Latent Lyme neuroborreliosis: presence of Borrelia burgdorferi in the cerebrospinal fluid without concurrent inflammatory signs.

Borrelia burgdorferi, the etiologic agent of Lyme borreliosis, was isolated from the CSF of a patient with elevated serum IgG antibody titers against B burgdorferi and a history of multiple tick bites. The absence of concurrent inflammatory signs of CSF as well as intrathecal antibody production indicates a phase of latent Lyme neuroborreliosis in which no tissue infection or reaction has yet occurred. Bilateral tinnitus was the only clinical symptom in this patient. The persistence of the bilateral tinnitus after antibiotic therapy did not support a causal relationship between this symptom and the borrelial infection.