Case Report: Subacute Sclerosing Panencephalitis in Pregnancy Mimicking Posterior Reversible Encephalopathy Syndrome

In posterior reversible encephalopathy syndrome, brain magnetic resonance imaging (MRI) reveals bilateral occipital, parietal, and subcortical white matter hyperintensities on T2/fluid-attenuated inversion recovery (FLAIR) sequences. After treatment, imaging abnormalities are usually reversible. Eclampsia is the most frequent cause of posterior reversible encephalopathy syndrome in pregnancy. We report a 24-year-old woman, who presented to our clinic 4 weeks after normal vaginal delivery with bilateral vision loss. Loss of vision was first noticed in the 20th week of pregnancy. Even after delivery, her vision did not improve. In the postpartum period, she started having periodic myoclonic jerks. Electroencephalography demonstrated periodic generalized discharges. A brain MRI performed in the 20th week of the antepartum period showed bilateral parieto-occipital cortical white matter T2/FLAIR hyperintensities. A follow-up brain MRI, 5 months later, revealed marked reversal of white matter signal changes. Cerebrospinal fluid examination revealed raised anti-measles antibody titer, confirming the diagnosis of subacute sclerosing panencephalitis. In conclusion, in a patient with subacute sclerosing panencephalitis (SSPE) during the postpartum period, cortical vision loss and parieto-occipital white matter T2/FLAIR hyperintensities can simulate eclampsia. Inadvertent treatment with magnesium sulfate is likely if the diagnosis is missed.