Etiological Spectrum with Diagnosis and Prognosis of Central Diabetes Insipidus needs Long Term Followup:A Single Centre Experience

Introduction:Central Diabetes insipidus(CDI)is a rare disorder caused by vasopressin deficiency characterized by the excretion of copious volumes of unconcentrated urine.Objective:To assess the etiological,clinical,biochemical and radiological spectrum of Central DI in our institute and long term follow up of these cases.Material and Methods:32 patients with Central DI admitted in Department of Endocrinology,Guwahati Medical College,Assam in the last 2.5 years were included.Detailed clinical assessment,biochemical evaluation and MRI(Magnetic Resonance imaging)brain were done in all the patients.Central DI without any identifiable cause was considered Idiopathic and those with structural lesion in hypothalamic pituitary region were considered organic.Result:Idiopathic CDI was present in 12(37.5%)patients and 20(62.5%)patients had organic CDI with acute onset of presentation.12(60%)patients with organic CDI present with neurological symptoms but 8(40%)patients had no neurological symptoms even with organic cause.Pituitary dysfunction was common in organic CDI as compared to idiopathic CDI.Paediatric patients commonly present with organic cause for CDI with low cortisol most common hormonal deficit.One patient of idiopathic CDI with normal stalk thickness at baseline presented with clinical and radiological features of LCH(Langerhans cell histiocytosis)on follow up.Conclusion:Organic CDI more likely to have acute onset of presentation than idiopathic CDI and even in absence of neurological features.Paediatric patients commonly have organic cause for CDI.We propose the paramount importance of long-term clinical follow-up and reassessment of endocrine function in patients with CDI for definitive diagnosis of autoimmune and inflammatory causes of idiopathic CDI and timely treatment of pituitary hypofunction.

Caution on diagnosis of idiopathetic central diabetes insipidus

Idiopathetic central diabetes insipidus （CDI） is a heterogeneous hypothalamus-pituitary disease due to the absence or deficiency of arginine vasopressin （AVP）.

Diabetes insipidus with impaired vision caused by germinoma and perioptic meningeal seeding:A case report

BACKGROUND Germinoma is a type of germ cell tumor that most frequently arises in the midline axis of the brain.Impaired vision is a clinical manifestation of germinnoma.Although rare,intracranial germinoma seeding to the perioptic arachnoid space is one cause of visual acuity decrease.CASE SUMMARY An 11yearold girl who presented with polyuria and polydipsia and subsequently developed diminution of vision.Imaging showed bilateral heterogeneous enhancement of the optic nerve sheaths and atrophy of the optic nerve,and transsphenoidal biopsy revealed a germinoma.The patient experienced poor visual recovery following chemotherapy and radiotherapy.Germinomas are rare and they are mostly identified in children and adolescents.The manifestations include diabetes insipidus,pituitary dysfunction,visual complaints,etc.The mechanisms that lead to visual loss include intracranial hypertension,compression of optic chiasma,and tumor invasion.A literature review was performed to summarize the cases with a tumor infiltrating the optic nerve.Most of the reported patients were adolescents and presented with anterior pituitary hormone deficiency.Enhancement of optic nerve sheaths and optic disc pallor could be identified in most of the cases.The purpose of this report is to provide awareness that in cases where a germinoma is associated with visual loss,though rare,perioptic meningeal seeding should be taken into consideration.CONCLUSION The case report suggests that children with diabetes insipidus need a complete differential diagnosis.