Clinical categories of neurobrucellosis. A report on 19 cases.

Brucellosis rarely can present with involvement restricted to the nervous system. We describe a total of 19 cases of neurobrucellosis in whom the clinical presentation lay in three distinct categories. The first was an acute presentation with meningoencephalitis. The disease also presented in a chronic form where the brunt of the illness can either be in the peripheral or the central nervous system (CNS). The chronic peripheral form is that of a proximal polyradiculoneuropathy. The central form is that of diffuse CNS involvement, predominantly with myelitis or cerebellar involvement with or without cranial nerve palsies. Although the two chronic forms, 'peripheral' and 'central', are distinct, some overlap is possible. This was not observed for the acute form. The pathology of the three presentations may be different, being a direct effect of infection in the acute form, and an immune-related process, possibly demyelinating in nature, in the chronic forms. The response to treatment in the acute and chronic forms is also different, being much better in the acute form. Awareness of the condition and performance of the appropriate serological tests will differentiate neurobrucellosis from other chronic CNS infections, especially tuberculosis and neurosyphilis.