Magnetic resonance imaging of vascular encephalopathy related to pregnancy.

Brain lesions related to pregnancy are not frequent, but are potentially lethal. About half of the cases are intracerebral hemorrhage, subarachnoid hemorrhage, infarction, and venous thrombosis. Their imaging characteristics are not much different from those caused by other reasons than pregnancy, and can be relatively easily recognized. The other half of cases are encephalopathy related to pregnancy-induced hypertension, eclampsia, and other factors. Such pregnancy-related vascular encephalopathy can be grossly sorted into 3 categories: posterior reversible encephalopathy syndrome, HELLP (hemolysis-elevated liver enzymes-low platelets) syndrome, and reversible cerebral vasoconstriction syndrome. These conditions are rare, but neurosurgeons must be able to recognize them.