Endocrinology & Metabolism, Medical College and Hospital Kolkata, Kolkata, West Bengal, India.
Endocrinology & Metabolism, Medical College and Hospital Kolkata, Kolkata, West Bengal, India
BMJ Case Rep. 2022 Feb 2;15(2):e247488. doi: 10.1136/bcr-2021-247488.
Dipsogenic polydipsia (DP), a distinct variety of primary polydipsia, is characterised by selective diminution of osmotic threshold for thirst leading to polydipsia and subsequent hypotonic polyuria. Seen in patients without underlying psychiatric illness, DP closely mimics central diabetes insipidus (CDI), making it difficult for clinicians to discriminate these two conditions from each other. Carefully performed osmotic stimulation study, incorporating objective assessment of threshold for thirst and arginine vasopressin (AVP) release is the key to differentiate DP from CDI or psychogenic polydipsia, also termed compulsive water drinking (CWD). Low thirst threshold and high AVP release threshold separate DP from CDI and CWD, respectively. Unlike CWD, desmopressin may be successfully used in DP without concomitant risk of hyponatremia. We describe a child, in whom an initial diagnosis of partial CDI was subsequently revised to DP based on osmotic stimulation test. The child was treated successfully with desmopressin therapy with a target to keep serum osmolality close to thirst threshold.
渴感过多性多尿症（DP）是一种原发性多尿症的特殊类型，其特征是口渴的渗透压阈值选择性降低，导致多尿继而出现低张性多尿。DP 可见于无潜在精神疾病的患者中，其临床表现与中枢性尿崩症（CDI）极为相似，这使得临床医生难以区分这两种疾病。仔细进行渗透压刺激试验，包括对口渴阈值和精氨酸加压素（AVP）释放的客观评估，是区分 DP 与 CDI 或精神性多尿症（也称为强迫性饮水）的关键。低口渴阈值和高 AVP 释放阈值分别将 DP 与 CDI 和 CWD 区分开来。与 CWD 不同，去氨加压素可成功用于 DP 治疗，而不会同时伴有低钠血症的风险。我们描述了一名儿童，最初诊断为部分 CDI，随后根据渗透压刺激试验修正为 DP。该儿童成功接受了去氨加压素治疗，治疗目标是使血清渗透压接近口渴阈值。
