Hypertension and the risk of new-onset unprovoked seizures.

We tested the a priori hypothesis that hypertension can lead to seizures through vascular brain damage that might or might not involve manifest stroke. A case-control study with 227 patients admitted for a first unprovoked seizure and 294 acute surgical controls was carried out at Harlem Hospital Center, New York City, between 1981 and 1984. History of hypertension was significantly associated with unprovoked seizures, even after adjustment for antecedent stroke and other potential confounders (adjusted odds ratio [OR] = 1.57; 95% confidence limit [CL], 1.0 to 2.44). There was marked synergism between history of stroke and history of hypertension; subjects with a history of both had a fourfold increase in seizure risk compared with subjects with neither (adjusted OR = 4.07; 95% CL, 1.50 to 11.0). In these data, history of hypertension appears to be an independent risk factor for new-onset unprovoked seizures, especially, but not only, in conjunction with a history of stroke.