Abstract
94-year-old male patient, with orthostatic hypotension, possibly due to impairment of vasoconstriction and parasympathetic nervous system dysfunction was reported. This patient experienced faintness and lower muscle weekness on standing. The blood pressure was 180/90mmHg in a supine position, while it significantly decreased to 100/58mmHg in an upright position. There was no evidences indicating the presence of organic brain diseases, cardiovascular diseases, and endocrine diseases. plasma catecholamine, renin, aldosterone, and vasopressin levels at rest were within normal range. Thus, the cause of orthostatic hypotension of this patient was unknown. His systolic blood pressure decreased by 70mmHg, and his diastolic blood pressure also decreased by 25mmHg in response to a 70° head-up tilting test (170/71→100/46mmHg). Plasma vasopressin level significantly increased in response to this test (0.62→67.2pg/ml). Plasma catecholamine levels also increased (Adr 0.01→0.10ng/ml, Ndr 0.05→0.22ng/ml). Other autonomic nervous system examinations revealed normal responses to mental arithmatic test, hyperventilation test, cold pressure test, and adrenalin test. However, the results of the carotid occlusion test, acetylcholine test, atropine test, phenilephline test were considered to be abnormal. From these findings, we concluded that the functions of sympathetic nervous system were almost intact, while the parasympathetic functions were impared in this case. The orthostatic hypotension of the patient as effectively treated with fludrocortisone. This report suggests that impairment of vasoconstriction and parasympathetic neurodysfunction might be involved in the development of orthostatic hypotension in the elderly.
