352 - Seronegative Relapse of Brucellosis in the Central Nervous System

Background: Brucellosis is the most common zoonotic infection in the world. High risk areas include the Mediterranean Basin, Eastern Europe and the Middle East. Clinical presentation is quite heterogenous.
CNS involvement (neurobrucellosis) varies widely, from 0,5 to 25%. This reflects a high prevalence in endemic areas and the lack of established criteria for a diagnosis. We present a patient with a seronegative relapse of brucellosis, confined in the CNS, identified by Brucella IgG ELISA and 16S rRNA sequencing.

Methods: Case Report

Results: A 60-year-old man, farmer, with a history of systematic brucellosis two years before admission, presented with high fever, headache and agitation. A serum agglutination test and anti-Brucella IgG ELISA were negative at baseline. Spinal tap revealed lymphocytosis and low glucose. CSF culture was negative. The patient received ceftriaxone, ampicillin and acyclovir with an initial remission. A week later the patient’s symptoms relapsed. Administration of ceftriaxone and acyclovir was reinitiated with clinical improvement, however, lymphocytic meningitis persisted even after 15 days of treatment.
Brain MRI demonstrated nonspecific white matter hyperintensities and severe meningitis as identified by contrast-enhanced 3D Flair MRI. CSF oligoclonal bands showed intrathecal immunoglobin synthesis. CSF agglutination tests and CSF IgG ELISA were positive for Brucella. Though CSF PCR for Brucella was negative, 16S rRNA sequencing revealed the presence of Brucella spp. Patient was treated with ceftriaxone and dexamethasone and despite an initial worsening of neurological symptoms of tremor, loss of balance, hearing loss and diplopia, a clinical remission was achieved after a month and a laboratory remission after eight months of treatment.Brain MRI: 3D Flair Sequence with Contrast Enhancement
Table. CSF Parameters


Conclusion: Neurobrucellosis presents with a variety of clinical symptoms and it should always be considered in neurological patients in highly endemic areas. Establishing a diagnosis is challenging. In our patient, CSF oligoclonal bands and the agglutination test in the CSF helped in achieving a diagnosis, suggesting their possible role in the diagnostic criteria. Although still under debate, the use of corticosteroids in our patient as well as the prolonged use of ceftriaxone in the therapeutic regime were crucial.