脳出血後に発見された選択的低アルドステロン症の1例

Abstract

A 54 year-old male who had suffered from an attack of cerebral hemorrhage five months before was admitted because of increasing dizziness and fatigue. Laboratory examinations on admission revealed both hyponatremia and hyperkalemia. Despite the elevation of plasma renin activity (PRA), plasma aldosterone level was markedly low. Both basal plasma cortisol level and urinary 17-OHCS excretion rate were normal. While cortisol showed a normal response to rapid ACTH infusion test, plasma aldosterone showed no or very low response to each of the endocrinological tests carried out (rapid ACTH infusion test, angiotensin Ⅱ infusion test and furosemide two-hour standing test). However, PRA showed a marked increase in response to furosemide two-hour standing test. On the basis of these findings, a diagnosis of selective hypoaldosteronism (Type Ⅰ) was entablished. The present disease was probably due to destruction of the zona glomerulosa of the adrenal cortex caused by some autoimmune mechanism.