrome: A Review From Pathophysiology to Therapeutic Targets.

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity characterized by nonspecific symptomatology (eg, headache, visual disturbances, encephalopathy, and seizures) and classically cortical and subcortical vasogenic edema predominantly affecting the parietooccipital region. PRES etiologies are usually dichotomized into toxic PRES (eg, antineoplastic drugs, illicit drugs) and clinical condition-associated PRES (eg, acute hypertension, dysimmune disorders). Although the pathophysiology of PRES remains elusive, 2 main pathogenic hypotheses have been suggested: cerebral hyperperfusion due to acute hypertension and cerebral hypoperfusion related to endothelial dysfunction. Research into the pathogenesis of PRES has emerged through the development of animal models in the last decade. The motivation for developing a suitable PRES model is 2-fold: to fill in knowledge gaps of the pathophysiological mechanisms involved, and to open new perspectives for clinical assessment of pharmacological targets to improve therapeutic management of PRES. All current models of PRES have a hypertensive background, on which other triggers (acute hypertension, inflammatory, drug toxicity) have been added to address specific facets of PRES (eg, seizures). The initial model consisted in inducing a reduced uterine perfusion pressure that mimics preeclampsia, a leading cause of PRES. More recently, a model of stroke-prone spontaneously hypertensive rats on high-salt diet, originally developed for hypertensive small vessel disease and vascular cognitive impairment, has been studied in PRES. This review aims to discuss, depending on the research objective, the benefits and limitations of current experimental approaches and thus to define the desirable characteristics for studying the pathophysiology of PRES and developing new therapies.

Posterior reversible encephalopathy syndrome and acute ischemic stroke: an underreported association.

INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is a rare and complex disorder with variable clinical presentation and a typical magnetic resonance imaging (MRI) pattern of vasogenic edema with typical and atypical locations. It is often triggered by other diseases and drugs and the most prototypical association is with persistently elevated arterial pressure values. Among the potential cerebrovascular complications, intracranial bleeding has been described, but ischemic stroke is uncommonly reported. METHODS: We are presenting a case of a male patient with prolonged and sustained arterial hypertension acutely presenting with lacunar ischemic stroke involving the right corona radiata and composite MRI findings with the association of chronic small vessel disease (SVD) markers, acute symptomatic lacunar stroke, and atypical, central variant, posterior fossa dominant PRES. In the MRI follow-up, the white matter hyperintensities in T2-fluid attenuated inversion recovery (FLAIR sequences) due to PRES. DISCUSSION: The pathophysiology of PRES is not yet fully known, but the association with markedly increased values of arterial pressure is typical. In this context, ischemic stroke has not been considered in the clinical and neuroradiological manifestations of PRES and it has been only occasionally reported in the literature. In this case, the main hypothesis is that sustained hypertension may have triggered both manifestations, PRES, and ischemic stroke and the last one allowed to diagnose the first one. CONCLUSIONS: Atypical variants of PRES are not so rare and it may also occur in typical triggering situations. The association with ischemic stroke is even rarer and it may add some clues to the pathomechanisms of PRES.

Eclampsia with hypothyroidism complicated with posterior reversible encephalopathy syndrome-a case report.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a rare neurological disorder with complex physiopathological mechanisms that have not been fully understood. Early identification is of great prognostic significance, of which the symptoms and radiological abnormalities can be completely reversed. If the diagnosis and treatment are delayed, ischemia and massive infarction may be developed in some patients. Posterior reversible encephalopathy syndrome (PRES) has been reported mainly in association with postpartum eclampsia, which have been rarely reported, while the association with hypothyroidism has not been reported at home or abroad. CASE PRESENTATION: Here we report on a pregnant 29-year-old with multipara and a chief complication of hypothyroidism. She presented in the emergency department with frequent attacks of severe headache symptoms resulting from reversible cerebral vasoconstriction syndrome (RCVS), accompanied with prenatal eclampsia. PRES was determined by radiological examination. CONCLUSION: To the best of our knowledge, this is the first case of PRES complicated by hypothyroidism and prepartum eclampsia.Clinicians should be alert for the co-occurence of eclampsia, PRES, and RCVS when patients have convulsions after a typical throbbing headache. Moreover, regular monitoring of thyroid function during pregnancy should also occupy certain special attention.

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.

Brainstem and upper cervical cord involvement in a patient with posterior reversible encephalopathy syndrome: Neuro-images.

INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome with acute heterogeneous neurological symptoms. It is usually preceded by hypertension or chemotherapy. Brain magnetic resonance imaging (MRI) shows vasogenic edema over the cortex and subcortex of parieto-occipital lobes. Involvement of the brainstem, basal ganglia, and spinal cord is rare. MATERIAL: Here we described an 18 years old woman with a history of systemic lupus erythematosus who was admitted due seizure and impaired consciousness. She had a mean arterial pressure of 160 and previously received cyclophosphamide. RESULTS: She had a unique involvement of diffuse bilateral asymmetric brain edema over the upper cervical cord, brainstem, cerebellum, thalami, basal ganglia, frontotemporal, and parieto-occipital lobes. She was diagnosed with PRES and after the treatment vasogenic edema vanished completely. CONCLUSION: When it is clinically applicable, physicians should consider PRES as the differential diagnosis of vasogenic edema over the upper cervical cord, cerebellum, and brainstem.

Posterior reversible encephalopathy syndrome triggered by FLOT (5-fluorouracil, oxaliplatin, docetaxel, and calcium levofolinate) chemotherapy and thrombocytopenia (docetaxel and cisplatin) chemotherapy.

INTRODUCTION: Posterior reversible encephalopathy syndrome is a clinical and imaging syndrome characterized by endothelial dysfunction, blood-brain barrier disruption, and vasogenic edema. The common clinical symptoms of posterior reversible encephalopathy syndrome include headache, altered consciousness, visual disturbances, and seizures, among which headache and seizures are the most common. The classic imaging patterns usually reveal vasogenic edema. CASE REPORT: We describe the case of a middle-aged woman with gastric cancer. She was under treatment by fluorouracil, leucovorin, oxaliplatin, and docetaxel regimen and thrombocytopenia regimen after tumor progression, but developed unconsciousness, irritability, and headache shortly after initiation of treatment. Her magnetic resonance imaging in our hospital shows abnormal signals in bilateral frontal parietal occipital lobes with hyperintensities on T2-weighted magnetic resonance imaging and fluid-attenuated inversion recovery imaging, accompanied by the increased value of apparent diffusion coefficient. And T1-weighted images illustrate hypointense foci, with increased diffusion-weighted imaging signals. MANAGEMENT AND OUTCOME: After admission, she was treated to control blood pressure, reduce brain edema, expand blood vessels, improve consciousness, and symptomatic support treatment. 3 days after the onset of the disease, her headache symptoms and state of consciousness gradually improved, and her blood pressure can be controlled at about 130/80 mmHg. DISCUSSION: This is the first report that posterior reversible encephalopathy syndrome is caused by a thrombocytopenia regimen, and our case highlights the pathogenic role of a thrombocytopenia regimen in posterior reversible encephalopathy syndrome. However, the association between the thrombocytopenia regimen and previous fluorouracil, leucovorin, oxaliplatin, and docetaxel regimens needs further study.

Posterior reversible encephalopathy syndrome following cervical spine surgery: insights from an interesting case.

A 14-month child presenting with complaints of spastic paraplegia was diagnosed with C6-D1 intramedullary cyst. A cysto-subarachnoid shunt was performed; the patient was clinically stable in the immediate post-operative period. On post-operative day 2, the patient developed multiple episodes of generalized tonic-clonic seizures (GTCS) with altered sensorium, NCCT head revealed bilateral diffuse parieto-occipital hypodensities. MRI brain showed on T2WI and FLAIR, diffuse hyperintensities in bilateral parieto-occipital region suggestive of posterior reversible encephalopathy syndrome (PRES). The patient never experienced hypertensive episodes and was treated with anti-epileptics. The patient's symptoms improved and repeat MRI after 10 weeks revealed normal signal intensity in bilateral parieto-occipital areas. PRES after spinal surgeries is very rare and more so in pediatric cases, CSF hypotension may contribute to PRES in such cases.

Perfusion-Dependent Focal Neurologic Deficits in a Critically Ill Heart Transplant Recipient: A Case of Tacrolimus-Associated Reversible Cerebral Vasospasm Syndrome?

TACROLIMUS, a mainstay of immunosuppression after orthotopic heart transplantation (OHT), is associated with a broad range of side effects. Vasoconstriction caused by tacrolimus has been proposed as a mechanism underlying common side effects such as hypertension and renal injury. Neurologic side effects attributed to tacrolimus include headaches, posterior reversible encephalopathy syndrome (PRES), or reversible cerebral vasospasm syndrome (RCVS). Six case reports have been published describing RCVS in the setting of tacrolimus administration after OHT. The authors report a case of perfusion-dependent focal neurologic deficits attributed to tacrolimus-induced RCVS in an OHT recipient.

Pediatric posterior reversible encephalopathy syndrome: Age related clinico-radiological profile and neurologic outcomes.

BACKGROUND: The aim of this study was to analyze the characteristics of pediatric posterior reversible encephalopathy syndrome (PRES) to determine clinical and radiologic differences between younger and older age groups, and to identify risk factors for development of any neurologic sequelae. METHODS: The study cohort consisted of confirmed pediatric PRES patients in a tertiary care university hospital from January, 2015, to December, 2020. Demographic and clinical properties, radiological manifestations, and neurologic outcomes were noted. Children aged ≤6 years were compared with those older than 6 years and factors affecting neurologic outcomes were evaluated. RESULTS: The most common underlying diseases were oncological (37%) and kidney diseases (29%). Epileptic seizures were the most frequent symptoms at initial clinical presentation. The regions in the brain that were most commonly involved were the occipital region (n = 65, 96%), the parietal region (n = 52, 77%), and the frontal lobe (n = 35, 54%). Magnetic resonance imaging (MRI) findings were consistent with atypical patterns in most of the study cohort (71%). Patients with unfavorable clinical outcomes (n = 13, 19.1%) had longer initial seizure times and longer encephalopathy times, lower leucocyte and absolute neutrophil counts, and lower neutrophil to lymphocyte ratios. No relationship was found between MRI findings, involvement patterns, and neurologic outcomes. CONCLUSIONS: No clinically specific differences between two different age groups were found. Atypical imaging manifestations of pediatric PRES in our study had an incidence that was as high as those found in earlier adult studies. Multivariate logistic regression analysis showed that the initial neutrophil to lymphocyte ratio, absolute neutrophil counts, and white cell counts could not predict poor neurologic outcomes.

Perfusion Deficits in Patients with Posterior Reversible Encephalopathy Syndrome: a Retrospective, Two-Center Study.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is manifested by acute neurological symptoms in patients with varied predisposing factors and characteristic findings on brain imaging. Cerebrovascular autoregulation is thought to be altered in PRES. However, it remains unclear whether cerebral hypoperfusion or hyperperfusion is the initiating event. We aimed to describe the brain perfusion status in untreated patients with PRES. METHODS: Patients with PRES who underwent cerebral perfusion studies on presentation were retrospectively identified from (1) a prospective database of patients with PRES admitted to Saint Mary's Hospital, Mayo Clinic, Rochester from January 2005 to December 2021 and (2) University of Nebraska Medical Center electronic database from January 2010 to December 2021. Demographics, past medical history, presenting symptoms, cause of PRES, and clinical outcomes were recorded. Brain imaging studies were reviewed. We recorded the location of brain lesions, the time from symptoms onset to perfusion study, blood pressure at the time of the perfusion study, and blood pressure lowering treatments. RESULTS: Five patients (four women, median age 66 years) were included. Causes of PRES were acute hypertension (n = 3), perioperative blood pressure fluctuations, and treatment with pazopanib. Four patients had chronic hypertension. Presenting symptoms were encephalopathy (n = 5), focal neurological symptoms (n = 4), and seizures (n = 2). All patients underwent computed tomography (CT) perfusion performed within 12 h of symptoms onset. All but one patient was hypertensive at the time of CT perfusion. Scans showed diffuse cerebral hypoperfusion, more pronounced in the corona radiata and areas with brain edema. No patient had critical cerebral ischemia or arterial vasoconstriction on CT angiogram. CONCLUSIONS: Patients with PRES can have cerebral hypoperfusion despite severe hypertension. A perfusion study in the acute setting may be helpful to better understand the perfusion status and guide blood pressure treatment.

Ultrasonographic Vasospasm and Outcome of Posterior Reversible Encephalopathy and Cerebral Vasoconstriction Syndromes.

PURPOSE: Posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) are often complicated by vasospasm and ischemia. Monitoring with transcranial color-coded Doppler (TCCD) could be useful, but its role is not established. We studied the incidence of ultrasonographic vasospasm (uVSP) in PRES/RCVS and its relationship with ischemic lesions and clinical outcome. MATERIALS AND METHODS: We conducted a multicenter retrospective study of all patients with PRES/RCVS from 2008 to 2020 who underwent TCCD and magnetic resonance imaging (MRI). TCCD exams were analyzed for uVSP. Diffusion-weighted MRI was analyzed for positive lesions (DWI-positive). Functional outcome was assessed by modified Rankin scale (mRS) at 90 days. The associations with outcomes were determined by logistic regression. RESULTS: We included 80 patients (mean age of 46 (standard deviation, 17) years; 66% females; 41 with PRES, 28 with RCVS and 11 with overlap phenotype). uVSP was detected in 25 (31%) patients. DWI-positive lesions were more often detected in uVSP-positive than uVSP-negative patients (36% vs. 15%; adjusted odds ratio [aOR] 4.05 [95% CI 1.06 - 15.5], P=0.04). DWI-positive lesions were independently associated with worse functional prognosis (mRS 2-6, 43% vs. 10%; aOR, 10 [95% CI 2.6 - 43], P<0.01). Having additional uVSP further increased the odds of a worse outcome (P interaction=0.03). CONCLUSION: Ultrasonographic vasospasm was detected in a third of patients with PRES/RCVS and was associated with brain ischemic lesions. TCCD bedside monitoring can help to stratify patients at risk for cerebral ischemia, a strong predictor of functional outcome.

Posterior reversible encephalopathy syndrome during convalescence from COVID-19.

Background and aim: With an ever-increasing population of patients recovering form severe coronavirus disease 2019 (COVID-19), recognizing long-standing and delayed neurologic manifestations is crucial. Here, we present a patient developing posterior reversible encephalopathy syndrome (PRES) in the convalescence form severe coronavirus disease 2019 (COVID-19).Case presentation: A 61-year-old woman with severe (COVID-19) confirmed by nasopharyngeal real-time reverse transcription-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) required invasive mechanical ventilation 24-hours after admission. During her intensive care unit stay, she developed transient acute kidney injury and septic shock. She was extubated after 22 days. On day 25, she developed generalized tonic-clonic seizures. Magnetic resonance imaging (MRI) of the brain showed bilateral subcortical lesions on the parietal and occipital lobes and multiple micro-and macro-bleeds, consistent with PRES. At this point, RT-PCR for SARS-CoV-2 in a respiratory specimen and cerebrospinal fluid was negative. She was discharged home 35 days after admission on oral levetiracetam. Control MRI five months after discharge showed bilateral focal gliosis. On follow-up, she remains seizure-free on levetiracetam.Conclusions: PRES has been observed before as a neurological manifestation of acute COVID-19; to our knowledge, this is the first PRES case occurring in a hospitalized patient already recovered from COVID-19. A persistent proinflammatory/prothrombotic state triggered by SARS-CoV-2 infection may lead to long-standing endothelial dysfunction, resulting in delayed PRES in patients recovering from COVID-19. With a rapid and exponential increase in survivors of acute COVID-19, clinicians should be aware of delayed (post-acute) neurological damage, including PRES.

Is decompressive craniectomy necessary in malignant posterior reversible encephalopathy syndrome with brain edema caused uncal herniation? A case report of reversible coma without surgical decompression.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is considered a benign entity and is usually reversible with only medical management, but persistent neurologic deficits and disability or death can occur without adequate treatment. Favorable outcomes have been associated with surgical decompression in malignant-type PRES in which hemorrhagic transformation or brain stem compression has developed. CASE DESCRIPTION: Here we report a case of malignant PRES in a 61-year-old female of Asian descent in which the disease rapidly progressed to coma and a near-fatal condition with uncal herniation caused by severe brain edema; however, this patient achieved a dramatic recovery without surgical decompression. CONCLUSION: After reviewing previous reports regarding malignant PRES, we propose that hemorrhagic transformation is a crucial indicator for surgical decompression and an important prognostic factor in malignant PRES.

Posterior reversible encephalopathy syndrome (PRES) in post liver transplantation.

PRES (posterior reversible encephalopathy syndrome) is a neurological condition characterised by epileptic seizures, altered consciousness, visual disturbances and/or headache with typical neuroimaging showing reversible subcortical vasogenic oedema mainly in parieto-occipital regions. The pathophysiological mechanism is not fully understood. We present a clinical case in the field of liver transplantation where tacrolimus neurotoxicity may play a relevant role in the development of this syndrome.

Posterior reversible encephalopathy syndrome in juvenile lupus- a case series and literature review.

INTRODUCTION: PRES, as a complication of juvenile lupus, is rarely reported in the literature. In this study, six juvenile lupus patients admitted with diagnosis of PRES were assessed on the basis of clinical characteristics, imaging findings, disease activity status, treatment response and prognosis. METHODOLOGY: Six juvenile (≤ 16 years) lupus patients with a diagnosis of PRES were included. Demographic, clinical, and laboratory features and outcomes of all six patients were noted. Literature review was performed on PubMed search forum. Search terms in English included Juvenile SLE, Lupus and PRES. RESULT: The youngest patient was seven years old while the oldest was sixteen years. All patients had history of lupus nephritis , presented with seizure and hypertension. In imaging, four out of six patients had hyperintensities in atypical distribution suggesting atypical PRES. All the patients had significant clinical recovery with resolution of hyperintensities in five out of six patients on repeat imaging. CONCLUSION: Juvenile lupus with PRES is considered an unusual neurologic manifestation triggered by multiple factors. It can be stipulated that PRES in juvenile lupus cases often remain undiagnosed. Early suspicion and treatment institution with reversal of triggers can result in a favorable outcome in these patients.

Mepolizumab-Induced Posterior Reversible Encephalopathy Syndrome (PRES), a new patient report.

BACKGROUND: Posterior Reversible Encephalopathy Syndrome (PRES) is a neurotoxic state characterized by seizures, headache, vision change, paresis, and altered mental status. PRES has an important place in medicine due to the wide variety of causative diseases, infections, and medications that precipitate its mysterious onset. Although exposure to medications, particularly immunosuppressants, cancer chemotherapy, and biologic drugs, is a common occurrence in patients who develop PRES, Mepolizumab has never before been associated. CASE PRESENTATION: This report of a 67-year-old male patient outlines the first reported case of Mepolizumab-induced PRES in the literature. CONCLUSIONS: Treatment of severe asthma, asthma-exacerbations, and diseases such as eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss) with Mepolizumab is rapidly gaining popularity ever since the drug's recent FDA-approval. This report aims to raise awareness of this potentially life-threatening and previously unreported side effect of Mepolizumab since early identification of the causative agent is the key to preventing the severe neurologic disability and possible death that may occur from the delayed treatment of PRES.

Cerebral amyloid angiopathy-related inflammation with posterior reversible encephalopathy syndrome-like presentation: a case report.

BACKGROUND: Cerebral amyloid angiopathy-related inflammation (CAA-RI), which presents with acute or subacute cognitive or functional decline, focal or multifocal neurologic deficits, new onset of seizures, or a combination of seizures and neurologic deficits, shares clinical and radiologic similarities with posterior reversible encephalopathy syndrome (PRES). Differential diagnosis is critical because the treatment principle for these 2 conditions differs greatly. Here, we present a case of PRES-like CAA-RI and the strategy used to discriminate between the 2 conditions. CASE PRESENTATION: A patient with probable CAA-RI was first thought to suffer from PRES. Initial high-dose methylprednisolone therapy caused rapid improvement of the neurologic symptoms but abrupt discontinuation of corticosteroids resulted in clinical relapse and deterioration. Subsequent reinitiation of high-dose methylprednisolone followed by tapering off of oral prednisone led to clinical and radiologic recovery at the 3-month follow-up. CONCLUSIONS: We suggest that in cases where it is difficult to distinguish between CAA-RI and PRES solely based on magnetic resonance imaging, a good response to corticosteroids and an apolipoprotein E (ApoE) ε4/ε4 genotype are critical for establishing a diagnosis of CAA-RI. If there is clinical deterioration, sudden withdrawal of high-dose corticosteroid during the active phase of CAA-RI should be avoided.

The pathogenesis and treatment of posterior reversible encephalopathy syndrome after neuromyelitis optica spectrum disorder: a case report and literature review.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a rare disease characterized by reversible subcortical vasogenic brain edema. Neuromyelitis optica spectrum disorder (NMOSD) is a frequent neurological autoimmune disease that is rarely reported to complicate PRES. CASE PRESENTATION: Here, we report a case of neuromyelitis optica (NMO) concurrent with PRES. A 50-year-old woman presented with severe impairment of her health visual acuity, with significantly worsening of the motor weakness in both lower limbs during methylprednisolone therapy after her diagnosis of NMO. MRI showed new-onset brain edematous lesions of the bilateral frontal, occipital, and parietal lobes. PRES was considered. Her vision impairment and weakness of the extremities were alleviated after antihypertensive treatment and dehydration. The edema lesions detected by MRI also completely disappeared. CONCLUSIONS: We reviewed 14 cases of NMO with PRES and concluded that the etiology of NMOSD concurrent PRES may be multifactorial, involving pathogenic IgGs against aquaporin-4 (AQP-4) and immunotherapy treatment. Different underlying pathogeneses require different treatment approaches.

Mesial Temporal Sclerosis as Late Consequence of Posterior Reversible Encephalopathy Syndrome in Pediatric Hemato-oncologic Patients.

OBJECTIVES: Drug resistant epilepsy has rarely been reported following posterior reversible encephalopathy syndrome (PRES), with few cases of mesial temporal sclerosis (MTS). The aim of this study was to report clinical and neuroimaging features of MTS subsequent to PRES in hemato-oncologic/stem cell transplanted children. MATERIALS AND METHODS: Among 70 children treated in 2 pediatric hemato-oncologic Italian centers between 1994 and 2018 and presenting an episode of PRES, we retrospectively identified and analyzed a subgroup of patients who developed epilepsy and MTS. RESULTS: Nine of 70 patients (12.8%) developed post-PRES persistent seizures with magnetic resonance imaging evidence of MTS. One patient died few months after MTS diagnosis, because of hematologic complications; the remaining 8 patients showed unprovoked seizures over time leading to the diagnosis of epilepsy, focal in all and drug resistant in 4. At PRES diagnosis, all patients with further evidence of epilepsy and MTS suffered of convulsive seizures, evolving into status epilepticus in 3. In 3 patients a borderline cognitive level or intellectual disability were diagnosed after the onset of epilepsy, and 2 had behavioral problems impacting their quality of life. CONCLUSIONS: MTS and long-term focal epilepsy, along with potential cognitive and behavioral disorders, are not uncommon in older pediatric patients following PRES.

Risk factors for posterior reversible encephalopathy syndrome in hypertensive pregnant women presenting with seizures.

Pregnant women developing generalised tonic-clonic seizures in the absence of a prior neurological disorder are often diagnosed as eclamptic. Posterior reversible encephalopathy syndrome (PRES) is a distinct neuroimaging condition associated with long-term sequelae, which may occur in pregnancy. Some reports suggested PRES to be the pathophysiological process leading to eclampsia, whereas others observed PRES and eclampsia to have varying clinical severity and risk factors. In this case-control study, risk factors associated with PRES were compared to those for eclampsia in women with hypertension presenting with seizures who had undergone neuroimaging. PRES was noted to occur in 22.5% (51/227) hypertensive pregnant women presenting with seizures that otherwise would have been classified as eclampsia. An additional 51 women with eclampsia underwent neuroimaging. Women who had PRES had higher systolic (155.3 vs 144.5, p = 0.04), diastolic (99.2 vs 93.4, p = 0.006) and mean (117.9 vs 110.4, p = 0.001) blood pressure at admission compared to those with eclampsia. Eclampsia and PRES may occur through a similar pathophysiological mechanism, resulting in the same spectrum of neurological complications of preeclampsia, with PRES being the severest form of the disease process. PRES is difficult to differentiate from eclampsia based on clinical and laboratory investigation, except for high blood pressures, without adjunctive MRI/CT neuroimaging. Future studies should assess the role of biomarkers as well as long-term neurological sequelae in pregnant women with a diagnosis of PRES.