Lyme disease is a cause of illness involving multiple organ systems, i
ncluding, in 10-15 % of cases, the nervous system. Peripheral radiculo
neuritis, cranial neuritis, encephalitis and myelitis are among the ne
urological manifestations found in the second and third stages. We pre
sent the MRI findings in isolated oculomotor nerve involvement by Lyme
disease and discuss the differential diagnosis.