INTRODUCTION

It has been more than 20 years since the first study on posterior reversible encephalopathy syndrome (PRES) was published by Hinchey et al.(¹); nowadays, PRES is known as a potentially reversible clinical-radiological disorder, which usually progresses with classical acute neurological symptoms like visual impairment, acute headache, altered level of consciousness, seizures, and even focal neurological deficit(²). It is associated with clinical scenarios of acute changes in arterial pressure, hypertensive disorders associated with pregnancy, sepsis, kidney disease, autoimmune diseases (e.g., SLE), and drugrelated conditions (immunosuppressive agents, cytotoxic drugs), among other causes(³,⁴). The natural history of symptoms is reversal; however, this syndrome may not always be reversible and may develop atypically, causing permanent neurological sequels(⁵).

Regarding its radiological correlation, computerized tomography (CT) scans may evidence subtle hypodense areas; however, brain MRI is currently the “Gold Standard” for PRES diagnosis. A vast majority of PRES cases affect the parietal and occipital lobes; however, it has been proved that it may affect different brain areas(⁶).

There is no treatment for this condition, and its management focuses on solving its underlying cause such as measures to control arterial pressure, anticonvulsant therapy, discontinuation of drugs administered, and treatment of triggering factor (sepsis, eclampsia, and preeclampsia), however, certain studies support the use of nimodipine in vasospasm cases(⁷).

CLINICAL CASE

A 21-year-old woman, housewife, G2C2, with a history of systemic lupus erythematosus since 2016, treated with prednisolone and hydroxychloroquine with a low adherence to treatment and multiple immunosuppressant schemes since 2019 and lupus nephritis class IV-G (A/C) A 18/24 and C 4/12 (ISN/RNP) classification, go to the emergency service on January of 2021 because of progressive, acute bifrontal headache which increased with physical effort, as well as visual alterations, hypertensive crisis (210/110 mmHg) and a focal to a bilateral tonic-clonic seizure. She was admitted to the intensive care unit and administered IV phenytoin, endovenous nitrates, and oral antihypertensive medica tion. After recovery, she was transferred to the general ward with generalized edemas, normal neurological examination, simple brain CT with no evident pathologi cal findings, and a brain MRI showing no abnormalities (Figure 1). Other tests showed an increase in creatinine levels to 1.5 mg/dL, hypocomplementemia C3:56 and C4:18, 26 g proteinuria in 24-h urine, and a score of 44 determined by SLEDAI-2K, for this reason, received pulse IV methylprednisolone therapy for three days, and a 500 mg single dose of cyclophosphamide; her edemas and headache improved, her pressure levels were within target limits (120/80 mmHg), and she was discharged from hospital to receive outpatient treat- ment.

On July 2021, she was readmitted to the ICU because of the recurrence of acute, pulsatile, bifrontal headache, visual changes, seizure, and severe HBP (220/110), as well as the mono paresis of the right lower limb with 2/5 muscle strength. The brain MRI taken on showed hyperintensity of the subcortical bilateral parie- tal lobes in the FLAIR and T2 sequences representing vasogenic edema, gray matter hyperintensity in the left medial parietal lobe associated with restricted diffusion suggesting cytotoxic edema and representing a brain infarct in the anterior cerebral artery area, finding su ggestive of PRES (Figure 2). During hospitalization, a second 500 mg dose of cyclophosphamide was admi- nistered. Clinical improvement was observed, absence of headache, no visual alterations, and no seizures, along with gradual recovery of strength in her lower right limb, which correlates with a decrease in the va- sogenic edema observed in a control brain MRI took 15 days after hospitalization. Our patient presents clinical improvement for 10 days, with pressure levels reaching target limits, no seizures, and no visual alterations. Be- cause of phenytoin intolerance, the neurology depart- ment decides to change the anticonvulsant therapy for levetiracetam. Subsequently, her kidney function progressively deteriorates until reaching serum creatinine levels of 3.6 mg/dL, the persistence of hypocomple- mentemia with no response to corticoid and cyclophos- phamide treatment. Biological therapy with anti-CD20 antibodies is initiated, with 500 mg Rituximab infusion as a first dose. Another seizure episode occurs, asso- ciated with high-pressure levels. Again, the neurology unit optimizes the anticonvulsant therapy and takes a new MRI scan, in which the following is evidenced: enlargement of T2 interval and hyperintensity of the sub cortical bilateral parietal lobe, suggesting an increase in the vasogenic edema, and Gyriform hyperintensity observed in the T1 scans suggests laminar necrosis of the left ACA area. An interval resolution of the restricted diffusion of the gray matter in the left parietal lobe suggests chronic changes in the left ACA infarct (Figure 3).

Figure 1 MRI of the brain on admission dated showed no abnormalities.