Eclampsia

Eclampsia is a generalized seizure occurring in the setting of the preeclampsia spectrum, without another cause that better explains the event. It may occur before labour, during labour or after birth. The seizure itself is a neurological manifestation of a systemic placental disorder, not simply an isolated blood-pressure problem. Abnormal placentation produces an antiangiogenic state, including excess soluble fms-like tyrosine kinase 1 relative to placental growth factor. The resulting endothelial dysfunction affects vascular tone, capillary permeability and organ perfusion. Cerebral vascular dysregulation can produce headache, visual disturbance, altered mental status and seizure; the same endothelial injury can cause pulmonary edema, kidney dysfunction, liver injury, thrombocytopenia and placental insufficiency. That mechanism explains why a patient may deteriorate even when proteinuria is modest or absent. Preeclampsia is diagnosed by new hypertension at or after 20 weeks plus proteinuria, maternal end-organ dysfunction or uteroplacental dysfunction. Eclampsia itself is a neurological feature sufficient to place the patient in that disease spectrum. A reassuring urine dipstick does not neutralize a seizure, severe headache or visual symptoms. Canadian classification distinguishes chronic hypertension, gestational hypertension, preeclampsia, preeclampsia...