Posterior Reversible Encephalopathy Syndrome Presenting as Late Postpartum Eclampsia in a Previously Normotensive Woman: A Case Report

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome characterized by acute neurological manifestations, including headache and seizures, with neuroimaging evidence of predominantly reversible vasogenic cerebral edema.It is commonly associated with hypertensive disorders of pregnancy, particularly preeclampsia and eclampsia.A 27-year-old primigravida with known Hashimoto thyroiditis, treated with levothyroxine 50 µg daily, presented on postpartum day seven with a severe headache followed by two generalized tonic-clonic seizures.Her blood pressure was 160/110 mmHg, and the urine protein-to-creatinine ratio was 6.96 g/g creatinine.Magnetic resonance imaging (MRI) of the brain demonstrated bilateral parieto-occipital cortical and subcortical T2-weighted/fluid-attenuated inversion recovery (FLAIR) hyperintensities consistent with PRES.Magnetic resonance venography excluded cerebral venous sinus thrombosis.Autoimmune investigations for alternative systemic autoimmune disorders, including antinuclear antibody, anti-double-stranded DNA antibody, antineutrophil cytoplasmic antibody, and complement levels, were unremarkable.She was treated with magnesium sulfate and antihypertensive therapy, resulting in complete clinical recovery and resolution of the radiological abnormalities.This case highlights late postpartum eclampsia presenting as PRES in a previously normotensive woman and emphasizes the importance of maintaining a high index of suspicion for postpartum hypertensive disorders in women presenting with new-onset headache or seizures, even after an apparently uncomplicated pregnancy and delivery.Early recognition and prompt treatment are essential to prevent potentially lifethreatening complications and achieve favorable clinical outcomes.