Endocrine Abstracts

Background: Central diabetes insipidus (CDI) presents with various underlying diagnoses in children.

Objective: To determine causes of CDI and long-term outcome in children and adolescents from a Tertiary Paediatric Endocrinology unit providing Regional Paediatric Neurosurgery and head trauma services.

Methods: The clinic database was searched to identify patients with CDI managed between 1993 and 2019. Relevant clinical information was collected from electronic patient records.

Results: A total of 155 CDI patients, median age 6 years (range <1–18) were identified. Principal CDI aetiologies were craniopharyngioma (n=44, only 1 had CDI pre-surgery), midline CNS malformation (n=20), post-neurosurgery (non-craniopharyngioma; n=18), germ cell tumor (GCT; n=15), CNS infection (n=14), head trauma (n=9) and Langerhans cell histiocytosis (n=6). Miscellaneous causes included raised intracranial pressure (n=8), ventricular haemorrhage (n=8), pituitary apoplexy (n=1) and IgG4 hypophysitis (n=1). Threepatients had familial disease. Eight patients currently have idiopathic disease. Of the 15 GCT patients with CDI, six presented with CDI and GCT concurrently and five were diagnosed with GCT after median interval of 4 years (range 3–5) from CDI presentation. Four patients developed CDI after tumour debulking/biopsy. An additional seven GCT patients in our database did not develop CDI. Of the seventeen patients with head trauma-/brain haemorrhage-associated CDI, seven died before hospital discharge, four had transient CDI and 1 was lost to follow-up. Of the 20 midline CNS malformation patients, 12 had Septo-optic Dysplasia (SOD). An additional 60 SOD patients in our cohort had hypopituitarism without CDI. Of the 14 patients with CDI associated with CNS infection, two died during the initial illness, one had transient CDI and three were lost to follow up. A further seven patients from this subgroup died subsequently, one of which was due to inappropriate management of CDI and one patient has persistent CDI.

Conclusion: In our Tertiary Paediatric Endocrine setting, the most common etiologies of CDI were craniopharyngioma, other intracranial tumors and malformations. Presentation of craniopharyngioma with CDI in this series was very rare. 50% of GCTs had CDI as part of first manifestation symptomatology. CDI associated with CNS trauma, haemorrhage and infection carries very poor prognostic outcome.