Arai K, Akimoto H, Inokami T, Kakuta S, Uchida S, Nagase M, Shimizu T
Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan.
Nihon Jinzo Gakkai Shi. 1999 Dec;41(8):804-12.
We here report a 17-year-old high school boy having suprasellar germinoma who presented marked hypernatremia probably due to damages of both the osmoregulation and thirst centers. He was in good health until July, 1996, when he noticed slight general malaise and complained of dryness of the mouth, but without polyuria. He was found to have hypernatremia of mild degree (serum Na 151 mEq/l), but dropped out from the follow-up. In April, 1997, he was admitted to our hospital with complaints of general malaise and weakness of the upper and lower extremities. Serum Na was high at 202 mEq/l with a plasma osmolality of 390 mOsm/kg H2O. He completely lacked a sense of thirst and polydipsia/polyuria. Computed tomography and magnetic resonance imaging indicated a suprasellar tumor, possibly a germinoma. Hypernatremia was first treated with intravenous infusion of a half-normal saline solution, followed by immediate polyuria of 3 to 6 l/day. Subsequently, nasal administration of desamino-D-arginine vasopressin (DDAVP) induced stabilization of serum Na to a range between 140 and 160 mEq/l. The tumor disappeared following steroid pulse therapy and irradiation of 50 Gy to the brain. At the time of discharge, he and his family were instructed to record the urine volume, amount of water intake, body weight and amount of DDAVP used. The patient was instructed to drink water corresponding to the urine volume while maintaining the dose of DDAVP. One year after treatment, the water balance reverted to a positive direction, leading to a normal range of serum Na probably because of partial recovery of the osmoreceptors and/or trained drinking habit. This case illustrates the so-called adipsic hypernatremia which is attributed to partial osmoreceptor destruction by a suprasellar germinoma.
我们在此报告一名17岁患有鞍上生殖细胞瘤的高中男生，其出现明显的高钠血症，可能是由于渗透压调节中枢和口渴中枢均受损所致。1996年7月前他身体健康，当时他注意到有轻微的全身不适，并主诉口干，但无多尿。他被发现有轻度高钠血症（血清钠151 mEq/l），但随后失访。1997年4月，他因全身不适及上下肢无力而入住我院。血清钠高达202 mEq/l，血浆渗透压为390 mOsm/kg H2O。他完全没有口渴感，也没有烦渴/多尿。计算机断层扫描和磁共振成像显示鞍上有一肿瘤，可能是生殖细胞瘤。高钠血症首先通过静脉输注半张生理盐水溶液进行治疗，随后立即出现每天3至6升的多尿。随后，经鼻腔给予去氨加压素（DDAVP）使血清钠稳定在140至160 mEq/l之间。经类固醇冲击治疗及脑部50 Gy的放疗后肿瘤消失。出院时，指导他和他的家人记录尿量、饮水量、体重及DDAVP的用量。指导患者在维持DDAVP剂量的同时，根据尿量饮水。治疗一年后，水平衡恢复为正向平衡，血清钠恢复至正常范围，这可能是由于渗透压感受器部分恢复和/或养成了规律的饮水习惯。该病例说明了所谓的失水性高钠血症，其病因是鞍上生殖细胞瘤导致渗透压感受器部分破坏。
