Posterior Reversible Encephalopathy Syndrome: Magnetic Resonance Imaging and Diffusion‐Weighted Imaging in 12 Cases

Abstract

Posterior reversible encephalopathy syndrome (PRES) is a potentially devastating neurologic syndrome, but timely treatment may lead to complete reversal of the disease course. We reviewed 12 cases of PRES and describe the clinical history and imaging findings, including conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and calculated apparent diffusion coefficient (ADC) maps, used to establish the diagnosis of PRES. Three male and nine female patients aged between 11 and 70 years (mean, 37 years) with clinical and imaging findings consistent with PRES were enrolled in the study. All patients had undergone conventional MRI and 10 had undergone additional DWI studies. Ten patients had follow-up MRI studies. DWI was performed using a 1.5T system with a single-shot spin-echo echoplanar pulse sequence. Initial and follow-up neuroimaging and clinical history were reviewed. Lesions were almost always present over the posterior circulation, mainly the parieto-occipital region, affecting primarily the white matter. The anterior circulation region, brainstem, cerebellum, deep cerebral white matter, and thalamus were also involved in five cases. Conventional MRI revealed hyperintensity on T2-weighted and fluid-attenuated inversion recovery images. DWI showed isointensity and increased signal intensity on ADC values in all cases, indicating vasogenic edema. Clinical and MRI follow-up showed that the symptoms and radiologic abnormalities could be reversed after appropriate treatment of the causes of PRES in most patients (9 of 10). In one patient, the ADC value was lower on follow-up images, indicating cytotoxic edema with ischemic infarct. DWI was a useful complement to MRI in the diagnosis of PRES.

Type of Edema in Posterior Reversible Encephalopathy Syndrome Depends on Serum Albumin Levels: An MR Imaging Study in 28 Patients

“…Cytotoxic edema was diagnosed by the combination of DWI hyperintensity with hypo-or isointensity on FLAIR, T2-weighted sequences, and ADC maps. 4,14 According to the described MR imaging criteria, 22 patients had vasogenic and 6 patients had cytotoxic edema (Fig 1). MR imaging was performed on the day of onset in 21/28 patients, on day 1 after symptom onset in 3/28, on day 2 in 1, on day 3 in 1, and on day 5 in 2 patients.…”

“…Cytotoxic edema was diagnosed by the combination of DWI hyperintensity with hypo-or isointensity on FLAIR, T2-weighted sequences, and ADC maps. 4,14 The location of lesions was classified as typical (uni-or bilateral occipital lesions, with or without involvement of frontal, temporal, or parietal lobes), atypical (supratentorial lesions without involvement of 1 or both occipital lobes), or …”

Electroencephalographic Changes and Prognosis for the Development of Epilepsy in Patients With Posterior Reversible Encephalopathy Syndrome (Pres): Literature Review

“…Своевременное распознавание данного синдрома и немедленное начало адекватной терапии могут предотвратить более тяжелые послед-ствия церебральной недостаточности. При адекватной терапии в 90 % случаев возможен регресс энцефало-патии [11]. Задержка в диагностике и лечении может привести к необратимому повреждению пострадавших тканей мозга с летальным исходом в 10-15 % случаев [7,18].…”

Hemorrhagic stroke with intraventricular extension in the setting of acute posterior reversible encephalopathy syndrome (PRES): Case report

“…It could be inferred that when symptoms occur in preeclampsia, the autoregulatory compensation mechanisms are impaired. It has been postulated that the lesser presence of sympathetic supply to the posterior circulation could be responsible for an increased susceptibility to losing autoregulatory compensation mechanisms, explaining the predominance of lesions in the occipital region 3,4 . Changes in the blood brain barrier as a consequence of dysautorregulation could therefore be responsible for the encephalopathy produced initially, and this disruption could potentially create a vulnerability and predisposition of the microcirculation to a hemorrhagic event.…”