Answer is A (Multiple sclerosis) : Multiple sclerosis has not been mentioned as a cause for diabetes insipidus. Diabetes insipidus is a syndrome caused by either deficiency of vasopressin or resistance to action of vasopressin in passage of abnormally large volume of urine of low specific gravity. Causes of diabetes insipidus Pituitary form of DI (Neurohypophysial or central) Deficient secretion of vasopressin from pituitary Nephrogenic DI (Renal D.I.) Resistance to action of vasopressin on kidney Primary polydispisa Congenital malformations Genetic Acquired Genetic Acquired Psychogenic Acquired Drugs Schizophrenia Head trauma (closed and penetrating) Lithium Obsesive-compulsive Neoplasms Demeclocyline disorder Primary Methoxyflurane Dipsogenic (abnormal thirst) Craniopharyngioma Amphotericin B Granulomas: Pituitary adenoma (suprasellar) Aminoglycosides Neurosarcoid Dysgerminoma Cisplatin Infectious: Tuberculous Meningioma Rifampin meningitis Metastatic (lung, breast) Foscarnet Head trauma (closed and Hematologic (lymphoma, leukemia) Metabolic penetrating) Granulomas: Neurosarcoid Hypercalcemia, hypercalcinuria Demyelimation: Multiple Histiocytosis Hypokalemia sclerosis Xanthoma disseminatum Obstruction (ureter or urethra) Drugs: Infectious: Chronic meningitis Vascular Lithium Viral encephalitis Sickle cell disease and trait Carbamazepine Toxoplasmosis lschemia (acute tubular necrosis) Idiopathic Inflammatory:Lymphocytic Granulomas Iatrogenic Infundibuloneurohypophysitis Neurosarcoid Wegener's granulomatosis Neoplasms Lupus erythematous Sarcoma Scleroderma Infiltration Chemical toxins: Tetrodotoxin, Snake venom Amyloidosis Vascular:Sheehan's syndrome Pregnancy Aneurysm (internal carotid) Idiopathic Aoocoronary bypass Hypoxic encephalopathy Pregnancy (vasopressinase) Idiopathic