Isolated posterior fossa involvement in posterior reversible encephalopathy syndrome

Pediatric posterior reversible encephalopathy syndrome: Can MR imaging features predict outcomes in non-oncologic patients?

PURPOSE

Identify MR features predictive of poor outcomes in non-oncologic pediatric PRES.

METHOD

A six-year search of all non-oncologic pediatric patients with clinical and MR features of PRES was performed. Modified Rankin scores were used to classify clinical outcomes into good versus poor, then clinical and MR features were compared among groups. Univariate and multivariate analysis was performed to identify MR predictors of poor outcomes for various imaging features, and p-values < 0.05 were considered statistically significant.

RESULTS

One hundred and forty-one patients (mean age 10.1 ± 3.0 years, male to female ratio 1:1.1) were included. Clinically, nephrotic syndrome (p = 0.03), focal deficits (p = 0.04), longer hospitalization (p < 0.001), and mechanical ventilation (p < 0.001) were significantly associated with poor outcomes. Univariate analysis revealed that deep grey matter nuclei (OR = 5.29, 95 % CI: 1.6-18.0) and cerebellar edema patterns (OR = 3.49, 95 % CI: 1.3-9.5), cytotoxic edema (OR = 63.6, 95 % CI:16.5-244.2), hemorrhage (OR = 16.58, 95 % CI: 4.3-64.2), and severe PRES patterns (OR = 11.0, 95 % CI: 3.5-34.7) on MR were all significantly associated with poor outcomes (p-values = 0.008 and 0.014, <0.001, <0.001, and < 0.001, respectively). This remained true for cytotoxic edema (OR = 84.26, 95 % CI: 17.3-410.9, p-value < 0.001) and hemorrhage (OR = 44.56, 95 % CI: 6.9-289.7, p-value < 0.001) on multivariate analysis.

CONCLUSION

Diffusion restriction and hemorrhage on initial MR scans were the two independent predictors of poor outcomes in non-oncologic pediatric patients.

A case report of Posterior reversible encephalopathy syndrome with spinal cord involvement (PRES-SCI) as an atypical presentation of PRES in children: A case report and review of the literature

Posterior reversible encephalopathy syndrome (PRES) has a broad spectrum of clinical presentations and radiological features. Diagnosis of PRES is established based on reversible clinical manifestations and sequential neuroimaging findings. Atypical MRI features include hemorrhage, restricted diffusion or contrast enhancement of lesions, and involvement of the temporal and frontal lobes, brainstem, basal ganglia, corpus callosum, cerebellum, and spine. Atypical PRES, with or without spinal cord involvement, is a rare presentation, especially in children. Until 2020, only five cases of PRES with spinal cord involvement (PRES-SCI) were reported in the pediatric population.

CASE REPORT

Here, we present the youngest diagnosed case of PRES-SCI so far. According to the literature, all six cases of PRES-SCI showed high signal intensities on T2-weighted images of the brainstem and cervical cord, which had completely resolved in the follow-up MRI of the brain and spinal cord. All six patients had hypertension due to renal disease, except one girl with chemotherapy-induced hypertension. Headache, altered mental status, seizure, and visual impairment were the most common symptoms, respectively. Facial palsy was a remarkable warning sign in some patients before hospitalization.Although PRES-SCI is rare in children, since it is a reversible condition, prompt diagnosis and management can positively affect its prognosis.

Detecting the Uncommon Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) in Adults: a Comprehensive Illustrated Guide for the Trainee Radiologist

Posterior reversible encephalopathy syndrome (PRES) has traditionally been described as a reversible leukoencephalopathy with a distinct pattern of posteriorly distributed vasogenic oedema involving the subcortical regions of parietal and occipital lobes. PRES commonly occurs in the setting of hypertensive emergencies, pre-eclampsia/eclampsia, impaired renal function, and immunosuppressive therapy. The various clinical presentations of PRES include encephalopathy, seizures, headache, visual, and focal neurological deficits. As knowledge of this entity grows, the range of clinical, and radiological features is seen to be much broader than originally described. The brain oedema may not always be posteriorly distributed and the syndrome may not be uniformly reversible. Of special note are some uncommon imaging features (unilateral cerebral involvement, and isolated posterior fossa involvement) and also some uncommon complications (haemorrhage, cytotoxic oedema, and vasoconstriction). These red herrings may lead to potential diagnostic challenges and pitfalls especially for trainee radiologists, who often read these scans in an emergency setting. Early and accurate diagnosis is crucial for prompt optimum management, thereby avoiding residual morbidity. This review article focusses on the atypical radiological features of PRES in adults with extensive case-based imaging examples. A brief description of the pathophysiology, clinical, and classic radiological features of PRES has also been included. A tabulated summary of potential mimics with diagnostic pearls is provided to highlight pertinent take home points and to serve as an easy guide for day-to-day clinical practice.

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 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 Isolated Involving Infratentorial Structures

Typical neuroimaging findings of posterior reversible encephalopathy syndrome include symmetrical white matter edema in subcortical white matter of bilateral occipital and parietal lobes, although variations do occur and more and more attention is being focused upon disease of infratentorial-isolated involved posterior reversible encephalopathy syndrome. In this article, we described 1 case of posterior reversible encephalopathy syndrome with isolated infratentorial brain involvement and reviewed the literature to identify an additional 36 cases in the PubMed database. We used various search terms, such as "brainstem/cerebella/spinal posterior reversible encephalopathy syndrome," "brainstem/cerebella/spinal reversible posterior leukoencephalopathy syndrome," "brainstem/cerebella/spinal hypertensive encephalopathy," "infratentorial posterior reversible encephalopathy syndrome," and "posterior reversible encephalopathy syndrome variant." Then, we systematically analyzed the clinical and imaging characteristics of the 37 cases and found that posterior reversible encephalopathy syndrome with isolated involving infratentorial structures predominantly affect male patients compared with typical posterior reversible encephalopathy syndrome. The presence of extremely high blood pressure at onset is essential to the development of infratentorial-isolated involved posterior reversible encephalopathy syndrome. A relatively high rate of hydrocephalus and spinal cord involvement can be a distinctive feature of this kind of variant. Symptoms and outcomes are basically similar to typical posterior reversible encephalopathy syndrome.

Posterior Reversible Encephalopathy Syndrome: Risk Factors and Impact on the Outcome in Children With Acute Lymphoblastic Leukemia Treated With Nordic Protocols

Posterior reversible encephalopathy syndrome (PRES) in children with acute lymphoblastic leukemia has been increasingly recognized as a clinicoradiological entity. Our aim was to describe the incidence of PRES in pediatric patients with ALL, identify its risk factors, and examine its prognostic importance. For this research, we conducted a systematic, retrospective review of the patient records in a population-based series of children with acute lymphoblastic leukemia (n=643) treated in Finland from 1992 to 2008. Of the patients with ALL, 4.5% (n=29) developed radiologically confirmed PRES, of which 28 cases occurred during induction. Hypertension (P=0.006; odds ratio [OR], 4.10, confidence interval [CI], 1.50-11.25), constipation (P=0.001; OR, 5.60; CI, 2.02-15.52), and >14 days of alkalinization (P=0.017; OR, 3.27; CI, 1.23-8.68) were significant independent risk factors for PRES. One-third of the patients developed epilepsy. Relapses occurred significantly more often in those patients with PRES (P=0.001), which was associated with worse overall survival (P=0.040; 5-year survival=75.9% [60.3%-91.4%] vs. 88.4% [85.8%-90.9%]). Using NOPHO-ALL 92/2000 protocols, PRES is a significant early complication of therapy in ALL, and was associated with a poorer prognosis and significant neurological morbidity.

Study of Posterior Reversible Encephalopathy Syndrome in Children With Acute Lymphoblastic Leukemia After Induction Chemotherapy

Increasing occurrence of posterior reversible encephalopathy syndrome has been reported in children with acute lymphoblastic leukemia. However, the etiology of posterior reversible encephalopathy syndrome is not clear. To study the possible pathogenetic mechanisms and treatment of this complication, we reported 11 cases of pediatric acute lymphoblastic leukemia who developed posterior reversible encephalopathy syndrome after induction chemotherapy. After appropriate treatment, the clinical symptoms of posterior reversible encephalopathy syndrome in most cases disappeared even though induction chemotherapy continued. During the 1-year follow-up, no recurrence of posterior reversible encephalopathy syndrome was observed. Although the clinical and imaging features of posterior reversible encephalopathy syndrome may be diverse, posterior reversible encephalopathy syndrome should be recognized as a possible important complication of acute lymphoblastic leukemia when neurologic symptoms appear. In line with previous reports, our study also indicated that posterior reversible encephalopathy syndrome was reversible when diagnosed and treated at an early stage. Thus, the occurrence of posterior reversible encephalopathy syndrome should be considered and investigated to optimize the early induction scheme of acute lymphoblastic leukemia treatment.