Posterior leukoencephalopathy syndrome as a cause of reversible blindness during pregnancy.

Cortical blindness is a rare and dramatic complication of pre-eclampsia. The precise nature of the pathogenesis of this condition has not previously been understood. Three preeclamptic patients with unremarkable previous medical history presented with acute blindness between the 28th and 33rd weeks of pregnancy. They were all diagnosed as posterior leukoencephalopathy syndrome (PLES). In all these patients, MRI study revealed the typical feature of gray-white matter edema localized to the temporo-parieto-occipital areas. Vision and MRI findings were restored in all patients after delivery. Although PLES has been described as a puerperal clinicoradiologic entity, it may be seen in preeclamptic-eclamptic patients during the pregnancy. Therefore neuro-imaging studies should be carried out in pregnant patients with visual disturbances in order to exclude PLES. Prompt diagnosis, immediate control of blood pressure, and elimination of possible causes resolves clinical and imaging findings.