The best descriptions of the gross and microscopic brain
pathology in eclampsia can be found in the extensive autopsy
series of Sheehan and Lynch,42 because most of these
necropsies were performed within 2 hours of death, thereby
eliminating the rapid autolytic postmortem changes that
might confound interpretation. They noted little evidence of
brain edema and postulated that brain swelling was a late
rather than a causal event. The major findings, however,
were both gross and microscopic evidence of bleeding.
Previous controversy regarding the pathogenesis of
eclampsia centered on whether it was a unique entity, due
mainly to severe vasoconstriction (occasionally localized in
the cerebral circulation) or more akin to hypertensive encephalopathy
appears to have been resolved. Studies using
sophisticated imaging techniques reveal increased cerebral
blood flow in preeclamptic women, whereas data derived
from animal models suggest that eclamptic women have
increased perfusion pressures, perhaps exceeding the cerebral
circulation’s autoregulatory capacity, and that their
vessels “leak” at perfusion pressures lower than what would
be expected in nonpregnant subjects.13,15,43,44 Reports
based on computed axial tomography and magnetic resonance
imaging describe transient abnormalities consistent
with localized hemorrhage or edema,45 with the latter described
as vasogenic and fully reversible, but occasionally
“cytotoxic” accompanied by infarction with lesions that
persist