Atypical imaging findings in a near-fatal case of posterior reversible encephalopathy syndrome in a child

Developmental anatomy of the thalamus, perinatal lesions, and neurological development

The thalamic nuclei develop before a viable preterm age. GABAergic neuronal migration is especially active in the third trimester. Thalamic axons meet cortical axons during subplate activation and create the definitive cortical plate in the second and third trimesters. Default higher-order cortical driver connections to the thalamus are then replaced by the maturing sensory networks, in a process that is driven by first-order thalamic neurons. Surface electroencephalographic activity, generated first in the subplate and later in the cortical plate, gradually show oscillations based on the interaction of the cortex with thalamus, which is controlled by the thalamic reticular nucleus. In viable newborn infants, in addition to sensorimotor networks, the thalamus already contributes to visual, auditory, and pain processing, and to arousal and sleep. Isolated thalamic lesions may present as clinical seizures. In addition to asphyxia and stroke, infection and network injury are also common. Cranial ultrasound can be used to classify neonatal thalamic injuries based on functional parcelling of the mature thalamus. We provide ample illustration and a detailed description of the impact of neonatal focal thalamic injury on neurological development, and discuss the potential for neuroprotection based on thalamocortical plasticity.

Imaging of Reversible Cerebral Vasoconstriction Syndrome and Posterior Reversible Encephalopathy Syndrome

PRES and RCVS are increasingly recognized due to the wider use of brain MRI and increasing clinical awareness. Imaging plays a crucial role in confirming the diagnosis and guiding clinical management for PRES and RCVS. Imaging also has a pivotal role in determining the temporal progression of these entities, detecting complications, and predicting prognosis. In this review, we aim to describe PRES and RCVS, discuss their possible pathophysiological mechanisms, and discuss imaging methods that are useful in the diagnosis, management, and follow-up of patients.

Etiologies, Cerebral Vasomotion, and Endothelial Dysfunction in the Pathophysiology of Posterior Reversible Encephalopathy Syndrome in Pediatric Patients

The posterior reversible encephalopathy syndrome was characterized by Hinchey and colleagues in the 1990s. The condition frequently afflicts patients suffering from hematologic and solid organ malignancy and individuals undergoing transplantation. Cases are more frequently described in the adult population compared with children. In the pediatric population, malignancy, transplantation, renal disease, and hypertension represent the most common etiologies. Theories on pathogenesis have centered upon cerebrovascular dysautoregulation with increases in blood–brain barrier permeability. This generates vasogenic edema of the cerebral parenchyma and consequent neurologic deficits. The parietal and occipital lobes are affected with greatest prevalence, though frontal and temporal lobe involvement is frequent, and that of the contents of the infratentorial posterior cranial fossa are occasionally described. The clinical presentation involves a characteristic constellation of neurologic signs and symptoms, most typically inclusive of headache, visual-field disturbances, abnormalities of visual acuity, and seizures. Supportive care, withdrawal of the offending agent, antihypertensive therapy, and prophylactic anticonvulsants affect convalescence in majority of cases. The principal challenge lies in identifying the responsible agent precipitating the condition in patients with malignancy and those having undergone transplantation and thus deciding which medication among a multidrug treatment regimen to withhold, the duration of drug cessation required to effect clinical resolution, and the safety of resuming treatment with the compound. We accordingly reviewed and evaluated the literature discussing the posterior reversible encephalopathy syndrome in children.

Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome: Distinct Clinical Entities with Overlapping Pathophysiology

The clinical and radiologic manifestations of posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome are reviewed. The relationship between these entities is discussed. A hypothesis of a common underlying pathophysiology is proposed and substantiated based on the current medical literature.

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

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

Posterior reversible encephalopathy syndrome with lumbar drainage and surgery: coincidence or correlation? A case report

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a rare neurological disorder usually associated with specific medical conditions that cause a disturbance of the CNS homeostasis. It has seldom been reported to be a consequence of an iatrogenic intervention causing intracranial hypotension.

CASE PRESENTATION

We report the case of an individual 69-year-old male presenting with headache and blurred vision following cerebrospinal fluid (CSF) leak from resection of a sellar mass. The patient developed the condition following removal of the lumbar drain post-operatively. Magnetic Resonance Imaging showed bilateral occipital, parieto-occipital, and cerebellar T2 FLAIR hyper-intensities, suggesting a radiological diagnosis of posterior reversible encephalopathy syndrome (PRES). The patient's symptoms started to improve shortly afterwards and had completely resolved at 3 months follow-up.

CONCLUSIONS

The absence of severe hypertension and presence of an intraoperative CSF leak requiring placement of the lumbar drain suggests that decreased CSF volume and associated reactive hyperemia could have a role in the pathophysiology of the disease.

Acute Kidney Injury, Recurrent Seizures, and Thrombocytopenia in a Young Patient with Lupus Nephritis: A Diagnostic Dilemma

Introduction. Posterior reversible encephalopathy syndrome (PRES) is a constellation of clinical and radiologic findings. Fluctuations in blood pressure, seizures, and reversible brain MRI findings mainly in posterior cerebral white matter are the main manifestations. PRES has been associated with multiple conditions such as autoimmune disorders, pregnancy, organ transplant, and thrombotic microangiopathy (TMA). Case Presentation. A 22-year-old woman with history of Systemic Lupus Erythematous complicated with chronic kidney disease secondary to lupus nephritis class IV presented with recurrent seizures and uncontrolled hypertension. She was found to have acute kidney injury and thrombocytopenia. Repeat kidney biopsy showed diffuse endocapillary and extracapillary proliferative and membranous lupus nephritis (ISN-RPS class IV-G+V) and endothelial swelling secondary to severe hypertension but no evidence of TMA. Brain MRI showed reversible left frontal and parietal lesions that resolved after controlling the blood pressure, making PRES the diagnosis. Conclusion. PRES is an important entity that must be recognized and treated early due to the potential reversibility in the early stages. Physicians must have high suspicion for these unusual presentations. We present a case where performing kidney biopsy clinched the diagnosis in our patient with multiple confounding factors.

Prognostic factors in children with PRES and hematologic diseases

OBJECTIVES

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity characterized by focal neurological signs, headache, confusion, and seizure, associated with transitory lesions in the posterior areas of the brain detectable with neuroimaging. Among children, one of the most common causes of PRES is cancer.

MATERIALS AND METHODS

In this review, we present the cases of 5 children developing PRES after stem cell transplantation for hematological disease and review all the cases reported in English literature to investigate outcomes and associated risk factors.

RESULTS

One hundred and eleven cases were reported. Hypertension was very frequent (80%). Clinical features included seizures (80.1%), headache (44.1%), visual disturbance (26.1%), and mental change (48.6%). EEG was abnormal in 27 of 32 patients. MRI revealed characteristic lesions in all patients even in early stages. Abnormal MRI findings in late stages were associated with neurological sequelae. Nineteen patients died (17.1%) of which 2 of PRES. Among alive patients, 17 had neurological sequelae. Four cases of PRES relapse were described.

CONCLUSIONS

Thus, all transplant recipients with symptoms consistent with PRES should be promptly recognized to avoid long-term complications or even death.

Life-threatening complications of posterior reversible encephalopathy syndrome in children

BACKGROUND

Although the posterior reversible encephalopathy syndrome (PRES) is considered to have a benign clinical outcome, the presentation of PRES can be associated with life-threatening complications such as severe cerebral hemorrhage, cerebellar herniation and refractory status epilepticus (SE). The aim of this paper is to report incidence, clinical features and outcome of life-threatening complications related to PRES in children.

METHODS

Patients who suffered from life-threatening complications were retrospectively identified from a group composed by 27 consecutive children diagnosed with PRES in our hospital between 2000 and 2012. The clinical, radiological and EEG features and the outcome of these patients were evaluated and compared to the characteristics of patients with no complications.

RESULTS

Five patients (18%) presented life-threatening complications: 2 cerebral hemorrhages with mass effect and midline shift (1 massive intraparenchymal hemorrhage and 1 subdural hemorrhage and intraparenchymal hemorrhage), 2 transforaminal cerebellar herniations and 1 refractory SE. Two children died because of complications and 2 children required urgent neurosurgical intervention. The infratentorial involvement at onset of PRES and the observation of focal neurological deficits other than visual disturbances were significantly more frequent in children with life-threatening complications (p < 0.01).

CONCLUSIONS

PRES is associated with a non-negligible incidence of life-threatening complications. A careful clinical, neuroradiological and EEG monitoring is necessary in order to improve the outcome especially in the case of focal neurological deficits and infratentorial involvement.

Posterior reversible encephalopathy syndrome

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

Isolated posterior fossa involvement in posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible vasogenic edema affecting the subcortical white matter of bilateral occipital and parietal lobes. We describe a case of isolated posterior fossa involvement of PRES which occurred during remission induction chemotherapy for T-cell acute lymphoblastic leukemia. Both the brainstem and cerebellum were extensively involved, but the supratentorial structures were completely spared. The follow-up magnetic resonance images revealed reversibility of most lesions. The knowledge of atypical radiological features of PRES is essential for prompt diagnosis.

Severe posterior reversible encephalopathy syndrome resolved with craniectomy

Posterior reversible encephalopathy syndrome (PRES) has been thought to be a benign disease, but recently severe cases have been reported with increasing recognition. A 3-year-old girl with congenital nephrotic syndrome had rapidly progressed to coma. Computed tomography (CT) of the head showed striking swelling of the brainstem and transtentorial herniation. Emergency decompressive craniectomy was performed. Consecutively, blood pressure was optimally controlled. The patient gradually recovered to the previous state before onset of PRES. Rapid improvement of clinical symptoms and rapid resolution of abnormal findings on serial CT led to diagnosis of PRES. In severe PRES with unstable vital signs, surgical intervention should be considered as well as appropriate blood pressure management.

Childhood posterior reversible encephalopathy syndrome

Posterior Reversible Encephalopathy Syndrome (PRES) is a clinicoradiologic syndrome characterised clinically by headaches, altered consciousness, visual disturbances and seizures and radiological changes which can resolve. However left untreated it can be fatal and not all cases are reversible. It can occur in many settings, the most common being hypertensive crisis. We discuss the clinical and radiological features of this increasingly diagnosed condition among children and current thinking on its pathogenesis. A brief case is used to highlight the variable presentation of PRES. PRES is often unsuspected by the clinician and radiologists may be first to suggest the diagnosis. Accurate assessment including blood pressure measurement, appropriate imaging and rapid treatment is required to avoid a devastating outcome.

Neuropathology of a fatal case of posterior reversible encephalopathy syndrome

The pathology of posterior reversible encephalopathy syndrome (PRES) is undefined, since it is rarely fatal and is biopsied in only exceptional circumstances. We describe rapidly progressive PRES following stem cell transplant for acute lymphoblastic leukemia. After development of altered mental status, this 8-year-old girl had T2 prolongation of the white matter in a posterior-dominant distribution, eventually developing cerebellar edema, hemorrhage, hydrocephalus, and herniation. Despite surgical and medical management, she died 36 hours later. At autopsy, the occipital and cerebellar white matter and focal occipital cortical gray matter showed a spectrum of microvascular changes, including dilated perivascular spaces containing proteinaceous exudates and macrophages, as well as fibrinoid necrosis and acute hemorrhage, in a distribution corresponding to the neuroimaging abnormalities and reminiscent of those seen in patients with acute hypertensive encephalopathy. Of note, similar microvascular changes were not seen in the kidney or other systemic sites. Thus, the findings indicate a brain-specific microvascular compromise as the substrate of PRES, at least in the rare instance of cases progressing to fatal outcome.

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

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state coupled with a unique CT or MR imaging appearance. Recognized in the setting of a number of complex conditions (preeclampsia/eclampsia, allogeneic bone marrow transplantation, organ transplantation, autoimmune disease and high dose chemotherapy) the imaging, clinical and laboratory features of this toxic state are becoming better elucidated. This review summarizes the basic and advanced imaging features of PRES, along with pertinent features of the clinical and laboratory presentation and available histopathology. Many common imaging/clinical/laboratory observations are present among these patients, despite the perception of widely different associated clinical conditions.

Posterior reversible encephalopathy syndrome: an emerging clinical entity in adult, pediatric, and obstetric critical care

PURPOSE

To describe the signs, symptoms, causative factors, and treatment for posterior reversible encephalopathy syndrome (PRES), an emerging clinical neuroradiologic entity which may be encountered by nurse practitioners in almost any clinical setting.

DATA SOURCES

Extensive review of worldwide literature, including peer-reviewed medical specialty journals, supplemented by an actual case study. Currently, a paucity of information exists in the nursing literature.

CONCLUSIONS

PRES occurs as a result of disordered cerebral circulatory autoregulation and/or endothelial dysfunction, usually as a result of acute, intermittent hypertension. Clinical manifestations include mental status change, headache, visual disturbance, and seizures. Characteristic abnormalities in the posterior cerebral white matter, seen best on diffusion-weighted magnetic resonance imaging, confirm the presence of the syndrome. PRES has been documented worldwide among a diverse patient population, yet many clinicians are still unfamiliar with this diagnosis.

IMPLICATIONS FOR PRACTICE

PRES is a clinical-radiographic diagnosis that requires close collaboration between the clinician and interpreting radiologist. Rapid identification and appropriate diagnostics are essential, as prompt treatment usually results in reversal of symptoms; permanent neurologic injury or death can occur with treatment delay.