Isolated cerebellar involvement in posterior reversible encephalopathy syndrome

Hypertensive posterior reversible encephalopathy causing obstructive hydrocephalus

Background:

Posterior reversible encephalopathy syndrome (PRES) can occur due to the detrimental effect of malignant hypertension on cerebral autoregulation. Most reported cases describe involvement of the supratentorial areas. Involvement of the posterior fossa structures in conjunction with supratentorial involvement has also been reported; however, PRES affecting the infratentorial structures without supratentorial involvement is a rare phenomenon. Clinical manifestations can involve severe headache, seizures, and reduced consciousness with treatment focused primarily on blood pressure control.

Case Description:

We report a case of PRES with isolated involvement of the infratentorial structures leading to obstructive hydrocephalus. The patient was managed with aggressive control of blood pressure and avoided ventriculostomy or posterior fossa decompression with a good outcome.

Conclusion:

Medical management in the absence of neurological deficit can be associated with a good outcome.

Acute obstructive hydrocephalus in posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is an uncommon, subacute neurological disorder that presents radiologically with a pattern of bilateral parieto-occipital areas of vasogenic oedema. Conditions commonly associated with PRES include autoimmune disorders, cytotoxic drugs, metabolic abnormalities and, most frequently, hypertensive emergencies. Clinically, headache, visual disturbances, seizures and an altered level of consciousness are often reported. The outcome is favourable if the underlying cause is addressed. Posterior fossa involvement resulting in obstructive hydrocephalus is a rare presentation and may be misdiagnosed as a mass lesion or infection, leading to delayed or unnecessary treatment. We describe the clinical presentation, findings on neuroimaging and conservative management of a man with PRES resulting in severe cerebellar oedema and acute obstructive hydrocephalus. This case illustrates that awareness of atypical neuroimaging in PRES is important for the management of these patients and to avoid morbidity and mortality.

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.

Clinical and MRI Features of Posterior Reversible Encephalopathy Syndrome With Atypical Regions: A Descriptive Study With a Large Sample Size

Background: Accurate diagnosis and timely treatment for posterior reversible encephalopathy syndrome (PRES) with atypical regions are very important in clinical practice. However, until now, little has been known about the clinical and MRI manifestations of this disease. Therefore, the aim of this study is to investigate the clinical and MRI features of PRES to promote clinical management and deepen our understanding of this disease. Materials and Methods: Data from six PRES patients with atypical regions were collected from our hospital. Data from another 550 cases were obtained by searching the PubMed, EMBASE and Web of Science databases with the keywords "posterior reversible encephalopathy syndrome" "PRES" "reversible posterior leukoencephalopathy" "RPLS" "hypertensive encephalopathy" "hyperperfusion encephalopathy" or "reversible posterior cerebral edema encephalopathy." The clinical and MRI features of these 556 cases were analyzed together. Results: A total of 305 patients were female, and 248 were male, with a median age of 34 years. The information on sex and age of three patients was not available. The most common symptom was headache (282/556, 50.7%), followed by altered mental status (243/556, 43.7%), seizures (233/556, 41.9%), visual disturbances (194/556, 34.9%), nausea/vomiting (130/556, 23.4%), and focal neurological deficits (101/556, 18.2%). Hypertension (425/556, 76.4%), renal diseases (152/556, 27.3%), immunosuppressant drugs (79/556, 14.2%), and chemotherapy/chemoradiotherapy (59/556, 10.6%) were the major predisposing factors. The atypical regions of the lesions were the cerebellum (331/556, 59.5%), basal ganglia (135/556, 24.3%), periventricular/deep white matter (125/556, 22.5%), pons (124/556, 22.3%), brainstem (115/556, 20.7%), thalamus (114/556, 20.5%), midbrain (48/556, 8.6%), spinal cord (33/556, 5.9%), and medulla (29/556, 5.2%). Additionally, the following typical regions were observed: occipital (278/556, 50.0%), parietal (234/556, 42.1%), frontal (150/556, 27.0%), and temporal (124/556, 22.3%) lobes. The major treatments were antihypertensives (358/515, 69.5%), antiepileptics/sedation (126/515, 24.5%), discontinuation/switching agents (67/515, 13.0%), and steroids (54/515, 10.5%). The median time of the clinical state improved and abnormal neuroimaging resolved is 2-3 weeks after appropriate treatment. Conclusion: The common symptoms of PRES with atypical regions include headaches, altered mental status, seizures, visual disturbances, nausea or vomiting, and focal neurological deficits. The frequent predisposing factors include hypertension, renal diseases, immunosuppressant drugs and chemotherapy/chemoradiotherapy. MRI features are mainly characterized by vasogenic edema in central zones always accompanied by typical regions. Most cases can be reversed in 2-3 weeks when promptly recognized and properly treated.

Posterior Reversible Encephalopathy Syndrome due to Hypomagnesemia: A Case Report and Literature Review

Background

Hypomagnesemia can cause various unspecific neurological complications, which can lead to diagnostic confusion. One of these complications is the posterior reversible encephalopathy syndrome (PRES), which is extremely uncommon and has been reported only twice in the English-language literature.

Case presentation

We report the case of a 60-year-old man who presented with PRES involving only the cerebellar hemispheres and associated with hypomagnesemia. After excluding all the other possible etiologies of PRES, we started magnesium replacement therapy, which led to a remarkable but fluctuating clinical and chemical improvement. A full recovery with no need for further supplementation was achieved only after discontinuation of a proton pump inhibitor.

Conclusions

This case highlights the role of magnesium in the pathophysiology of PRES; thereby, underlying hypomagnesemia should be considered in every PRES case with unclear etiology.

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.

Recurrent posterior reversible encephalopathy syndrome with cerebellar involvement leading to acute hydrocephalus

Posterior reversible encephalopathy syndrome or PRES is a proposed cliniconeuroradiological entity that is characterized by headache, confusion, seizure, cortical visual disturbances or even blindness and, to a lesser extent, focal neurological signs. The etiology of this entity includes a sudden increase in blood pressure, renal failure, immunosuppressive drugs, infections, and intravenous immunoglobulin (IVIG). Classically, magnetic resonance imaging (MRI) findings show a symmetric reversible vasogenic edema in the parietooccipital lobes. PRES can involve the brainstem and cerebellum and sometimes can leave irreversible lesions but it can also recur, which is a very rare presentation. In this article, we report a case of recurrent PRES with cerebellar involvement associated with non-communicating hydrocephalus in a 2-year-old child with renal failure on peritoneal dialysis after receiving Etoposide for macrophage activation syndrome.

Posterior Reversible Encephalopathy Syndrome With Spinal Cord Involvement in Children

We characterized a cohort of patients with posterior reversible encephalopathy syndrome with spinal cord involvement. We encountered 2 children and identified an additional 19 patients from the internet databases. Of the 21 patients analyzed, 8 were children. The mean peak systolic blood pressure in adults was significantly higher than in children (221.8 ± 14.3 vs 191.4 ± 31.3 mm Hg; P < .01). Regardless of age, the most common clinical symptom was headache (90%) and the least common clinical symptom was seizures (28%). Atypical neuroimaging was more common in children (63%) than in adults (8%). Abnormal cerebrospinal fluid results were frequently found in children (83%). All children recovered uneventfully, but 3 adults had sequelae. A broader clinicoradiologic spectrum makes the diagnosis of children more complex than in adults. Awareness of the atypical features with a meticulous management of hypertension is imperative to avoid unnecessary invasive workups and to achieve an uneventful recovery.