Lyme disease, caused by the Borrelia burgdorferi bacterium, is the most common
vector-borne disease in the northern hemisphere. The clinical presentation varies with disease stage, and
neurological manifestations (often referred to as
Lyme neuroborreliosis) are reported in up to 12% of patients with
Lyme disease. Most aspects of the epidemiology, clinical manifestation and treatment of
Lyme neuroborreliosis are well known and accepted; only the management of so-called
chronic Lyme disease is surrounded by considerable controversy. This term is used for disparate patient groups, including those who have untreated late-stage
infection (for example, late neuroborreliosis), those with subjective symptoms that persist
after treatment (termed '
post-treatment Lyme disease syndrome' [PTLDS]), and those with unexplained subjective complaints that may or may not be accompanied by positive test results for B. burgdorferi
infection in serum (here called '
chronic Lyme disease'). The incidence of PTLDS is still a matter of debate, and its pathogenesis is unclear, but there is evidence that these patients do not have ongoing B. burgdorferi
infection and, thus, do not benefit from additional
antibiotic therapy.
Chronic Lyme disease lacks an accepted clinical definition, and most patients who receive this diagnosis have other illnesses. Thus, a careful diagnostic work-up is needed to ensure proper treatment.