<prompt> A 35 year old man presents with vomitings and confusion. On examination Na 120 m molL, K 4.2 m mon, Uric acid 2 mgdl. Patient is not edematous. The diagnosis is:Cerebral toxoplasmosis with SIADHHepatic failureSevere dehydrationCongestive hea failure  <response>: Answer is A Cerebral toxoplasmosis with SIADH: The patient in question satisfies all the diagnostic features of SIADH, leaving no doubt as regards the diagnosis. Laboratory parameters in patient Normal values SIADH CRITERIA 1. Serum Na.: 120 mmol1 i.e. Hyponatremia 137-145 mmol1 135 mmol1 2. Uric acid: 2 mgdl i.e. Hypouricemia 2.5-8.5 mgdl 4 mgdi 3. Serum ICI: 4.2 mmol i.e. Normokalemia 3.5-4.5 mmol1 3.5-4.5 mmol1 Edema does not occur in SIADH despite hypervolumia. The patient in question has distinctly been mentioned as non edematous, thus providing us with an impoant lead to the answer. 