Clinical, imaging spectrum and outcome of PRES

Abstract

Background: Posterior reversible encephalopathy syndrome (PRES), also called the acute hypertensive encephalopathy and reversible leukoencephalopathy syndrome (RPLS), is a clinico-radiological syndrome presents with rapid onset of headache, seizures, loss of consciousness, visual loss and characterized by white matter vasogenic edema affecting parietal and occipital lobes of the brain predominantly. However, the imaging findings are variable and may occur in other locations such as the frontal lobes, thalami, basal ganglia and brainstem. Objective: To study the clinical, imaging spectrum and final disease outcome of PRES Materials And Methods: The study was conducted on 52 patients who presented with clinical features and radiological diagnosis of PRES The clinical, imaging features and outcome of each patient were analyzed Results: The study was conducted on 52 patients with age range from below 10yrs to 65 yrs. Patients presented with various symptoms of which seizures(84.6%) is most common followed by headache(59.6%), vomiting (36.5%), visual disturbances(32.7%), altered sensorium(15.3%), thalamic aphasia (5.7%), hemiparesis(3.8%), paresthesia(3.8%), ataxia(3.8%), Quadriparesis (3.8%) and facial numbness (1.9%) is the least. On MR imaging typical parieto-occipital lobe involvement(98%)is seen in most of the cases, however other atypical regions involved were frontal lobe(52%),temporal lobe (17.3%), cerebellum (27%),thalamus (15.3%), brainstem (13.4%), basal ganglia (9.6%) and corpus callosum (1.9%) Lesions in atypical locations also had lesions in typical locations in all cases except in one case of central PRES. Dominant parieto-occipital pattern was seen in 32%,superior frontal sulcus pattern in 27%,holohemispheric pattern in 34.6%,Partial or asymmetric expression of primary patterns in 5.2% cases Diffusion restriction and postcontrast enhancement was seen in less than 25% cases. Complete resolution of symptoms was seen in 90.5% cases,3.8% of them succumbed to death. On follow up 5.7% of cases showed persistence of symptoms. Conclusion: PRES is a clinico-radiological syndrome with varied clinical and imaging spectrum. Involvement of atypical regions is not uncommon. However lesions in atypical locations often have lesions in typical locations also.Atypical imaging features like restricted diffusion and contrast enhancement are also not uncommon. Knowledge of atypical lesion location, atypical imaging features is necessary for the clinicians and radiologists not to misdiagnose PRES in the appropriate clinical setting