- Have had one or more of the following symptoms and conditions that have persisted for at least 6 months (but less than 12 years) and are not attributable to another cause or condition: a) widespread musculoskeletal pain and fatigue that began coincident with or within 6 months following initial infection with B. burgdorferi. b) certain neurologic symptoms including memory impairment and nerve pain, beginning within 6 months following initial infection with B. burgdorferi.