Various Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) on Magnetic Resonance Imaging (MRI)

Abstract

SummaryBackgroundPosterior reversible encephalopathy syndrome (PRES), also called the acute hypertensive encephalopathy and reversible posterior leukoencephalopathy syndrome (RPLS), is a neurotoxic syndrome of cerebral vasoregulation classically characterized by bilaterally symmetrical parieto-occipital edema. However, the imaging findings are variable and may occur in other locations such as the frontal lobes, thalami, basal ganglia and brainstem. Most commonly, PRES presents with hyperintense signals on T2 and FLAIR sequences. Restricted diffusion and hemorrhage are rare. This study presents the typical and atypical manifestations of PRES on 3T MR images.Material/MethodsIt is a retrospective study analyzing a radiology report database and MR images of 92 patients with a clinical and radiological diagnosis of PRES. The brain MRI images of these patients were evaluated. The regions involved and the signal intensity of the affected areas on T1, T2, FLAIR and DW sequences were recorded. The location of the abnormal signal intensity as well as the presence or absence of atypical features such as diffusion restriction and hemorrhage were also recorded.ResultsThe most commonly affected region was the parieto-occipital lobes (100%), however, other atypical regions involved were the frontal lobes (30.4%), temporal lobes (8.69%), basal ganglia (22%), cerebellum(17.39%), brainstem(9%) and thalamus(4%). Some of the cases showed restricted diffusion (43%) and hemorrhage (9%).ConclusionsThe involvement of the parieto-occipital, frontal and temporal lobes is common in PRES. Occasionally, there may be an involvement of the basal ganglia, cerebellum and brainstem, with or without hemorrhage and restricted diffusion. Radiologists should be aware of the typical and atypical imaging manifestations of PRES in order to make an accurate diagnosis.

A Case Report of Posterior Reversible Encephalopathy Syndrome with a Review of Literature

“…Raman et al investigated 92 patients with PRES and found that the most commonly affected region was the parietal and occipital lobes. 13 However, it was also specified that frontal lobes, temporal lobes, basal ganglia, cerebellum, brainstem and thalamus could be in- volved. Similarly, Fugate et al who evaluated 120 patients with PRES reported that parietal and occipital lobes were most commonly affected, followed by the frontal lobe, temporal lobe and cerebellum.…”

Atypical Posterior Reversible Encephalopathy Syndrome and Systemic Lupus Erythematosus

“…Laboratuvar tetkiklerinde serum kreatinin değeri:1,46 mg/dL (0,8-1,2), üre:70 mg/dL (17-43), albumin:2,1 g/dL (3,5-5,2), tam idrar tetkikinde ise 3+ protein ve 7 eritrosit mevcuttu. Hematolojik değerlendirmede beyaz küre 3400/mm 3 (4.000-10.000), hemoglobin:7,6 g/dL (11)(12)(13)(14)(15)(16)(17)(18), trombosit:120.000/mm 3 (150.000-450.000) idi. rek yetmezliği yapan çeşitli sebeplere sekonder gelişen reversibl semptom ve görüntüleme bulgularıyla karakterizedir.…”

“…Örneğin; PRES tanısı almış 92 hastanın incelendiği bir çalışmada, hastaların %57'sinde difüzyon sekanslarda hiperintensite izlenirken, ADC görüntülerde anlamlı sinyal kaybı izlenmediği (psödo-normalizasyon) saptanmıştır. 15 Olgumuzda ise lezyonlar difüzyon sekansta hiperintens ADC sekansta hipointens izlenmiştir, psödo-normalizasyon saptanmamıştır.…”

Neurotoxicity including posterior reversible encephalopathy syndrome after initiation of calcineurin inhibitors in transplanted methylmalonic acidemia patients: Two case reports and review of the literature

“…17 CNIinduced neurotoxicity in non-MMA organ transplanted patients can present with a variety of symptoms such as confusion, tremor, seizures, cerebral hemorrhage, ischemic stroke, and posterior reversible encephalopathy syndrome (PRES). 15,[18][19][20] In CNI-induced PRES, the brain magnetic resonance imaging (MRI)-scan typically shows bilateral areas of vasogenic edema, which may be located in the cortex and/or subcortical white matter of brain areas; supplied by posterior circulation. However, an atypical distribution pattern is not infrequently observed, for example, involving the basal ganglia and/or the brain stem, 20 with or without atypical imaging findings (contrast enhancement, hemorrhage or restricted diffusion).…”

“…15,[18][19][20] In CNI-induced PRES, the brain magnetic resonance imaging (MRI)-scan typically shows bilateral areas of vasogenic edema, which may be located in the cortex and/or subcortical white matter of brain areas; supplied by posterior circulation. However, an atypical distribution pattern is not infrequently observed, for example, involving the basal ganglia and/or the brain stem, 20 with or without atypical imaging findings (contrast enhancement, hemorrhage or restricted diffusion). 18 Recently, two adult MMA patients received combined liver/kidney transplantation in our center.…”