Isolated Adrenocorticotropic Hormone Deficiency Accompanied by Impaired Cognitive Function: A Case Report
Abstract Background: Isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) is an adrenal insufficiency caused by a decrease in ACTH alone among the anterior pituitary hormones. IAD is often overlooked because it causes nonspecific symptoms. We report a case of IAD diagnosed after the appearance of mild cognitive impairment (MCI).Case presentation: Our department was consulted on a case of a 46-year-old man for whom dementia was suspected because he was speaking incoherently, wiped his nose with his hands and showed mild brain atrophy on MRI. He was previously diagnosed with some psychiatric diseases, such as narcolepsy and adjustment disorder. He could not continue working due to somnolence, general fatigue and appetite loss. At the examination, he had difficulty concentrating and sustaining attention, exhibited restlessness, and scored 25 points on the Mini Mental State Examination-Japanese (MMSE-J); MCI was observed. Blood tests showed decreased ACTH, cortisol and free thyroxine and increased thyroid-stimulating hormone levels. He received further evaluation, and he was diagnosed with IAD and primary hypothyroidism. Hydrocortisone (15 mg) was started, after which his physical problems and his difficulty concentrating disappeared. His MMSE-J score also increased to 30. His cognitive functions completely recovered. He returned to work and continued to work stably.Conclusion: This patient was diagnosed with IAD and treated with adrenocortical hormone replacement therapy. His cognitive functions recovered, his physical and mental disorders were alleviated, and he returned to society. It is important not to miss neurological and psychiatric symptoms that can be cured by physical treatment.