Although an association has been reported between the presence of lipid‐specific oligoclonal IgM bands (LS‐OCMB) in cerebrospinal fluid and a more severe clinical multiple sclerosis course, no remarkable cognitive differences were found in this study between LS‐OCMB– and LS‐OCMB+ patients in the early stages of MS. This evidence concerns the gene CD40LG and myeloid sarcoma.