Severe, uncontrolled hypertension and adult-onset seizures: A case-control study in Rochester, Minnesota

Purpose: Hypertension is an established risk factor for clinically detected stroke, which is in turn a risk factor for epilepsy. This relation suggested that hypertension, particularly severe and uncontrolled, might increase the risk of epilepsy in the absence of prior clinically detected stroke. Methods: Subjects in this population-based case-control study were the 145 incident cases of first unprovoked seizure aged 55 years or older and 290 controls matched to cases on age, gender, and duration of medical follow-up. Using the records-linkage system of the Rochester Epidemiology Project, we obtained, for both cases and matched controls, all blood pressure readings before each case's first seizure came to medical attention. Subjects were classified as hypertensive if they had at least two readings of greater than or equal to 160/95 mm Hg or if there was electrocardiographic evidence for left ventricular hypertrophy. Results: Severe uncontrolled hypertension increased the risk of unprovoked seizure. Left ventricular hypertrophy without diuretic treatment was associated with an Ii-fold increased risk of unprovoked seizure: left ventricular hypertrophy treated with diuretics did not increase the risk. Conclusions: In the absence of clinically detected stroke, left ventricular hypertrophy without diuretic use may increase the risk of unprovoked seizures, and diuretic treatment may protect against this increased risk.