LBMON139 A Case of Adipsic Diabetes Insipidus In Patient With Third Ventricular Tumor And Right Frontal Craniotomy.

Abstract

Abstract Introduction Adipsic diabetes insipidus (ADI) is a rare hypothalamic disorder consisting of central diabetes insipidus (CDI) and loss of thirst. In hyperosmolar state, signals from osmosensors integrate in the central thirst center resulting in stimulatory signals between subfornical-oragan, organum-vasculosm of lamina terminalis and median preoptic nucleus increasing thirst and release of vasopressin. Disruption in this mechanism leads to adipsia. Case presentation 27 yr old male with history of prediabetes, 4.6cm third ventricular epidermoid cyst s/p endoscopic ventriculosmoy, hypogonadotropic hypogonadism, central hypothyroidism, and CDI underwent right frontal craniotomy for residual third ventricular cyst. Developed worsening DI, new onset hyperglycemia, and secondary adrenal insufficiency. Discharged with oral DDAVP 300mcg oral twice daily for CDI. 1 week later presented to ED with weakness. BP 132/112, HR 139, RR 38, SPO2 94%. Labs significant for corrected sodium of 172 (136-145mmol/L), glucose 699 (70-99mg/dl), calcium 11.8 (8.3-10.6 mg/dl). Discharged after 3 weeks with intranasal DDAVP 10mcg twice daily (BID). Again presented 1 week after for weakness. Vitals BP 105/64, HR 134, F 37.3 C, RR 31, SPO2 96%. Corrected sodium of 174 (136-145mmol/L) and glucose 708 (70-99mg/dl). Denied missing medication. Reported no increased water intake. Patient was diagnosed with adipsic DI based on subjective lack of thirst during period of significant hyperosmolar hypernatremia state. Overtime switched to 10mcg BID intranasal DDAVP and started on 4L fixed water intake. Had 5L urine output daily. Sodium levels ranged from 132-137. Discharged on intranasal DDAVP 10mcg AM/20mcg PM, 4L daily fixed water intake, and twice weekly sodium checks as outpatient. Goal sodium 135-140. DDAVP adjusted after sodium rose to 145. At recent clinic visit continued fixed 4L fluid intake with extra 500-1L intake for increased sweating/exercise, and sodium level 134. A1c 10% on insulin, and weight gain of 70lbs since surgery (8mon piror), BMI of 45. Started on GLP-1RA and sleep study. Learning points: Less than 100 cases of ADI reported worldwide and associated with increased morbidity/mortality1. This patient likely developed ADI due to disruption of central thirst center from epidermoid cyst and trans frontal craniotomy. We must be hypervigilant for ADI in patients with third ventricular tumors who undergo frontal craniotomy. Management is complex and requires patients are followed closely with weekly labs, either fixed water intake or fixed DDAVP dose and adjustment depending on labs. Important to screen these patients for obesity and sleep apnea given increased likelihood of hypothalamic dysfunction1. Reference: Cuesta, M., Hannon, M. J. & Thompson, C. J. Adipsic diabetes insipidus in adult patients. Pituitary 20, 372-380 (2017). https://doi.org/10.1007/s11102-016-0784-4 Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.