Isolated pons involvement in Posterior Reversible Encephalopathy Syndrome: Case report and review of the literature

Tacrolimus induced diffuse pontine hyperintensity in status epilepticus: a rare entity

Posterior Reversible Encephalopathy Syndrome resulting from the hypertension-induced Failure of cerebral autoregulation, is a well-described neuro-imaging finding resulting from vasogenic oedema. Pontine Hyperintensities resulting from this condition need recognition to prognosticate and avoid unnecessary investigations.  We report a 48 year old male with chronic diabetes mellitus, Hypertension, and chronic kidney disease, and history of liver transplantation who presented with established status epilepticus. He was on Tacrolimus for prophylaxis for graft rejection. His MRI brain showed diffuse pontine and predominantly left thalamic hyperintensity, which suggested the diagnosis of central PRES. His evaluation for CNS infections and autoimmune encephalitis was negative.  On stopping Tacrolimus, the imputed drug, and control of hypertension, along with dialysis, and symptomatic management for seizures, a complete recovery was observed over one week. Repeat MRI also showed partial regression of the pontine hyperintensity. This report documents the importance of this less described neuroradiological finding that can change the management significantly and have a bearing on the prognosis.

A Case Report: Isolated Pontine Lesion in Hypertensive of a Pregnant Patient with Idiopathic Thrombocytopenia

Posterior reversible encephalopathy syndrome (PRES) is a neuroradiologic diagnosis characterised by headache, seizures, altered mental status, and a spectrum of visual deficits ranging from visual neglect to cortical blindness. PRES manifestation is a situation of medical emergency; however, it is a fully reversible condition, especially when diagnosed and treated immediately. The main problem lies in the impairment of cerebral blood flow autoregulation which, in turn, leads to endothelial dysfunction and vasogenic brain oedema. MRI indicates cerebral oedema in the occipital, temporal, and parietal lobes. Brainstem involvement is very rare in the literature. Idiopathic thrombocytopenia-related PRES is also rare in the literature. In this article, a case of PRES with only pons involvement in MRI after hypertensive attack in a pregnant patient with idiopathic thrombocytopenia is presented. PRES may present only brainstem involvement, as seen in this present case. Whether or not mild hypertension and mild thrombocytopenia found in this case are associated with limited disease should be evaluated. Prolonged spreading depression may have a role in the pathophysiology of PRES.

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.

Isolated pontine involvement in posterior reversible encephalopathy syndrome with coincidental acute ischaemic stroke

Posterior reversible encephalopathy syndrome (PRES) is a cliniconeuroradiological syndrome characterised by a unique reversible pattern on imaging and total regression of clinical symptoms and signs. We describe an unusual case of PRES with isolated pontine involvement with coincidental acute ischaemic stroke in a 60-year-old man who presented with headache, unsteadiness of gait, blurred vision and elevated blood pressure. MRI scan revealed an expanded pons with diffuse T2 and Fluid attenuated Inversion Recovery (FLAIR) hyperintensities and an acute infarct in the right temporal lobe. A diagnosis of PRES was considered most likely after exclusion of other differentials and the patient was started on antihypertensive treatment as for hypertensive encephalopathy. He became asymptomatic after controlling blood pressure and the follow-up MRI scan at 3 weeks showed complete resolution of the pontine high signals which confirmed the diagnosis of PRES.

Isolated brainstem involvement in posterior reversible encephalopathy syndrome: a case report and review of the literature

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological syndrome, reversible vasogenic edema predominantly within parieto-occipital regions. However, isolated brainstem involvement in PRES has been rarely reported, little is known about its clinical manifestations, radiological features and outcomes. We reported a case with PRES with only brainstem involvement and performed a systematic review of published cases. Twenty-four cases, together with our case, were included in the analysis. Mean age was 43 years and 63% were males. Hypertension (50%), nephropathy (25%) and chemotherapy (21%) were the major risk factors. All patients except two had acute hypertension and 50% of patients had renal dysfunction at onset. The most common symptoms were altered consciousness (46%) and headache (46%), Seizure was only presented in 21% of patients. All patients except two were treated with antihypertension. Most patients recovered to their neurological baseline. Clinicians should recognize this unique variant finding in PRES. which always affects males with severe hypertension, especially combined with renal dysfunction. Antihypertensive treatment is the most widely used therapy. Outcome is usually well.

Posterior reversible encephalopathy syndrome (PRES) and infection: a systematic review of the literature

Posterior reversible encephalopathy syndrome (PRES) is an encephalopathy characterized by a rapid onset of symptoms including headache, seizures, confusion, blurred vision, and nausea associated with a typical magnetic resonance imaging appearance of reversible subcortical vasogenic edema prominent and not exclusive of parieto-occipital lobes. Vasogenic edema is caused by a blood-brain barrier leak induced by endothelial damage or a severe arterial hypertension exceeding the limits of cerebral blood flow autoregulation. Although the exact pathophysiological mechanism is still unclear, frequent conditions that may induce PRES include severe hypertension, eclampsia/pre-eclampsia, acute kidney diseases and failure, immunosuppressive therapy, solid organ, or bone marrow transplantation. Conversely to other conditions, which may induce PRES, the link between severe infection or sepsis and PRES, often associated with gram-positive bacteria, is still poorly understood and less well known. Clinicians from multiple disciplines, such as neurologists and internists, may encounter during their profession patients with severe infection or sepsis and should consider the possible association between PRES and these conditions. We systematically reviewed the literature about this association in order to provide a helpful clinical insight of such complex pathophysiological mechanism, highlighting the importance of recognizing PRES in such a complex clinical scenario.