Last revised by Rohit Sharma on 29 Mar 2024

Neurobrucellosis refers to central nervous system involvement by brucellosis and occurs secondary to ingestion or contact with gram-negative, facultative intracellular coccobacilli of the Brucella species. Up to 10% of infections are complicated by neurological involvement 1

The remainder of this article is a discussion of CNS brucellosis. For a general discussion on systemic infection, please refer to the article on brucellosis.

Brucella is found worldwide. High-risk areas include countries surrounding the Mediterranean Sea, Eastern Europe, Mexico, South and Central America, Africa, Asia, the Caribbean and the Middle East 2

Onset is insidious; undulant, low-grade fever, headache, fatigue and malaise may precede any neurological findings by a number of months. A study of 128 patients with brucellosis found that central nervous symptom involvement is more likely if the following signs and symptoms are present 3:

  • blurred vision

  • sensorineural hearing loss

  • disorientation

  • recent behavioral change

  • agitation

  • muscle weakness

  • neck stiffness

  • deep tendon reflex change

  • paresthesia

  • diplopia

  • ataxia

  • pseudotumor cerebri

  • facial paralysis

Brucella may be isolated from blood cultures and/or cerebrospinous fluid (CSF). Additional CSF abnormalities include the presence of anti-Brucella antibodies, pleocytosis, high protein and low glucose levels 4.

Transmission occurs secondary to direct contact with infected animals or the consumption of unpasteurised dairy products. In addition to the four main species causing brucellosis​B. ceti and B. pinnipediae have also been isolated in the context of neurobrucellosis 2

In just under half of brucellosis cases with neurological findings, imaging of the CNS is unremarkable 5,6. Abnormal neuroimaging may involve the meninges, cranial nerves, white and grey matter, vasculature, and spinal nerve roots 5,6

Diffuse white matter changes, meningeal enhancement, lacunae and hemorrhages within the basal ganglia, hydrocephalus and cerebral edema may be demonstrated.

  • T1: arachnoiditis

  • T2/FLAIR: ​arachnoiditis; diffuse, hyperintense lesions affecting the white matter, with an appearance of focal demyelination

  • T1/T2 C+ (Gd): brain abscess or granuloma with ring enhancement; leptomeningeal, basal meningeal, perivascular and/or spinal root enhancement

The heterogenous presentation and imaging findings of neurobrucellosis warrant a thorough history and risk-stratification. Clarification of recent travel and exposure to unpasteurised dairy is important, remembering that both acute and chronic presentations are possible.

Differentials are therefore numerous, but include:

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.