With interest we read the article by Brewer et al, who described the use of various neuroimaging modalities such as magnetic resonance imaging (MRI) and computed tomography in women with eclamptic seizures. The posterior reversible encephalopathy syndrome was found in all but 1 patient. In 2003, Loureiro et al published a series of 14 women with eclampsia and 3 women with severe preeclampsia and neurological symptoms who all underwent cranial MRI. In 2004, we published a similar series of 27 nulliparous eclamptic women who had cranial MRI following their eclamptic seizure. In both series, as also described by Brewer et al, posterior reversible encephalopathy syndrome was found to be a core component of the pathogenesis of eclampsia.

Although fluid attenuated inversion recovery MRI and computed tomography, as described by Brewer et al, can identify only the presence of cerebral edema per se, it does not distinguish between reversible areas of vasogenic edema and areas of cytotoxic edema, which may progress to tissue loss. The study by Loureiro in 2003 and our study in 2004 specifically reported the use of diffusion-weighted MRI and apparent diffusion coefficient mapping to distinguish between these 2 forms of cerebral edema. Whereas in our study all but 2 had reversible vasogenic edema, 6 eclamptic women were also found to have areas of cytotoxic edema, consistent with cerebral infarction. Five of these 6 women had persistent imaging findings of brain tissue loss (gliosis) when studied 6-8 weeks’ postpartum.

Our study as well as that of Loureiro et al documented a transition between reversible vasogenic edema to irreversible cerebral ischemia and infarction in a fourth of eclamptic women. Although long-term clinical consequences of eclampsia, such as subtle brain dysfunction, need to be determined the presence of cytotoxic edema and tissue loss on follow-up seems ominous. There is a predictive role for diffusion-weighted MRI in the evaluation of the course of cerebral edema in the acute phase in women with eclampsia and women with severe preeclampsia who have neurological symptoms. Therefore, we recommend adding this modality, including and apparent diffusion coefficient MRI modalities, to the standard neuroimaging protocol for women with eclampsia and those women with preeclampsia and concomitant neurological symptoms.