Two cases of traumatic isolated ACTH deficiency

Abstract

Isolated ACTH deficiency is a rare disease characterized by secondary adrenal insufficiency with low or absent cortisol production and normal secretion of pituitary hormones other than ACTH and the absence of structural pituitary defects. Isolated ACTH deficiency has been caused by traumatic injury, lymphocytic hypophysitis due to autoimmune etiology, genetic origin in neonatal or childhood, and unknown origin We have shown two cases of traumatic isolated ACTH deficiency. Case 1: A 65- year-old man was accidentally injured by wooden hammer on his top of head on 34 years before. He was suffered from vomiting, diarrhea and hypotension, and the laboratory examination revealed increased CRP (4.0 mg/dl) level, hyponatremia and decreased plasma cortisol (less than 1 mg/dl) and ACTH (less than 2.0 pg/ml) levels, suggesting isolated ACTH deficiency and Crohn disease diagnosed by colonoscopic biopsy, and finally transferred to University Hospital. LHRH, TRH, CRH and GHRP stimulation tests showed normal response of plasma pituitary hormones except for no response of plasma ACTH and cortisol levels by CRH stimulation. ACTH stimulation test showed no response of plasma cortisol levels although hydrocotisone replacement therapy had already been started. MRI imaging showed bottom of anterior lobe was crushed and pituitary gland was atrophied, which suggested brain might be injured by any strong trauma. Case 2: An 83-years-old man was injured on brain contusion by staff's violence in nursing home, and introduce to Gifu Municipal hospital to remove brain hematoma on 6 months before. He presented transient loss of consciousness because of hypoglycemia (37 mg/dl), and transferred to our hospital. Laboratory examinations revealed hyponatremia (126 mEq/l), normal HbA1c (5.1 %) level, and low levels of plasma ACTH (6.8 pg/ml), cortisol (15.2 mg/dl), PRA (less than 0.1 ng/ml/hr) and aldosterone (less than 10.0 pg/ml). Endocrinological examination showed normal LH-RH and TRH stimulation test, normal plasma basal GH (3.73 ng/ml) and IGF-1 (37 ng/ml) levels and no response of plasma ACTH and cortisol levels by CRH stimulation, showing traumatic isolated ACTH deficiency. ACTH stimulation test showed delayed low response of plasma cortisol levels. MRI imaging showed atrophic pituitary gland. Two cases of these disorders were treated with 15-20 mg of hydrocortisone and continued to live in good health. These results suggest that traumatic isolated ACTH deficiency may be able to appear for short and long period after brain injury.