Borreliosis is a common affliction in northern countries and its neurological manifestations often mislead trained clinicians. We present three cases of Lyme neuroborreliosis, with intrathecal synthesis of specific antibodies, lymphocytic meningitis and magnetic-resonance imaging (MRI) findings. Our description aims at illustrating the natural history of the infection, highlighting persistent intrathecal synthesis of anti-Borrelia antibodies months after treatment completion, and its clinical significance. We then review the literature on MRI findings in neuroborreliosis and the kinetics of intrathecal synthesis of specific anti-Borrelia antibodies.