Neurobrucellosis Associated with Syndrome of Inappropriate Antidiuretic Hormone with Resultant Diabetes Insipidus and Hypothyroidism

Abstract

Neurological involvement of the central nervous system in brucellosis is uncommon. We describe a rare case of meningoencephalitis due to Brucella melitensis infection, associated with the syndrome of inappropriate antidiuretic hormone secretion and leading to diabetes insipidus and hypothyroidism. Neurobrucellosis, although rare, should be considered in cases of neurological disease of unknown etiology. CASE REPORTA 17-year-old male patient presented with headache, backache, fever, and marked asthenia. After 10 days, his headache worsened and vomiting occurred. He was admitted to the Department of Infectious Diseases of the Cutroni Zodda Hospital, Barcellona P.G., Sicily, Italy. Neurological examination upon admission revealed diffuse hyperreflexia, nuchal rigidity, and hyposthenia of both legs. Laboratory examinations revealed leukopenia with lymphocytosis and severe hyponatremia (118 mEq/liter) with reduced serum osmolality (241 mOsm/kg) and elevated urine osmolality (455 mOsm/kg). Renal, thyroid, and adrenal functions were normal. These data were consistent with the diagnosis of syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient was treated with intravenous NaCl (3%) and water restriction. His plasma sodium concentration increased to 125 mmol/liter.Analysis of the cerebrospinal fluid (CSF) showed pleocytosis (175 white blood cells/mm 3 , predominantly polymorphonuclear leukocytes), low glucose levels (11 mg/dl), and high protein levels (1,020 mg/dl), indicating a disruption of the bloodbrain barrier. Both serum and CSF samples tested negative for Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae antigens. At admission, the standard Brucella tube agglutination test (Wright test) result was also negative (titer Ͻ 1:100). This result was further confirmed by the slide agglutination rose bengal test (4). While waiting for microbiological results, the patient was treated with ceftriaxone (4 g/day), ampicillin/sulbactam (12 g/day), and dexamethasone (16 mg/day).Suspected Brucella colonies were isolated from both blood and CSF 7-day cultures and identified following standard procedures (4). Biochemical and agglutination tests identified the pathogen isolated from both body fluids as Brucella melitensis biovar 3. A diagnosis of meningoencephalitis due to Brucella infection was made, and the therapy was promptly modified as follows: ampicillin-sulbactam was discontinued, and chloramphenicol (4 g/day), rifampin (900 mg/day), and trimethoprim (Trimetoprim)-sulfamethoxazole (1,600/320 mg/day) were started. The serum agglutination test for Brucella bacteria was repeated a week after admission: the patient had seroconverted (anti-Brucella antibody titer, 1:320).To characterize the isolate at the molecular level, rpoB sequencing and typing by the multiple-locus variable-number repeat analysis of 16 loci (MLVA-16) were performed as previously described (22). The former showed the presence of a nucleotide substitution (ATC to ATA) at codon position 1249 (M1249I), identifyi...

What have we learned from brucellosis in the mouse model?

“…This phenomenon (linked to the virulence of Brucella strains and to the severity of the infection) is consistent with the observed pathological changes of the spleen and suggests some inhibitory action related to the presence of regulatory CD4 + CD25+ T cells [4,120]. This is also in agreement with the tendency of spleen lymphocytes from mice repeatedly immunized with Brucella antigens to produce less INF-γ when stimulated in culture with the cognate antigen [155].…”

The Syndrome of Inappropriate Secretion of AntiDiuretic Hormone in Patients With Brucellosis

“…However, signs of severe disease such as hypoalbuminemia and hyperglobulinemia also playing a role were not mentioned in those first 14 documented cases . A case report of Brucella‐related SIADH was described in a recent report from Italy ; however, this report described a patient with neurobrucellosis‐associated SIADH. It is also known that SIADH is commonly found in CNS infections.…”

Hyponatremia as the Presenting Feature of a Pituitary Abscess in a Calf

“…Conversely, a mild amount of diffuse pulmonary edema and congestion were reported at necropsy, likely another sequela to these systemic effects. To the authors’ knowledge, there are no reports in cattle that have implicated a pituitary abscess as a primary cause of SIADH, although it has previously been reported in humans [ 8 , 9 ] and a dog [ 10 ].…”