Teaching Case

Right-sided sciatica and leg pain of 6 weeks duration. Positive Lasègue test on the right, limited lumbar spine motion and no reflex changes or motor weakness. History of a trip to Poland to buy cows.

The patient, a farmer, was referred to the hospital for investigation of right-sided sciatica and leg pain of 6 weeks duration. Physical examination revealed a positive Lasègue test on the right, limited lumbar spine motion and no reflex changes or motor weakness. A few months before admission he had been to Poland to buy cows. Radiculo-saccography followed by CT scan were performed. One day later, a MRI study of the lumbar spine was obtained. CT and MRI findings were consistent with spondylodiscitis. A CT-guided biopsy was performed and the diagnosis of brucellar spondylitis was established. Serologic examinations showed increased titers of antibodies for Brucella abortus bovis and Brucella melitensis.

Brucellosis is a zoonosis that is caused by small, gram-negative bacilli of the genus Brucella. It is spread to humans by direct contact with infected tissue or by ingestion of infected animal products, most commonly milk or milk products. Brucellosis has a worldwide distribution but in western countries it is an occupational disease found mainly in farmers and veterinary surgeons. The musculoskeletal system is the most frequently affected, and the spine is the most common site of bone brucellosis. Spinal infection can be either focal or diffuse. There is a predilection for the lower lumbar spine. Characteristic findings of brucellar spondylitis include bone destruction limited to the endplates, disc collapse and moderate epidural and paravertebral extension of the inflammatory process. In early stages, MR findings are loss of the margin between the disc and adjacent end-plates on T1-WI, along with abnormally high signal intensity of the disc space and adjacent bone on T2-WI. In later stages there is evidence of osteomyelitis with morphologically intact aspect of the vertebral bodies, reduction in size of the disc space and presence of a paravertebral soft tissue mass. The diagnosis is confirmed by serologic examination. MRI is the most sensitive imaging technique allowing early diagnosis and treatment with anti-brucellar chemotherapy. Prompt treatment is essential to prevent permanent neurologic deficit and/or spinal deformity. Differential diagnosis should be made with pyogenic and tuberculous spondylitis.