Objective. To describe clinical cases with neurological manifestations associated with Borrelia burgdorferi infection in a large cohort of children and adults from Mexico. Material and Methods. Patients with neurological manifestation (cranial neuritis, radiculoneuritis, meningitis and encephalomyelitis) were recruited in one pediatric and two general hospitals, during January 2006eDecember 2015. Blood and cerebrospinal fluid (CSF) samples were drawn from each patient at inclusion. IgM and IgG antibodies against B. burgdorferi were detected using a commercial ELISA test, and confirmed by Western-Blot test (WB) using three different antigens from Borrelia burgdorferi complex. Following CDC criteria were considered true cases with both positive tests. Results. Of 606 patients recruited, 403 (66.5%) were adults and 203 (33.4%) children, 50.5% were male. B. burgdorferi infection was diagnosed in 168 patients (27.7%), 97 adults, mean age 42 14.7 years and 71 children, mean age 9.6 5 years; early disseminated disease occurred in 130 cases (77.4 %) and chronic stage in 38 (22.6 %). A previous tick bite was reported by 21% cases, and 5% recalled an erythema migrans lesion. Polyradiculoneuropathy and encephalomyelitis were the most common manifestations, whereas 14.8% presented an initial Guillain-Barre Syndrome. B. burgdorferi sensu stricto was identified in 142 (84%) cases, B. garinii in 14 (8%), B. afzelii in three, and nine cases presented coinfection with two species. Conclusion. Lyme neuroborreliosis is a frequent condition in patients with neurological diseases in Mexico. Key Words: Lyme neuroborreliosis, Borrelia garinii, Borrelia afzelii, Facial palsy, Guillain-Barre syndrome-like.
