[Diabetes insipidus as a manifestation of cerebral toxoplasmosis in an AIDS patient].

INTRODUCTION: In AIDS patients the endocrine system is often affected. Diabetes insipidus (DI) is uncommon and has been related to drugs and infections of the central nervous system (toxoplasmosis, cryptococcic meningitis, cytomegalovirus encephalitis). In these patients at the time of diagnosis, imaging investigations are often normal.

CLINICAL CASE: We report the case of a 40 year old man with infection category HIV C3 (CD4 < 50 mm3 and viral load 301,258 copies/ml), not on antiretroviral treatment at the time of hospital admission. He had polyuria (8-10 litres/day) and polydipsia for the previous 15 days, with no other symptoms. The dehydration test showed central DI (raised osmolarity following subcutaneous desmopresin). On MNR there were bilateral periventricular nodular images, also present in both caudate nuclei, with ring increased uptake following administration of paramagnetic contrast. On the clinical suspicion of cerebral toxoplasmosis empirical treatment was started with sulphadiazine and pyrimethamine together with nasal DDAVP, obtaining a good clinical response.

CONCLUSIONS: In patients with HIV infection, DI, although uncommon, may be the first sign of cerebral toxoplasmosis. Imaging studies may be pathological and assist diagnosis.