An isotopic diagnosis of seizure.

A 22-year-old healthy woman visited our clinic for seizure and consciousness loss. A thorough history taking and physical examination was negative except for persistent high blood pressure. Serial workup for suspicious secondary hypertension revealed secondary hyperaldosteronism. Further image study showed diminished unilateral kidney size, but the computed tomographic angiogram was unremarkable. Radionuclide renography disclosed a specific pattern of compromised unilateral renal function after captopril challenge, suggesting a high probability of renal artery stenosis. Renal artery angiography finally confirmed the diagnosis, and angioplasty with stenting successfully reversed the refractory hypertension despite the shrinking kidney size. Although isotopic study is gradually fading away among our diagnostic tools, the value it demonstrates in this case warrants attention.