Central nervous system abnormalities in Lyme neuroborreliosis.

Intrathecal production of anti-Borrelia burgdorferi antibody occurs frequently in CNS Lyme, yet reliable diagnosis of neuroborreliosis is still considered difficult and controversial. Therefore, we assessed the utility of this measurement in 103 Lyme patients. Among 15 patients with Lyme meningoradiculitis and 41 controls, diagnostic specificity was 93% and sensitivity 87%. Application of this method permits the identification of a rare B burgdorferi-associated multifocal encephalitis (brain infection) and its differentiation from a milder encephalopathy, or confusional state; the latter may not require CNS bacterial invasion. The encephalitis involves white matter more often than gray; severity varies widely. Of six patients with this antibiotic-responsive encephalitis, five were positive for HLA DQw3(DQw7). We conclude that (1) measurement of intrathecal antibody production is a reliable indicator of CNS infection, (2) North American neuroborreliosis includes the same spectrum of neurologic dysfunction as described in Europe, and (3) HLA typing may be useful in furthering our understanding of severe CNS involvement.