Seronegative brucella meningitis diagnosed by CSF PCR: report on seven cases

Abstract

Introduction: Neurobrucellosis (NB) can be associated with meningitis and present as a headache with or without meningeal signs. Pseudotumor presentation of NB has been reported to be accompanied by lymphocytic predominant cerebrospinal fluid(CSF) pleocytosis. NB is diagnosed by means of isolation of Brucella from blood or CSF and/or the presence of anti-Brucella antibodies in the CSF. Molecular techniques have been used in chronic or challenging cases of NB.

Clinical findings: We report on seven cases of NB presenting with different types of headache and signs of meningeal involvement. In five cases, signs of intracranial hypertension were evident in the form of papilledema, sixth nerve palsy and blurred vision.

Diagnosis: MRIs of the brain revealed signs of intracranial hypertension in three patients, basal meningeal enhancement in one patient and white matter lesions in one patient. Brucella serology in the blood and CSF was negative in all patients. It was interesting that four patients had normocellular CSF analysis with normal glucose and protein results. The diagnosis was made by Brucella PCR in all patients.

Conclusion: NB should be considered in the differential diagnoses of pseudotumor cerebri syndrome in endemic areas. It is important to employ molecular techniques using sterile CSF samples in the investigation of Brucella.

Keywords: Brucella PCR; Neurobrucellosis; Pseudotumor Cerebri; Seronegative.

Fig. 1

Brain MRI with gadolinium of case 1: (left) meningeal enhancement; (right) increased ONSD

Fig. 2

Brain MRI of case 3: (left) axial image of multiple abnormal signal intensity in subcortical and juxtacortical white matter; (right) sagittal T2 image with partial empty sella