Visual evoked potential and multifocal electroretinography findings in posterior reversible encephalopathy syndrome: a case report

Posterior Reversible Encephalopathy Syndrome (PRES) is characterized by sudden vasogenic edema primarily in the occipital and parietal lobes of the brain. It is associated with hypertension, renal failure, and pre-eclampsia. Diagnosis relies on history, clinical examination, and MRI findings. This case report focuses on the electrophysiological approach in diagnosing and monitoring PRES, aiming to unders-tand whether improvements seen on MRI also reflect electrophysiological changes. Upon discharge from the intensive care unit, a 27-year-old patient with PRES related to eclampsia underwent 60 arcmin pat-tern-reversal VEP, 60 arcmin pattern ON-OFF VEP, and multifocal electroretinography (mfERG) recor-dings, which were descriptively compared with our laboratory’s previously established normative data-base. The initial VEP recordings showed reduced amplitudes and prolonged implicit times in several components compared with the normative database. In the left eye, multifocal ERG recording on the first day after discharge showed reduced responses in several retinal eccentricity rings compared with the normative database. On the seventh day after discharge, VEP amplitudes improved; however, reduced amplitudes persisted in some components compared with the normative database. In addition, multifocal ERG responses returned to within the normative reference range. Visual electrophysiological tests may provide useful information regarding functional recovery in patients with PRES. These findings suggest that visual electrophysiological tests may provide complementary functional information during short-term follow-up in PRES. Furthermore, our case suggests the possibility of transient retinal functional involvement in addition to visual pathway dysfunction, indicating the need for further research.