Lyme borreliosisassociated encephalopathy

Borrelia burgdorferiinfection (Lyme disease) is frequently accompanied by CNS dysfunction. Particularly common is a mild confusional state, the mechanism of which is unknown. Since CNS infection with B burgdorferiis usually accompanied by intrathecal synthesis of specific antibody, we studied CSF in 73 patients referred for presumed CNS Lyme, manifested primarily as this confusional state. Of 30 seropositive patients evaluated, only 5 had intrathecal antibody production. Seven seronegative patients had positive cell-mediated immune responses to B burgdorferiin the peripheral blood none had antibody production in the CSF. Of the remaining 36 patients referred with this diagnosis despite negative serologic studies, none had compelling evidence of CNS infection by this criterion. We conclude that CNS infection with B burgdorferidoes occur in a small proportion of seropositive patients with this confusional state but is extremely uncommon among seronegative individuals with this clinical presentation.