Neurobrucellosis: clinical and neuroimaging correlation

Abstract

Background and purpose: Manifestation of nervous system involvement by neurobrucellosis, a treatable infection, is not well documented. We investigated patterns of nervous system involvement and determined if neuroimaging abnormalities correlated with clinical manifestations of neurobrucellosis.

Methods: We reviewed 23 MR imaging studies (17 of brain, six of spine) and seven CT scans of brain in 23 patients (14 male and nine female patients; age range 17-71 years) with positive Brucella titers in their serum and CSF.

Results: Twelve patients had central nervous system (CNS) involvement, four had peripheral nervous system (PNS) involvement, two had combined PNS and CNS involvement, and five had isolated hearing loss. Imaging findings were variable: five of seven brain CT studies were normal, and 10 of 23 MR studies were normal (eight brain, one thoracic, one lumbar). One brain CT study showed subthalamic hemorrhage, mild perivascular enhancement, left caudate lacunae, and diffuse white matter changes. One other brain CT study showed enhancement of the tentorium in addition to white matter changes. Abnormal MR findings were basal meningeal enhancement (n = 3), lumbar nerve root enhancement (n = 3), granuloma of the suprasellar region (n = 1), diffuse white matter changes (n = 7), and spinal cord atrophy (n = 1). All patients improved after treatment with three antimicrobial drugs for 3-12 months. Seven patients had follow-up imaging; the enhancement disappeared but the white matter and ischemic changes persisted despite almost complete clinical recovery.

Conclusion: Clinical-radiologic correlation in neurobrucellosis varies from a normal imaging study despite positive clinical findings, to a variety of imaging abnormalities that reflect either an inflammatory process, an immune-mediated process, or a vascular insult.

Fig 1.

Patient 13. A, Nonenhanced (top) and enhanced (bottom) brain CT scans show left small subthalamic hematoma with perivascular enhancement (left), left caudate lacunar infarct, and diffuse periventricular white matter hypoattenuation (right). B, CT scans obtained 4 months after treatment show that hemorrhage and perivascular enhancement have disappeared, but lacunar infarcts and white matter abnormality persist. C, Brain T2-weighted (top) and FLAIR (bottom) MR images show increased signal intensity in periventricular white matter

Fig 2.

Patient 6. Gadolinium-enhanced T1-weighted brain MR images obtained before (top) and after (bottom) treatment show disappearance of dural enhancement

Fig 3.

Patient 3. A–C, Gadolinium-enhanced T1-weighted brain MR images show granuloma in the hypothalamus and pituitary granuloma. D–F, Gadolinium-enhanced T1-weighted brain MR images obtained 4 months after treatment show resolution of the granuloma.

Fig 4.

Patient 9. A–D, T1-weighted lumbar MR images obtained before (A and D) and after (B and C) injection of a gadolinium-based contrast agent show enhancement of the lumbar nerve root

Fig 5.

Patient 14. FLAIR brain MR images show diffuse peripheral subcortical white matter increased signal intensity with predilection to arcuate fibers.