Neuroborreliosis interpreted as multiple sclerosis by MRI.

Lyme neuroborreliosis (LNB) is the most prevalent nervous system bacterial infection in Denmark. In a young man with LNB, brain MRI and cerebrospinal fluid (CSF) demonstrated findings compatible with multiple sclerosis. This case report underlines the requirement for testing for intrathecal Borrelia antibody production when the number of cells in the CSF is low or even normal. It also demonstrates the unchanged diagnostic delay of NBL observed during the last 20 years.