Posterior reversible encephalopathy syndrome, part 1: fundamental imaging and clinical features

The effect of presymptomatic hypertension in posterior reversible encephalopathy syndrome

OBJECTIVE

The effect of blood pressure (BP) on the lesion distribution of posterior reversible encephalopathy syndrome (PRES) is controversial. The aim of this study was to identify the relationship between brain lesion distribution patterns and BP.

METHODS

Sixty-five patients with PRES were selected from the database. Data regarding brain MRI findings, clinical symptoms, medical conditions, and BP at the presymptomatic period (24 hr before the symptom onset) and at the symptom onset were collected. The brain lesion distribution degree was numerically calculated (lesion scoring point [LSP]) and compared with BP and medical conditions.

RESULTS

Mean onset-MAP was higher than mean pre-MAP. Pre-MAP correlated with onset-MAP. The LSP was significantly correlated with pre-MAP (p = 0.009, correlation coefficient [cc] = 0.323), whereas no significant correlation was found between LSP and onset-MAP (p = 0.159, cc = 0.177). Similarly, when patients were grouped by mean MAP values, LSP was significantly higher in the patients with high MAP at the presymptomatic period (p = 0.004), whereas no difference was found in the LSP value between patients with low MAP and high MAP at the symptom onset (p = 0.272).

CONCLUSION

The patient with PRES who has relatively higher BP in the presymptomatic period would be more likely to have wider lesion distribution than the patient with lower BP. BP elevation during presymptomatic period may be a heralding sign of impending PRES and a factor affecting the severity of PRES although BP was not investigated at earlier time points.

Transient cortical blindness in posterior reversible encephalopathy syndrome after postpartum eclampsia

Posterior reversible encephalopathy syndrome (PRES) is a clinical condition that can cause different ophthalmological and neurological symptoms. Preeclampsia toxemia or eclampsia is one of the leading causes of PRES. Herein, we present a study of a 35-year old woman who gave birth to healthy twins at 35 weeks of gestation by cesarean section because of threatened preterm delivery. On the 1^st postoperative day, the woman developed a severe headache, arterial hypertension, tachycardia, generalized tonic-clonic seizures, and loss of consciousness that persisted for about 2 min. A provisional diagnosis of eclampsia was made, and the woman was then quickly transferred to the intensive care unit where she was treated with antihypertensive therapy, magnesium sulphate, and diazepam. Following stabilization of the general condition, the patient noticed sudden bilateral blindness. An ophthalmological examination revealed significant bilateral loss of vision at the level of insecured light perception, normal pupillary responses to a light stimulus, and normal fundus findings. On this basis, an ophthalmologist made the diagnosis to cortical blindness. Radiographic analysis showed an edematous change in the occipital and parietal brain regions, thus suggesting a diagnosis of PRES. In conclusion, cortical blindness is a clinically striking ophthalmic disorder that may occur in PRES associated with postpartum eclampsia.

Imaging neurological emergencies in pregnancy and puerperium

The altered physiologic state of female patients during and just after pregnancy places them at an increased risk for several potentially life-threatening neurologic disorders. Swift diagnosis of such pathology and related complications is critical in order to reduce risk of morbidity and mortality to both the mother and the fetus. Neuroimaging plays an important role in the emergent diagnosis of pathology associated with pregnancy and puerperium, and it is critical for the radiologist to be cognizant of correlative imaging findings. Furthermore, given concerns regarding risks of neuroimaging to the fetus, it is important for the radiologist to act as an informed consultant regarding balancing fetal risks and the mother's health. The purpose of this review is to elucidate the underlying pathophysiology and neuroimaging findings associated with diagnoses that are unique to or highly associated with pregnancy and puerperium, as well as to understand the role that CT and MR play in diagnosis during and just after pregnancy, and their respective risks to the fetus.

Paradoxical hypertension

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome characterized by white matter vasogenic edema affecting the posterior occipital and parietal lobes of the brain predominantly. A 48-year-old female patient presented to ER with complaints of breathlessness and developed sudden painless loss of vision while eliciting history. The patient had a heart rate of 104/min and accelerated hypertension (BP of 220/120 mm of Hg). MRI Brain showed subcortical white matter T2/Fluid-attenuated inversion recovery hyperintensities, suggestive of PRES. The patient regained vision completely over 5 days after nitroglycerin infusion and calcium channel blockers. Beta blocker was started in view of increased BP and anxiety. Blood pressure paradoxically increased from 170/90 mm of Hg to 200/100 mm of Hg. Urine and plasma metanephrines were elevated. Contrast-enhanced computerized tomography abdomen showed locally infiltrative, retroperitoneal mass in left para-aortic prevertebral region diagnosed as paraganglioma. The patient improved with alpha blockers and surgical removal of paraganglioma. 0.1% of hypertensive patients harbor a pheochromocytoma or paraganglioma and its presentation as PRES is very rare.

Posterior Reversible Encephalopathic Syndrome in the Setting of Induced Elevated Mean Arterial Pressure in Patients With Spinal Cord Injury

BACKGROUND AND IMPORTANCE

Acute spinal cord injury (SCI) is managed by avoiding hypotension and elevating mean arterial pressure (MAP) to attain optimal perfusion of the spinal cord. Few studies have been published regarding complications related to this treatment paradigm.

CLINICAL PRESENTATION

Three patients with SCI developed posterior reversible encephalopathic syndrome (PRES) during treatment with intravenous fluids and vasopressors administered to maintain elevated MAPs. All of them experienced temporary elevations well above the standard blood pressure goals for acute SCI and deterioration of neurological status.

CONCLUSION

PRES is a potential complication of elevated MAPs in patients with SCI, particularly if the blood pressure rises above the goals of standard treatment paradigms. The neurosurgical staff should be suspicious of possible PRES early in the course of acute SCI in patients with unexplained neurological decline. This case series is the first report of PRES in patients with acute SCI.

Association between Posterior Reversible Encephalopathy Syndrome and Mycoplasma pneumoniae infection

Mycoplasma pneumoniae is a microbe known to affect numerous organ systems, and in particular, can cause neurological manifestations. We describe an otherwise healthy child who presented with acute onset intractable headache with magnetic resonance imaging (MRI) findings consistent with posterior reversible encephalopathy syndrome (PRES), a neurological manifestation that presents with headache, vision changes, altered mental status, or seizures. Our patient did not have any of the common etiologies for PRES reported but tested positive for acute M. pneumonia infection. The clinical course followed that expected in PRES with rapid resolution of symptoms and MRI findings in subsequent imaging. Literature review shows association between Mycoplasma infection with encephalitis and cerebellitis, but none with PRES in children. Evidence of recent mycoplasma infection in a healthy patient presenting with clinical/radiological findings consistent with PRES, especially in the absence of known predisposing factors, raises the question of M. pneumoniae infection being a trigger for PRES.

Posterior Reversible Encephalopathy Syndrome as a Complication of Induced Hypertension in Subarachnoid Hemorrhage: A Case-Control Study

BACKGROUND

Induced hypertension (IH) remains the mainstay of medical management for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH). However, raising blood pressure above normal levels may be associated with systemic and neurological complications, of which posterior reversible encephalopathy syndrome (PRES) has been increasingly recognized.

OBJECTIVE

To ascertain the frequency and predisposing factors for PRES during IH therapy.

METHODS

We identified 68 patients treated with IH from 345 SAH patients over a 3-yr period. PRES was diagnosed based on clinical suspicion, confirmed by imaging. We extracted additional data on IH, including baseline and highest target mean arterial pressure (MAP), comparing PRES to IH-treated controls.

RESULTS

Five patients were diagnosed with PRES at median 6.6 d (range 1-8 d) from vasopressor initiation. All presented with lethargy, 3 had new focal deficits, and 1 had a seizure. Although baseline MAP (prior to DCI) did not differ between cases and controls, both MAP immediately prior to IH (112 vs 90) and highest MAP targeted were greater (140 vs 120 mm Hg, both P < .01). Magnitude of MAP elevation was greater (54 vs 34 above baseline, P = .004) while degree of IH was not (37 vs 38 above pre-IH MAP). All 4 surviving PRES patients had complete resolution with IH discontinuation.

CONCLUSION

PRES was diagnosed in 7% of SAH patients undergoing IH therapy, most often when MAP was raised well above baseline to levels that exceed traditional autoregulatory thresholds. High suspicion for this reversible disorder appears warranted in the face of unexplained neurological deterioration during aggressive IH.

Posterior Reversible Encephalopathy Syndrome with Status Epilepticus Following Surgery for Lumbar Stenosis and Spondylolisthesis

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic condition encountered in many different clinical settings; it generally occurs in the context of hypertensive crisis, immunosuppressive therapy, or autoimmune diseases. It is characterized by headache, stupor, seizures, and visual alterations. Magnetic resonance imaging findings include white matter changes preferentially in the parieto-occipital regions. Although pathogenesis is not fully elucidated, vasoconstriction and brain hypoperfusion seem to be the cause of brain ischemia and vasogenic edema. Cerebrospinal fluid hypotension is also a reported plausible pathogenic mechanism.

CASE DESCRIPTION

We present a case of PRES following laminectomy and fixation for L4-5 lumbar stenosis and spondylolisthesis. The patient presented with status epilepticus immediately after surgery that lasted 5 days. Brain magnetic resonance imaging showed fluid attenuated inversion recovery and T2 hyperintensities in the bilateral parietal and occipital lobes and external capsules. On the basis of postoperative lumbar images, we hypothesized that an unnoticed cerebrospinal fluid leak might have contributed to development of PRES. The patient developed multiple postoperative complications but ultimately recovered after treatment for severe hypertension and seizures.

CONCLUSIONS

Prompt recognition and treatment of this potentially life-threatening syndrome is necessary to increase the likelihood of favorable outcome. Spinal surgeons need to be aware of the possibility of neurologic deterioration after spinal surgery and be alert about the occurrence of a dural leak, either recognized or unnoticed, as the plausible mechanism triggering PRES.

Posterior reversible encephalopathy syndrome in a pregnant patient without eclampsia or preeclampsia

Posterior Reversible Encephalopathy syndrome (PRES) is a rare neurologic disorder characterised by vasogenic edema in occipital and parietal lobes on MR. Patients usually complain about headache, visual disturbance, seizure and altered mental status. We repot a case of PRES seen in a pregnant patient. Although pre-eclampsia and eclampsia are among the common causes of this syndrome in this case patient was normotensive and no proteinuria was present. To our knowledge this is the first PRES case presented of a pregnant patient without eclampsia or pre-eclampsia.

Posterior reversible encephalopathy syndrome (PRES) in mesenteric leiomyosarcoma: A case report

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a syndrome characterized by headache, confusion, visual loss and seizures. Many factors influence the appearance of this syndrome, predominantly eclampsia, certain medical treatments and malignant hypertension. Diagnosed by typical transient lesions on magnetic resonance imaging.

CASE REPORT

We present a case of mesenteric leiomyosarcoma in a 52 year old woman, who had severe headache, abdominal heaviness, and hypertension. Investigations revealed a mesenteric mass and a Posterior Reversible Encephalopathy Syndrome features on brain MRI, suggesting renin secretion by the tumor, causing the patient's symptoms.

CONCLUSION

Patient's symptoms disappeared after resection of the tumor, suggesting a renin production cessation.

Posterior reversible leukoencephalopathy syndrome (PRES) after kidney transplantation: a case report

INTRODUCTION

Posterior reversible leukoencephalopathy syndrome (PRES) was first described by Hinchey in 1996. The syndrome is characterized by altered level of consciousness, headache, visual changes, and seizures associated with a vasogenic edema of the white matter that occurs predominantly in the occipital and parietal lobes. Imaging tests such as computed tomography (CT) and especially magnetic resonance imaging (MRI) support the diagnosis.

CASE REPORT

We report a case of a 48-year-old female patient who underwent a deceased donor kidney transplant and received tacrolimus as a part of the immunosuppressive regimen. Five weeks after transplantation she was admitted to the emergency due to sudden onset of confusion, disorientation, visual disturbances, and major headache. PRES was suspected and the diagnosis confirmed by brain MRI. Tacrolimus was withdrawn and rapid improvement of the neurological signs occurred leading to the conclusion that this drug triggered the syndrome.

CONCLUSION

PRES is an unusual complication after organ transplantation and should be considered in the appropriate clinical setting. Physicians must be aware of this condition in order to provide early detection and appropriate treatment since delay in removing the cause may lead to permanent sequelae.

First case of neurofibromatosis with posterior reversible encephalopathy syndrome showing spinal cord involvement

Posterior reversible encephalopathy syndrome (PRES) is a well-documented pathology of the brain in systemic upsets. Majority of PRES cases present with edema in the cerebrum, most commonly in the territory of posterior circulation. It has been reported to show spinal cord involvement in a rare subgroup known as PRES with spinal cord involvement (PRES-SCI), with very limited existing literature even in adult patients. Our institution recently encountered a pediatric case with neurofibromatosis type I (NF 1) showing PRES with extensive reversible spinal cord changes. This case illustrates the features of this rare entity in the pediatric group of patients, and is the first reported case in NF 1 patients.

Magnesium Sulfate Treatment Correlates With Improved Neurological Function in Posterior Reversible Encephalopathy Syndrome (PRES): Report of a Case

Posterior reversible encephalopathy syndrome (PRES) is a potentially reversible failure of cerebral autoregulation managed by correction of hypertension or underlying medical condition. Nonresponding cases progress to irreversible brain damage. There is some evidence of association of hypomagnesemia with PRES. We describe a case of nonresolving PRES where use of magnesium sulfate led to improvement in neurological function and eventual recovery. Our case highlights the need for a randomized controlled trial to test the efficacy of magnesium in PRES.

New Developments in Hypertensive Encephalopathy

PURPOSE OF REVIEW

This review summarizes the latest science on hypertensive encephalopathy and posterior reversible encephalopathy syndrome (PRES). We review the epidemiology and pathophysiology of these overlapping syndromes and discuss best practices for diagnosis and management.

RECENT FINDINGS

Diagnosis of hypertensive encephalopathy largely relies on exclusion of other neurological emergencies. We review the extensive causes of PRES and its imaging characteristics. Management strategies have not changed substantially in the past decade, though newer calcium channel blockers simplify the approach to blood pressure reduction. While this alone may be sufficient for treatment of hypertensive encephalopathy in most cases, management of PRES also depends on modification of other precipitating factors. Hypertensive encephalopathy and PRES are overlapping disorders for which intensive blood pressure lowering is critical. Further research is indicated to both in diagnosis and additional management strategies for these critical conditions.

Acute visual loss in a patient with spinal cord injury

Introduction

Patients with spinal cord injury (SCI), especially those with injury at and above T6, are prone to transient episodes of hypertension induced by noxious triggers below the level of SCI, known as autonomic dysreflexia (AD). An uncommonly reported presentation of AD is posterior reversible encephalopathy syndrome (PRES).

Case Presentation

A 50-year-old male with the history of paraplegia from SCI presented with sepsis secondary to baclofen pump and urinary tract infections. On hospital day 4, he developed acute bilateral vision loss. The next morning he had a generalized-tonic-clonic seizure followed by cardiac arrest, with return of spontaneous circulation following resuscitation. Magnetic resonance imaging brain demonstrated multifocal areas of hyperintensity on T2 fluid-attenuated inversion recovery sequence, most pronounced in the occipital lobes. Systolic blood pressures (SBP) were under 180 mmHg throughout hospital stay but above his baseline (SBP 90 mmHg). PRES was diagnosed on the basis of clinical and radiologic evidence. With strict blood pressure (BP) control, there was resolution of visual abnormalities, headaches, encephalopathy, and seizures.

Discussion

Although PRES has been most commonly described in malignant hypertension, it can be seen in patients with normotension or moderate hypertension who have low baseline BPs, such as patients with SCI. These patients are prone to AD due to imbalanced sympathetic outflow to vasculature below the level of injury caused by noxious stimulus. This results in massive regional vasoconstriction leading to an uncontrolled rise in BP above baseline. This episode of PRES could have been prevented by identifying patient's risk, recognizing early signs and potential triggers of AD, and implementing aggressive treatment of the underlying noxious stimuli.

Posterior Reversible Encephalopathy Syndrome: A Rare Childhood Case with Unconsciousness

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a condition characterized by seizures, altered consciousness, visual disturbances, and headache. Characteristic findings on neuroimaging include cerebral edema, typically involving the parieto-occipital white matter. PRES has been associated with hypertension, autoimmune disease, and Henoch-Schölein purpura (HSP), but few cases have been reported, and fewer cases of PRES have been reported in children.

CASE REPORT

We report the case of a 4-year-old girl who presented with blindness and semi-consciousness. The patient had no significant medical history and no abnormalities on physical examination or laboratory testing, although she had slightly elevated blood pressure. After hospitalization, the patient showed some characteristic signs of HSP and cranial magnetic resonance imaging revealed PRES as the cause of semi-consciousness. In our discussion, we examine the clinical features of PRES and remarkable points for the clinical diagnosis and management of this rare but important disease. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although reports of PRES in children are rare, PRES should be considered in the differential diagnosis of children presenting with disturbance of consciousness. Emergency physicians should consult with pediatric physicians to confirm diagnoses of PRES and determine an appropriate treatment plan, given its variable etiology. Measurements of blood pressure, which are often missing in pediatric cases, can help physicians to arrive at a correct diagnosis.

Focal segmental glomerulosclerosis in children complicated by posterior reversible encephalopathy syndrome

An uncommon side effect of cyclosporine A (CsA) use is posterior reversible encephalopathy syndrome (PRES). PRES usually develops because of disturbed capacity of posterior cerebral blood flow to autoregulate an acute rise in blood pressure. We present the case of a 10-year-old girl who was previously diagnosed in our department with focal segmental glomerulosclerosis. She was treated with CsA and developed seizures, progressive loss of consciousness, and visual disturbance on the 7th day of treatment. Brain magnetic resonance imaging showed degeneration of white matter with diffuse demyelination in the parietal and posterior occipital lobes, consistent with the diagnosis of PRES. Cases of PRES reported in children are usually secondary to immunosuppressive therapy in oncological and haematological diseases. Our case is the fifth reported case of focal segmental glomerulosclerosis in children treated with CsA and complicated by PRES. Rapid recognition of PRES and stopping neurotoxic therapy early are essential for a good prognosis.

1.5 Tesla Magnetic Resonance Imaging to Investigate Potential Etiologies of Brain Swelling in Pediatric Cerebral Malaria

The hallmark of pediatric cerebral malaria (CM) is sequestration of parasitized red blood cells in the cerebral microvasculature. Malawi-based research using 0.35 Tesla (T) magnetic resonance imaging (MRI) established that severe brain swelling is associated with fatal CM, but swelling etiology remains unclear. Autopsy and clinical studies suggest several potential etiologies, but limitations of 0.35 T MRI precluded optimal investigations into swelling pathophysiology. A 1.5 T MRI in Zambia allowed for further investigations including susceptibility-weighted imaging (SWI). SWI is an ideal sequence for identifying regions of sequestration and microhemorrhages given the ferromagnetic properties of hemozoin and blood. Using 1.5 T MRI, Zambian children with retinopathy-confirmed CM underwent imaging with SWI, T2, T1 pre- and post-gadolinium, diffusion-weighted imaging (DWI) with apparent diffusion coefficients and T2/fluid attenuated inversion recovery sequences. Sixteen children including two with moderate/severe edema were imaged; all survived. Gadolinium extravasation was not seen. DWI abnormalities spared the gray matter suggesting vasogenic edema with viable tissue rather than cytotoxic edema. SWI findings consistent with microhemorrhages and parasite sequestration co-occurred in white matter regions where DWI changes consistent with vascular congestion were seen. Imaging findings consistent with posterior reversible encephalopathy syndrome were seen in children who subsequently had a rapid clinical recovery. High field MRI indicates that vascular congestion associated with parasite sequestration, local inflammation from microhemorrhages and autoregulatory dysfunction likely contribute to brain swelling in CM. No gross radiological blood brain barrier breakdown or focal cortical DWI abnormalities were evident in these children with nonfatal CM.

Clinical and Imaging Findings in Childhood Posterior Reversible Encephalopathy Syndrome

OBJECTIVE

Posterior reversible encephalopathy syndrome (PRES) is characterized by typical radiologic findings in the posterior regions of the cerebral hemispheres and cerebellum. The symptoms include headache, nausea, vomiting, visual disturbances, focal neurologic deficits, and seizures. The aim of this study is to evaluate the clinical and radiological features of PRES in children and to emphasize the recognition of atypical features.

MATERIALS & METHODS

We retrospectively examined 23 children with PRES from Mar 2010-Apr 2015 in Inonu University Turgut Ozal Medical Center in Turkey. We compared the clinical features and cranial MRI findings between underlying diseases of PRES.

RESULTS

The most common precipitating factors were hypertension (78.2%) and medications, namely immunosuppressive and antineoplastic agents (60.8%). Manifestations included mental changes (100%), seizures (95.6%), headache (60.8%), and visual disturbances (21.7%) of mean 3.6 (range 1-10) days' duration. Cranial magnetic resonance imaging (MRI) showed bilateral occipital lesions in all patients, associated in 82.6% with less typical distribution of lesions in frontal, temporal or parietal lobes, cerebellum, corpus callosum, basal ganglia, thalamus, and brain stem. Frontal involvement was predominant, observed in 56.5% of patients. Clinical recovery was followed by radiologic resolution in all patients.

CONCLUSION

PRES is often unsuspected by the clinician, thus radiologists may be the first to suggest this diagnosis on an MRI obtained for seizures or encephalopathy. Atypical MRI finding is seen quite often. Rapid diagnosis and treatment are required to avoid a devastating outcome.

Controversy of posterior reversible encephalopathy syndrome: what have we learnt in the last 20 years?

Over two decades have passed since posterior reversible encephalopathy syndrome (PRES) was first described in 1996. It has becoming increasingly recognised because of improved and more readily available imaging modality. The exact pathophysiological mechanism is not completely understood and remains controversial at present. Precise diagnosis is essential to guide prompt, proper management. Our ability of differentiating it from other acute neurological disorders is likely to improve as we learnt more about the spectrum of this entity in the last 20 years. We emphasise the importance of recognising its diagnostic criteria and biomarker, which would be of great relevance to either outcome evaluation or study design. PRES has a favourable prognosis generally, but neurological sequelae and even fatalities can occur, especially in severe forms that might cause substantial morbidity and even mortality, particularly when the syndrome is complicated by intracranial haemorrhage or brain infarction. In this review, the pathophysiology, approach to diagnosis, some controversies as to the prognosis, as well as the future research direction of PRES are described.

Posterior Reversible Leukoencephalopathy Syndrome (PRES) in Intensive Care Unit - Case series

Introduction:

Posterior reversible encephalopathy syndrome (PRES) is characterized by a range of clinico neuro radiological manifestation along with hypertension due to varied etiology. Contrary to its name, a small number of patients have residual neurological deficits. Patients with severe manifestation of PRES may get admitted to the Intensive Care Unit (ICU) due to coma or status epilepticus. Small case series and large multicenter studies have been reported.

Materials and Methods:

We report a single center series of ten cases admitted to ICU over a 5 year period in a tertiary care centre. We retrospectively analyzed patients, admitted to adult ICU with different etiologies, and diagnosed to have PRES. Outcome at discharge and at 90 days after ICU admission was noted.

Result:

The most common etiologies were medications. ICU admissions were mainly for uncontrolled hypertension, seizures, and low level of consciousness. All except one patient were ventilated. Four patients had residual neurological damage.

Conclusion:

Irrespective of the etiology, early control of blood pressure, and removal of precipitating factors is of paramount importance to prevent morbidity and mortality. Awareness about PRES among the intensivist is necessary to ensure early recognition and treatment.

Anti-Angiogenic Tyrosine Kinase Inhibitors and Reversible Posterior Leukoencephalopathy Syndrome: Could Hypomagnesaemia Be the Trigger?

Reversible posterior leukoencephalopathy syndrome (RPLS), also known frequently as posterior reversible encephalopathy syndrome (PRES), is a characteristic acute neuro-radiology syndrome with clinical presentation that typically includes acute hypertension, seizures and other neurological symptoms and signs. Many patients with RPLS have (a history of) pre-existing hypertension and in receipt of diuretics. It is being diagnosed more frequently and in association with an increasing number of morbidities and medications. Drugs most frequently implicated are immunosuppressant drugs and anticancer agents, including a number of anti-angiogenic tyrosine kinase inhibitors (TKIs). Hypomagnesaemia is a frequent finding at presentation in RPLS patients, which is known to lead to or aggravate hypertension. Pre-eclampsia, a variant of RPLS, responds effectively to intravenous magnesium. Cyclosporin, tacrolimus and some TKIs that induce RPLS are also known to give rise to both hypertension and hypomagnesaemia. This raises an interesting hypothesis that hypomagnesaemia may play a contributory role in triggering RPLS in some patients by acutely raising the blood pressure further. Additional systematic studies are required to test this hypothesis. If the hypothesis is confirmed, hypomagnesaemia offers an effective target for risk mitigation and prevention of RPLS in patients identified at risk.

Neuroradiologic Pearls for Neuro-oncology

PURPOSE OF REVIEW

This article reviews key principles in the identification of tumors of the central nervous system (CNS) using standard and advanced imaging modalities. This article highlights the pitfalls and pearls of the imaging evaluation of patients with cancer at time of diagnosis and during cancer therapy and discusses the challenges of the imaging evaluation of treatment-related toxicities.

RECENT FINDINGS

Treatment of CNS tumors with surgery, chemotherapy, or radiation alters the imaging appearance of the tumor and can be associated with a variety of treatment-related toxicities. The clinician must be familiar with how to assess response to treatment and how to differentiate tumor progression from treatment-related effects.

SUMMARY

Management and follow-up of neuro-oncology patients is optimized by a comprehensive radiologic approach to CNS tumors and recognition of the challenges in the assessment of response to treatments.

Stroke-like migraine attacks after radiation therapy syndrome: Case report and review of the literature

A 26-year-old female presented with vision loss accompanied by migraine-like headaches. A contrast-enhanced magnetic resonance imaging of the brain was performed which revealed findings suggestive of stroke-like migraine attacks after radiation therapy (SMART) syndrome. SMART syndrome is a delayed complication of brain radiation characterized by neurologic symptoms including migraine-like headaches, seizures, and hemispheric impairment. The purpose of this article is to make the readers aware of this rare complication of brain irradiation. Appropriate diagnosis of SMART syndrome is essential to avoid invasive tests.

Stroke-like migraine attacks after radiation therapy: A misnomer?

OBJECTIVE

To understand the frequency of electrographic and clinical seizures in patients with stroke-like migraine attacks after radiation therapy (SMART), and determine whether SMART warrants comprehensive electroencephalographic (EEG) monitoring and aggressive seizure management.

METHODS

We searched our magnetic resonance brain imaging report database for all patients between January 2013 and December 2015 for suspected SMART syndrome. Clinical inclusion criteria were further applied as follows: inpatient adults (>18 years of age) with history of cranial radiation presenting with acute neurologic deficits as primary admission reason who lacked evidence of recurrent or new brain malignancy, stroke, or infectious agents in cerebrospinal fluid. Six patients were identified. All 6 patients underwent prolonged video EEG monitoring as part of our standard protocol.

RESULTS

All patients but 1 were found to have multiple or prolonged electrographic seizures consistent with status epilepticus during video EEG monitoring. Their neurological deficit and/or mental status change improved in parallel with resolution of the seizure activity.

SIGNIFICANCE

SMART is likely a misnomer that underestimates the significance of seizures and status epilepticus in the pathophysiology and clinical presentation of the syndrome. Systematic continuous EEG monitoring and appropriate seizure management is warranted to reduce symptom duration and optimize clinical outcome.

[Maternal death by stroke. Results from the French enquiry into maternal deaths, 2010-2012]

Stroke is a rare event during pregnancy (10/100,000) and can be ischemic (24%), hemorrhagic (74%) or both (2%). Pregnancy probably increases the risk even if it is discussed for arteriovenous malformation (AVM), aneurismal subarachnoid hemorrhage (SAH) and cavernomas. Between 2010 and 2012, 31 maternal deaths were associated with stroke. In 22 cases, stroke was the direct cause of death giving a maternal mortality ratio of 0,9/100,000 witch is not different from the former report (2007-2009). There were 2 cerebral thrombophlebitis, 2 ischemic strokes and 18 hemorrhagic strokes (4 SAH, 2 AVM). These deaths occurred during ongoing pregnancy in 5 cases (25%), after miscarriage in 1 case (5%) and in the post-partum period in 14 cases (70%). In this last situation, stroke occurred before delivery in 4 cases and during the post-partum period in 9 cases (1 to 9 days) (1 unknown). There were 7 vaginal deliveries (50%) and 6 emergency cesarean sections (43%) (1 unknown). Most of those deaths were considered to be unavoidable (13/17, 76%). Four deaths were considered by the experts as being possibly avoidable (delay diagnosis, diagnostic error, inadequate treatment, lake of interruption of the pregnancy). Analyzing those deaths remind that any sudden, severe and unusual headache must be explored and that pregnancy does not contraindicate any of the diagnostic examinations (TDM, angio-TDM, MRI) or invasive treatments (surgery, arterio-embolization, fibrinolysis) necessary for its management. Furthermore, the diagnosis of postdural puncture headache should not be establishedwithout imaging when the symptomatology is not absolutely typical.

Reversible brain lesion following growth hormone replacement therapy in an adolescent

A 12.6-year-old girl presented with a 2-month history of headache, recurrent vomiting and 5 kg weight loss. She had been receiving recombinant human growth hormone (rhGH) replacement therapy at a dose of 0.035 mg/kg for the past 10 months, due to short stature. Investigations before initiating rhGH, including brain MRI, had been normal. Physical examination revealed a nystagmus and a mildly elevated arterial blood pressure. Brain MRI revealed a lesion in the posterior aspect of the medulla oblongata, adjacent to the foramen of Magendie. rhGH therapy was discontinued, followed by a gradual resolution of the symptoms. At follow-up 3 months later, she was asymptomatic and physical examination was unremarkable. A subsequent repeat brain MRI showed complete resolution of the lesion, supporting the diagnosis of a variant of reversible posterior leucoencephalopathy syndrome. This is the first case report of a reversible brain lesion linked to rhGH replacement therapy.

Neurologic complications after allogeneic hematopoietic stem cell transplantation: risk factors and impact

Neurologic complications (NCs) may be a significant source of morbidity and mortality after hematopoietic cell transplantation (HCT). We performed a retrospective study of 263 consecutive patients undergoing allogeneic HCT for hematological malignancies to determine the incidence, risk factors and clinical impact of NCs in the first 5 years after HCT. We determined the incidence of central nervous system (CNS) infection, intracranial hemorrhage, ischemic stroke, metabolic encephalopathy, posterior reversal encephalopathy syndrome, seizure and peripheral neuropathy. In all, 50 patients experienced 63 NCs-37 early (⩽day +100), 21 late (day +101 to 2 years) and 5 very late (2 to 5 years). The 1- and 5-year cumulative incidences of all NCs were 15.6% and 19.2%, respectively, and of CNS complication (CNSC; all of the above complications except peripheral neuropathy) were 12.2 and 14.5%. Risk factors for CNSC were age (hazard ratio (HR)=1.06 per year, P=0.0034), development of acute GvHD grade III-IV (HR=2.78, P=0.041), transfusion-dependent thrombocytopenia (HR=3.07, P=0.025) and delayed platelet engraftment (>90th centile; HR=2.77, P=0.043). CNSCs negatively impacted progression-free survival (HR=2.29, P=0.0001), overall survival (HR=2.63, P<0.0001) and non-relapse mortality (HR=8.51, P<0.0001). NCs after HCT are associated with poor outcomes, and usually occur early after HCT.

Calcineurin inhibitor-free strategies for prophylaxis and treatment of GVHD in children with posterior reversible encephalopathy syndrome after stem cell transplantation

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a distinct clinico-radiologic entity that can occur following allogeneic hematopoietic stem cell transplantation, often in the context of treatment with calcineurin inhibitors (CNIs).

PROCEDURE

We describe the results of CNI-free management of 14 children with PRES and review the clinical and radiologic manifestations of their presentation.

RESULTS

Discontinuation of CNIs usually resulted in remission of PRES, but patients with established graft versus host disease (GVHD) at the time when treatment was changed often experienced progressive GVHD despite administration of immune suppressive and modulating treatments. All but three patients experienced full neurologic recovery. Nine children died as a result of either GVHD, disease relapse, or severe infection.

CONCLUSIONS

Discontinuation of CNIs results in neurologic improvement in most cases, but superior alternative immune modulatory treatment is needed to prevent progression of established GVHD.

Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome associated with intracranial hypotension

BACKGROUND

Reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) are both rare disorders. The pathophysiology of both diseases is not yet fully understood.

METHODS

We report the unique case of a 19-year-old comatose woman who was brought to the ER after a series of generalized tonic-clonic seizures 6 days post peridural anesthesia for cesarean section. Vital signs and initial laboratory testing including urine analysis and drug screening were unremarkable. Initial cranial CT scan showed an acute small subdural hematoma (17 mm length × 6 mm width × 30 mm height), cerebral edema with slit ventricles, and slight cerebellar tonsillar herniation as signs of intracranial hypotension. CT angiography depicted narrowing of the proximal intracranial vessels consistent with RCVS. MR imaging was also suggestive of both intracranial hypotension and RCVS and showed, in addition, vasogenic edema consistent with PRES. An extensive CSF leakage involving T1 to L2/L3 was confirmed by spinal MRI.

RESULTS

The patient underwent conservative therapy for intracranial hypotension (e.g., head-down position) as well as epidural blood patch, which led to regression of the clinical symptoms within a few days. Follow-up MRI showed complete resolution of all radiological changes.

CONCLUSIONS

In summary, our patient developed clinical and neuroradiological signs of intracranial hypotension and a combination of PRES and RCVS associated with a CSF leakage caused by peridural anesthesia; by treating the intracranial hypotension, the other syndromes resolved. From a clinical point of view, it is important to look for CSF leakage as a treatable possible cause of PRES and/or RCVS triggered by intracranial hypotension as in our patient postpartum. Moreover, it is vital to obtain a good history as, in cases of suspected CSF leakage with classic postural headache, a recent spinal/cranial procedure is typically present.

An atypical subacute presentation of posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) characteristically presents with rapid onset of headache, seizure, encephalopathy, and visual changes, along with evidence of parieto-occipital vasogenic edema on magnetic resonance imaging. We describe the case of a 41-year-old female with a protracted presentation of two of the four classic PRES symptoms, which were not immediately recognized as PRES due to the presence of multiple other comorbidities and reasons for encephalopathy. This case highlights the possibility of atypical presentations of PRES and the diagnostic challenges in making this clinical diagnosis when competing diagnoses are present.

Imaging spectrum of immunomodulating, chemotherapeutic and radiation therapy-related intracranial effects

OBJECTIVE

A wide range of treatment-related side effects result in specific neurologic symptoms and signs and neuroimaging features. Even to the most seasoned neuroradiologist, elucidating therapy-related side effects from other common mimics can be challenging. We provide a pictorial survey of some common and uncommon medication-induced and therapy-related neuroimaging manifestations, discuss pathophysiology and common pitfalls in imaging and diagnosis.

METHODS

A case-based review is utilized to depict scenarios on a routine basis in a general radiology or neuroradiology practice such as medication-induced posterior reversible encephalopathy syndrome to the more challenging cases of pseudoprogression and pseudoregression in temozolmide and bevacizumab therapy in gliobastoma treatment protocols.

CONCLUSION

Knowledge of the treatment-induced imaging abnormalities is essential in the accurate interpretation and diagnosis from the most routine to most challenging of clinical situations. We provide a pictorial review for the radiologist to employ in order to be an invaluable provider to our clinical colleagues and patients.

Central nervous system complications after allogeneic hematopoietic stem cell transplantation

Allogenic hematopoietic stem cell transplant (alloSCT) is a potentially curative modality of treatment for patients with hematological malignancies. However, CNS complications following transplant pose a risk to survival of the patients. Early recognition and management of these complications are crucial to reduce morbidity and mortality of patients following transplant. Early CNS complications associated with alloSCT are infection, cerebrovascular events, chemotherapy and radiation-induced toxicities while late complications include post-transplant lymphoproliferative disorder, CNS relapse of underlying malignancy and viral and fungal infections. Development of graft-versus-host disease can further increase the risk of CNS complications and outcomes after alloSCT. Strategies aimed to reduce the risk of CNS complications and early management may ameliorate the morbidity and mortality in transplant recipients.

Bilateral Occipital Lobe Hemorrhages Presenting as Denial of Blindness in Posterior Reversible Encephalopathy Syndrome- A Rare Combination of Anton Syndrome and Encephalopathy

Posterior reversible encephalopathy syndrome (PRES) or reversible posterior leukoencephalopathy (RPL) is an acute neurological syndrome characterized by the development of radiological abnormalities on brain imaging along with clinical manifestations, such as a headache, seizures, encephalopathy, etc. We report the case of a middle-aged male who presented to the emergency department after he woke up with complete blindness and was found to have hemorrhagic PRES. Intracranial hemorrhages were seen in around 15% of patients who presented with this condition. In this article, we review the different types of hemorrhages seen in the setting of PRES and their associations.

Oxaliplatin-induced posterior reversible encephalopathy syndrome (PRES)

Posterior reversible encephalopathy syndrome (PRES), first introduced in 1996, is a neurotoxic state characterised by seizures, headache, vision change, paresis, nausea and altered mental status. Risk factors include hypertension, eclampsia/pre-eclampsia, infection/sepsis and cancer chemotherapy. Although exposure to toxic agents is a common occurrence in patients who develop PRES, oxaliplatin has rarely been associated with it, with only 10 cases reported worldwide. We present the case of an oxaliplatin-induced PRES in a 23-year-old male patient who was started on oxaliplatin/capecitabine as adjuvant chemotherapy for anal canal adenocarcinoma. The patient developed symptoms of headache, slurred speech and left-sided facial weakness on the ninth day after the first dose of oxaliplatin that lasted for 6-8 hours. The patient experienced another episode next day with similar symptoms that lasted for 8 hours. Oxaliplatin was withheld and the patient was discharged on capecitabine only. The patient had no new episodes since discharge on follow-up.

Perioperative Vision Loss after Non-Ocular Surgery

Perioperative vision loss (POVL) may cause devastating visual morbidity. A prompt anatomical and etiologic diagnosis is paramount to guide management and assess prognosis. Where possible, steps should be undertaken to minimize risk of POVL for vulnerable patients undergoing high-risk procedures. We review the specific risk factors, pathophysiology, and management and prevention strategies for various etiologies of POVL.

The imaging spectrum of posterior reversible encephalopathy syndrome: A pictorial review

Posterior reversible encephalopathy syndrome (PRES) is characterized by the acute onset of neurologic symptoms (headache, altered mental status, visual changes, seizures) with accompanying vasogenic edema on brain imaging. Risk factors for PRES include infection, uremia, malignancy, autoimmune disorders, the peripartum state and hypertension. PRES is classically described as being posterior (i.e. parieto-occipital) but radiologic variants are increasingly recognized. This pictorial review demonstrates the heterogeneity of the different radiologic presentations of PRES in reference to lesion distribution, hemorrhage, diffusion restriction, contrast enhancement, and other associated findings.

A Case of Familial Hemophagocytic Lymphohistiocytosis Type 4 With Involvement of the Central Nervous System Complicated With Infarct

BACKGROUND

Familial hemophagocytic lymphohistiocytosis (HLH) is a fatal disease affecting infants and very young children. Central nervous system involvement of HLH can cause catastrophic results.

METHOD

We present a case with cranial involvement of familial HLH type 4 who showed diffuse infiltration of white matter complicated with intracranial thrombosis. A 5-year-old girl from a consanguineous couple presented with fever and pancytopenia, and was referred to our hematology unit. Examination revealed fever, lymphadenopathy, and hepatosplenomegaly. Ultrasound examination revealed hepatosplenomegaly and free intra-abdominal fluid. HLH was revealed on bone marrow aspiration biopsy. Defective natural killer and T lymphocyte cytotoxicity using degranulation tests was determined. In the genetic analysis, syntaxin gene mutation was found. On T2-weighted and T2-fluid-attenuated inversion recovery magnetic resonance imaging (MRI), diffuse hyperintense signal changes of cerebral white matter, indicating white matter demyelination, were observed. A second brain MRI showed an acute infarct involving the left temporooccipital region. Immunosuppressive therapy according to the HLH 2004 protocol was started. The infarct resolved but white matter lesions were stable on the brain MRI that was performed 1 month later. Brain MRI taken 4 months after the first examination showed stable cerebral white matter lesions, but hyperintense signal changes appeared in the cerebellar white matter and were regarded as progression. The patient died because of infection despite immunosuppressive therapy.

CONCLUSIONS

Physicians managing patients with HLH must be vigilant about the possibility of central nervous system involvement including stroke.

Dengue encephalopathy: very unusual neuroimaging findings

Neuroimaging, in many patients with dengue encephalopathy, may reveal periventricular signal changes. We report a 25-year-old man, who presented with altered sensorium. Dengue-IgM test in serum was positive. Cerebrospinal fluid examination was normal. MRI brain revealed presence of bilateral parieto-occipital intraparenchymal bleed with mass effect. Neuroimaging was consistent with posterior reversible encephalopathy syndrome. We report posterior reversible encephalopathy syndrome in a normotensive patient with dengue encephalopathy and systemic metabolic alterations.